diff --git a/vna_system/api/endpoints/settings.py b/vna_system/api/endpoints/settings.py
index 8e8cf38..440a418 100644
--- a/vna_system/api/endpoints/settings.py
+++ b/vna_system/api/endpoints/settings.py
@@ -19,6 +19,9 @@ from vna_system.api.models.settings import (
     SetCalibrationRequest,
     RemoveStandardRequest,
     WorkingCalibrationModel,
+    ReferenceModel,
+    CreateReferenceRequest,
+    SetReferenceRequest,
 )
 
 router = APIRouter(prefix="/api/v1/settings", tags=["settings"])
@@ -36,19 +39,10 @@ async def get_status() -> dict[str, Any]:
 
 
 @router.get("/presets", response_model=List[PresetModel])
-async def get_presets(mode: str | None = None) -> list[PresetModel]:
+async def get_presets() -> list[PresetModel]:
     """Get all available configuration presets, optionally filtered by mode."""
     try:
-        if mode:
-            from vna_system.core.settings.preset_manager import VNAMode
-
-            try:
-                vna_mode = VNAMode(mode.lower())
-            except ValueError:
-                raise HTTPException(status_code=400, detail=f"Invalid mode: {mode}")
-            presets = singletons.settings_manager.get_presets_by_mode(vna_mode)
-        else:
-            presets = singletons.settings_manager.get_available_presets()
+        presets = singletons.settings_manager.get_available_presets()
 
         return [
             PresetModel(
@@ -61,8 +55,6 @@ async def get_presets(mode: str | None = None) -> list[PresetModel]:
             )
             for p in presets
         ]
-    except HTTPException:
-        raise
     except Exception as exc:  # noqa: BLE001
         logger.error("Failed to list presets")
         raise HTTPException(status_code=500, detail=str(exc))
@@ -415,3 +407,217 @@ async def get_working_calibration_standards_plots() -> dict[str, Any]:
     except Exception as exc:  # noqa: BLE001
         logger.error("Failed to build working calibration standards plots")
         raise HTTPException(status_code=500, detail=str(exc))
+
+
+# ================================================================ #
+# Reference Management Endpoints
+# ================================================================ #
+
+@router.get("/references", response_model=List[ReferenceModel])
+async def get_references(preset_filename: str | None = None) -> List[dict[str, Any]]:
+    """Get available references for a preset."""
+    try:
+        settings_manager = singletons.settings_manager
+
+        if preset_filename:
+            preset = next(
+                (p for p in settings_manager.get_available_presets() if p.filename == preset_filename),
+                None
+            )
+            if not preset:
+                raise HTTPException(status_code=404, detail=f"Preset '{preset_filename}' not found")
+        else:
+            preset = settings_manager.get_current_preset()
+            if not preset:
+                raise HTTPException(status_code=400, detail="No current preset set and no preset_filename provided")
+
+        references = settings_manager.get_available_references(preset)
+
+        return [
+            {
+                "name": ref.name,
+                "timestamp": ref.timestamp.isoformat(),
+                "preset_filename": ref.preset_filename,
+                "description": ref.description,
+                "metadata": ref.metadata
+            }
+            for ref in references
+        ]
+    except HTTPException:
+        raise
+    except Exception as exc:  # noqa: BLE001
+        logger.error("Failed to get references", error=repr(exc))
+        raise HTTPException(status_code=500, detail=str(exc))
+
+
+@router.get("/reference/current", response_model=ReferenceModel | None)
+async def get_current_reference(preset_filename: str | None = None) -> dict[str, Any] | None:
+    """Get the currently selected reference."""
+    try:
+        settings_manager = singletons.settings_manager
+
+        if preset_filename:
+            preset = next(
+                (p for p in settings_manager.get_available_presets() if p.filename == preset_filename),
+                None
+            )
+            if not preset:
+                raise HTTPException(status_code=404, detail=f"Preset '{preset_filename}' not found")
+        else:
+            preset = settings_manager.get_current_preset()
+            if not preset:
+                raise HTTPException(status_code=400, detail="No current preset set and no preset_filename provided")
+
+        current_ref = settings_manager.get_current_reference(preset)
+
+        if not current_ref:
+            return None
+
+        return {
+            "name": current_ref.name,
+            "timestamp": current_ref.timestamp.isoformat(),
+            "preset_filename": current_ref.preset_filename,
+            "description": current_ref.description,
+            "metadata": current_ref.metadata
+        }
+    except HTTPException:
+        raise
+    except Exception as exc:  # noqa: BLE001
+        logger.error("Failed to get current reference", error=repr(exc))
+        raise HTTPException(status_code=500, detail=str(exc))
+
+
+@router.post("/reference/create")
+async def create_reference(request: CreateReferenceRequest) -> dict[str, Any]:
+    """Create a new reference from current sweep data."""
+    try:
+        settings_manager = singletons.settings_manager
+        data_acquisition = singletons.vna_data_acquisition_instance
+
+        if request.preset_filename:
+            preset = next(
+                (p for p in settings_manager.get_available_presets() if p.filename == request.preset_filename),
+                None
+            )
+            if not preset:
+                raise HTTPException(status_code=404, detail=f"Preset '{request.preset_filename}' not found")
+        else:
+            preset = settings_manager.get_current_preset()
+            if not preset:
+                raise HTTPException(status_code=400, detail="No current preset set and no preset_filename provided")
+
+        # Create reference using the new capture method
+        reference_info = settings_manager.capture_reference_from_acquisition(
+            reference_name=request.name,
+            data_acquisition=data_acquisition,
+            description=request.description,
+            metadata=request.metadata,
+            preset=preset
+        )
+
+        return {
+            "success": True,
+            "message": f"Reference '{request.name}' created successfully",
+            "reference": {
+                "name": reference_info.name,
+                "timestamp": reference_info.timestamp.isoformat(),
+                "preset_filename": reference_info.preset_filename,
+                "description": reference_info.description,
+                "metadata": reference_info.metadata
+            }
+        }
+    except HTTPException:
+        raise
+    except Exception as exc:  # noqa: BLE001
+        logger.error("Failed to create reference", name=request.name, error=repr(exc))
+        raise HTTPException(status_code=500, detail=str(exc))
+
+
+@router.post("/reference/set")
+async def set_current_reference(request: SetReferenceRequest) -> dict[str, Any]:
+    """Set the current reference."""
+    try:
+        settings_manager = singletons.settings_manager
+
+        if request.preset_filename:
+            preset = next(
+                (p for p in settings_manager.get_available_presets() if p.filename == request.preset_filename),
+                None
+            )
+            if not preset:
+                raise HTTPException(status_code=404, detail=f"Preset '{request.preset_filename}' not found")
+        else:
+            preset = settings_manager.get_current_preset()
+            if not preset:
+                raise HTTPException(status_code=400, detail="No current preset set and no preset_filename provided")
+
+        success = settings_manager.set_current_reference(request.name, preset)
+
+        if not success:
+            raise HTTPException(status_code=404, detail=f"Reference '{request.name}' not found")
+
+        return {
+            "success": True,
+            "message": f"Reference '{request.name}' set as current"
+        }
+    except HTTPException:
+        raise
+    except Exception as exc:  # noqa: BLE001
+        logger.error("Failed to set current reference", name=request.name, error=repr(exc))
+        raise HTTPException(status_code=500, detail=str(exc))
+
+
+@router.delete("/reference/current")
+async def clear_current_reference() -> dict[str, Any]:
+    """Clear the current reference selection."""
+    try:
+        settings_manager = singletons.settings_manager
+        success = settings_manager.clear_current_reference()
+
+        if not success:
+            raise HTTPException(status_code=500, detail="Failed to clear current reference")
+
+        return {
+            "success": True,
+            "message": "Current reference cleared"
+        }
+    except HTTPException:
+        raise
+    except Exception as exc:  # noqa: BLE001
+        logger.error("Failed to clear current reference", error=repr(exc))
+        raise HTTPException(status_code=500, detail=str(exc))
+
+
+@router.delete("/reference/{reference_name}")
+async def delete_reference(reference_name: str, preset_filename: str | None = None) -> dict[str, Any]:
+    """Delete a reference."""
+    try:
+        settings_manager = singletons.settings_manager
+
+        if preset_filename:
+            preset = next(
+                (p for p in settings_manager.get_available_presets() if p.filename == preset_filename),
+                None
+            )
+            if not preset:
+                raise HTTPException(status_code=404, detail=f"Preset '{preset_filename}' not found")
+        else:
+            preset = settings_manager.get_current_preset()
+            if not preset:
+                raise HTTPException(status_code=400, detail="No current preset set and no preset_filename provided")
+
+        success = settings_manager.delete_reference(reference_name, preset)
+
+        if not success:
+            raise HTTPException(status_code=404, detail=f"Reference '{reference_name}' not found")
+
+        return {
+            "success": True,
+            "message": f"Reference '{reference_name}' deleted successfully"
+        }
+    except HTTPException:
+        raise
+    except Exception as exc:  # noqa: BLE001
+        logger.error("Failed to delete reference", name=reference_name, error=repr(exc))
+        raise HTTPException(status_code=500, detail=str(exc))
+
diff --git a/vna_system/api/models/settings.py b/vna_system/api/models/settings.py
index 56b5d50..2053c81 100644
--- a/vna_system/api/models/settings.py
+++ b/vna_system/api/models/settings.py
@@ -56,4 +56,25 @@ class WorkingCalibrationModel(BaseModel):
     progress: str | None = None
     is_complete: bool | None = None
     completed_standards: List[str] | None = None
-    missing_standards: List[str] | None = None
\ No newline at end of file
+    missing_standards: List[str] | None = None
+
+
+# Reference models
+class ReferenceModel(BaseModel):
+    name: str
+    timestamp: str
+    preset_filename: str
+    description: str
+    metadata: Dict[str, Any]
+
+
+class CreateReferenceRequest(BaseModel):
+    name: str
+    description: str = ""
+    metadata: Dict[str, Any] = {}
+    preset_filename: str | None = None
+
+
+class SetReferenceRequest(BaseModel):
+    name: str
+    preset_filename: str | None = None
\ No newline at end of file
diff --git a/vna_system/binary_input/current_input.bin b/vna_system/binary_input/current_input.bin
index e701777..7f4ad93 120000
--- a/vna_system/binary_input/current_input.bin
+++ b/vna_system/binary_input/current_input.bin
@@ -1 +1 @@
-config_inputs/s21_start100_stop8800_points1000_bw1khz.bin
\ No newline at end of file
+config_inputs/s11_start100_stop8800_points1000_bw1khz.bin
\ No newline at end of file
diff --git a/vna_system/calibration/current_calibration b/vna_system/calibration/current_calibration
deleted file mode 120000
index 635f973..0000000
--- a/vna_system/calibration/current_calibration
+++ /dev/null
@@ -1 +0,0 @@
-s21_start100_stop8800_points1000_bw1khz/bambambum
\ No newline at end of file
diff --git a/vna_system/core/acquisition/data_acquisition.py b/vna_system/core/acquisition/data_acquisition.py
index cf440e2..f373b25 100644
--- a/vna_system/core/acquisition/data_acquisition.py
+++ b/vna_system/core/acquisition/data_acquisition.py
@@ -75,7 +75,7 @@ class VNADataAcquisition:
     @property
     def is_running(self) -> bool:
         """Return True if the acquisition thread is alive."""
-        return self._running and (self._thread is not None and self._thread.is_alive())
+        return self._running and (self._thread is not None and self._thread.is_alive()) and not self._paused 
 
