added GPR

python_app/gui/app_window.py

@@ -104,6 +104,18 @@ class AppWindow(
         self._bscan_depth_axis_by_combo = {}
         self._bscan_history_floor_collection_id = 0
         self._bscan_render_signature = None
+        self._gpr_lookup_table = None
+        self._gpr_image_item = None
+        self._gpr_tx_item = None
+        self._gpr_rx_item = None
+        self._gpr_points_item = None
+        self._gpr_region_centers_item = None
+        self._gpr_point_labels = []
+        self._gpr_region_center_labels = []
+        self._gpr_region_mask_items = []
+        self._gpr_region_contours = []
+        self._gpr_geometry_signature = None
+        self._gpr_selected_geometry = None
         self._phase_viewbox = None
         self._history_run_signature = None
         self._radar_limits: dict[str, float | int] | None = None

python_app/gui/controllers/app_window_config_mixin.py

@@ -4,7 +4,8 @@ from __future__ import annotations
 
 from python_app.gui.runtime.history import remove_last_aligned_histories
 from python_app.hardware_full.librevna_service import LibreVnaService
-from python_app.models.run_config_model import ComboModel, RunConfigModel
+from python_app.models.run_config_model import ComboModel, GprRxGeometryModel, GprTxGeometryModel, RunConfigModel
+from python_app.models.run_config_validation import validate_gpr_model
 from python_app.orchestration.config_writer import parse_combos_from_text
 from python_app.orchestration.live_processing_config import ProcessingLiveConfig
 from python_app.storage.npz_store import radar_key_from_config
@@ -13,6 +14,58 @@ from python_app.storage.npz_store import radar_key_from_config
 class AppWindowConfigMixin:
     """Builds runtime config models from current UI state."""
 
+    @staticmethod
+    def _parse_csv_int_list(text: str) -> list[int]:
+        """Parse comma-separated integer selection list."""
+        cleaned = text.strip()
+        if not cleaned:
+            return []
+        values: list[int] = []
+        for part in cleaned.split(","):
+            token = part.strip()
+            if not token:
+                continue
+            values.append(int(token))
+        return values
+
+    @staticmethod
+    def _parse_gpr_tx_geometry_text(text: str) -> list[GprTxGeometryModel]:
+        """Parse line-based Tx geometry editor text."""
+        entries: list[GprTxGeometryModel] = []
+        for line_number, raw_line in enumerate(text.splitlines(), start=1):
+            line = raw_line.strip()
+            if not line:
+                continue
+            parts = line.split()
+            if len(parts) != 2:
+                raise ValueError(f"Invalid Tx geometry line {line_number}: expected `output_pos x_m`")
+            entries.append(
+                GprTxGeometryModel(
+                    output_pos=int(parts[0]),
+                    x_m=float(parts[1]),
+                )
+            )
+        return entries
+
+    @staticmethod
+    def _parse_gpr_rx_geometry_text(text: str) -> list[GprRxGeometryModel]:
+        """Parse line-based Rx geometry editor text."""
+        entries: list[GprRxGeometryModel] = []
+        for line_number, raw_line in enumerate(text.splitlines(), start=1):
+            line = raw_line.strip()
+            if not line:
+                continue
+            parts = line.split()
+            if len(parts) != 2:
+                raise ValueError(f"Invalid Rx geometry line {line_number}: expected `input_pos x_m`")
+            entries.append(
+                GprRxGeometryModel(
+                    input_pos=int(parts[0]),
+                    x_m=float(parts[1]),
+                )
+            )
+        return entries
+
     def _save_current_config(self) -> None:
         """Persist currently selected GUI settings into root run_config.json."""
         try:
@@ -68,6 +121,15 @@ class AppWindowConfigMixin:
 
         config.preprocess.calibration_set = self._selected_calibration_set
         config.preprocess.reference_set = self._selected_reference_set
+        config.gpr.mode = self._gpr_config_mode.currentText()
+        config.gpr.relative_permittivity = float(self._gpr_relative_permittivity.value())
+        config.gpr.tx_geometry = self._parse_gpr_tx_geometry_text(self._gpr_tx_geometry_input.toPlainText())
+        config.gpr.rx_geometry = self._parse_gpr_rx_geometry_text(self._gpr_rx_geometry_input.toPlainText())
+        validate_gpr_model(
+            config.gpr,
+            input_switch_positions=config.input_switch.positions,
+            output_switch_positions=config.output_switch.positions,
+        )
         return config
 
     def _radar_key(self, config: RunConfigModel) -> str:
@@ -85,16 +147,31 @@ class AppWindowConfigMixin:
     def _live_processing_config(self, *, history_command: str = "none") -> ProcessingLiveConfig:
         """Build live processing config from current processing widgets."""
         self._sync_bscan_frequency_limits_with_radar()
+        self._sync_gpr_frequency_limits_with_radar()
+        y_min_db = float(self._pass_through_y_min_db.value())
+        y_max_db = float(self._pass_through_y_max_db.value())
         return ProcessingLiveConfig(
             processor_mode=self._processing_mode.currentText(),
             gain_db=float(self._processing_gain_db.value()),
             phase_deg=float(self._processing_phase_deg.value()),
+            pass_through_fixed_y_enabled=bool(self._pass_through_fixed_y_enabled.isChecked()),
+            pass_through_y_min_db=min(y_min_db, y_max_db),
+            pass_through_y_max_db=max(y_min_db, y_max_db),
             bscan_axis=self._bscan_axis.currentText(),
             bscan_cut_m=float(self._bscan_cut_m.value()),
             bscan_max_depth_m=float(self._bscan_max_depth_m.value()),
             bscan_gain=float(self._bscan_gain.value()),
             bscan_start_freq_mhz=float(self._bscan_start_freq_mhz.value()),
             bscan_stop_freq_mhz=float(self._bscan_stop_freq_mhz.value()),
+            gpr_input_positions=self._parse_csv_int_list(self._gpr_input_positions_input.text()),
+            gpr_output_positions=self._parse_csv_int_list(self._gpr_output_positions_input.text()),
+            gpr_min_depth_m=float(self._gpr_min_depth_m.value()),
+            gpr_max_depth_m=float(self._gpr_max_depth_m.value()),
+            gpr_comp_power=float(self._gpr_comp_power.value()),
+            gpr_start_freq_mhz=float(self._gpr_start_freq_mhz.value()),
+            gpr_stop_freq_mhz=float(self._gpr_stop_freq_mhz.value()),
+            gpr_background_subtract_enabled=bool(self._gpr_background_subtract_enabled.isChecked()),
+            gpr_background_mean_count=int(self._gpr_background_mean_count.value()),
             history_command_seq=int(self._history_command_seq),
             history_command=str(history_command),
         )
@@ -109,10 +186,18 @@ class AppWindowConfigMixin:
         """Handle live-processing setting changes and trigger redraw when needed."""
         try:
             self._write_live_processing_config()
-            if self._processing_mode.currentText() == "bscan":
+            current_mode = self._processing_mode.currentText()
+            if current_mode == "bscan":
                 self._drain_results_until_quiet(timeout_s=0.25, poll_s=0.01)
                 self._sync_bscan_history_from_results()
                 self._draw_bscan_heatmap_from_history()
+            elif current_mode == "gpr":
+                self._drain_results_until_quiet(timeout_s=0.35, poll_s=0.01)
+                if self._result_history:
+                    if not self._draw_results(self._result_history[-1]):
+                        self._clear_gpr_plot()
+                else:
+                    self._clear_gpr_plot()
             elif self._result_history:
                 self._draw_results(self._result_history[-1])
         except Exception as exc:  # noqa: BLE001
@@ -123,6 +208,7 @@ class AppWindowConfigMixin:
         mode_to_page = {
             "pass_through": 0,
             "bscan": 1,
+            "gpr": 2,
         }
         self._set_plot_mode(mode)
         self._processing_mode_pages.setCurrentIndex(mode_to_page.get(mode, 0))
@@ -134,17 +220,31 @@ class AppWindowConfigMixin:
 
