diff --git a/python_app/gui/app_window.py b/python_app/gui/app_window.py
index 6e99764..f875833 100644
--- a/python_app/gui/app_window.py
+++ b/python_app/gui/app_window.py
@@ -35,6 +35,8 @@ from python_app.orchestration.preprocess_assets import VISIBLE_PREPROCESS_ASSET_
 from python_app.orchestration.process_supervisor import ProcessSupervisor
 from python_app.orchestration.shm_reader import ShmRingReader
 from python_app.storage.npz_store import NpzStore
+from python_app.workflows.multi_radar_capture_workflow import MultiRadarSequentialCaptureSession
+from python_app.workflows.radar_config_variants import RadarConfigScanSummary, RadarConfigVariant
 from python_app.workflows.sequential_capture_workflow import SequentialCaptureSession
 
 
@@ -122,6 +124,17 @@ class AppWindow(
         """Initialize preprocessing dialog and selected set names."""
         self._preprocess_dialog: PreprocessDialog | None = None
         self._preprocess_set_name = str(self._gui_defaults.preprocess_dialog.set_name)
+        self._preprocess_radar_config_dir = str(self._gui_defaults.preprocess_dialog.radar_config_dir)
+        self._preprocess_use_all_radar_configs = bool(self._gui_defaults.preprocess_dialog.use_all_radar_configs)
+        self._preprocess_radar_variants: list[RadarConfigVariant] = []
+        self._preprocess_radar_scan_summary = RadarConfigScanSummary(
+            directory_path=self._preprocess_radar_config_dir,
+            json_file_count=0,
+            valid_variant_count=0,
+            skipped_file_count=0,
+            duplicate_variant_count=0,
+            issues=(),
+        )
         self._selected_preprocess_sets = {
             key: str(preprocess_asset_model(self._defaults_config, key).set_name)
             for key in VISIBLE_PREPROCESS_ASSET_KEYS
@@ -130,7 +143,7 @@ class AppWindow(
 
     def _init_capture_state(self) -> None:
         """Initialize one-shot capture and sequence-control flags."""
-        self._capture_session: SequentialCaptureSession | None = None
+        self._capture_session: SequentialCaptureSession | MultiRadarSequentialCaptureSession | None = None
         self._resume_pipeline_after_capture = False
         self._single_capture_active = False
         self._single_capture_start_ns: int | None = None
diff --git a/python_app/gui/controllers/app_window_config/profile_io_mixin.py b/python_app/gui/controllers/app_window_config/profile_io_mixin.py
index e0c7cb4..cdb12a7 100644
--- a/python_app/gui/controllers/app_window_config/profile_io_mixin.py
+++ b/python_app/gui/controllers/app_window_config/profile_io_mixin.py
@@ -274,6 +274,8 @@ class AppWindowConfigProfileIOMixin:
         self._selected_preprocess_sets = selected_preprocess_sets
         self._selected_preprocess_radar_key = self._radar_key(config)
         self._preprocess_set_name = str(gui_state.preprocess_dialog.set_name)
+        self._preprocess_radar_config_dir = str(gui_state.preprocess_dialog.radar_config_dir)
+        self._preprocess_use_all_radar_configs = bool(gui_state.preprocess_dialog.use_all_radar_configs)
         self._apply_history_limit_from_config(config)
         self._gpr_geometry_signature = None
         self._gpr_selected_geometry = None
@@ -283,12 +285,18 @@ class AppWindowConfigProfileIOMixin:
         if self._preprocess_dialog is not None:
             with ExitStack() as dialog_blockers:
                 dialog_blockers.enter_context(QSignalBlocker(self._preprocess_dialog._set_name_input))
+                dialog_blockers.enter_context(QSignalBlocker(self._preprocess_dialog._radar_config_dir_input))
+                dialog_blockers.enter_context(QSignalBlocker(self._preprocess_dialog._use_all_radar_configs_checkbox))
                 for combo in self._preprocess_dialog._set_combos.values():
                     dialog_blockers.enter_context(QSignalBlocker(combo))
                 self._preprocess_dialog.set_set_name(self._preprocess_set_name)
+                self._preprocess_dialog.set_radar_config_dir(self._preprocess_radar_config_dir)
+                self._preprocess_dialog.set_use_all_radar_configs(self._preprocess_use_all_radar_configs)
                 self._preprocess_dialog.set_selected_sets(self._selected_preprocess_sets, emit_signal=False)
 
         self._apply_initial_radar_limits()
+        if self._preprocess_dialog is not None:
+            self._refresh_sets()
         self._reload_locator_service_from_config()
         self._on_processing_mode_changed(gui_state.processing.selected_mode)
         self._update_history_indicator()
diff --git a/python_app/gui/controllers/app_window_config/state_builders.py b/python_app/gui/controllers/app_window_config/state_builders.py
index 285d5ec..2a05d6b 100644
--- a/python_app/gui/controllers/app_window_config/state_builders.py
+++ b/python_app/gui/controllers/app_window_config/state_builders.py
@@ -185,7 +185,11 @@ class AppWindowConfigStateBuildersMixin:
                 save_path=str(self._project_root / "python_app/data/snapshots"),
                 save_name="snapshot_manual",
             ),
-            preprocess_dialog=GuiPreprocessDialogStateModel(set_name="set_001"),
+            preprocess_dialog=GuiPreprocessDialogStateModel(
+                set_name="set_001",
+                radar_config_dir="",
+                use_all_radar_configs=False,
+            ),
         )
 
     def _current_preprocess_set_name(self) -> str:
@@ -194,6 +198,18 @@ class AppWindowConfigStateBuildersMixin:
             self._preprocess_set_name = self._preprocess_dialog.set_name()
         return self._preprocess_set_name
 