     @property
     def sweep_buffer(self) -> SweepBuffer:
diff --git a/vna_system/core/processors/base_processor.py b/vna_system/core/processors/base_processor.py
index 7a2e9a6..9842cac 100644
--- a/vna_system/core/processors/base_processor.py
+++ b/vna_system/core/processors/base_processor.py
@@ -299,7 +299,7 @@ class BaseProcessor:
     # --------------------------------------------------------------------- #
     # Data path: accept new sweep, recompute, produce result
     # --------------------------------------------------------------------- #
-    def add_sweep_data(self, sweep_data: Any, calibrated_data: Any, vna_config: ConfigPreset | None):
+    def add_sweep_data(self, sweep_data: Any, calibrated_data: Any, vna_config: ConfigPreset | None, reference_data: Any = None):
         """
         Add the latest sweep to the in-memory history and trigger recalculation.
 
@@ -311,6 +311,8 @@ class BaseProcessor:
             Data post-calibration (structure is processor-specific).
         vna_config:
             Snapshot of VNA settings (dataclass or pydantic model supported).
+        reference_data:
+            Open air reference sweep data for background subtraction/normalization.
 
         Returns
         -------
@@ -323,6 +325,7 @@ class BaseProcessor:
                     "sweep_data": sweep_data,
                     "calibrated_data": calibrated_data,
                     "vna_config": asdict(vna_config) if vna_config is not None else {},
+                    "reference_data": reference_data,
                     "timestamp": datetime.now().timestamp(),
                 }
             )
diff --git a/vna_system/core/processors/configs/bscan_config.json b/vna_system/core/processors/configs/bscan_config.json
new file mode 100644
index 0000000..15d18c4
--- /dev/null
+++ b/vna_system/core/processors/configs/bscan_config.json
@@ -0,0 +1,12 @@
+{
+  "open_air": true,
+  "axis": "real",
+  "data_limitation": null,
+  "cut": 0.824,
+  "max": 1.1,
+  "gain": 1.2,
+  "start_freq": 100.0,
+  "stop_freq": 8800.0,
+  "clear_history": false,
+  "data_limit": 500
+}
\ No newline at end of file
diff --git a/vna_system/core/processors/implementations/bscan_processor.py b/vna_system/core/processors/implementations/bscan_processor.py
new file mode 100644
index 0000000..638ee04
--- /dev/null
+++ b/vna_system/core/processors/implementations/bscan_processor.py
@@ -0,0 +1,575 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any, Final
+
+import numpy as np
+from numpy.typing import NDArray
+
+from vna_system.core.logging.logger import get_component_logger
+from vna_system.core.processors.base_processor import BaseProcessor, UIParameter
+from vna_system.core.acquisition.sweep_buffer import SweepData
+
+logger = get_component_logger(__file__)
+
+
+class BScanProcessor(BaseProcessor):
+    """
+    B-Scan processor for time-domain analysis of VNA measurements.
+
+    Features
+    -------
+    - Optional open-air reference subtraction
+    - Configurable axis: "real", "abs", "phase"
+    - IFFT with frequency range filtering
+    - Depth windowing with gain shaping
+    - Plot history accumulation for multi-sweep heatmaps
+    """
+
+    # Physical and display-related constants
+    SPEED_OF_LIGHT_M_S: Final[float] = 299_700_000.0  # m/s
+
+    def __init__(self, config_dir: Path) -> None:
+        super().__init__("bscan", config_dir)
+
+        # Increase history size for multi-sweep plotting
+        self.max_history = 10
+
+        # Local plot history (separate from sweep history maintained by BaseProcessor)
+        self._plot_history: list[dict[str, Any]] = []
+        self._max_plot_history = 50
+
+        logger.info("BScanProcessor initialized", processor_id=self.processor_id)
+
+    # -------------------------------------------------------------------------
+    # Configuration
+    # -------------------------------------------------------------------------
+
+    def _get_default_config(self) -> dict[str, Any]:
+        """Return default configuration values."""
+        return {
+            "open_air": False,          # Toggle for reference usage
+            "axis": "abs",              # "real", "abs", or "phase"
+            "data_limitation": None,    # None, "ph_only_1", "ph_only_2"
+            "cut": 0.824,               # Cut parameter (meters)
+            "max": 1.0,                 # Max depth (meters)
+            "gain": 1.0,                # Gain exponent
+            "start_freq": 100.0,        # Start frequency (MHz)
+            "stop_freq": 8800.0,        # Stop frequency (MHz)
+            "clear_history": False,     # UI button; not persisted
+        }
+
+    def get_ui_parameters(self) -> list[UIParameter]:
+        """Return UI parameter schema for configuration."""
+        cfg = self._config  # Local alias for brevity
+
+        return [
+            UIParameter(
+                name="open_air",
+                label="Open Air Reference",
+                type="toggle",
+                value=cfg["open_air"],
+            ),
+            UIParameter(
+                name="axis",
+                label="Axis",
+                type="select",
+                value=cfg["axis"],
+                options={"choices": ["real", "abs", "phase"]},
+            ),
+            UIParameter(
+                name="data_limitation",
+                label="Data Limitation",
+                type="select",
+                value=cfg["data_limitation"],
+                options={"choices": [None, "ph_only_1", "ph_only_2"]},
+            ),
+            UIParameter(
+                name="cut",
+                label="Cut (m)",
+                type="slider",
+                value=cfg["cut"],
+                options={"min": 0.0, "max": 2.0, "step": 0.001, "dtype": "float"},
+            ),
+            UIParameter(
+                name="max",
+                label="Max Depth (m)",
+                type="slider",
+                value=cfg["max"],
+                options={"min": 0.1, "max": 5.0, "step": 0.1, "dtype": "float"},
+            ),
+            UIParameter(
+                name="gain",
+                label="Gain Factor",
+                type="slider",
+                value=cfg["gain"],
+                options={"min": 0.0, "max": 3.0, "step": 0.1, "dtype": "float"},
+            ),
+            UIParameter(
+                name="start_freq",
+                label="Start Frequency (MHz)",
+                type="slider",
+                value=cfg["start_freq"],
+                options={"min": 100.0, "max": 8800.0, "step": 10.0, "dtype": "float"},
+            ),
+            UIParameter(
+                name="stop_freq",
+                label="Stop Frequency (MHz)",
+                type="slider",
+                value=cfg["stop_freq"],
+                options={"min": 100.0, "max": 8800.0, "step": 10.0, "dtype": "float"},
+            ),
+            UIParameter(
+                name="clear_history",
+                label="Clear Plot History",
+                type="button",
+                value=False,
+                options={"action": "Clear accumulated plot history"},
+            ),
+        ]
+
+    def update_config(self, updates: dict[str, Any]) -> None:
+        """Handle config updates, including the 'clear history' button action."""
+        if updates.get("clear_history"):
+            self._clear_plot_history()
+            # Remove button flag before delegating to base class
+            updates = {k: v for k, v in updates.items() if k != "clear_history"}
+
+        if updates:
+            super().update_config(updates)
+
+    def _clear_plot_history(self) -> None:
+        """Clear the accumulated plot history."""
+        with self._lock:
+            self._plot_history.clear()
+        logger.info("Plot history cleared", processor_id=self.processor_id)
+
+    # -------------------------------------------------------------------------
+    # Processing
+    # -------------------------------------------------------------------------
+
+    def process_sweep(
+        self,
+        sweep_data: SweepData,
+        calibrated_data: SweepData | None,
+        vna_config: dict[str, Any],
+    ) -> dict[str, Any]:
+        """
+        Process a single sweep and prepare B-scan data.
+
+        Returns
+        -------
+        dict
+            Keys: time_domain_data, distance_data, frequency_range, reference_used,
+                  axis_type, data_limitation, points_processed, plot_history_count
+            Or: {"error": "..."} on failure.
+        """
+        try:
+            # Choose calibrated data when provided
+            data_to_process = calibrated_data or sweep_data
+
+            complex_data = self._get_complex_s11(data_to_process)
+            if complex_data is None or complex_data.size == 0:
+                logger.warning("No valid complex data for B-scan processing")
+                return {"error": "No valid complex data"}
+
+            # Optional reference subtraction (latest stored reference in sweep history)
+            reference_data: SweepData | None = None
+            if self._config["open_air"] and self._sweep_history:
+                latest_history = self._sweep_history[-1]
+                reference_data = latest_history.get("reference_data")
+
+            if self._config["open_air"] and reference_data is not None:
+                reference_complex = self._get_complex_s11(reference_data)
+                if reference_complex is not None and reference_complex.size:
+                    complex_data = self._subtract_reference(complex_data, reference_complex)
+                    logger.debug("Applied open-air reference subtraction")
+
+            # Keep frequency controls in sync with the current VNA config
+            self._update_frequency_ranges(vna_config)
+
+            # Perform the main analysis pipeline
+            analysis = self._perform_data_analysis(complex_data, vna_config)
+            if analysis is None:
+                logger.warning("Data analysis failed")
+                return {"error": "Data analysis failed"}
+
+            plot_record = {
+                "time_domain_data": analysis["time_data"].tolist(),
+                "distance_data": analysis["distance"].tolist(),
+                "sweep_number": sweep_data.sweep_number,
+                "timestamp": sweep_data.timestamp,
+                "frequency_range": analysis["freq_range"],
+            }
+
+            with self._lock:
+                self._plot_history.append(plot_record)
+                if len(self._plot_history) > self._max_plot_history:
+                    self._plot_history = self._plot_history[-self._max_plot_history :]
+
+            return {
+                "time_domain_data": analysis["time_data"].tolist(),
+                "distance_data": analysis["distance"].tolist(),
+                "frequency_range": analysis["freq_range"],
+                "reference_used": bool(self._config["open_air"] and reference_data is not None),
+                "axis_type": self._config["axis"],
+                "data_limitation": self._config["data_limitation"],
+                "points_processed": int(complex_data.size),
+                "plot_history_count": len(self._plot_history),
+            }
+
+        except Exception as exc:  # noqa: BLE001
+            logger.error("B-scan processing failed", error=repr(exc))
+            return {"error": str(exc)}
+
+    # -------------------------------------------------------------------------
+    # Visualization
+    # -------------------------------------------------------------------------
+
+    def generate_plotly_config(
+        self,
+        processed_data: dict[str, Any],
+        vna_config: dict[str, Any],  # noqa: ARG002 - reserved for future layout tweaks
+    ) -> dict[str, Any]:
+        """
+        Produce a Plotly-compatible heatmap configuration from accumulated sweeps.
+        """
+        if "error" in processed_data:
+            return {
+                "data": [],
+                "layout": {
+                    "title": "B-Scan Analysis - Error",
+                    "annotations": [
+                        {
+                            "text": f"Error: {processed_data['error']}",
+                            "x": 0.5,
+                            "y": 0.5,
+                            "xref": "paper",
+                            "yref": "paper",
+                            "showarrow": False,
+                        }
+                    ],
+                    "template": "plotly_dark",
+                },
+            }
+
+        with self._lock:
+            history = list(self._plot_history)
+
+        if not history:
+            return {