     def _on_bscan_clear_history_clicked(self) -> None:
         """Permanently clear all runtime histories, ring backlogs, and B-scan cache."""
-        self._apply_bscan_history_deletion(remove_last_only=False)
+        self._apply_history_mode_deletion(mode_label="B-scan", remove_last_only=False)
 
     def _on_bscan_remove_last_sweep_clicked(self) -> None:
         """Permanently delete the latest sweep from runtime histories and rings."""
-        self._apply_bscan_history_deletion(remove_last_only=True)
+        self._apply_history_mode_deletion(mode_label="B-scan", remove_last_only=True)
 
-    def _apply_bscan_history_deletion(self, *, remove_last_only: bool) -> None:
-        """Apply destructive B-scan history deletion via C++ processor history commands."""
+    def _on_gpr_clear_history_clicked(self) -> None:
+        """Permanently clear all runtime histories, ring backlogs, and GPR cache."""
+        self._apply_history_mode_deletion(mode_label="GPR", remove_last_only=False)
+
+    def _on_gpr_remove_last_measurement_clicked(self) -> None:
+        """Permanently delete the latest measurement from runtime histories and rings."""
+        self._apply_history_mode_deletion(mode_label="GPR", remove_last_only=True)
+
+    def _clear_history_mode_caches(self) -> None:
+        """Drop mode-specific cached render state."""
+        self._clear_bscan_plot_history()
+        if hasattr(self, "_gpr_plot"):
+            self._clear_gpr_plot()
+
+    def _apply_history_mode_deletion(self, *, mode_label: str, remove_last_only: bool) -> None:
+        """Apply destructive history deletion via C++ processor history commands."""
         resume_acquisition = self._supervisor.is_running()
         history_command = "remove_last" if remove_last_only else "clear_all"
-        action = "last sweep removed" if remove_last_only else "history fully cleared"
+        action = "last measurement removed" if remove_last_only else "history fully cleared"
         dropped_results = 0
 
         try:
@@ -169,7 +269,7 @@ class AppWindowConfigMixin:
                 retained_pre=retained_pre,
                 retained_result=retained_result,
             )
-            self._clear_bscan_plot_history()
+            self._clear_history_mode_caches()
 
             self._write_live_processing_config(history_command=history_command, bump_history_seq=True)
 
@@ -180,9 +280,9 @@ class AppWindowConfigMixin:
             self._redraw_after_history_deletion()
             if resume_acquisition:
                 self._start_run()
-            self._log(f"B-scan {action}; dropped pending results={dropped_results}")
+            self._log(f"{mode_label} {action}; dropped pending results={dropped_results}")
         except Exception as exc:  # noqa: BLE001
-            self._show_error(f"Failed to delete B-scan history: {exc}")
+            self._show_error(f"Failed to delete {mode_label} history: {exc}")
 
     def _redraw_after_history_deletion(self) -> None:
         """Refresh plot immediately after destructive history deletion."""
@@ -192,6 +292,11 @@ class AppWindowConfigMixin:
             if not self._draw_bscan_heatmap_from_history():
                 self._bscan_plot.clear()
             return
+        if self._processing_mode.currentText() == "gpr":
+            if self._result_history and self._draw_results(self._result_history[-1]):
+                return
+            self._clear_gpr_plot()
+            return
         if self._result_history:
             self._draw_results(self._result_history[-1])
             return
@@ -208,8 +313,8 @@ class AppWindowConfigMixin:
             self._on_processing_live_settings_changed()
 
     def _on_radar_sweep_limits_changed(self) -> None:
-        """Clamp B-scan frequency bounds after sweep start/stop edits."""
-        if self._sync_bscan_frequency_limits_with_radar():
+        """Clamp processing frequency bounds after sweep start/stop edits."""
+        if self._sync_processing_frequency_limits_with_radar():
             self._on_processing_live_settings_changed()
 
     def _refresh_radar_limits_from_device(self) -> bool:
@@ -301,7 +406,7 @@ class AppWindowConfigMixin:
             or prev_power != self._power_input.text().strip()
         )
 
-        self._sync_bscan_frequency_limits_with_radar()
+        self._sync_processing_frequency_limits_with_radar()
         return changed
 
     @staticmethod
@@ -326,16 +431,16 @@ class AppWindowConfigMixin:
         widget.setText(str(value))
         return value
 
-    def _sync_bscan_frequency_limits_with_radar(self) -> bool:
-        """Synchronize B-scan start/stop MHz widget ranges with radar sweep bounds."""
-        required_widgets = (
-            "_start_hz_input",
-            "_stop_hz_input",
-            "_bscan_start_freq_mhz",
-            "_bscan_stop_freq_mhz",
-        )
+    def _sync_processing_frequency_limits_with_radar(self) -> bool:
+        """Synchronize all processing frequency widgets with radar sweep bounds."""
+        bscan_changed = self._sync_bscan_frequency_limits_with_radar()
+        gpr_changed = self._sync_gpr_frequency_limits_with_radar()
+        return bscan_changed or gpr_changed
+
+    def _sync_frequency_spinboxes_with_radar(self, widget_names: tuple[str, ...]) -> bool:
+        """Synchronize one or more MHz spin boxes with current radar sweep bounds."""
+        required_widgets = ("_start_hz_input", "_stop_hz_input", *widget_names)
         if not all(hasattr(self, widget_name) for widget_name in required_widgets):
-            # Processing callbacks can fire while UI groups are still being built.
             return False
 
         try:
@@ -348,28 +453,41 @@ class AppWindowConfigMixin:
         radar_max_mhz = max(radar_start_hz, radar_stop_hz) / 1_000_000.0
 
         changed = False
-        for widget in (self._bscan_start_freq_mhz, self._bscan_stop_freq_mhz):
+        widgets = [getattr(self, widget_name) for widget_name in widget_names]
+        for widget in widgets:
             if widget.minimum() != radar_min_mhz or widget.maximum() != radar_max_mhz:
                 changed = True
             widget.blockSignals(True)
             widget.setRange(radar_min_mhz, radar_max_mhz)
             widget.blockSignals(False)
 