+    def _current_preprocess_radar_config_dir(self) -> str:
+        """Return current preprocess dialog radar-config directory path."""
+        if self._preprocess_dialog is not None:
+            self._preprocess_radar_config_dir = self._preprocess_dialog.radar_config_dir()
+        return self._preprocess_radar_config_dir
+
+    def _current_preprocess_use_all_radar_configs(self) -> bool:
+        """Return whether multi-radar preprocessing is enabled in the dialog."""
+        if self._preprocess_dialog is not None:
+            self._preprocess_use_all_radar_configs = self._preprocess_dialog.use_all_radar_configs()
+        return bool(self._preprocess_use_all_radar_configs)
+
     def _build_gui_state(self) -> GuiStateModel:
         """Build GUI-only persistent state from current widget values."""
         return GuiStateModel(
@@ -249,6 +265,8 @@ class AppWindowConfigStateBuildersMixin:
             ),
             preprocess_dialog=GuiPreprocessDialogStateModel(
                 set_name=self._current_preprocess_set_name(),
+                radar_config_dir=self._current_preprocess_radar_config_dir(),
+                use_all_radar_configs=self._current_preprocess_use_all_radar_configs(),
             ),
         )
 
diff --git a/python_app/gui/controllers/app_window_preprocess_mixin.py b/python_app/gui/controllers/app_window_preprocess_mixin.py
index 3a2f514..737347f 100644
--- a/python_app/gui/controllers/app_window_preprocess_mixin.py
+++ b/python_app/gui/controllers/app_window_preprocess_mixin.py
@@ -9,6 +9,11 @@ from python_app.orchestration.preprocess_assets import (
     preprocess_asset_channel,
     preprocess_asset_display_name,
 )
+from python_app.workflows.multi_radar_capture_workflow import (
+    MultiRadarCaptureBatch,
+    MultiRadarSequentialCaptureSession,
+)
+from python_app.workflows.radar_config_variants import scan_radar_config_variants
 from python_app.workflows.sequential_capture_workflow import SequentialCaptureSession
 
 
@@ -16,10 +21,18 @@ class AppWindowPreprocessMixin:
     """Handles preprocess set management and sequential capture workflows."""
 
     @staticmethod
-    def _capture_log_entries_for_session(session: SequentialCaptureSession) -> list[str]:
+    def _capture_log_entries_for_session(session: SequentialCaptureSession | MultiRadarSequentialCaptureSession) -> list[str]:
         """Build capture-log rows from current session traces."""
         display_name = preprocess_asset_display_name(session.kind)
         total_count = session.state().total_count
+        if isinstance(session, MultiRadarSequentialCaptureSession):
+            return [
+                f"{display_name}: {index}/{total_count} | "
+                f"input={batch.combo.input} output={batch.combo.output} | "
+                f"radar_configs={session.radar_variant_count()}"
+                for index, batch in enumerate(session.captured_batches(), start=1)
+            ]
+
         entries: list[str] = []
         for index, trace in enumerate(session.captured_traces(), start=1):
             entries.append(
@@ -98,18 +111,36 @@ class AppWindowPreprocessMixin:
         dialog = PreprocessDialog(self)
         self._preprocess_dialog = dialog
         dialog.set_set_name(self._preprocess_set_name)
+        dialog.set_radar_config_dir(self._preprocess_radar_config_dir)
+        dialog.set_use_all_radar_configs(self._preprocess_use_all_radar_configs)
         dialog.set_selected_sets(self._selected_preprocess_sets, emit_signal=False)
         dialog.refresh_requested.connect(self._refresh_sets)
         dialog.selection_changed.connect(self._on_preprocess_selection_changed)
+        dialog.radar_config_dir_changed.connect(self._on_preprocess_radar_config_inputs_changed)
+        dialog.multi_radar_option_changed.connect(self._on_preprocess_radar_config_inputs_changed)
         dialog.start_sequence_requested.connect(self._start_capture_sequence)
         dialog.capture_next_requested.connect(self._capture_next_combo)
         dialog.capture_all_requested.connect(self._capture_all_remaining)
         dialog.undo_last_requested.connect(self._undo_last_capture)
         dialog.finalize_sequence_requested.connect(self._finalize_capture_sequence)
         dialog.abort_sequence_requested.connect(self._abort_capture_sequence)
+        dialog.set_radar_config_summary(
+            directory_path=self._preprocess_radar_scan_summary.directory_path,
+            json_file_count=self._preprocess_radar_scan_summary.json_file_count,
+            valid_variant_count=self._preprocess_radar_scan_summary.valid_variant_count,
+            skipped_file_count=self._preprocess_radar_scan_summary.skipped_file_count,
+            duplicate_variant_count=self._preprocess_radar_scan_summary.duplicate_variant_count,
+        )
         self._update_capture_dialog_state()
         return dialog
 
+    def _on_preprocess_radar_config_inputs_changed(self) -> None:
+        """Persist preprocess radar-config directory options and refresh the scan result."""
+        dialog = self._ensure_preprocess_dialog()
+        self._preprocess_radar_config_dir = dialog.radar_config_dir()
+        self._preprocess_use_all_radar_configs = dialog.use_all_radar_configs()
+        self._refresh_sets()
+
     def _on_preprocess_selection_changed(self) -> None:
         """Persist selected preprocessing set names from dialog."""
         dialog = self._ensure_preprocess_dialog()
@@ -139,9 +170,12 @@ class AppWindowPreprocessMixin:
         radar_key = self._radar_key_from_ui()
         self._selected_preprocess_radar_key = radar_key
         dialog = self._ensure_preprocess_dialog()
+        self._preprocess_radar_config_dir = dialog.radar_config_dir()
+        self._preprocess_use_all_radar_configs = dialog.use_all_radar_configs()
 
         available_sets = self._available_preprocess_sets_for_radar_key(radar_key)
         dialog.set_available_sets(available_sets)
+        self._refresh_preprocess_radar_variants()
 
         unavailable_selections: list[str] = []
         for key, names in available_sets.items():
@@ -166,6 +200,32 @@ class AppWindowPreprocessMixin:
                 details="\n".join(unavailable_selections),
             )
 