+                "data": [],
+                "layout": {
+                    "title": "B-Scan Analysis - No Data",
+                    "xaxis": {"title": "Sweep Number"},
+                    "yaxis": {"title": "Depth (m)"},
+                    "template": "plotly_dark",
+                },
+            }
+
+        # Build scatter-like heatmap (irregular grid) from history
+        x_coords: list[int] = []
+        y_coords: list[float] = []
+        z_values: list[float] = []
+
+        for item in history:
+            sweep_num = item["sweep_number"]
+            depths = item["distance_data"]
+            amps = item["time_domain_data"]
+
+            for d, a in zip(depths, amps, strict=False):
+                x_coords.append(sweep_num)
+                y_coords.append(d)
+                z_values.append(a)
+
+        # Colorscale selection
+        if self._config["axis"] == "abs":
+            colorscale = "Viridis"
+            heatmap_kwargs: dict[str, Any] = {}
+        else:
+            colorscale = "RdBu"
+            heatmap_kwargs = {"zmid": 0}
+
+        heatmap_trace = {
+            "type": "heatmap",
+            "x": x_coords,
+            "y": y_coords,
+            "z": z_values,
+            "colorscale": colorscale,
+            "colorbar": {"title": "Amplitude"},
+            "hovertemplate": (
+                "Sweep: %{x}<br>"
+                "Depth: %{y:.3f} m<br>"
+                "Amplitude: %{z:.3f}<br>"
+                "<extra></extra>"
+            ),
+            **heatmap_kwargs,
+        }
+
+        freq_start, freq_stop = processed_data.get("frequency_range", [0.0, 0.0])
+        config_info = (
+            f"Freq: {freq_start/1e6:.1f}-{freq_stop/1e6:.1f} MHz | "
+            f"Gain: {self._config['gain']:.1f} | "
+            f"Cut: {self._config['cut']:.3f} m | "
+            f"Max: {self._config['max']:.1f} m | "
+            f"Axis: {self._config['axis']} | "
+            f"Sweeps: {len(history)}"
+        )
+
+        if processed_data.get("reference_used", False):
+            config_info += " | Open Air: ON"
+
+        if self._config["data_limitation"]:
+            config_info += f" | Limit: {self._config['data_limitation']}"
+
+        layout = {
+            "title": f"B-Scan Heatmap - {config_info}",
+            "xaxis": {"title": "Sweep Number", "side": "top"},
+            "yaxis": {"title": "Depth (m)", "autorange": "reversed"},
+            "hovermode": "closest",
+            "height": 600,
+            "width": 500,
+            "template": "plotly_dark",
+        }
+
+        return {"data": [heatmap_trace], "layout": layout}
+
+    # -------------------------------------------------------------------------
+    # Low-level helpers
+    # -------------------------------------------------------------------------
+
+    def _get_complex_s11(self, sweep_data: SweepData) -> NDArray[np.complex128] | None:
+        """Extract complex S11 array from sweep points."""
+        try:
+            if not sweep_data.points:
+                return None
+
+            # Each point is expected as a pair (real, imag)
+            arr = np.asarray(sweep_data.points, dtype=float)
+            if arr.ndim != 2 or arr.shape[1] != 2:
+                raise ValueError("Expected Nx2 array for (real, imag) points")
+
+            complex_data = arr[:, 0] + 1j * arr[:, 1]
+            return complex_data.astype(np.complex128, copy=False)
+
+        except Exception as exc:  # noqa: BLE001
+            logger.error("Failed to extract complex S11 data", error=repr(exc))
+            return None
+
+    def _subtract_reference(
+        self,
+        signal: NDArray[np.complex128],
+        reference: NDArray[np.complex128],
+    ) -> NDArray[np.complex128]:
+        """Subtract reference from signal (complex subtraction), length-safe."""
+        try:
+            n = min(signal.size, reference.size)
+            if n == 0:
+                return signal
+            result = signal[:n] - reference[:n]
+            logger.debug("Reference subtraction completed", points=n)
+            return result
+        except Exception as exc:  # noqa: BLE001
+            logger.error("Reference subtraction failed", error=repr(exc))
+            return signal  # Non-fatal; continue with original signal
+
+    def _update_frequency_ranges(self, vna_config: dict[str, Any]) -> None:
+        """Clamp configured frequency sliders to VNA limits."""
+        if not vna_config:
+            return
+
+        start_freq_hz = float(vna_config.get("start_freq", 100e6))
+        stop_freq_hz = float(vna_config.get("stop_freq", 8.8e9))
+
+        start_mhz = start_freq_hz / 1e6
+        stop_mhz = stop_freq_hz / 1e6
+
+        current_start = float(self._config["start_freq"])
+        current_stop = float(self._config["stop_freq"])
+
+        # Ensure order and clamp to VNA bounds
+        new_start = max(start_mhz, min(stop_mhz, current_start))
+        new_stop = max(new_start, min(stop_mhz, current_stop))
+
+        self._config["start_freq"] = new_start
+        self._config["stop_freq"] = new_stop
+
+    def _perform_data_analysis(
+        self,
+        complex_data: NDArray[np.complex128],
+        vna_config: dict[str, Any],
+    ) -> dict[str, Any] | None:
+        """Full analysis pipeline: limit -> IFFT -> depth shaping."""
+        try:
+            # Determine effective frequency range (Hz)
+            if vna_config:
+                freq_start = max(float(vna_config.get("start_freq", 100e6)), self._config["start_freq"] * 1e6)
+                freq_stop = min(float(vna_config.get("stop_freq", 8.8e9)), self._config["stop_freq"] * 1e6)
+            else:
+                freq_start = self._config["start_freq"] * 1e6
+                freq_stop = self._config["stop_freq"] * 1e6
+
+            # Frequency vector over current data length
+            freq_axis = np.linspace(freq_start, freq_stop, complex_data.size, dtype=float)
+
+            # Optionally normalize amplitude (phase-only modes)
+            limited = self._apply_data_limitations(complex_data)
+
+            # IFFT to time domain
+            depth_m, time_response = self._perform_ifft(limited, freq_axis, axis=self._config["axis"])
+
+            # Depth windowing and gain shaping
+            depth_out, time_out = self._apply_depth_processing(depth_m, time_response)
+
+            return {
+                "time_data": time_out,
+                "distance": depth_out,
+                "freq_range": [freq_start, freq_stop],
+                "complex_time": limited,
+            }
+        except Exception as exc:  # noqa: BLE001
+            logger.error("Data analysis failed", error=repr(exc))
+            return None
+
+    def _apply_data_limitations(self, s: NDArray[np.complex128]) -> NDArray[np.complex128]:
+        """
+        Apply optional amplitude normalization to emphasize phase information.
+
+        Modes
+        -----
+        - None: passthrough
+        - "ph_only_1": normalize by magnitude
+        - "ph_only_2": same normalization (kept for behavioral parity)
+        """
+        try:
+            mode = self._config.get("data_limitation")
+            if mode in {"ph_only_1", "ph_only_2"}:
+                # Avoid division by zero
+                return s / (np.abs(s) + 1e-12)
+            return s
+        except Exception as exc:  # noqa: BLE001
+            logger.error("Data limitation processing failed", error=repr(exc))
+            return s
+
+    def _perform_ifft(
+        self,
+        s_array: NDArray[np.complex128],
+        frequencies_hz: NDArray[np.floating],
+        *,
+        axis: str = "abs",
+    ) -> tuple[NDArray[np.floating], NDArray[np.floating]]:
+        """
+        Frequency-to-time conversion with zero-padding and frequency offset handling.
+
+        Returns
+        -------
+        depth_m : ndarray
+            One-way distance in meters corresponding to the time axis.
+        y_fin : ndarray
+            Time-domain response (abs/real/phase per `axis`).
+        """
+        try:
+            # Apply frequency band mask from current config (Hz)
+            start_hz = float(self._config.get("start_freq", 100.0)) * 1e6
+            stop_hz = float(self._config.get("stop_freq", 8800.0)) * 1e6
+
+            mask = (frequencies_hz >= start_hz) & (frequencies_hz <= stop_hz)
+            f = frequencies_hz[mask]
+            s = s_array[mask]
+
+            n = f.size
+            if n < 2:
+                raise ValueError("Not enough frequency points after filtering")
+
+            df = (f[-1] - f[0]) / (n - 1)
+            if df <= 0.0:
+                raise ValueError("Non-increasing frequency grid")
+
+            # Frequency offset index
+            k0 = int(np.round(f[0] / df))
+
+            # FFT size (next power of two for 2*(k0 + n - 1))
+            min_len = 2 * (k0 + n - 1)
+            N_fft = 1 << int(np.ceil(np.log2(min_len)))
+
+            dt = 1.0 / (N_fft * df)
+            t_sec = np.arange(N_fft, dtype=float) * dt
+
+            # Build shifted spectrum
+            H = np.zeros(N_fft, dtype=np.complex128)
+            H[k0 : k0 + n] = s
+
+            y = np.fft.ifft(H)
+
+            # Convert time (s) to one-way distance (m): d = c * t
+            depth_m = t_sec * self.SPEED_OF_LIGHT_M_S
+
+            if axis == "abs":
+                y_fin = np.abs(y)
+            elif axis == "real":
+                y_fin = np.real(y)
+            elif axis == "phase":
+                y_fin = np.angle(y)
+            else:
+                raise ValueError(f"Invalid axis parameter: {axis!r}")
+
+            # Truncate output to computed length (optional: keep full)
+            return depth_m[: y_fin.size], y_fin.astype(float, copy=False)
+
+        except Exception as exc:  # noqa: BLE001
+            logger.error("IFFT failed", error=repr(exc))
+            # Graceful fallback: synthetic axes with magnitude of input
+            depth_fallback = np.linspace(0.0, 1.0, s_array.size, dtype=float)
+            return depth_fallback, np.abs(s_array).astype(float, copy=False)
+
+    def _apply_depth_processing(
+        self,
+        depth_m: NDArray[np.floating],
+        response: NDArray[np.floating],
+    ) -> tuple[NDArray[np.floating], NDArray[np.floating]]:
+        """
+        Apply depth windowing and gain shaping.
+
+        Window
+        ------
+        Keep samples where:
+            depth in [2*cut, 2*cut + 2*max]
+        Then map depth to:
+            depth' = (depth - 2*cut) / 2
+
+        Gain
+        ----
+        response' = response * (depth' ** gain)
+        """
+        try:
+            cut = float(self._config["cut"])
+            max_depth = float(self._config["max"])
+            gain = float(self._config["gain"])
+
+            # Window: account for two-way path in raw depth (factor 2)
+            lo = 2.0 * cut
+            hi = lo + 2.0 * max_depth
+            mask = (depth_m >= lo) & (depth_m <= hi)
+
+            if not np.any(mask):
+                # Nothing in window; return empty arrays
+                return depth_m[:0], response[:0]
+
+            depth_win = depth_m[mask]
+            resp_win = response[mask]
+
+            # Convert to one-way depth relative to the cut
+            depth_out = (depth_win - lo) / 2.0
+
+            # Depth-dependent gain (safe for zero depth with exponent >= 0)
+            with np.errstate(invalid="ignore"):
+                gain_shape = np.power(depth_out, gain, dtype=float)
+                # Replace NaN/inf (e.g., 0**negative) with 0
+                gain_shape[~np.isfinite(gain_shape)] = 0.0
+
+            response_out = resp_win * gain_shape
+            return depth_out, response_out
+
+        except Exception as exc:  # noqa: BLE001
+            logger.error("Depth processing failed", error=repr(exc))
+            return depth_m, response
diff --git a/vna_system/core/processors/manager.py b/vna_system/core/processors/manager.py
index c622fc0..6c3ccae 100644
--- a/vna_system/core/processors/manager.py
+++ b/vna_system/core/processors/manager.py
@@ -99,7 +99,7 @@ class ProcessorManager:
     # --------------------------------------------------------------------- #
     # Main processing actions
     # --------------------------------------------------------------------- #
-    def process_sweep(self, sweep_data: SweepData, calibrated_data: Any, vna_config: ConfigPreset | None) -> dict[str, ProcessedResult]:
+    def process_sweep(self, sweep_data: SweepData, calibrated_data: Any, vna_config: ConfigPreset | None, reference_data: Any = None) -> dict[str, ProcessedResult]:
         """
         Feed a sweep into all processors and dispatch results to callbacks.
 