-        clamped_start_mhz = min(max(self._bscan_start_freq_mhz.value(), radar_min_mhz), radar_max_mhz)
-        clamped_stop_mhz = min(max(self._bscan_stop_freq_mhz.value(), radar_min_mhz), radar_max_mhz)
-        if clamped_start_mhz != self._bscan_start_freq_mhz.value():
-            changed = True
-            self._bscan_start_freq_mhz.blockSignals(True)
-            self._bscan_start_freq_mhz.setValue(clamped_start_mhz)
-            self._bscan_start_freq_mhz.blockSignals(False)
-        if clamped_stop_mhz != self._bscan_stop_freq_mhz.value():
-            changed = True
-            self._bscan_stop_freq_mhz.blockSignals(True)
-            self._bscan_stop_freq_mhz.setValue(clamped_stop_mhz)
-            self._bscan_stop_freq_mhz.blockSignals(False)
-
+        for widget in widgets:
+            clamped_value = min(max(widget.value(), radar_min_mhz), radar_max_mhz)
+            if clamped_value != widget.value():
+                changed = True
+                widget.blockSignals(True)
+                widget.setValue(clamped_value)
+                widget.blockSignals(False)
         return changed
 
+    def _sync_bscan_frequency_limits_with_radar(self) -> bool:
+        """Synchronize B-scan start/stop MHz widget ranges with radar sweep bounds."""
+        return self._sync_frequency_spinboxes_with_radar(
+            (
+                "_bscan_start_freq_mhz",
+                "_bscan_stop_freq_mhz",
+            )
+        )
+
+    def _sync_gpr_frequency_limits_with_radar(self) -> bool:
+        """Synchronize GPR start/stop MHz widget ranges with radar sweep bounds."""
+        return self._sync_frequency_spinboxes_with_radar(
+            (
+                "_gpr_start_freq_mhz",
+                "_gpr_stop_freq_mhz",
+            )
+        )
+
     @staticmethod
     def _switches_are_effectively_static(config: RunConfigModel) -> bool:
         """Return `True` when switch setup effectively yields one fixed combo."""

python_app/gui/controllers/app_window_pipeline_mixin.py

@@ -353,7 +353,7 @@ class AppWindowPipelineMixin:
         """Reset runtime history and B-scan caches."""
         self._replace_runtime_history(retained_raw=[], retained_pre=[], retained_result=[])
         self._bscan_history_floor_collection_id = 0
-        self._clear_bscan_plot_history()
+        self._clear_history_mode_caches()
         self._update_history_indicator()
 
     def _replace_runtime_history(
@@ -385,4 +385,8 @@ class AppWindowPipelineMixin:
 
     def _validate_processing_mode_constraints(self, config: RunConfigModel) -> None:
         """Validate processing-mode constraints for run start."""
-        validate_processing_mode_constraints(self._processing_mode.currentText(), config)
+        validate_processing_mode_constraints(
+            self._processing_mode.currentText(),
+            config,
+            self._live_processing_config(),
+        )

python_app/gui/controllers/app_window_plot_mixin.py

@@ -36,6 +36,8 @@ class AppWindowPlotMixin:
         """Draw collection based on currently selected processing mode."""
         if self._processing_mode.currentText() == "bscan":
             return self._draw_bscan_heatmap(collection)
+        if self._processing_mode.currentText() == "gpr":
+            return self._draw_gpr_map(collection)
         return self._draw_trace_lines(collection)
 
     def _show_magnitude_curves(self) -> bool:
@@ -46,9 +48,24 @@ class AppWindowPlotMixin:
         """Return whether phase curves should be rendered."""
         return self._show_phase_checkbox.isChecked()
 
+    def _pass_through_fixed_y_range(self) -> tuple[bool, float, float]:
+        """Return normalized magnitude Y-range override for pass-through mode."""
+        y_min = float(self._pass_through_y_min_db.value())
+        y_max = float(self._pass_through_y_max_db.value())
+        return bool(self._pass_through_fixed_y_enabled.isChecked()), min(y_min, y_max), max(y_min, y_max)
+
+    def _configure_pass_through_magnitude_axis(self, plot: pg.PlotWidget) -> None:
+        """Apply pass-through magnitude-axis autorange or fixed Y window."""
+        fixed_y_enabled, y_min, y_max = self._pass_through_fixed_y_range()
+        view_box = plot.getViewBox()
+        view_box.invertY(False)
+        view_box.enableAutoRange(x=True, y=not fixed_y_enabled)
+        if fixed_y_enabled:
+            plot.setYRange(y_min, y_max, padding=0.0)
+
     def _on_trace_visibility_changed(self, *_args) -> None:
         """Redraw pass-through traces when magnitude/phase toggles changed."""
-        if self._processing_mode.currentText() == "bscan":
+        if self._processing_mode.currentText() in {"bscan", "gpr"}:
             return
         if self._result_history:
             self._draw_results(self._result_history[-1])
@@ -98,8 +115,7 @@ class AppWindowPlotMixin:
 
         if show_magnitude:
             mag_item = magnitude_plot.getPlotItem()
-            magnitude_plot.getViewBox().invertY(False)
-            magnitude_plot.getViewBox().enableAutoRange(x=True, y=True)
+            self._configure_pass_through_magnitude_axis(magnitude_plot)
             mag_item.showAxis("left", show=True)
             mag_item.showAxis("bottom", show=not show_phase)
             magnitude_plot.setLabel("left", "Magnitude", units="dB")
@@ -219,6 +235,8 @@ class AppWindowPlotMixin:
                     phase_plot.setXRange(x_min, x_max, padding=0.02)
             if show_phase:
                 phase_plot.setYRange(-180.0, 180.0, padding=0.02)
+            if show_magnitude:
+                self._configure_pass_through_magnitude_axis(magnitude_plot)
         return has_data
 
     @staticmethod
@@ -481,8 +499,290 @@ class AppWindowPlotMixin:
         """Hide right axis and clear phase overlay when phase is not rendered."""
         self._clear_phase_overlay()
 