+    def _refresh_preprocess_radar_variants(self) -> None:
+        """Reload valid radar sweep variants from the preprocess dialog directory."""
+        config = self._build_config()
+        variants, summary = scan_radar_config_variants(
+            self._preprocess_radar_config_dir,
+            base_config=config,
+        )
+        self._preprocess_radar_variants = variants
+        self._preprocess_radar_scan_summary = summary
+
+        if self._preprocess_dialog is not None:
+            self._preprocess_dialog.set_radar_config_summary(
+                directory_path=summary.directory_path,
+                json_file_count=summary.json_file_count,
+                valid_variant_count=summary.valid_variant_count,
+                skipped_file_count=summary.skipped_file_count,
+                duplicate_variant_count=summary.duplicate_variant_count,
+            )
+
+        if summary.issues:
+            self._log_warning(
+                "Some radar config JSON files were skipped during preprocess scan.",
+                details="\n".join(summary.issues),
+                once_key=f"preprocess_radar_config_scan_{summary.directory_path}",
+            )
+
     def _start_capture_sequence(self, kind: str) -> None:
         """Start sequential capture session for requested preprocess asset."""
         if self._capture_session is not None:
@@ -187,13 +247,20 @@ class AppWindowPreprocessMixin:
 
         try:
             config = self._build_config()
-            radar_key = self._radar_key(config)
-            existing_sets = self._store.list_sets(PREPROCESS_ASSET_SPECS[kind].set_kind, radar_key)
             display_name = preprocess_asset_display_name(kind)
-            if set_name in existing_sets:
-                raise RuntimeError(f"Set '{set_name}' already exists for {display_name} and cannot be overwritten")
+            if self._preprocess_use_all_radar_configs:
+                session = self._build_multi_radar_capture_session(config=config, kind=kind, set_name=set_name)
+                radar_summary = (
+                    f"radar_variants={session.radar_variant_count()}, "
+                    f"combos={session.state().total_count}"
+                )
+            else:
+                session = self._build_single_radar_capture_session(config=config, kind=kind, set_name=set_name)
+                radar_summary = (
+                    f"radar_key={self._radar_key(config)}, "
+                    f"combos={session.state().total_count}"
+                )
 
-            session = SequentialCaptureSession(config=config, kind=kind, set_name=set_name)
             session.open()
             self._capture_session = session
 
@@ -203,14 +270,59 @@ class AppWindowPreprocessMixin:
             self._clear_trace_plots()
             self._update_capture_dialog_state()
             self._log(
-                f"{display_name} sequence started: set={set_name}, radar_key={radar_key}, "
-                f"combos={session.state().total_count}"
+                f"{display_name} sequence started: set={set_name}, {radar_summary}"
             )
         except Exception as exc:  # noqa: BLE001
             self._cleanup_capture_session()
             self._show_exception(f"Failed to start {kind} sequence", exc)
             self._resume_pipeline_if_needed()
 
+    def _build_single_radar_capture_session(
+        self,
+        *,
+        config,
+        kind: str,
+        set_name: str,
+    ) -> SequentialCaptureSession:
+        """Validate and create the existing single-radar capture session."""
+        radar_key = self._radar_key(config)
+        existing_sets = self._store.list_sets(PREPROCESS_ASSET_SPECS[kind].set_kind, radar_key)
+        display_name = preprocess_asset_display_name(kind)
+        if set_name in existing_sets:
+            raise RuntimeError(f"Set '{set_name}' already exists for {display_name} and cannot be overwritten")
+        return SequentialCaptureSession(config=config, kind=kind, set_name=set_name)
+
+    def _build_multi_radar_capture_session(
+        self,
+        *,
+        config,
+        kind: str,
+        set_name: str,
+    ) -> MultiRadarSequentialCaptureSession:
+        """Validate and create the multi-radar capture session."""
+        self._refresh_preprocess_radar_variants()
+        if not self._preprocess_radar_variants:
+            raise RuntimeError("No valid radar config variants were found in the selected directory")
+
+        display_name = preprocess_asset_display_name(kind)
+        duplicate_set_keys: list[str] = []
+        for variant in self._preprocess_radar_variants:
+            existing_sets = self._store.list_sets(PREPROCESS_ASSET_SPECS[kind].set_kind, variant.radar_key)
+            if set_name in existing_sets:
+                duplicate_set_keys.append(f"{variant.display_name} -> {variant.radar_key}")
+        if duplicate_set_keys:
+            raise RuntimeError(
+                f"Set '{set_name}' already exists for {display_name} in these radar variants:\n"
+                + "\n".join(duplicate_set_keys)
+            )
+
+        return MultiRadarSequentialCaptureSession(
+            base_config=config,
+            kind=kind,
+            set_name=set_name,
+            radar_variants=self._preprocess_radar_variants,
+        )
+
     def _capture_next_combo(self) -> None:
         """Capture next combo in active sequential capture session."""
         session = self._capture_session
@@ -219,8 +331,8 @@ class AppWindowPreprocessMixin:
             return
 
         try:
-            trace = session.capture_current_combo()
-            self._record_preprocess_capture(session, trace)
+            capture_result = session.capture_current_combo()
+            self._record_preprocess_capture(session, capture_result)
         except Exception as exc:  # noqa: BLE001
             self._show_exception("Failed to capture preprocess combo", exc)
             self._abort_capture_sequence()
@@ -247,31 +359,47 @@ class AppWindowPreprocessMixin:
         )
         try:
             while not session.is_complete():
-                trace = session.capture_current_combo()
-                self._record_preprocess_capture(session, trace)
+                capture_result = session.capture_current_combo()
+                self._record_preprocess_capture(session, capture_result)
         except Exception as exc:  # noqa: BLE001
             self._show_exception("Failed to capture preprocess combo", exc)
             self._abort_capture_sequence()
 