@@ -113,7 +113,7 @@ class ProcessorManager:
 
         for processor_id, processor in processors_items:
             try:
-                result = processor.add_sweep_data(sweep_data, calibrated_data, vna_config)
+                result = processor.add_sweep_data(sweep_data, calibrated_data, vna_config, reference_data)
                 if result:
                     results[processor_id] = result
                     for cb in callbacks:
@@ -215,7 +215,8 @@ class ProcessorManager:
                 if latest and latest.sweep_number > self._last_processed_sweep:
                     calibrated = self._apply_calibration(latest)
                     vna_cfg = self.settings_manager.get_current_preset()
-                    self.process_sweep(latest, calibrated, vna_cfg)
+                    reference_data = self.settings_manager.get_current_reference_sweep(vna_cfg)
+                    self.process_sweep(latest, calibrated, vna_cfg, reference_data)
                     self._last_processed_sweep = latest.sweep_number
 
                 # Light-duty polling to reduce wakeups
@@ -267,9 +268,11 @@ class ProcessorManager:
         """
         try:
             from .implementations import MagnitudeProcessor, PhaseProcessor, SmithChartProcessor
+            from .implementations.bscan_processor import BScanProcessor
 
             self.register_processor(MagnitudeProcessor(self.config_dir))
             self.register_processor(PhaseProcessor(self.config_dir))
+            self.register_processor(BScanProcessor(self.config_dir))
             # self.register_processor(SmithChartProcessor(self.config_dir))
 