+    def _clear_gpr_plot(self) -> None:
+        """Clear latest GPR plot surface."""
+        if not hasattr(self, "_gpr_plot"):
+            return
+        self._clear_gpr_point_labels()
+        self._clear_gpr_region_labels()
+        self._clear_gpr_region_masks()
+        if self._gpr_image_item is not None:
+            self._gpr_image_item.hide()
+        if self._gpr_tx_item is not None:
+            self._gpr_tx_item.setData(x=[], y=[])
+            self._gpr_tx_item.hide()
+        if self._gpr_rx_item is not None:
+            self._gpr_rx_item.setData(x=[], y=[])
+            self._gpr_rx_item.hide()
+        if self._gpr_points_item is not None:
+            self._gpr_points_item.setData(x=[], y=[])
+            self._gpr_points_item.hide()
+        if self._gpr_region_centers_item is not None:
+            self._gpr_region_centers_item.setData(x=[], y=[])
+            self._gpr_region_centers_item.hide()
+        self._gpr_plot.setTitle(f"GPR {self._gpr_config_mode.currentText()}")
+
+    def _ensure_gpr_plot_items(self) -> None:
+        """Create persistent GPR plot items once and reuse them on redraw."""
+        if self._gpr_image_item is not None:
+            return
+
+        plot = self._gpr_plot
+        plot_item = plot.getPlotItem()
+        plot_item.showAxis("left", show=True)
+        plot_item.showAxis("bottom", show=True)
+        plot_item.setClipToView(True)
+        plot.setLabel("bottom", "X", units="m")
+        plot.setLabel("left", "Depth", units="m")
+
+        view_box = plot.getViewBox()
+        view_box.invertY(True)
+        view_box.enableAutoRange(x=False, y=False)
+
+        if self._gpr_lookup_table is None:
+            self._gpr_lookup_table = self._build_lut(["#081c15", "#1b4332", "#ffd166", "#f94144"])
+
+        self._gpr_image_item = pg.ImageItem(axisOrder="row-major")
+        self._gpr_image_item.setZValue(0)
+        self._gpr_image_item.hide()
+        plot.addItem(self._gpr_image_item)
+
+        self._gpr_tx_item = pg.ScatterPlotItem()
+        self._gpr_tx_item.setZValue(20)
+        self._gpr_tx_item.hide()
+        plot.addItem(self._gpr_tx_item)
+
+        self._gpr_rx_item = pg.ScatterPlotItem()
+        self._gpr_rx_item.setZValue(20)
+        self._gpr_rx_item.hide()
+        plot.addItem(self._gpr_rx_item)
+
+        self._gpr_points_item = pg.ScatterPlotItem()
+        self._gpr_points_item.setZValue(30)
+        self._gpr_points_item.hide()
+        plot.addItem(self._gpr_points_item)
+
+        self._gpr_region_centers_item = pg.ScatterPlotItem()
+        self._gpr_region_centers_item.setZValue(30)
+        self._gpr_region_centers_item.hide()
+        plot.addItem(self._gpr_region_centers_item)
+
+    def _clear_gpr_point_labels(self) -> None:
+        """Remove dynamic point-score labels from GPR plot."""
+        for item in self._gpr_point_labels:
+            try:
+                self._gpr_plot.removeItem(item)
+            except Exception:  # noqa: BLE001
+                pass
+        self._gpr_point_labels.clear()
+
+    def _clear_gpr_region_labels(self) -> None:
+        """Remove dynamic region labels from GPR plot."""
+        for item in self._gpr_region_center_labels:
+            try:
+                self._gpr_plot.removeItem(item)
+            except Exception:  # noqa: BLE001
+                pass
+        self._gpr_region_center_labels.clear()
+
+    def _clear_gpr_region_masks(self) -> None:
+        """Remove dynamic region contour carriers from GPR plot."""
+        for item in self._gpr_region_mask_items:
+            try:
+                self._gpr_plot.removeItem(item)
+            except Exception:  # noqa: BLE001
+                pass
+        self._gpr_region_mask_items.clear()
+        self._gpr_region_contours.clear()
+
+    @staticmethod
+    def _collection_payload_by_name(collection: ResultCollection, name: str, kind: int | None = None):
+        """Return first collection payload matching name and optional kind."""
+        for payload in collection.collection_payloads:
+            if payload.processing_name != name:
+                continue
+            if kind is not None and int(payload.kind) != int(kind):
+                continue
+            return payload
+        return None
+
+    @staticmethod
+    def _collection_payloads_by_prefix(collection: ResultCollection, prefix: str, kind: int | None = None):
+        """Return collection payloads matching processing-name prefix."""
+        payloads = []
+        for payload in collection.collection_payloads:
+            if not str(payload.processing_name).startswith(prefix):
+                continue
+            if kind is not None and int(payload.kind) != int(kind):
+                continue
+            payloads.append(payload)
+        return payloads
+
+    def _selected_gpr_geometry(self) -> tuple[np.ndarray, np.ndarray]:
+        """Resolve selected Tx/Rx geometry arrays for current GPR selection."""
+        requested_inputs = tuple(self._parse_csv_int_list(self._gpr_input_positions_input.text()))
+        requested_outputs = tuple(self._parse_csv_int_list(self._gpr_output_positions_input.text()))
+        signature = (
+            self._gpr_tx_geometry_input.toPlainText(),
+            self._gpr_rx_geometry_input.toPlainText(),
+            requested_inputs,
+            requested_outputs,
+        )
+        if signature == self._gpr_geometry_signature and self._gpr_selected_geometry is not None:
+            return self._gpr_selected_geometry
+
+        tx_entries = self._parse_gpr_tx_geometry_text(signature[0])
+        rx_entries = self._parse_gpr_rx_geometry_text(signature[1])
+        requested_input_set = set(requested_inputs)
+        requested_output_set = set(requested_outputs)
+
+        rx_entries = sorted(rx_entries, key=lambda entry: int(entry.input_pos))
+        tx_entries = sorted(tx_entries, key=lambda entry: int(entry.output_pos))
+        if requested_input_set:
+            rx_entries = [entry for entry in rx_entries if int(entry.input_pos) in requested_input_set]
+        if requested_output_set:
+            tx_entries = [entry for entry in tx_entries if int(entry.output_pos) in requested_output_set]
+
+        x_tx = np.asarray([float(entry.x_m) for entry in tx_entries], dtype=np.float32)
+        x_rx = np.asarray([float(entry.x_m) for entry in rx_entries], dtype=np.float32)
+        self._gpr_geometry_signature = signature
+        self._gpr_selected_geometry = (x_tx, x_rx)
+        return self._gpr_selected_geometry
+
+    def _draw_gpr_map(self, collection: ResultCollection) -> bool:
+        """Draw latest collection-level GPR accumulator and annotations."""
+        accumulator_payload = self._collection_payload_by_name(collection, "gpr_accumulator", kind=3)
+        if accumulator_payload is None:
+            self._clear_gpr_plot()
+            return False
+
+        image = np.asarray(accumulator_payload.image, dtype=np.float32)
+        x_axis = np.asarray(accumulator_payload.image_x_axis, dtype=np.float32)
+        y_axis = np.asarray(accumulator_payload.image_y_axis, dtype=np.float32)
+        if image.ndim != 2 or image.size == 0 or x_axis.size == 0 or y_axis.size == 0:
+            self._clear_gpr_plot()
+            return False
+
+        x_min = float(x_axis[0])
+        x_max = float(x_axis[-1])
+        y_min = float(y_axis[0])
+        y_max = float(y_axis[-1])
+        rect = QRectF(x_min, y_min, max(x_max - x_min, 1e-6), max(y_max - y_min, 1e-6))
+
+        plot = self._gpr_plot
+        plot.setUpdatesEnabled(False)
+        try:
+            self._ensure_gpr_plot_items()
+            self._clear_gpr_point_labels()
+            self._clear_gpr_region_labels()
+            self._clear_gpr_region_masks()
+
+            self._gpr_image_item.setImage(image, autoLevels=False)
+            self._gpr_image_item.setRect(rect)
+            self._gpr_image_item.setLookupTable(self._gpr_lookup_table)
+            self._gpr_image_item.setLevels((float(np.min(image)), float(np.max(image) + 1e-6)))
+            self._gpr_image_item.show()
+
+            plot.setXRange(x_min, x_max, padding=0.02)
+            plot.setYRange(y_min, y_max, padding=0.02)
+
+            x_tx, x_rx = self._selected_gpr_geometry()
+            if x_tx.size > 0:
+                self._gpr_tx_item.setData(
+                    x=x_tx,
+                    y=np.zeros_like(x_tx),
+                    symbol="t",
+                    size=13,
+                    brush=pg.mkBrush("#ff595e"),
+                    pen=pg.mkPen("#ffca3a", width=1.0),
+                )
+                self._gpr_tx_item.show()
+            else:
+                self._gpr_tx_item.setData(x=[], y=[])
+                self._gpr_tx_item.hide()
+
+            if x_rx.size > 0:
+                self._gpr_rx_item.setData(
+                    x=x_rx,
+                    y=np.zeros_like(x_rx),
+                    symbol="t1",
+                    size=13,
+                    brush=pg.mkBrush("#4cc9f0"),
+                    pen=pg.mkPen("#e0fbfc", width=1.0),
+                )
+                self._gpr_rx_item.show()
+            else:
+                self._gpr_rx_item.setData(x=[], y=[])
+                self._gpr_rx_item.hide()
+
+            points_payload = self._collection_payload_by_name(collection, "gpr_points", kind=4)
+            if points_payload is not None and np.asarray(points_payload.table).size > 0:
+                points = np.asarray(points_payload.table, dtype=np.float32)
+                self._gpr_points_item.setData(
+                    x=points[:, 0],
+                    y=points[:, 1],
+                    symbol="d",
+                    size=11,
+                    brush=pg.mkBrush("#ffffff"),
+                    pen=pg.mkPen("#111111", width=1.1),
+                )
+                self._gpr_points_item.show()
+                for x_value, y_value, score in points:
+                    label = pg.TextItem(text=f"{float(score):.0f}", color="#ffffff", anchor=(0.0, 1.0))
+                    label.setZValue(40)
+                    label.setPos(float(x_value), float(y_value))
+                    plot.addItem(label)
+                    self._gpr_point_labels.append(label)
+            else:
+                self._gpr_points_item.setData(x=[], y=[])
+                self._gpr_points_item.hide()
+
+            region_centers_payload = self._collection_payload_by_name(collection, "gpr_region_centers", kind=4)
+            if region_centers_payload is not None and np.asarray(region_centers_payload.table).size > 0:
+                centers = np.asarray(region_centers_payload.table, dtype=np.float32)
+                self._gpr_region_centers_item.setData(
+                    x=centers[:, 0],
+                    y=centers[:, 1],
+                    symbol="o",
+                    size=10,
+                    brush=pg.mkBrush("#80ed99"),
+                    pen=pg.mkPen("#081c15", width=1.1),
+                )
+                self._gpr_region_centers_item.show()
+                for row in centers:
+                    label = pg.TextItem(text=f"{float(row[2]):.0f}", color="#d8f3dc", anchor=(0.0, 1.0))
+                    label.setZValue(40)
+                    label.setPos(float(row[0]), float(row[1]))
+                    plot.addItem(label)
+                    self._gpr_region_center_labels.append(label)
+            else:
+                self._gpr_region_centers_item.setData(x=[], y=[])
+                self._gpr_region_centers_item.hide()
+
+            for payload in self._collection_payloads_by_prefix(collection, "gpr_region_mask_", kind=3):
+                mask = np.asarray(payload.image, dtype=np.float32)
+                if mask.ndim != 2 or mask.size == 0:
+                    continue
+                mask_image = pg.ImageItem(axisOrder="row-major")
+                mask_image.setZValue(5)
+                mask_image.setImage(mask, autoLevels=False)
+                mask_image.setRect(rect)
+                mask_image.setOpacity(0.0)
+                plot.addItem(mask_image)
+                contour = pg.IsocurveItem(data=mask, level=0.5, pen=pg.mkPen("#4cc9f0", width=1.3))
+                contour.setParentItem(mask_image)
+                self._gpr_region_mask_items.append(mask_image)
+                self._gpr_region_contours.append(contour)
+
+            plot.setTitle(f"GPR {self._gpr_config_mode.currentText()}")
+        finally:
+            plot.setUpdatesEnabled(True)
+        return True
+
     def _result_collection_has_trace(self, collection: ResultCollection) -> bool:
         """Return `True` when collection contains at least one trace payload."""
+        if collection.collection_payloads:
+            return True
         for block in collection.blocks:
             for payload in block.payloads:
                 if payload.kind == 1 and payload.trace.size > 0:
@@ -503,8 +803,7 @@ class AppWindowPlotMixin:
             return
 