-    def _record_preprocess_capture(self, session: SequentialCaptureSession, trace) -> None:
+    def _record_preprocess_capture(
+        self,
+        session: SequentialCaptureSession | MultiRadarSequentialCaptureSession,
+        capture_result,
+    ) -> None:
         """Update UI, preview, and logs after one successful preprocess capture."""
         dialog = self._ensure_preprocess_dialog()
         state = session.state()
         display_name = preprocess_asset_display_name(session.kind)
         channel = preprocess_asset_channel(session.kind)
+        if isinstance(session, MultiRadarSequentialCaptureSession):
+            assert isinstance(capture_result, MultiRadarCaptureBatch)
+            trace = capture_result.display_trace
+            input_pos = capture_result.combo.input
+            output_pos = capture_result.combo.output
+            extra_details = f" | radar_configs={len(capture_result.traces)}"
+        else:
+            trace = capture_result
+            input_pos = trace.combo.input_pos
+            output_pos = trace.combo.output_pos
+            extra_details = ""
 
         dialog.append_capture_log_entry(
             kind=display_name,
             captured_count=state.captured_count,
             total_count=state.total_count,
-            input_pos=trace.combo.input_pos,
-            output_pos=trace.combo.output_pos,
+            input_pos=input_pos,
+            output_pos=output_pos,
+            extra_details=extra_details,
         )
         dialog.draw_last_trace(trace, title=f"{display_name} captured", channel=channel)
         self._draw_single_trace(trace, title=f"{display_name} last trace", channel=channel)
         self._log(
             f"{display_name} capture: {state.captured_count}/{state.total_count} | "
-            f"input={trace.combo.input_pos} output={trace.combo.output_pos}"
+            f"input={input_pos} output={output_pos}{extra_details}"
         )
 
         self._update_capture_dialog_state()
@@ -291,10 +419,19 @@ class AppWindowPreprocessMixin:
 
         dialog = self._ensure_preprocess_dialog()
         try:
-            removed_trace = session.undo_last_capture()
+            removed_capture = session.undo_last_capture()
             state = session.state()
             display_name = preprocess_asset_display_name(session.kind)
             channel = preprocess_asset_channel(session.kind)
+            if isinstance(session, MultiRadarSequentialCaptureSession):
+                assert isinstance(removed_capture, MultiRadarCaptureBatch)
+                removed_input = removed_capture.combo.input
+                removed_output = removed_capture.combo.output
+                extra_details = f" | radar_configs={len(removed_capture.traces)}"
+            else:
+                removed_input = removed_capture.combo.input_pos
+                removed_output = removed_capture.combo.output_pos
+                extra_details = ""
 
             dialog.set_capture_log_entries(self._capture_log_entries_for_session(session))
             last_trace = session.last_captured_trace()
@@ -309,8 +446,8 @@ class AppWindowPreprocessMixin:
 
             self._update_capture_dialog_state()
             self._log(
-                f"{display_name} undo last capture: removed input={removed_trace.combo.input_pos} "
-                f"output={removed_trace.combo.output_pos}; remaining={state.captured_count}/{state.total_count}"
+                f"{display_name} undo last capture: removed input={removed_input} "
+                f"output={removed_output}{extra_details}; remaining={state.captured_count}/{state.total_count}"
             )
         except Exception as exc:  # noqa: BLE001
             self._show_exception("Failed to undo last preprocess capture", exc)
@@ -333,16 +470,33 @@ class AppWindowPreprocessMixin:
 
         dialog = self._ensure_preprocess_dialog()
         try:
-            radar_key, collection = session.finalize(self._store)
             set_name = session.set_name
             kind = session.kind
             display_name = preprocess_asset_display_name(kind)
+            if isinstance(session, MultiRadarSequentialCaptureSession):
+                saved_sets = session.finalize(self._store)
+            else:
+                radar_key, collection = session.finalize(self._store)
             self._cleanup_capture_session()
 
             self._selected_preprocess_sets[kind] = set_name
             self._refresh_sets()
-            dialog.set_status(f"{display_name} set saved: {set_name} ({len(collection.traces)} traces)")
-            self._log(f"{display_name} sequence completed and saved: set={set_name}, key={radar_key}")
+            if isinstance(session, MultiRadarSequentialCaptureSession):
+                assert isinstance(saved_sets, list)
+                dialog.set_status(
+                    f"{display_name} set saved: {set_name} ({len(saved_sets)} radar variants)"
+                )
+                saved_summary = ", ".join(
+                    f"{saved.display_name}:{saved.trace_count}"
+                    for saved in saved_sets
+                )
+                self._log(
+                    f"{display_name} sequence completed and saved: set={set_name}, "
+                    f"radar_variants={len(saved_sets)} [{saved_summary}]"
+                )
+            else:
+                dialog.set_status(f"{display_name} set saved: {set_name} ({len(collection.traces)} traces)")
+                self._log(f"{display_name} sequence completed and saved: set={set_name}, key={radar_key}")
             self._resume_pipeline_if_needed()
         except Exception as exc:  # noqa: BLE001
             self._show_exception("Failed to save preprocess set", exc)
@@ -375,6 +529,7 @@ class AppWindowPreprocessMixin:
                 can_undo=False,
                 can_finalize=False,
                 can_capture_all=False,
+                variant_count=1,
             )
             return
 
@@ -394,6 +549,7 @@ class AppWindowPreprocessMixin:
             can_undo=state.can_undo,
             can_finalize=state.is_complete,
             can_capture_all=(not state.is_complete and state.current_combo is not None),
+            variant_count=state.variant_count,
         )
 
     def _cleanup_capture_session(self) -> None:
diff --git a/python_app/gui/preprocess_dialog.py b/python_app/gui/preprocess_dialog.py
index ba051f2..b6d8e9f 100644
--- a/python_app/gui/preprocess_dialog.py
+++ b/python_app/gui/preprocess_dialog.py
@@ -4,8 +4,10 @@ from __future__ import annotations
 
 from PyQt6.QtCore import QSignalBlocker, pyqtSignal
 from PyQt6.QtWidgets import (
+    QCheckBox,
     QComboBox,
     QDialog,
+    QFileDialog,
     QFormLayout,
     QGridLayout,
     QGroupBox,
@@ -34,6 +36,8 @@ class PreprocessDialog(QDialog):
 
     refresh_requested = pyqtSignal()
     selection_changed = pyqtSignal()
+    radar_config_dir_changed = pyqtSignal()
+    multi_radar_option_changed = pyqtSignal()
     start_sequence_requested = pyqtSignal(str)
     capture_next_requested = pyqtSignal()
     capture_all_requested = pyqtSignal()
@@ -88,10 +92,39 @@ class PreprocessDialog(QDialog):
         header_row.addWidget(self._set_name_input, stretch=1)
         header_row.addWidget(refresh_button)
         layout.addLayout(header_row)
+        layout.addWidget(self._build_radar_config_group(group))
 
         layout.addWidget(self._build_selector_group("S21", VISIBLE_PREPROCESS_ASSET_KEYS, group))
         return group
 