             logger.info("Default processors registered", count=len(self._processors))
diff --git a/vna_system/core/settings/reference_manager.py b/vna_system/core/settings/reference_manager.py
new file mode 100644
index 0000000..d3432c3
--- /dev/null
+++ b/vna_system/core/settings/reference_manager.py
@@ -0,0 +1,464 @@
+"""
+Open Air Reference Manager
+
+Manages open air reference sweep data for background subtraction and normalization.
+References are stored per preset configuration and can be captured from live sweeps.
+"""
+
+import json
+import shutil
+from datetime import datetime
+from pathlib import Path
+
+from vna_system.core import config as cfg
+from vna_system.core.logging.logger import get_component_logger
+from vna_system.core.acquisition.sweep_buffer import SweepData
+from vna_system.core.settings.preset_manager import ConfigPreset
+
+logger = get_component_logger(__file__)
+
+
+class ReferenceInfo:
+    """Information about a stored reference."""
+
+    def __init__(
+        self,
+        name: str,
+        timestamp: datetime,
+        preset_filename: str,
+        description: str = "",
+        metadata: dict | None = None
+    ):
+        self.name = name
+        self.timestamp = timestamp
+        self.preset_filename = preset_filename
+        self.description = description
+        self.metadata = metadata or {}
+
+    def to_dict(self) -> dict:
+        """Convert to dictionary for JSON serialization."""
+        return {
+            "name": self.name,
+            "timestamp": self.timestamp.isoformat(),
+            "preset_filename": self.preset_filename,
+            "description": self.description,
+            "metadata": self.metadata
+        }
+
+    @classmethod
+    def from_dict(cls, data: dict) -> "ReferenceInfo":
+        """Create from dictionary loaded from JSON."""
+        return cls(
+            name=data["name"],
+            timestamp=datetime.fromisoformat(data["timestamp"]),
+            preset_filename=data["preset_filename"],
+            description=data.get("description", ""),
+            metadata=data.get("metadata", {})
+        )
+
+
+class ReferenceManager:
+    """
+    Manages open air reference sweep data.
+
+    References are stored in the following structure:
+    references/
+    ├── current_reference -> symlink to active reference
+    ├── <preset_name>/
+    │   ├── <reference_name>/
+    │   │   ├── info.json       # Reference metadata
+    │   │   └── sweep_data.json # Raw sweep data
+    │   └── ...
+    └── ...
+    """
+
+    def __init__(self):
+        self.references_dir = Path(cfg.BASE_DIR) / "references"
+        self.current_reference_symlink = self.references_dir / "current_reference"
+
+        # Ensure directory structure exists
+        self.references_dir.mkdir(exist_ok=True)
+
+        logger.info("ReferenceManager initialized", references_dir=str(self.references_dir))
+
+    # ------------------------------------------------------------------ #
+    # Reference Creation and Storage
+    # ------------------------------------------------------------------ #
+
+    def create_reference(
+        self,
+        name: str,
+        preset: ConfigPreset,
+        sweep_data: SweepData,
+        description: str = "",
+        metadata: dict | None = None
+    ) -> ReferenceInfo:
+        """
+        Create a new reference from sweep data.
+
+        Args:
+            name: Unique name for the reference
+            preset: Current configuration preset
+            sweep_data: Raw sweep data to store
+            description: Optional description
+            metadata: Optional additional metadata
+
+        Returns:
+            ReferenceInfo: Created reference information
+
+        Raises:
+            ValueError: If reference name already exists for this preset
+            OSError: If file operations fail
+        """
+        if not name or not name.strip():
+            raise ValueError("Reference name cannot be empty")
+
+        preset_dir = self._get_preset_dir(preset)
+        reference_dir = preset_dir / name
+
+        if reference_dir.exists():
+            raise ValueError(f"Reference '{name}' already exists for preset {preset.filename}")
+
+        # Create reference directory
+        reference_dir.mkdir(parents=True, exist_ok=True)
+
+        # Create reference info
+        reference_info = ReferenceInfo(
+            name=name,
+            timestamp=datetime.now(),
+            preset_filename=preset.filename,
+            description=description.strip(),
+            metadata=metadata or {}
+        )
+
+        try:
+            # Save reference metadata
+            info_file = reference_dir / "info.json"
+            with info_file.open("w", encoding="utf-8") as f:
+                json.dump(reference_info.to_dict(), f, indent=2, ensure_ascii=False)
+
+            # Save sweep data
+            sweep_file = reference_dir / "sweep_data.json"
+            sweep_dict = {
+                "sweep_number": sweep_data.sweep_number,
+                "timestamp": sweep_data.timestamp,
+                "points": sweep_data.points,
+                "total_points": sweep_data.total_points
+            }
+            with sweep_file.open("w", encoding="utf-8") as f:
+                json.dump(sweep_dict, f, indent=2)
+
+            logger.info(
+                "Created reference",
+                name=name,
+                preset=preset.filename,
+                sweep_number=sweep_data.sweep_number,
+                points=len(sweep_data.points)
+            )
+
+            return reference_info
+
+        except Exception as exc:
+            # Clean up on failure
+            if reference_dir.exists():
+                shutil.rmtree(reference_dir, ignore_errors=True)
+            logger.error("Failed to create reference", name=name, error=repr(exc))
+            raise
+
+    def delete_reference(self, name: str, preset: ConfigPreset) -> bool:
+        """
+        Delete a reference.
+
+        Args:
+            name: Reference name to delete
+            preset: Configuration preset
+
+        Returns:
+            bool: True if deleted successfully
+        """
+        preset_dir = self._get_preset_dir(preset)
+        reference_dir = preset_dir / name
+
+        if not reference_dir.exists():
+            logger.warning("Reference not found for deletion", name=name, preset=preset.filename)
+            return False
+
+        try:
+            # Check if this is the current reference
+            current_ref = self.get_current_reference(preset)
+            if current_ref and current_ref.name == name:
+                self.clear_current_reference()
+
+            shutil.rmtree(reference_dir)
+            logger.info("Deleted reference", name=name, preset=preset.filename)
+            return True
+
+        except Exception as exc:
+            logger.error("Failed to delete reference", name=name, error=repr(exc))
+            return False
+
+    # ------------------------------------------------------------------ #
+    # Reference Selection and Retrieval
+    # ------------------------------------------------------------------ #
+
+    def set_current_reference(self, name: str, preset: ConfigPreset) -> bool:
+        """
+        Set the current active reference.
+
+        Args:
+            name: Reference name to activate
+            preset: Configuration preset
+
+        Returns:
+            bool: True if set successfully
+        """
+        preset_dir = self._get_preset_dir(preset)
+        reference_dir = preset_dir / name
+
+        if not reference_dir.exists():
+            raise ValueError(f"Reference '{name}' not found for preset {preset.filename}")
+
+        try:
+            # Remove existing symlink
+            if self.current_reference_symlink.exists() or self.current_reference_symlink.is_symlink():
+                self.current_reference_symlink.unlink()
+
+            # Create relative symlink for portability
+            try:
+                relative_target = reference_dir.relative_to(self.references_dir)
+            except ValueError:
+                relative_target = reference_dir
+
+            self.current_reference_symlink.symlink_to(relative_target)
+
+            logger.info("Set current reference", name=name, preset=preset.filename)
+            return True
+
+        except Exception as exc:
+            logger.error("Failed to set current reference", name=name, error=repr(exc))
+            return False
+
+    def get_current_reference(self, preset: ConfigPreset) -> ReferenceInfo | None:
+        """
+        Get information about the currently active reference.
+
+        Args:
+            preset: Configuration preset to check against
+
+        Returns:
+            ReferenceInfo | None: Current reference info, or None if no reference is set
+                                    or if the current reference doesn't match the preset
+        """
+        if not self.current_reference_symlink.exists():
+            return None
+
+        try:
+            target_dir = self.current_reference_symlink.resolve()
+
+            if not target_dir.exists():
+                logger.warning("Current reference symlink points to non-existent directory")
+                return None
+
+            # Load reference info
+            info_file = target_dir / "info.json"
+            if not info_file.exists():
+                logger.warning("Current reference missing info.json")
+                return None
+
+            with info_file.open("r", encoding="utf-8") as f:
+                info_data = json.load(f)
+
+            reference_info = ReferenceInfo.from_dict(info_data)
+
+            # Check if reference matches current preset
+            if reference_info.preset_filename != preset.filename:
+                logger.debug(
+                    "Current reference is for different preset",
+                    reference_preset=reference_info.preset_filename,
+                    current_preset=preset.filename
+                )
+                return None
+
+            return reference_info
+
+        except Exception as exc:
+            logger.warning("Failed to get current reference", error=repr(exc))
+            return None
+
+    def clear_current_reference(self) -> bool:
+        """
+        Clear the current reference selection.
+
+        Returns:
+            bool: True if cleared successfully
+        """
+        try:
+            if self.current_reference_symlink.exists() or self.current_reference_symlink.is_symlink():
+                self.current_reference_symlink.unlink()
+                logger.info("Cleared current reference")
+            return True
+        except Exception as exc:
+            logger.error("Failed to clear current reference", error=repr(exc))
+            return False
+
+    def get_current_reference_sweep(self, preset: ConfigPreset) -> SweepData | None:
+        """
+        Get the sweep data for the currently active reference.
+
+        Args:
+            preset: Configuration preset
+
+        Returns:
+            SweepData | None: Current reference sweep data, or None if no reference is active
+        """
+        current_ref = self.get_current_reference(preset)
+        if not current_ref:
+            return None
+
+        return self.get_reference_sweep(current_ref.name, preset)
+
+    def get_reference_sweep(self, name: str, preset: ConfigPreset) -> SweepData | None:
+        """
+        Get sweep data for a specific reference.
+
+        Args:
+            name: Reference name
+            preset: Configuration preset
+
+        Returns:
+            SweepData | None: Reference sweep data, or None if not found
+        """
+        preset_dir = self._get_preset_dir(preset)
+        reference_dir = preset_dir / name
+        sweep_file = reference_dir / "sweep_data.json"
+
+        if not sweep_file.exists():
+            logger.warning("Reference sweep data not found", name=name, preset=preset.filename)
+            return None
+
+        try:
+            with sweep_file.open("r", encoding="utf-8") as f:
+                sweep_dict = json.load(f)
+
+            return SweepData(
+                sweep_number=sweep_dict["sweep_number"],
+                timestamp=sweep_dict["timestamp"],
+                points=sweep_dict["points"],
+                total_points=sweep_dict["total_points"]
+            )
+
+        except Exception as exc:
+            logger.error("Failed to load reference sweep data", name=name, error=repr(exc))
+            return None
+
+    # ------------------------------------------------------------------ #
+    # Reference Listing and Information
+    # ------------------------------------------------------------------ #
+
+    def list_references(self, preset: ConfigPreset) -> list[ReferenceInfo]:
+        """
+        List all references for a given preset.
+
+        Args:
+            preset: Configuration preset
+
+        Returns:
+            list[ReferenceInfo]: List of available references, sorted by timestamp (newest first)
+        """
+        preset_dir = self._get_preset_dir(preset)
+
+        if not preset_dir.exists():
+            return []
+
+        references = []
+
+        for ref_dir in preset_dir.iterdir():
+            if not ref_dir.is_dir():
+                continue
+
+            info_file = ref_dir / "info.json"
+            if not info_file.exists():
+                logger.warning("Reference missing info.json", reference_dir=str(ref_dir))
+                continue
+
+            try:
+                with info_file.open("r", encoding="utf-8") as f:
+                    info_data = json.load(f)
+
+                reference_info = ReferenceInfo.from_dict(info_data)
+                references.append(reference_info)
+
+            except Exception as exc:
+                logger.warning("Failed to load reference info", reference_dir=str(ref_dir), error=repr(exc))
+
+        # Sort by timestamp, newest first
+        references.sort(key=lambda r: r.timestamp, reverse=True)
+        return references
+
+    def get_reference_info(self, name: str, preset: ConfigPreset) -> ReferenceInfo | None:
+        """
+        Get information about a specific reference.
+
+        Args:
+            name: Reference name
+            preset: Configuration preset
+
+        Returns:
+            ReferenceInfo | None: Reference information, or None if not found
+        """
+        preset_dir = self._get_preset_dir(preset)
+        reference_dir = preset_dir / name
+        info_file = reference_dir / "info.json"
+
+        if not info_file.exists():
+            return None
+
+        try:
+            with info_file.open("r", encoding="utf-8") as f:
+                info_data = json.load(f)
+
+            return ReferenceInfo.from_dict(info_data)
+
+        except Exception as exc:
+            logger.warning("Failed to load reference info", name=name, error=repr(exc))
+            return None
+
+    # ------------------------------------------------------------------ #
+    # Helper Methods
+    # ------------------------------------------------------------------ #
+
+    def _get_preset_dir(self, preset: ConfigPreset) -> Path:
+        """Get directory path for a preset's references."""
+        # Use preset filename without extension as directory name
+        preset_name = Path(preset.filename).stem
+        return self.references_dir / preset_name
+
+    def cleanup_orphaned_references(self) -> int:
+        """
+        Clean up reference directories that don't have valid preset files.
+
+        Returns:
+            int: Number of orphaned references cleaned up
+        """
+        cleaned_count = 0
+
+        for preset_dir in self.references_dir.iterdir():
+            if not preset_dir.is_dir() or preset_dir.name == "current_reference":
+                continue
+
+            # Check if corresponding preset file exists
+            preset_filename = f"{preset_dir.name}.bin"
+            preset_path = Path(cfg.BASE_DIR) / "binary_input" / "config_inputs" / preset_filename
+
+            if not preset_path.exists():
+                try:
+                    shutil.rmtree(preset_dir)
+                    cleaned_count += 1
+                    logger.info("Cleaned up orphaned reference directory", preset=preset_dir.name)
+                except Exception as exc:
+                    logger.warning("Failed to clean up orphaned references", preset=preset_dir.name, error=repr(exc))
+
+        if cleaned_count > 0:
+            logger.info("Reference cleanup completed", cleaned_count=cleaned_count)
+
+        return cleaned_count
\ No newline at end of file
diff --git a/vna_system/core/settings/settings_manager.py b/vna_system/core/settings/settings_manager.py
index 8e8d900..4dd1277 100644
--- a/vna_system/core/settings/settings_manager.py
+++ b/vna_system/core/settings/settings_manager.py
@@ -11,6 +11,7 @@ from vna_system.core.settings.calibration_manager import (
     CalibrationSet,
     CalibrationStandard,
 )
+from vna_system.core.settings.reference_manager import ReferenceManager, ReferenceInfo
 
 logger = get_component_logger(__file__)
 
@@ -38,6 +39,7 @@ class VNASettingsManager:
         # Sub-managers
         self.preset_manager = PresetManager(self.base_dir / "binary_input")
         self.calibration_manager = CalibrationManager(self.base_dir)
+        self.reference_manager = ReferenceManager()
 
         logger.debug(
             "VNASettingsManager initialized",
@@ -50,11 +52,7 @@ class VNASettingsManager:
     def get_available_presets(self) -> list[ConfigPreset]:
         """Return all available configuration presets."""
         return self.preset_manager.get_available_presets()
-
-    def get_presets_by_mode(self, mode: VNAMode) -> list[ConfigPreset]:
-        """Return presets filtered by VNA mode."""
-        return [p for p in self.get_available_presets() if p.mode == mode]
-
+    
     def set_current_preset(self, preset: ConfigPreset) -> ConfigPreset:
         """Set the current configuration preset (updates the symlink)."""
         chosen = self.preset_manager.set_current_preset(preset)
@@ -148,6 +146,48 @@ class VNASettingsManager:
             return [CalibrationStandard.THROUGH]
         return []
 