         if show_magnitude:
-            magnitude_plot.getViewBox().invertY(False)
-            magnitude_plot.getViewBox().enableAutoRange(x=True, y=True)
+            self._configure_pass_through_magnitude_axis(magnitude_plot)
             magnitude_plot.getPlotItem().showAxis("bottom", show=not show_phase)
             magnitude_plot.setLabel("left", "Magnitude", units="dB")
             magnitude_plot.setTitle(title)
@@ -548,5 +847,6 @@ class AppWindowPlotMixin:
             x_max = float(np.max(trace.frequency_hz))
             if show_magnitude:
                 magnitude_plot.setXRange(x_min, x_max, padding=0.02)
+                self._configure_pass_through_magnitude_axis(magnitude_plot)
             if show_phase:
                 phase_plot.setXRange(x_min, x_max, padding=0.02)

python_app/gui/controllers/app_window_snapshot_mixin.py

@@ -111,7 +111,7 @@ class AppWindowSnapshotMixin:
 
             self._replace_runtime_history(retained_raw=[], retained_pre=[], retained_result=[])
             self._bscan_history_floor_collection_id = 0
-            self._clear_bscan_plot_history()
+            self._clear_history_mode_caches()
 
             # Clear processor-side replay cache so newly rendered B-scan starts clean.
             self._write_live_processing_config(history_command="clear_all", bump_history_seq=True)

python_app/gui/controllers/app_window_ui_mixin.py

@@ -2,6 +2,7 @@
 
 Layout is intentionally split into two independent plot surfaces:
 - single `PlotWidget` for B-scan heatmap rendering;
+- single `PlotWidget` for GPR accumulator/annotation rendering;
 - stacked magnitude/phase `PlotWidget`s for pass-through traces.
 