+    def _build_radar_config_group(self, parent: QGroupBox) -> QGroupBox:
+        """Build radar-config directory controls for multi-radar preprocessing."""
+        group = QGroupBox("Radar Config Variants", parent)
+        layout = QVBoxLayout(group)
+
+        dir_row = QHBoxLayout()
+        self._radar_config_dir_input = QLineEdit(group)
+        self._radar_config_dir_input.setPlaceholderText("Directory with radar JSON configs")
+        self._radar_config_dir_input.editingFinished.connect(self.radar_config_dir_changed.emit)
+        browse_button = QPushButton("Browse...", group)
+        browse_button.clicked.connect(self._choose_radar_config_dir)
+        dir_row.addWidget(QLabel("Directory"))
+        dir_row.addWidget(self._radar_config_dir_input, stretch=1)
+        dir_row.addWidget(browse_button)
+        layout.addLayout(dir_row)
+
+        self._radar_config_summary_label = QLabel("No radar config directory selected.", group)
+        self._radar_config_summary_label.setWordWrap(True)
+        layout.addWidget(self._radar_config_summary_label)
+
+        self._use_all_radar_configs_checkbox = QCheckBox(
+            "Capture current combo for all found radar configs",
+            group,
+        )
+        self._use_all_radar_configs_checkbox.toggled.connect(self.multi_radar_option_changed.emit)
+        layout.addWidget(self._use_all_radar_configs_checkbox)
+        return group
+
     def _build_selector_group(self, title: str, keys: tuple[str, ...], parent: QGroupBox) -> QGroupBox:
         """Build one selector subgroup for a channel family."""
         group = QGroupBox(title, parent)
@@ -201,6 +234,41 @@ class PreprocessDialog(QDialog):
         """Replace requested target set name."""
         self._set_name_input.setText(value)
 
+    def radar_config_dir(self) -> str:
+        """Return configured radar-config directory path."""
+        return self._radar_config_dir_input.text().strip()
+
+    def set_radar_config_dir(self, value: str) -> None:
+        """Replace configured radar-config directory path."""
+        self._radar_config_dir_input.setText(value)
+
+    def use_all_radar_configs(self) -> bool:
+        """Return whether multi-radar capture mode is enabled."""
+        return bool(self._use_all_radar_configs_checkbox.isChecked())
+
+    def set_use_all_radar_configs(self, enabled: bool) -> None:
+        """Update multi-radar capture checkbox state."""
+        self._use_all_radar_configs_checkbox.setChecked(bool(enabled))
+
+    def set_radar_config_summary(
+        self,
+        *,
+        directory_path: str,
+        json_file_count: int,
+        valid_variant_count: int,
+        skipped_file_count: int,
+        duplicate_variant_count: int,
+    ) -> None:
+        """Update one-line radar-config scan summary."""
+        if not directory_path:
+            self._radar_config_summary_label.setText("No radar config directory selected.")
+            return
+        self._radar_config_summary_label.setText(
+            f"Directory: {directory_path} | "
+            f"json={json_file_count}, valid={valid_variant_count}, "
+            f"skipped={skipped_file_count}, duplicates={duplicate_variant_count}"
+        )
+
     def selection_snapshot(self) -> dict[str, str]:
         """Return currently selected set names keyed by preprocess asset key."""
         return {key: self._set_combos[key].currentText().strip() for key in VISIBLE_PREPROCESS_ASSET_KEYS}
@@ -221,11 +289,12 @@ class PreprocessDialog(QDialog):
         total_count: int,
         input_pos: int,
         output_pos: int,
+        extra_details: str = "",
     ) -> None:
         """Append one capture progress row to dialog log."""
         self._capture_log.appendPlainText(
             f"{kind}: {captured_count}/{total_count} | "
-            f"input={input_pos} output={output_pos}"
+            f"input={input_pos} output={output_pos}{extra_details}"
         )
 
     def set_capture_state(
@@ -239,6 +308,7 @@ class PreprocessDialog(QDialog):
         can_undo: bool,
         can_finalize: bool,
         can_capture_all: bool,
+        variant_count: int = 1,
     ) -> None:
         """Update sequence progress/status widgets."""
         if kind is None:
@@ -265,7 +335,10 @@ class PreprocessDialog(QDialog):
             self._combo_label.setText("<complete>")
             self._capture_next_button.setEnabled(False)
         else:
-            self._combo_label.setText(f"input={next_input}, output={next_output}")
+            combo_text = f"input={next_input}, output={next_output}"
+            if int(variant_count) > 1:
+                combo_text += f" | radar configs={int(variant_count)}"
+            self._combo_label.setText(combo_text)
             self._capture_next_button.setEnabled(True)
 
     def set_available_sets(self, available_sets: dict[str, list[str]]) -> None:
@@ -360,6 +433,18 @@ class PreprocessDialog(QDialog):
         """Emit current selection snapshot change."""
         self.selection_changed.emit()
 