+    # ------------------------------------------------------------------ #
+    # Reference Management
+    # ------------------------------------------------------------------ #
+    def get_available_references(self, preset: ConfigPreset | None = None) -> list[ReferenceInfo]:
+        """Return all available references for the given preset (or current preset)."""
+        current_preset = preset or self.get_current_preset()
+        if not current_preset:
+            return []
+        return self.reference_manager.list_references(current_preset)
+
+    def get_current_reference(self, preset: ConfigPreset | None = None) -> ReferenceInfo | None:
+        """Return the currently selected reference for the given preset (or current preset)."""
+        current_preset = preset or self.get_current_preset()
+        if not current_preset:
+            return None
+        return self.reference_manager.get_current_reference(current_preset)
+
+    def set_current_reference(self, reference_name: str, preset: ConfigPreset | None = None) -> bool:
+        """Set the current reference for the given preset (or current preset)."""
+        current_preset = preset or self.get_current_preset()
+        if not current_preset:
+            raise ValueError("No current preset available")
+        return self.reference_manager.set_current_reference(reference_name, current_preset)
+
+    def clear_current_reference(self) -> bool:
+        """Clear the current reference selection."""
+        return self.reference_manager.clear_current_reference()
+
+    def get_current_reference_sweep(self, preset: ConfigPreset | None = None) -> SweepData | None:
+        """Get sweep data for the currently selected reference."""
+        current_preset = preset or self.get_current_preset()
+        if not current_preset:
+            return None
+        return self.reference_manager.get_current_reference_sweep(current_preset)
+
+    def delete_reference(self, reference_name: str, preset: ConfigPreset | None = None) -> bool:
+        """Delete a reference for the given preset (or current preset)."""
+        current_preset = preset or self.get_current_preset()
+        if not current_preset:
+            raise ValueError("No current preset available")
+        return self.reference_manager.delete_reference(reference_name, current_preset)
+
     # ------------------------------------------------------------------ #
     # Acquisition integration
     # ------------------------------------------------------------------ #
@@ -169,7 +209,18 @@ class VNASettingsManager:
         RuntimeError
             If no sweep is available in the acquisition buffer.
         """
-        latest = data_acquisition.sweep_buffer.get_latest_sweep()
+        # Get current sweep number before any operations
+        current_sweep = data_acquisition.sweep_buffer.get_latest_sweep()
+        current_sweep_number = current_sweep.sweep_number if current_sweep else -1
+
+        # Check if acquisition is running, if not - trigger single sweep
+        if not data_acquisition.is_running:
+            logger.info("Acquisition not running, triggering single sweep for calibration")
+            data_acquisition.trigger_single_sweep()
+
+        # Wait for new sweep to appear (regardless of acquisition state)
+        latest = self._wait_for_new_sweep(data_acquisition.sweep_buffer, current_sweep_number)
+
         if latest is None:
             raise RuntimeError("No sweep data available in acquisition buffer")
 
@@ -181,6 +232,66 @@ class VNASettingsManager:
         )
         return latest.sweep_number
 
+    def capture_reference_from_acquisition(
+        self,
+        reference_name: str,
+        data_acquisition: VNADataAcquisition,
+        description: str = "",
+        metadata: dict | None = None,
+        preset: ConfigPreset | None = None,
+    ) -> ReferenceInfo:
+        """
+        Capture the latest sweep from acquisition as an open air reference.
+
+        Args:
+            reference_name: Name for the new reference
+            data_acquisition: Data acquisition instance to capture from
+            description: Optional description for the reference
+            metadata: Optional additional metadata
+            preset: Preset to use (defaults to current preset)
+
+        Returns:
+            ReferenceInfo: Created reference information
+
+        Raises:
+            RuntimeError: If no sweep is available in the acquisition buffer
+            ValueError: If no current preset is available
+        """
+        # Get current sweep number before any operations
+        current_sweep = data_acquisition.sweep_buffer.get_latest_sweep()
+        current_sweep_number = current_sweep.sweep_number if current_sweep else -1
+
+        # Check if acquisition is running, if not - trigger single sweep
+        if not data_acquisition.is_running:
+            logger.info("Acquisition not running, triggering single sweep for reference")
+            data_acquisition.trigger_single_sweep()
+
+        # Wait for new sweep to appear (regardless of acquisition state)
+        latest = self._wait_for_new_sweep(data_acquisition.sweep_buffer, current_sweep_number)
+
+        if latest is None:
+            raise RuntimeError("No sweep data available in acquisition buffer")
+
+        current_preset = preset or self.get_current_preset()
+        if not current_preset:
+            raise ValueError("No current preset available")
+
+        reference_info = self.reference_manager.create_reference(
+            name=reference_name,
+            preset=current_preset,
+            sweep_data=latest,
+            description=description,
+            metadata=metadata or {}
+        )
+
+        logger.info(
+            "Captured open air reference from acquisition",
+            reference_name=reference_name,
+            preset=current_preset.filename,
+            sweep_number=latest.sweep_number,
+        )
+        return reference_info
+
     def get_status_summary(self) -> dict[str, object]:
         """Get comprehensive status of current configuration and calibration"""
         current_preset = self.get_current_preset()
@@ -223,4 +334,39 @@ class VNASettingsManager:
                 "missing_standards": [s.value for s in working_calibration.get_missing_standards()]
             }
 
-        return summary
\ No newline at end of file
+        return summary
+
+    def _wait_for_new_sweep(self, sweep_buffer, current_sweep_number: int, timeout_seconds: float = 5.0) -> SweepData | None:
+        """
+        Wait for a new sweep to appear in the buffer with a higher sweep number.
+
+        Args:
+            sweep_buffer: The sweep buffer to monitor
+            current_sweep_number: Current sweep number to wait beyond
+            timeout_seconds: Maximum time to wait
+
+        Returns:
+            SweepData | None: New sweep data, or None if timeout occurred
+        """
+        import time
+        start_time = time.time()
+
+        while time.time() - start_time < timeout_seconds:
+            latest = sweep_buffer.get_latest_sweep()
+            if latest and latest.sweep_number > current_sweep_number:
+                logger.debug(
+                    "New sweep detected",
+                    old_sweep=current_sweep_number,
+                    new_sweep=latest.sweep_number
+                )
+                return latest
+
+            # Short sleep to avoid busy waiting
+            time.sleep(0.01)
+
+        logger.warning(
+            "Timeout waiting for new sweep",
+            current_sweep=current_sweep_number,
+            timeout=timeout_seconds
+        )
+        return None
\ No newline at end of file
diff --git a/vna_system/references/current_reference b/vna_system/references/current_reference
new file mode 120000
index 0000000..0911f55
--- /dev/null
+++ b/vna_system/references/current_reference
@@ -0,0 +1 @@
+s11_start100_stop8800_points1000_bw1khz/test1
\ No newline at end of file
diff --git a/vna_system/web_ui/static/css/settings.css b/vna_system/web_ui/static/css/settings.css
index 52ccf8a..9cad7d4 100644
--- a/vna_system/web_ui/static/css/settings.css
+++ b/vna_system/web_ui/static/css/settings.css
@@ -489,4 +489,138 @@
 .calibration-standard-btn.btn--warning:hover:not(:disabled) {
     background-color: var(--color-warning-600);
     border-color: var(--color-warning-600);
+}
+
+/* ========================================
+   Reference Management Styles
+   ======================================== */
+
+/* Reference Creation */
+.reference-creation {
+    display: flex;
+    flex-direction: column;
+    gap: var(--space-3);
+    margin-bottom: var(--space-4);
+}
+
+.reference-name-input,
+.reference-description-input {
+    padding: var(--space-2) var(--space-3);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-md);
+    font-size: var(--text-sm);
+    background: var(--color-bg);
+    color: var(--color-text);
+    transition: all 0.2s ease;
+}
+
+.reference-name-input:focus,
+.reference-description-input:focus {
+    outline: none;
+    border-color: var(--color-primary-500);
+    box-shadow: 0 0 0 3px var(--color-primary-100);
+}
+
+.reference-name-input::placeholder,
+.reference-description-input::placeholder {
+    color: var(--color-text-secondary);
+}
+
+/* Reference Actions */
+.reference-actions {
+    display: flex;
+    gap: var(--space-3);
+    align-items: stretch;
+    margin-top: var(--space-3);
+    flex-wrap: wrap;
+}
+
+.reference-dropdown {
+    flex: 1;
+    min-width: 200px;
+    padding: var(--space-2) var(--space-3);
+    border: 1px solid var(--color-border);
+    border-radius: var(--radius-md);
+    font-size: var(--text-sm);
+    background: var(--color-bg);
+    color: var(--color-text);
+}
+
+.reference-dropdown:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+    background: var(--color-gray-50);
+}
+
+/* Current Reference Info */
+.current-reference-info {
+    margin-top: var(--space-4);
+    padding-top: var(--space-4);
+    border-top: 1px solid var(--color-border);
+}
+
+.reference-info-card {
+    background: var(--color-gray-800);
+    border: 1px solid var(--color-gray-600);
+    border-radius: var(--radius-lg);
+    padding: var(--space-4);
+}
+
+.reference-info-card h5 {
+    margin: 0 0 var(--space-3) 0;
+    font-size: var(--text-sm);
+    font-weight: var(--weight-semibold);
+    color: var(--color-gray-300);
+    text-transform: uppercase;
+    letter-spacing: 0.05em;
+}
+
+.reference-details {
+    display: flex;
+    flex-direction: column;
+    gap: var(--space-2);
+    background: var(--color-gray-900);
+    padding: var(--space-3);
+    border-radius: var(--radius-md);
+    border: 1px solid var(--color-gray-700);
+}
+
+.reference-name {
+    font-size: var(--text-base);
+    font-weight: var(--weight-semibold);
+    color: var(--color-white);
+}
+
+.reference-timestamp {
+    font-size: var(--text-sm);
+    color: var(--color-gray-300);
+    font-family: var(--font-mono);
+}
+
+.reference-description {
+    margin: 0;
+    font-size: var(--text-sm);
+    color: var(--color-gray-400);
+    font-style: italic;
+}
+
+.reference-description:empty::before {
+    content: "No description provided";
+    opacity: 0.7;
+}
+
+/* Responsive adjustments */
+@media (max-width: 768px) {
+    .reference-creation {
+        gap: var(--space-2);
+    }
+
+    .reference-actions {
+        flex-direction: column;
+        gap: var(--space-2);
+    }
+
+    .reference-dropdown {
+        min-width: unset;
+    }
 }
\ No newline at end of file
diff --git a/vna_system/web_ui/static/js/modules/settings.js b/vna_system/web_ui/static/js/modules/settings.js
index 6ddd947..b6ad17e 100644
--- a/vna_system/web_ui/static/js/modules/settings.js
+++ b/vna_system/web_ui/static/js/modules/settings.js
@@ -90,12 +90,11 @@ export class SettingsManager {
     this.currentPreset = null;
     this.currentCalibration = null;
     this.workingCalibration = null;
+    this.availableReferences = [];
+    this.currentReference = null;
 
-    // Калибровка: ожидание свипа
-    this.waitingForSweep = false;
-    this.pendingStandard = null;
+    // Калибровка: состояние захвата
     this.disabledStandards = new Set();
-    this.calibrationTimeout = null;
 
     // DOM cache
     this.elements = {};
@@ -105,7 +104,6 @@ export class SettingsManager {
     this.reqGuard = new RequestGuard();
 
     // Единственный bound-обработчик, чтобы корректно отписываться
-    this._boundHandleSweepForCalibration = this.handleSweepForCalibration.bind(this);
 
     // Bind UI handlers
     this.handlePresetChange = this.handlePresetChange.bind(this);
@@ -118,6 +116,13 @@ export class SettingsManager {
     this.handleViewPlots = this.handleViewPlots.bind(this);
     this.handleViewCurrentPlots = this.handleViewCurrentPlots.bind(this);
 
+    // Reference handlers
+    this.handleCreateReference = this.handleCreateReference.bind(this);
+    this.handleReferenceChange = this.handleReferenceChange.bind(this);
+    this.handleSetReference = this.handleSetReference.bind(this);
+    this.handleClearReference = this.handleClearReference.bind(this);
+    this.handleDeleteReference = this.handleDeleteReference.bind(this);
+
     // Пакет данных для модалки с графиками
     this.currentPlotsData = null;
   }
@@ -179,6 +184,19 @@ export class SettingsManager {
       plotsGrid: document.getElementById('plotsGrid'),
       downloadAllBtn: document.getElementById('downloadAllBtn'),
 
+      // References
+      referenceNameInput: document.getElementById('referenceNameInput'),
+      referenceDescriptionInput: document.getElementById('referenceDescriptionInput'),
+      createReferenceBtn: document.getElementById('createReferenceBtn'),
+      referenceDropdown: document.getElementById('referenceDropdown'),
+      setReferenceBtn: document.getElementById('setReferenceBtn'),
+      clearReferenceBtn: document.getElementById('clearReferenceBtn'),
+      deleteReferenceBtn: document.getElementById('deleteReferenceBtn'),
+      currentReferenceInfo: document.getElementById('currentReferenceInfo'),
+      currentReferenceName: document.getElementById('currentReferenceName'),
+      currentReferenceTimestamp: document.getElementById('currentReferenceTimestamp'),
+      currentReferenceDescription: document.getElementById('currentReferenceDescription'),
+
       // Status
       presetCount: document.getElementById('presetCount'),
       calibrationCount: document.getElementById('calibrationCount'),
@@ -199,6 +217,13 @@ export class SettingsManager {
     this.elements.viewPlotsBtn?.addEventListener('click', this.handleViewPlots);
     this.elements.viewCurrentPlotsBtn?.addEventListener('click', this.handleViewCurrentPlots);
 
+    // References
+    this.elements.createReferenceBtn?.addEventListener('click', this.handleCreateReference);
+    this.elements.referenceDropdown?.addEventListener('change', this.handleReferenceChange);
+    this.elements.setReferenceBtn?.addEventListener('click', this.handleSetReference);
+    this.elements.clearReferenceBtn?.addEventListener('click', this.handleClearReference);
+    this.elements.deleteReferenceBtn?.addEventListener('click', this.handleDeleteReference);
+
     // Name input → enables Save
     this.elements.calibrationNameInput?.addEventListener('input', () => {
       const hasName = this.elements.calibrationNameInput.value.trim().length > 0;
@@ -217,6 +242,13 @@ export class SettingsManager {
     this.elements.viewPlotsBtn?.removeEventListener('click', this.handleViewPlots);
     this.elements.viewCurrentPlotsBtn?.removeEventListener('click', this.handleViewCurrentPlots);
 
+    // References
+    this.elements.createReferenceBtn?.removeEventListener('click', this.handleCreateReference);
+    this.elements.referenceDropdown?.removeEventListener('change', this.handleReferenceChange);
+    this.elements.setReferenceBtn?.removeEventListener('click', this.handleSetReference);
+    this.elements.clearReferenceBtn?.removeEventListener('click', this.handleClearReference);
+    this.elements.deleteReferenceBtn?.removeEventListener('click', this.handleDeleteReference);
+
     // WebSocket
     if (this.websocket) {
       this.websocket.off?.('processor_result', this._boundHandleSweepForCalibration);
@@ -229,7 +261,8 @@ export class SettingsManager {
     await Promise.all([
       this._loadPresets(),
       this._loadStatus(),
-      this._loadWorkingCalibration()
+      this._loadWorkingCalibration(),
+      this._loadReferences()
     ]);
   }
 
@@ -464,7 +497,11 @@ export class SettingsManager {
     }
     if (this.elements.saveCalibrationBtn) this.elements.saveCalibrationBtn.disabled = true;
     if (this.elements.progressText) this.elements.progressText.textContent = '0/0';
-    console.log('🔄 Calibration UI reset after preset change');
+
+    // Reset reference state
+    this.availableReferences = [];
+    this.currentReference = null;
+    console.log('🔄 Calibration and reference UI reset after preset change');
   }
 
   /* ----------------------------- Event Handlers (UI) ----------------------------- */
@@ -554,39 +591,30 @@ export class SettingsManager {
           this.disabledStandards.add(standard);
 
           const btn = document.querySelector(`[data-standard="${standard}"]`);
-          ButtonState.set(btn, { state: 'loading', icon: 'clock', text: 'Waiting for next sweep...' });
+          ButtonState.set(btn, { state: 'loading', icon: 'upload', text: 'Capturing...' });
 
-          // Если acquisition не работает — попросим один свип
-          const running = this.acquisition?.isRunning?.() ?? false;
-          if (!running) {
-            this._notify('info', 'Triggering Sweep', `Requesting single sweep for ${standard.toUpperCase()} standard`);
-            try {
-              await this.acquisition?.triggerSingleSweep?.();
-            } catch (e) {
-              console.error('Trigger sweep failed:', e);
-              this._notify('error', 'Sweep Error', 'Failed to trigger single sweep for calibration');
-              this._resetCalibrationCaptureState(standard);
-              return;
-            }
-          } else {
-            // Если уже работает — просим пользователя запустить новый свип (или просто ждём)
-            this._notify('info', 'Waiting for Sweep', `Please trigger a new sweep to capture ${standard.toUpperCase()} standard`);
-          }
+          this._notify('info', 'Capturing Standard', `Capturing ${standard.toUpperCase()} standard...`);
 
-          // Ожидаем следующий свип через WebSocket; подписка единым обработчиком
-          this.waitingForSweep = true;
-          this.pendingStandard = standard;
-          this.websocket?.on?.('processor_result', this._boundHandleSweepForCalibration);
+          // Прямой вызов API - бэкенд сам обработает ожидание и триггеринг
+          const r = await fetch('/api/v1/settings/calibration/add-standard', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ standard })
+          });
 
-          // Таймаут ожидания (5с)
-          this._clearCalibrationTimeout();
-          this.calibrationTimeout = setTimeout(() => {
-            this._notify('warning', 'Calibration Timeout', `No sweep received within 5 seconds for ${standard.toUpperCase()}. Please try again.`);
-            this._resetCalibrationCaptureState(standard);
-          }, 5000);
+          if (!r.ok) throw new Error(`HTTP ${r.status}`);
+          const result = await r.json();
+
+          this._notify('success', 'Standard Captured', result.message);
+
+          // Сброс состояния
+          this._resetCalibrationCaptureState();
+
+          // Обновить рабочую калибровку
+          await this._loadWorkingCalibration();
         } catch (e) {
-          console.error('Start standard capture failed:', e);
-          this._notify('error', 'Calibration Error', 'Failed to start calibration standard capture');
+          console.error('Capture standard failed:', e);
+          this._notify('error', 'Calibration Error', 'Failed to capture calibration standard');
           this._resetCalibrationCaptureState(standard);
         }
       }), 500
@@ -716,65 +744,16 @@ export class SettingsManager {
 
   /* ----------------------------- WebSocket sweep capture ----------------------------- */
 
-  async handleSweepForCalibration() {
-    // реагируем только если действительно ждём свип
-    if (!this.waitingForSweep || !this.pendingStandard) return;
-
-    try {
-      console.log(`📡 New sweep → capture ${this.pendingStandard}...`);
-
-      // Сразу отключаем подписку и таймер
-      this.websocket?.off?.('processor_result', this._boundHandleSweepForCalibration);
-      this._clearCalibrationTimeout();
-
-      const btn = document.querySelector(`[data-standard="${this.pendingStandard}"]`);
-      ButtonState.set(btn, { state: 'loading', icon: 'upload', text: 'Capturing...' });
-
-      const r = await fetch('/api/v1/settings/calibration/add-standard', {
-        method: 'POST',
-        headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ standard: this.pendingStandard })
-      });
-      if (!r.ok) throw new Error(`HTTP ${r.status}`);
-      const result = await r.json();
-
-      this._notify('success', 'Standard Captured', result.message);
-
-      // Сброс
-      this._resetCalibrationCaptureState();
-
-      // Обновить рабочую калибровку
-      await this._loadWorkingCalibration();
-    } catch (e) {
-      console.error('Capture standard failed:', e);
-      this._notify('error', 'Calibration Error', 'Failed to capture calibration standard');
-      this._resetCalibrationCaptureState();
-    }
-  }
 
   _resetCalibrationCaptureState(standard = null) {
     if (standard) this.disabledStandards.delete(standard);
     else this.disabledStandards.clear();
 
-    if (!standard || standard === this.pendingStandard) {
-      this.waitingForSweep = false;
-      this.pendingStandard = null;
-
-      this.websocket?.off?.('processor_result', this._boundHandleSweepForCalibration);
-      this._clearCalibrationTimeout();
-    }
-
     if (this.workingCalibration) {
       this._renderStandardButtons(this.workingCalibration);
     }
   }
 
-  _clearCalibrationTimeout() {
-    if (this.calibrationTimeout) {
-      clearTimeout(this.calibrationTimeout);
-      this.calibrationTimeout = null;
-    }
-  }
 
   /* ----------------------------- Plots Modal ----------------------------- */
 
@@ -1230,26 +1209,242 @@ export class SettingsManager {
 
   /* ----------------------------- Helpers ----------------------------- */
 
+  /* ----------------------------- Reference Management ----------------------------- */
+
+  async _loadReferences() {
+    try {
+      if (!this.currentPreset) {
+        this._renderReferencesDropdown([]);
+        this._updateCurrentReferenceInfo(null);
+        return;
+      }
+
+      // Load available references
+      const referencesResponse = await fetch(`/api/v1/settings/references?preset_filename=${encodeURIComponent(this.currentPreset.filename)}`);
+      if (!referencesResponse.ok) throw new Error(`HTTP ${referencesResponse.status}`);
+      this.availableReferences = await referencesResponse.json();
+
+      // Load current reference
+      const currentResponse = await fetch(`/api/v1/settings/reference/current?preset_filename=${encodeURIComponent(this.currentPreset.filename)}`);
+      if (!currentResponse.ok) throw new Error(`HTTP ${currentResponse.status}`);
+      this.currentReference = await currentResponse.json();
+
+      this._renderReferencesDropdown(this.availableReferences);
+      this._updateCurrentReferenceInfo(this.currentReference);
+    } catch (error) {
+      console.error('Failed to load references:', error);
+      this._renderReferencesDropdown([]);
+      this._updateCurrentReferenceInfo(null);
+    }
+  }
+
+  _renderReferencesDropdown(references) {
+    if (!this.elements.referenceDropdown) return;
+
+    // Clear existing options
+    this.elements.referenceDropdown.innerHTML = '';
+
+    if (references.length === 0) {
+      this.elements.referenceDropdown.innerHTML = '<option value="">No references available</option>';
+      this.elements.referenceDropdown.disabled = true;
+      this.elements.setReferenceBtn.disabled = true;
+      this.elements.clearReferenceBtn.disabled = true;
+      this.elements.deleteReferenceBtn.disabled = true;
+    } else {
+      this.elements.referenceDropdown.innerHTML = '<option value="">Select a reference...</option>';
+
+      references.forEach(ref => {
+        const option = document.createElement('option');
+        option.value = ref.name;
+        option.textContent = `${ref.name} (${new Date(ref.timestamp).toLocaleDateString()})`;
+        this.elements.referenceDropdown.appendChild(option);
+      });
+
+      this.elements.referenceDropdown.disabled = false;
+
+      // Select current reference if any
+      if (this.currentReference) {
+        this.elements.referenceDropdown.value = this.currentReference.name;
+      }
+    }
+
+    this._updateReferenceButtons();
+  }
+
+  _updateReferenceButtons() {
+    const hasSelection = this.elements.referenceDropdown.value !== '';
+    const hasCurrent = this.currentReference !== null;
+
+    this.elements.setReferenceBtn.disabled = !hasSelection;
+    this.elements.deleteReferenceBtn.disabled = !hasSelection;
+    this.elements.clearReferenceBtn.disabled = !hasCurrent;
+  }
+
+  _updateCurrentReferenceInfo(reference) {
+    if (!this.elements.currentReferenceInfo) return;
+
+    if (!reference) {
+      this.elements.currentReferenceInfo.style.display = 'none';
+      return;
+    }
+
+    this.elements.currentReferenceInfo.style.display = 'block';
+
+    if (this.elements.currentReferenceName) {
+      this.elements.currentReferenceName.textContent = reference.name;
+    }
+
+    if (this.elements.currentReferenceTimestamp) {
+      this.elements.currentReferenceTimestamp.textContent = new Date(reference.timestamp).toLocaleString();
+    }
+
+    if (this.elements.currentReferenceDescription) {
+      this.elements.currentReferenceDescription.textContent = reference.description || '';
+    }
+  }
+
+  async handleCreateReference() {
+    const name = this.elements.referenceNameInput.value.trim();
+    if (!name) {
+      this._notify('warning', 'Missing Name', 'Please enter a name for the reference');
+      return;
+    }
+
+    const description = this.elements.referenceDescriptionInput.value.trim();
+
+    this.debouncer.debounce('create-reference', () =>
+      this.reqGuard.runExclusive('create-reference', async () => {
+        try {
+          ButtonState.set(this.elements.createReferenceBtn, { state: 'loading', icon: 'loader', text: 'Creating...' });
+
+          const response = await fetch('/api/v1/settings/reference/create', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ name, description })
+          });
+
+          if (!response.ok) throw new Error(`HTTP ${response.status}`);
+          const result = await response.json();
+
+          this._notify('success', 'Reference Created', result.message);
+
+          // Clear inputs
+          this.elements.referenceNameInput.value = '';
+          this.elements.referenceDescriptionInput.value = '';
+
+          // Reload references
+          await this._loadReferences();
+        } catch (error) {
+          console.error('Create reference failed:', error);
+          this._notify('error', 'Reference Error', 'Failed to create reference');
+        } finally {
+          ButtonState.set(this.elements.createReferenceBtn, { state: 'normal', icon: 'target', text: 'Capture Reference' });
+        }
+      }), 500
+    );
+  }
+
+  handleReferenceChange() {
+    this._updateReferenceButtons();
+  }
+
+  async handleSetReference() {
+    const referenceName = this.elements.referenceDropdown.value;
+    if (!referenceName) return;
+
+    this.debouncer.debounce('set-reference', () =>
+      this.reqGuard.runExclusive('set-reference', async () => {
+        try {
+          ButtonState.set(this.elements.setReferenceBtn, { state: 'loading', icon: 'loader', text: 'Setting...' });
+
+          const response = await fetch('/api/v1/settings/reference/set', {
+            method: 'POST',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ name: referenceName })
+          });
+
+          if (!response.ok) throw new Error(`HTTP ${response.status}`);
+          const result = await response.json();
+
+          this._notify('success', 'Reference Set', result.message);
+
+          // Reload references to update current
+          await this._loadReferences();
+        } catch (error) {
+          console.error('Set reference failed:', error);
+          this._notify('error', 'Reference Error', 'Failed to set reference');
+        } finally {
+          ButtonState.set(this.elements.setReferenceBtn, { state: 'normal', icon: 'check', text: 'Set Active' });
+        }
+      }), 400
+    );
+  }
+
+  async handleClearReference() {
+    this.debouncer.debounce('clear-reference', () =>
+      this.reqGuard.runExclusive('clear-reference', async () => {
+        try {
+          ButtonState.set(this.elements.clearReferenceBtn, { state: 'loading', icon: 'loader', text: 'Clearing...' });
+
+          const response = await fetch('/api/v1/settings/reference/current', {
+            method: 'DELETE'
+          });
+
+          if (!response.ok) throw new Error(`HTTP ${response.status}`);
+          const result = await response.json();
+
+          this._notify('success', 'Reference Cleared', result.message);
+
+          // Reload references to update current
+          await this._loadReferences();
+        } catch (error) {
+          console.error('Clear reference failed:', error);
+          this._notify('error', 'Reference Error', 'Failed to clear reference');
+        } finally {
+          ButtonState.set(this.elements.clearReferenceBtn, { state: 'normal', icon: 'x', text: 'Clear' });
+        }
+      }), 400
+    );
+  }
+
+  async handleDeleteReference() {
+    const referenceName = this.elements.referenceDropdown.value;
+    if (!referenceName) return;
+
+    // Confirm deletion
+    if (!confirm(`Are you sure you want to delete reference "${referenceName}"? This action cannot be undone.`)) {
+      return;
+    }
+
+    this.debouncer.debounce('delete-reference', () =>
+      this.reqGuard.runExclusive('delete-reference', async () => {
+        try {
+          ButtonState.set(this.elements.deleteReferenceBtn, { state: 'loading', icon: 'loader', text: 'Deleting...' });
+
+          const response = await fetch(`/api/v1/settings/reference/${encodeURIComponent(referenceName)}`, {
+            method: 'DELETE'
+          });
+
+          if (!response.ok) throw new Error(`HTTP ${response.status}`);
+          const result = await response.json();
+
+          this._notify('success', 'Reference Deleted', result.message);
+
+          // Reload references
+          await this._loadReferences();
+        } catch (error) {
+          console.error('Delete reference failed:', error);
+          this._notify('error', 'Reference Error', 'Failed to delete reference');
+        } finally {
+          ButtonState.set(this.elements.deleteReferenceBtn, { state: 'normal', icon: 'trash-2', text: 'Delete' });
+        }
+      }), 400
+    );
+  }
+
   _notify(type, title, message) {
     this.notifications?.show?.({ type, title, message });
   }
 
-  _resetCalibrationCaptureState(standard = null) {
-    // публичная версия для внешних вызовов
-    this._resetCalibrationCaptureStateInternal(standard);
-  }
 
-  _resetCalibrationCaptureStateInternal(standard = null) {
-    if (standard) this.disabledStandards.delete(standard);
-    else this.disabledStandards.clear();
-
-    if (!standard || standard === this.pendingStandard) {
-      this.waitingForSweep = false;
-      this.pendingStandard = null;
-      this.websocket?.off?.('processor_result', this._boundHandleSweepForCalibration);
-      this._clearCalibrationTimeout();
-    }
-
-    if (this.workingCalibration) this._renderStandardButtons(this.workingCalibration);
-  }
 }
diff --git a/vna_system/web_ui/templates/index.html b/vna_system/web_ui/templates/index.html
index 850272d..400c6cd 100644
--- a/vna_system/web_ui/templates/index.html
+++ b/vna_system/web_ui/templates/index.html
@@ -244,6 +244,62 @@
                         </div>
                     </div>
 
+                    <!-- Open Air Reference -->
+                    <div class="settings-card">
+                        <h3 class="settings-card-title">Open Air Reference</h3>
+                        <div class="settings-card-content">
+
+                            <!-- Create Reference -->
+                            <div class="workflow-section">
+                                <h4 class="workflow-title">Create Reference</h4>
+                                <div class="reference-creation">
+                                    <input type="text" class="reference-name-input" id="referenceNameInput" placeholder="Enter reference name">
+                                    <input type="text" class="reference-description-input" id="referenceDescriptionInput" placeholder="Description (optional)">
+                                    <button class="btn btn--primary" id="createReferenceBtn">
+                                        <i data-lucide="target"></i>
+                                        Capture Reference
+                                    </button>
+                                </div>
+                            </div>
+
+                            <!-- Existing References -->
+                            <div class="workflow-section">
+                                <h4 class="workflow-title">Existing References</h4>
+                                <div class="existing-references" id="existingReferences">
+                                    <select class="reference-dropdown" id="referenceDropdown" disabled>
+                                        <option value="">No references available</option>
+                                    </select>
+                                    <div class="reference-actions">
+                                        <button class="btn btn--primary" id="setReferenceBtn" disabled>
+                                            <i data-lucide="check"></i>
+                                            Set Active
+                                        </button>
+                                        <button class="btn btn--secondary" id="clearReferenceBtn" disabled>
+                                            <i data-lucide="x"></i>
+                                            Clear
+                                        </button>
+                                        <button class="btn btn--danger" id="deleteReferenceBtn" disabled>
+                                            <i data-lucide="trash-2"></i>
+                                            Delete
+                                        </button>
+                                    </div>
+                                </div>
+
+                                <!-- Current Reference Info -->
+                                <div class="current-reference-info" id="currentReferenceInfo" style="display: none;">
+                                    <div class="reference-info-card">
+                                        <h5>Current Reference</h5>
+                                        <div class="reference-details">
+                                            <span class="reference-name" id="currentReferenceName">-</span>
+                                            <span class="reference-timestamp" id="currentReferenceTimestamp">-</span>
+                                            <p class="reference-description" id="currentReferenceDescription">-</p>
+                                        </div>
+                                    </div>
+                                </div>
+                            </div>
+                        </div>
+                    </div>
+
                     <!-- Status Summary -->
                     <div class="settings-card">
                         <h3 class="settings-card-title">Status Summary</h3>