 `_set_plot_mode()` switches between these surfaces via `QStackedWidget`.
@@ -26,6 +27,7 @@ import pyqtgraph as pg
 
 from python_app.gui.controllers.sections import (
     build_data_actions_group,
+    build_gpr_config_group,
     build_hardware_actions_group,
     build_pipeline_group,
     build_preprocess_summary_group,
@@ -72,6 +74,7 @@ class AppWindowUiMixin:
         # We create both upfront and only switch active page at runtime.
         self._plot_stack = QStackedWidget(root)
         self._build_bscan_plot_page()
+        self._build_gpr_plot_page()
         self._build_trace_plot_page()
 
         # Default view on startup is pass-through traces.
@@ -121,6 +124,12 @@ class AppWindowUiMixin:
 
         self._plot_stack.addWidget(self._trace_plots_container)
 
+    def _build_gpr_plot_page(self) -> None:
+        """Create GPR page in plot stack."""
+        self._gpr_plot = pg.PlotWidget(background="#0f141c")
+        self._gpr_plot.showGrid(x=True, y=True, alpha=0.2)
+        self._plot_stack.addWidget(self._gpr_plot)
+
     def _build_settings_toggle(self, root_layout: QHBoxLayout) -> None:
         """Create narrow button used to collapse or show settings panel."""
         self._settings_toggle_button = QPushButton("<")
@@ -182,6 +191,7 @@ class AppWindowUiMixin:
             build_data_actions_group(self),
             build_preprocess_summary_group(self),
             build_processing_group(self),
+            build_gpr_config_group(self),
             build_radar_group(self),
             build_switch_group(self),
         ]
@@ -205,12 +215,16 @@ class AppWindowUiMixin:
     def _set_plot_mode(self, mode: str) -> None:
         """Switch visible plot page according to processing mode.
 
-        `bscan`   -> show `self._bscan_plot` (single heatmap surface)
-        otherwise -> show `self._trace_plots_container` (magnitude + phase)
+        `bscan`   -> show `self._bscan_plot`
+        `gpr`     -> show `self._gpr_plot`
+        otherwise -> show `self._trace_plots_container`
         """
         if mode == "bscan":
             self._plot_stack.setCurrentWidget(self._bscan_plot)
             return
+        if mode == "gpr":
+            self._plot_stack.setCurrentWidget(self._gpr_plot)
+            return
         self._plot_stack.setCurrentWidget(self._trace_plots_container)
 
     @staticmethod

python_app/gui/controllers/sections/__init__.py

@@ -1,6 +1,7 @@
 """Composable UI section builders used by AppWindow UI mixin."""
 
 from python_app.gui.controllers.sections.data_actions_section import build_data_actions_group
+from python_app.gui.controllers.sections.gpr_config_section import build_gpr_config_group
 from python_app.gui.controllers.sections.hardware_actions_section import build_hardware_actions_group
 from python_app.gui.controllers.sections.pipeline_section import build_pipeline_group
 from python_app.gui.controllers.sections.preprocess_summary_section import build_preprocess_summary_group
@@ -10,6 +11,7 @@ from python_app.gui.controllers.sections.switch_section import build_switch_grou
 
 __all__ = [
     "build_data_actions_group",
+    "build_gpr_config_group",
     "build_hardware_actions_group",
     "build_pipeline_group",
     "build_preprocess_summary_group",

python_app/gui/controllers/sections/gpr_config_section.py

@@ -0,0 +1,53 @@
+"""Builder for stable GPR configuration section."""
+
+from __future__ import annotations
+
+from PyQt6.QtWidgets import QComboBox, QDoubleSpinBox, QFormLayout, QGroupBox, QPlainTextEdit
+
+
+def _format_tx_geometry(owner) -> str:
+    """Render Tx geometry defaults into editable line-based text."""
+    return "\n".join(
+        f"{int(entry.output_pos)} {float(entry.x_m):g}"
+        for entry in owner._defaults_config.gpr.tx_geometry
+    )
+
+
+def _format_rx_geometry(owner) -> str:
+    """Render Rx geometry defaults into editable line-based text."""
+    return "\n".join(
+        f"{int(entry.input_pos)} {float(entry.x_m):g}"
+        for entry in owner._defaults_config.gpr.rx_geometry
+    )
+
+
+def build_gpr_config_group(owner) -> QGroupBox:
+    """Create stable GPR config controls backed by run_config.json."""
+    group = QGroupBox("GPR Config")
+    form = QFormLayout(group)
+    form.setFieldGrowthPolicy(QFormLayout.FieldGrowthPolicy.AllNonFixedFieldsGrow)
+    defaults = owner._defaults_config.gpr
+
+    owner._gpr_config_mode = QComboBox()
+    owner._gpr_config_mode.addItems(["point", "extended"])
+    owner._set_combo_current_text(owner._gpr_config_mode, defaults.mode)
+
+    owner._gpr_relative_permittivity = QDoubleSpinBox()
+    owner._gpr_relative_permittivity.setDecimals(4)
+    owner._gpr_relative_permittivity.setRange(0.0001, 1000.0)
+    owner._gpr_relative_permittivity.setSingleStep(0.05)
+    owner._gpr_relative_permittivity.setValue(float(defaults.relative_permittivity))
+
+    owner._gpr_tx_geometry_input = QPlainTextEdit(_format_tx_geometry(owner))
+    owner._gpr_tx_geometry_input.setPlaceholderText("output_pos x_m")
+    owner._gpr_tx_geometry_input.setMinimumHeight(88)
+
+    owner._gpr_rx_geometry_input = QPlainTextEdit(_format_rx_geometry(owner))
+    owner._gpr_rx_geometry_input.setPlaceholderText("input_pos x_m")
+    owner._gpr_rx_geometry_input.setMinimumHeight(120)
+
+    form.addRow("Mode", owner._gpr_config_mode)
+    form.addRow("Relative Permittivity", owner._gpr_relative_permittivity)
+    form.addRow("Tx Geometry", owner._gpr_tx_geometry_input)
+    form.addRow("Rx Geometry", owner._gpr_rx_geometry_input)
+    return group

python_app/gui/controllers/sections/processing_section.py

@@ -9,21 +9,39 @@ from PyQt6.QtWidgets import (
     QFormLayout,
     QGroupBox,
     QHBoxLayout,
+    QLineEdit,
     QPushButton,
     QSizePolicy,
+    QSpinBox,
     QStackedWidget,
     QWidget,
 )
 
 
+def _default_gpr_input_positions(owner) -> str:
+    """Build default live input-position selection from stable GPR config."""
+    geometry_values = {int(entry.input_pos) for entry in owner._defaults_config.gpr.rx_geometry}
+    combo_values = {int(combo.input) for combo in owner._defaults_config.combos}
+    values = sorted(geometry_values & combo_values) or sorted(geometry_values)
+    return ",".join(str(value) for value in values)
+
+
+def _default_gpr_output_positions(owner) -> str:
+    """Build default live output-position selection from stable GPR config."""
+    geometry_values = {int(entry.output_pos) for entry in owner._defaults_config.gpr.tx_geometry}
+    combo_values = {int(combo.output) for combo in owner._defaults_config.combos}
+    values = sorted(geometry_values & combo_values) or sorted(geometry_values)
+    return ",".join(str(value) for value in values)
+
+
 def build_processing_group(owner) -> QGroupBox:
-    """Create processing mode section with pass-through and B-scan pages."""
+    """Create processing mode section with pass-through, B-scan, and GPR pages."""
     group = QGroupBox("Processing")
     form = QFormLayout(group)
     form.setFieldGrowthPolicy(QFormLayout.FieldGrowthPolicy.AllNonFixedFieldsGrow)
 
     owner._processing_mode = QComboBox()
-    owner._processing_mode.addItems(["pass_through", "bscan"])
+    owner._processing_mode.addItems(["pass_through", "bscan", "gpr"])
 
     owner._processing_mode_pages = QStackedWidget(group)
     owner._processing_mode_pages.setSizePolicy(QSizePolicy.Policy.Preferred, QSizePolicy.Policy.Fixed)
@@ -51,10 +69,35 @@ def build_processing_group(owner) -> QGroupBox:
     owner._show_phase_checkbox = QCheckBox("Show phase")
     owner._show_phase_checkbox.setChecked(True)
 
+    owner._pass_through_fixed_y_enabled = QCheckBox("Fix magnitude Y range")
+    owner._pass_through_fixed_y_enabled.setChecked(False)
+
+    owner._pass_through_y_min_db = QDoubleSpinBox()
+    owner._pass_through_y_min_db.setDecimals(1)
+    owner._pass_through_y_min_db.setRange(-240.0, 240.0)
+    owner._pass_through_y_min_db.setSingleStep(1.0)
+    owner._pass_through_y_min_db.setValue(-100.0)
+
+    owner._pass_through_y_max_db = QDoubleSpinBox()
+    owner._pass_through_y_max_db.setDecimals(1)
+    owner._pass_through_y_max_db.setRange(-240.0, 240.0)
+    owner._pass_through_y_max_db.setSingleStep(1.0)
+    owner._pass_through_y_max_db.setValue(0.0)
+
+    def sync_pass_through_y_controls() -> None:
+        enabled = owner._pass_through_fixed_y_enabled.isChecked()
+        owner._pass_through_y_min_db.setEnabled(enabled)
+        owner._pass_through_y_max_db.setEnabled(enabled)
+
+    sync_pass_through_y_controls()
+
     pass_through_form.addRow("Gain dB (live)", owner._processing_gain_db)
     pass_through_form.addRow("Phase deg (live)", owner._processing_phase_deg)
     pass_through_form.addRow(owner._show_magnitude_checkbox)
     pass_through_form.addRow(owner._show_phase_checkbox)
+    pass_through_form.addRow(owner._pass_through_fixed_y_enabled)
+    pass_through_form.addRow("Y min dB", owner._pass_through_y_min_db)
+    pass_through_form.addRow("Y max dB", owner._pass_through_y_max_db)
     owner._processing_mode_pages.addWidget(pass_through_page)
 
     bscan_page = QWidget(owner._processing_mode_pages)
@@ -115,11 +158,86 @@ def build_processing_group(owner) -> QGroupBox:
     bscan_form.addRow(bscan_actions)
     owner._processing_mode_pages.addWidget(bscan_page)
 
+    gpr_page = QWidget(owner._processing_mode_pages)
+    gpr_page.setSizePolicy(QSizePolicy.Policy.Preferred, QSizePolicy.Policy.Fixed)
+    gpr_form = QFormLayout(gpr_page)
+    gpr_form.setFieldGrowthPolicy(QFormLayout.FieldGrowthPolicy.AllNonFixedFieldsGrow)
+
+    owner._gpr_input_positions_input = QLineEdit(_default_gpr_input_positions(owner))
+    owner._gpr_input_positions_input.setPlaceholderText("0,1,2")
+
+    owner._gpr_output_positions_input = QLineEdit(_default_gpr_output_positions(owner))
+    owner._gpr_output_positions_input.setPlaceholderText("0,1")
+
+    owner._gpr_min_depth_m = QDoubleSpinBox()
+    owner._gpr_min_depth_m.setDecimals(2)
+    owner._gpr_min_depth_m.setRange(0.0, 50.0)
+    owner._gpr_min_depth_m.setSingleStep(0.1)
+    owner._gpr_min_depth_m.setValue(2.0)
+
+    owner._gpr_max_depth_m = QDoubleSpinBox()
+    owner._gpr_max_depth_m.setDecimals(2)
+    owner._gpr_max_depth_m.setRange(0.1, 50.0)
+    owner._gpr_max_depth_m.setSingleStep(0.1)
+    owner._gpr_max_depth_m.setValue(14.0)
+
+    owner._gpr_comp_power = QDoubleSpinBox()
+    owner._gpr_comp_power.setDecimals(3)
+    owner._gpr_comp_power.setRange(0.0, 5.0)
+    owner._gpr_comp_power.setSingleStep(0.05)
+    owner._gpr_comp_power.setValue(0.2)
+
+    owner._gpr_start_freq_mhz = QDoubleSpinBox()
+    owner._gpr_start_freq_mhz.setDecimals(1)
+    owner._gpr_start_freq_mhz.setRange(100.0, 8800.0)
+    owner._gpr_start_freq_mhz.setSingleStep(10.0)
+    owner._gpr_start_freq_mhz.setValue(3000.0)
+
+    owner._gpr_stop_freq_mhz = QDoubleSpinBox()
+    owner._gpr_stop_freq_mhz.setDecimals(1)
+    owner._gpr_stop_freq_mhz.setRange(100.0, 8800.0)
+    owner._gpr_stop_freq_mhz.setSingleStep(10.0)
+    owner._gpr_stop_freq_mhz.setValue(6000.0)
+
+    owner._gpr_background_subtract_enabled = QCheckBox("Subtract mean of previous collections")
+    owner._gpr_background_subtract_enabled.setChecked(True)
+
+    owner._gpr_background_mean_count = QSpinBox()
+    owner._gpr_background_mean_count.setRange(0, 10_000)
+    owner._gpr_background_mean_count.setValue(10)
+
+    owner._gpr_clear_history_button = QPushButton("Clear GPR History")
+    owner._gpr_clear_history_button.clicked.connect(owner._on_gpr_clear_history_clicked)
+    owner._gpr_remove_last_button = QPushButton("Remove Last Measurement")
+    owner._gpr_remove_last_button.clicked.connect(owner._on_gpr_remove_last_measurement_clicked)
+    gpr_actions = QWidget(owner._processing_mode_pages)
+    gpr_actions_layout = QHBoxLayout(gpr_actions)
+    gpr_actions_layout.setContentsMargins(0, 0, 0, 0)
+    gpr_actions_layout.setSpacing(8)
+    gpr_actions_layout.addWidget(owner._gpr_remove_last_button)
+    gpr_actions_layout.addWidget(owner._gpr_clear_history_button)
+
+    gpr_form.addRow("Input positions", owner._gpr_input_positions_input)
+    gpr_form.addRow("Output positions", owner._gpr_output_positions_input)
+    gpr_form.addRow("Min depth m", owner._gpr_min_depth_m)
+    gpr_form.addRow("Max depth m", owner._gpr_max_depth_m)
+    gpr_form.addRow("Comp power", owner._gpr_comp_power)
+    gpr_form.addRow("Start MHz", owner._gpr_start_freq_mhz)
+    gpr_form.addRow("Stop MHz", owner._gpr_stop_freq_mhz)
+    gpr_form.addRow(owner._gpr_background_subtract_enabled)
+    gpr_form.addRow("Mean count", owner._gpr_background_mean_count)
+    gpr_form.addRow(gpr_actions)
+    owner._processing_mode_pages.addWidget(gpr_page)
+
     owner._processing_mode.currentTextChanged.connect(owner._on_processing_mode_changed)
     owner._processing_gain_db.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._processing_phase_deg.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._show_magnitude_checkbox.toggled.connect(owner._on_trace_visibility_changed)
     owner._show_phase_checkbox.toggled.connect(owner._on_trace_visibility_changed)
+    owner._pass_through_fixed_y_enabled.toggled.connect(sync_pass_through_y_controls)
+    owner._pass_through_fixed_y_enabled.toggled.connect(owner._on_processing_live_settings_changed)
+    owner._pass_through_y_min_db.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._pass_through_y_max_db.valueChanged.connect(owner._on_processing_live_settings_changed)
     form.addRow("Mode", owner._processing_mode)
     form.addRow(owner._processing_mode_pages)
 
@@ -129,6 +247,15 @@ def build_processing_group(owner) -> QGroupBox:
     owner._bscan_gain.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._bscan_start_freq_mhz.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._bscan_stop_freq_mhz.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_input_positions_input.editingFinished.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_output_positions_input.editingFinished.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_min_depth_m.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_max_depth_m.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_comp_power.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_start_freq_mhz.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_stop_freq_mhz.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_background_subtract_enabled.toggled.connect(owner._on_processing_live_settings_changed)
+    owner._gpr_background_mean_count.valueChanged.connect(owner._on_processing_live_settings_changed)
 
     owner._on_processing_mode_changed(owner._processing_mode.currentText())
     return group

python_app/gui/runtime/constraints.py

@@ -3,19 +3,53 @@
 from __future__ import annotations
 
 from python_app.models.run_config_model import RunConfigModel
+from python_app.orchestration.live_processing_config import ProcessingLiveConfig
 
 
-def validate_processing_mode_constraints(processing_mode: str, config: RunConfigModel) -> None:
+def validate_processing_mode_constraints(
+    processing_mode: str,
+    config: RunConfigModel,
+    live_config: ProcessingLiveConfig,
+) -> None:
     """Validate mode-specific constraints for current run configuration."""
-    if processing_mode != "bscan":
+    if processing_mode == "bscan":
+        any_native_switch = config.input_switch.driver_mode == "native" or config.output_switch.driver_mode == "native"
+        if not any_native_switch:
+            return
+
+        combo_count = len({(int(combo.input), int(combo.output)) for combo in config.combos})
+        if combo_count != 1:
+            raise RuntimeError(
+                f"B-scan with native switches requires exactly one run combo (now {combo_count})"
+            )
         return
 
-    any_native_switch = config.input_switch.driver_mode == "native" or config.output_switch.driver_mode == "native"
-    if not any_native_switch:
+    if processing_mode != "gpr":
         return
 
-    combo_count = len({(int(combo.input), int(combo.output)) for combo in config.combos})
-    if combo_count != 1:
+    available_inputs = sorted({int(entry.input_pos) for entry in config.gpr.rx_geometry})
+    available_outputs = sorted({int(entry.output_pos) for entry in config.gpr.tx_geometry})
+    if not available_inputs or not available_outputs:
+        raise RuntimeError("GPR requires non-empty Tx/Rx geometry in run_config")
+
+    requested_inputs = sorted({int(value) for value in live_config.gpr_input_positions})
+    requested_outputs = sorted({int(value) for value in live_config.gpr_output_positions})
+
+    selected_inputs = requested_inputs or available_inputs
+    selected_outputs = requested_outputs or available_outputs
+
+    missing_inputs = [value for value in selected_inputs if value not in available_inputs]
+    missing_outputs = [value for value in selected_outputs if value not in available_outputs]
+    if missing_inputs:
+        raise RuntimeError(f"GPR input positions are missing from geometry config: {missing_inputs}")
+    if missing_outputs:
+        raise RuntimeError(f"GPR output positions are missing from geometry config: {missing_outputs}")
+
+    required_combos = {(int(input_pos), int(output_pos)) for input_pos in selected_inputs for output_pos in selected_outputs}
+    configured_combos = {(int(combo.input), int(combo.output)) for combo in config.combos}
+    missing_combos = sorted(required_combos - configured_combos)
+    if missing_combos:
         raise RuntimeError(
-            f"B-scan with native switches requires exactly one run combo (now {combo_count})"
+            "GPR run combos do not cover selected input/output positions: "
+            f"{missing_combos}"
         )