+    def _choose_radar_config_dir(self) -> None:
+        """Pick radar-config directory and notify controller code."""
+        selected_dir = QFileDialog.getExistingDirectory(
+            self,
+            "Select Radar Config Directory",
+            self.radar_config_dir(),
+        )
+        if not selected_dir:
+            return
+        self._radar_config_dir_input.setText(selected_dir)
+        self.radar_config_dir_changed.emit()
+
     @staticmethod
     def _asset_row_label(key: str) -> str:
         """Return short selector label for one preprocess asset."""
diff --git a/python_app/models/gui_profile_codec.py b/python_app/models/gui_profile_codec.py
index b0e452d..fae07e7 100644
--- a/python_app/models/gui_profile_codec.py
+++ b/python_app/models/gui_profile_codec.py
@@ -313,6 +313,18 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
             gui.preprocess_dialog.set_name,
             "gui.preprocess_dialog",
         ),
+        radar_config_dir=_optional_string(
+            preprocess_dialog_object,
+            "radar_config_dir",
+            gui.preprocess_dialog.radar_config_dir,
+            "gui.preprocess_dialog",
+        ),
+        use_all_radar_configs=_optional_bool(
+            preprocess_dialog_object,
+            "use_all_radar_configs",
+            gui.preprocess_dialog.use_all_radar_configs,
+            "gui.preprocess_dialog",
+        ),
     )
 
     profile.gui = gui
@@ -377,6 +389,8 @@ def gui_profile_to_dict(model: GuiProfileModel) -> dict[str, Any]:
         },
         "preprocess_dialog": {
             "set_name": gui.preprocess_dialog.set_name,
+            "radar_config_dir": gui.preprocess_dialog.radar_config_dir,
+            "use_all_radar_configs": gui.preprocess_dialog.use_all_radar_configs,
         },
     }
     return payload
diff --git a/python_app/models/gui_profile_schema.py b/python_app/models/gui_profile_schema.py
index 094e76d..be29138 100644
--- a/python_app/models/gui_profile_schema.py
+++ b/python_app/models/gui_profile_schema.py
@@ -93,6 +93,8 @@ class GuiPreprocessDialogStateModel:
     """UI-only defaults for preprocessing dialog controls."""
 
     set_name: str = "set_001"
+    radar_config_dir: str = ""
+    use_all_radar_configs: bool = False
 
 
 @dataclass(slots=True)
diff --git a/python_app/workflows/multi_radar_capture_workflow.py b/python_app/workflows/multi_radar_capture_workflow.py
new file mode 100644
index 0000000..3606b10
--- /dev/null
+++ b/python_app/workflows/multi_radar_capture_workflow.py
@@ -0,0 +1,261 @@
+"""Sequential capture workflow that captures each combo across multiple radar sweep variants."""
+
+from __future__ import annotations
+
+from contextlib import suppress
+from dataclasses import dataclass
+import time
+
+import numpy as np
+
+from python_app.hardware_full.librevna_service import LibreVnaService
+from python_app.hardware_full.switch_service import SwitchService
+from python_app.models.dataset_model import ComboKey, SweepCollection, TraceData
+from python_app.models.run_config_model import ComboModel, RunConfigModel
+from python_app.storage.npz_store import NpzStore
+from python_app.workflows.radar_config_variants import RadarConfigVariant
+from python_app.workflows.sequential_capture_workflow import SequentialCaptureState
+
+
+@dataclass(frozen=True, slots=True)
+class MultiRadarCaptureBatch:
+    """One completed combo capture across all configured radar variants."""
+
+    combo: ComboModel
+    traces: tuple[TraceData, ...]
+    variant_labels: tuple[str, ...]
+
+    @property
+    def display_trace(self) -> TraceData:
+        """Return the last trace in the batch for preview rendering."""
+        return self.traces[-1]
+
+
+@dataclass(frozen=True, slots=True)
+class MultiRadarSavedSet:
+    """One preprocess set persisted for one radar variant."""
+
+    display_name: str
+    radar_key: str
+    trace_count: int
+
+
+class MultiRadarSequentialCaptureSession:
+    """Capture a full combo matrix for one preprocess asset across multiple radar sweep variants."""
+
+    def __init__(
+        self,
+        *,
+        base_config: RunConfigModel,
+        kind: str,
+        set_name: str,
+        radar_variants: list[RadarConfigVariant],
+    ) -> None:
+        """Create capture session for one preprocess asset set and multiple radar variants."""
+        if kind not in {"s21_calibration", "s21_reference", "s11_open", "s11_short", "s11_load", "s11_reference"}:
+            raise RuntimeError(f"Unsupported capture kind: {kind}")
+        if not set_name:
+            raise RuntimeError("Set name is required")
+        if not radar_variants:
+            raise RuntimeError("At least one radar variant is required")
+
+        self._base_config = base_config
+        self._kind = kind
+        self._set_name = set_name
+        self._radar_variants = list(radar_variants)
+        self._combos = RunConfigModel.build_full_combos(
+            base_config.input_switch.positions,
+            base_config.output_switch.positions,
+        )
+        if not self._combos:
+            raise RuntimeError("No switch combinations available for capture")
+
+        self._captured_batches: list[MultiRadarCaptureBatch] = []
+        self._traces_by_radar_key = {
+            variant.radar_key: []
+            for variant in self._radar_variants
+        }
+        self._next_index = 0
+        self._opened = False
+
+        self._radar = LibreVnaService(serial=base_config.radar.serial or None)
+        self._input_switch = SwitchService(
+            name=base_config.input_switch.name,
+            positions=base_config.input_switch.positions,
+            mode=base_config.input_switch.driver_mode,
+            driver=base_config.input_switch.driver,
+            gpio_chip=base_config.input_switch.gpio_chip,
+            pin_a=base_config.input_switch.pin_a,
+            pin_b=base_config.input_switch.pin_b,
+            invert_logic=base_config.input_switch.invert_logic,
+        )
+        self._output_switch = SwitchService(
+            name=base_config.output_switch.name,
+            positions=base_config.output_switch.positions,
+            mode=base_config.output_switch.driver_mode,
+            driver=base_config.output_switch.driver,
+            gpio_chip=base_config.output_switch.gpio_chip,
+            pin_a=base_config.output_switch.pin_a,
+            pin_b=base_config.output_switch.pin_b,
+            invert_logic=base_config.output_switch.invert_logic,
+        )
+
+    @property
+    def kind(self) -> str:
+        """Return canonical preprocess asset key for this capture session."""
+        return self._kind
+
+    @property
+    def set_name(self) -> str:
+        """Return destination set name."""
+        return self._set_name
+
+    def open(self) -> None:
+        """Open radar and switch resources."""
+        if self._opened:
+            return
+        self._opened = True
+        try:
+            self._radar.open()
+            self._radar.configure(self._base_config.radar.sweep)
+            self._input_switch.open()
+            self._output_switch.open()
+        except Exception:
+            self.close()
+            raise
+
+    def close(self) -> None:
+        """Close all opened hardware resources."""
+        with suppress(Exception):
+            self._output_switch.close()
+        with suppress(Exception):
+            self._input_switch.close()
+        with suppress(Exception):
+            self._radar.close()
+        self._opened = False
+
+    def state(self) -> SequentialCaptureState:
+        """Return current progress snapshot."""
+        current_combo = self._current_combo()
+        return SequentialCaptureState(
+            kind=self._kind,
+            set_name=self._set_name,
+            captured_count=len(self._captured_batches),
+            total_count=len(self._combos),
+            current_combo=current_combo,
+            can_undo=bool(self._captured_batches),
+            is_complete=self.is_complete(),
+            variant_count=len(self._radar_variants),
+        )
+
+    def capture_current_combo(self) -> MultiRadarCaptureBatch:
+        """Capture the current combo across all radar variants and advance the combo cursor."""
+        if not self._opened:
+            raise RuntimeError("Capture session is not opened")
+        combo = self._current_combo()
+        if combo is None:
+            raise RuntimeError("Capture session is already complete")
+
+        self._output_switch.switch_to(combo.output)
+        self._input_switch.switch_to(combo.input)
+        if self._base_config.runtime.settling_ms > 0:
+            time.sleep(self._base_config.runtime.settling_ms / 1000.0)
+
+        traces: list[TraceData] = []
+        variant_labels: list[str] = []
+        for variant in self._radar_variants:
+            self._radar.configure(variant.config.radar.sweep)
+            if self._base_config.runtime.settling_ms > 0:
+                time.sleep(self._base_config.runtime.settling_ms / 1000.0)
+            sweep = self._radar.acquire()
+            trace = TraceData(
+                combo=ComboKey(input_pos=combo.input, output_pos=combo.output),
+                frequency_hz=np.asarray(sweep.x, dtype=np.float32),
+                s11=np.asarray(sweep.trace("s11"), dtype=np.complex64),
+                s21=np.asarray(sweep.trace("s21"), dtype=np.complex64),
+            )
+            traces.append(trace)
+            variant_labels.append(variant.display_name)
+            self._traces_by_radar_key[variant.radar_key].append(trace)
+
+        batch = MultiRadarCaptureBatch(
+            combo=combo,
+            traces=tuple(traces),
+            variant_labels=tuple(variant_labels),
+        )
+        self._captured_batches.append(batch)
+        self._next_index += 1
+        return batch
+
+    def undo_last_capture(self) -> MultiRadarCaptureBatch:
+        """Remove the most recently captured combo batch and rewind the cursor."""
+        if not self._opened:
+            raise RuntimeError("Capture session is not opened")
+        if not self._captured_batches or self._next_index <= 0:
+            raise RuntimeError("No captured combo is available to undo")
+
+        expected_combo = self._combos[self._next_index - 1]
+        removed_batch = self._captured_batches[-1]
+        if (
+            int(removed_batch.combo.input) != int(expected_combo.input)
+            or int(removed_batch.combo.output) != int(expected_combo.output)
+        ):
+            raise RuntimeError("Capture session state is inconsistent; last batch does not match rewind combo")
+
+        for variant in self._radar_variants:
+            traces = self._traces_by_radar_key[variant.radar_key]
+            if not traces:
+                raise RuntimeError("Capture session state is inconsistent; missing trace during undo")
+            traces.pop()
+
+        self._next_index -= 1
+        self._captured_batches.pop()
+        return removed_batch
+
+    def last_captured_trace(self) -> TraceData | None:
+        """Return the most recent trace from the most recent combo batch, if any."""
+        if not self._captured_batches:
+            return None
+        return self._captured_batches[-1].display_trace
+
+    def captured_batches(self) -> list[MultiRadarCaptureBatch]:
+        """Return completed combo batches in capture order."""
+        return list(self._captured_batches)
+
+    def radar_variant_count(self) -> int:
+        """Return how many radar variants are captured per combo."""
+        return len(self._radar_variants)
+
+    def is_complete(self) -> bool:
+        """Return `True` when all combos were captured."""
+        return self._next_index >= len(self._combos)
+
+    def finalize(self, store: NpzStore) -> list[MultiRadarSavedSet]:
+        """Persist completed captures as one preprocess set per radar variant."""
+        if not self.is_complete():
+            raise RuntimeError("Capture session is not complete")
+
+        monotonic_ns = time.monotonic_ns()
+        saved_sets: list[MultiRadarSavedSet] = []
+        for variant in self._radar_variants:
+            traces = list(self._traces_by_radar_key[variant.radar_key])
+            collection = SweepCollection(
+                collection_id=1,
+                monotonic_ns=monotonic_ns,
+                traces=traces,
+            )
+            store.save_set(self._kind, variant.radar_key, self._set_name, collection)
+            saved_sets.append(
+                MultiRadarSavedSet(
+                    display_name=variant.display_name,
+                    radar_key=variant.radar_key,
+                    trace_count=len(traces),
+                )
+            )
+        return saved_sets
+
+    def _current_combo(self) -> ComboModel | None:
+        """Return next combo to capture, or `None` if session is complete."""
+        if self._next_index >= len(self._combos):
+            return None
+        return self._combos[self._next_index]
diff --git a/python_app/workflows/radar_config_variants.py b/python_app/workflows/radar_config_variants.py
new file mode 100644
index 0000000..2c02521
--- /dev/null
+++ b/python_app/workflows/radar_config_variants.py
@@ -0,0 +1,154 @@
+"""Helpers for loading radar sweep variants from a directory of JSON files."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+import json
+from pathlib import Path
+
+from python_app.models.run_config_model import RunConfigModel
+from python_app.storage.npz_store import radar_key_from_config
+
+_RADAR_SWEEP_KEYS = (
+    "start_hz",
+    "stop_hz",
+    "points",
+    "if_bandwidth_hz",
+    "stimulus_power_dbm",
+)
+
+
+@dataclass(frozen=True, slots=True)
+class RadarConfigVariant:
+    """One capture-ready radar sweep variant loaded from JSON."""
+
+    source_path: Path
+    display_name: str
+    config: RunConfigModel
+    radar_key: str
+
+
+@dataclass(frozen=True, slots=True)
+class RadarConfigScanSummary:
+    """Scan results for one radar-config directory refresh."""
+
+    directory_path: str
+    json_file_count: int
+    valid_variant_count: int
+    skipped_file_count: int
+    duplicate_variant_count: int
+    issues: tuple[str, ...]
+
+
+def scan_radar_config_variants(
+    directory_path: str,
+    *,
+    base_config: RunConfigModel,
+) -> tuple[list[RadarConfigVariant], RadarConfigScanSummary]:
+    """Load valid radar sweep variants from `directory_path` using `base_config` as the baseline."""
+    normalized_path = str(directory_path).strip()
+    if not normalized_path:
+        return [], RadarConfigScanSummary(
+            directory_path="",
+            json_file_count=0,
+            valid_variant_count=0,
+            skipped_file_count=0,
+            duplicate_variant_count=0,
+            issues=(),
+        )
+
+    directory = Path(normalized_path).expanduser()
+    if not directory.exists():
+        return [], RadarConfigScanSummary(
+            directory_path=str(directory),
+            json_file_count=0,
+            valid_variant_count=0,
+            skipped_file_count=0,
+            duplicate_variant_count=0,
+            issues=(f"Directory does not exist: {directory}",),
+        )
+    if not directory.is_dir():
+        return [], RadarConfigScanSummary(
+            directory_path=str(directory),
+            json_file_count=0,
+            valid_variant_count=0,
+            skipped_file_count=0,
+            duplicate_variant_count=0,
+            issues=(f"Path is not a directory: {directory}",),
+        )
+
+    variants: list[RadarConfigVariant] = []
+    issues: list[str] = []
+    duplicate_variant_count = 0
+    seen_radar_keys: set[str] = set()
+    json_paths = sorted(path for path in directory.glob("*.json") if path.is_file())
+
+    for path in json_paths:
+        try:
+            variant = _load_radar_config_variant(path, base_config=base_config)
+        except Exception as exc:  # noqa: BLE001
+            issues.append(f"{path.name}: {type(exc).__name__}: {exc}")
+            continue
+        if variant.radar_key in seen_radar_keys:
+            duplicate_variant_count += 1
+            issues.append(
+                f"{path.name}: duplicate radar variant key {variant.radar_key}; keeping the first matching file only"
+            )
+            continue
+        seen_radar_keys.add(variant.radar_key)
+        variants.append(variant)
+
+    return variants, RadarConfigScanSummary(
+        directory_path=str(directory),
+        json_file_count=len(json_paths),
+        valid_variant_count=len(variants),
+        skipped_file_count=max(0, len(json_paths) - len(variants) - duplicate_variant_count),
+        duplicate_variant_count=duplicate_variant_count,
+        issues=tuple(issues),
+    )
+
+
+def _load_radar_config_variant(path: Path, *, base_config: RunConfigModel) -> RadarConfigVariant:
+    """Load one radar sweep variant by overlaying JSON `radar.sweep` onto `base_config`."""
+    payload = json.loads(path.read_text(encoding="utf-8"))
+    if not isinstance(payload, dict):
+        raise ValueError("JSON root must be an object")
+
+    radar_payload = payload.get("radar")
+    if not isinstance(radar_payload, dict):
+        raise ValueError("Missing radar section")
+
+    sweep_payload = radar_payload.get("sweep")
+    if not isinstance(sweep_payload, dict):
+        raise ValueError("Missing radar.sweep section")
+    if not any(key in sweep_payload for key in _RADAR_SWEEP_KEYS):
+        raise ValueError("radar.sweep does not contain any supported sweep keys")
+
+    config = base_config.clone()
+    sweep = config.radar.sweep
+    if "start_hz" in sweep_payload:
+        sweep.start_hz = float(sweep_payload["start_hz"])
+    if "stop_hz" in sweep_payload:
+        sweep.stop_hz = float(sweep_payload["stop_hz"])
+    if "points" in sweep_payload:
+        sweep.points = int(sweep_payload["points"])
+    if "if_bandwidth_hz" in sweep_payload:
+        sweep.if_bandwidth_hz = float(sweep_payload["if_bandwidth_hz"])
+    if "stimulus_power_dbm" in sweep_payload:
+        sweep.power_dbm = float(sweep_payload["stimulus_power_dbm"])
+
+    radar_key = radar_key_from_config(
+        model_name=config.radar.model,
+        serial=config.radar.serial,
+        sweep_start_hz=config.radar.sweep.start_hz,
+        sweep_stop_hz=config.radar.sweep.stop_hz,
+        sweep_points=config.radar.sweep.points,
+        ifbw_hz=config.radar.sweep.if_bandwidth_hz,
+        power_dbm=config.radar.sweep.power_dbm,
+    )
+    return RadarConfigVariant(
+        source_path=path,
+        display_name=path.stem,
+        config=config,
+        radar_key=radar_key,
+    )
diff --git a/python_app/workflows/sequential_capture_workflow.py b/python_app/workflows/sequential_capture_workflow.py
index 0904630..529c666 100644
--- a/python_app/workflows/sequential_capture_workflow.py
+++ b/python_app/workflows/sequential_capture_workflow.py
@@ -26,6 +26,7 @@ class SequentialCaptureState:
     current_combo: ComboModel | None
     can_undo: bool
     is_complete: bool
+    variant_count: int = 1
 
 
 class SequentialCaptureSession: