diff --git a/data_acq_and_processing/processing/data_processor/include/processing_live_config.hpp b/data_acq_and_processing/processing/data_processor/include/processing_live_config.hpp
index 4d2abbb..4f12a95 100644
--- a/data_acq_and_processing/processing/data_processor/include/processing_live_config.hpp
+++ b/data_acq_and_processing/processing/data_processor/include/processing_live_config.hpp
@@ -13,10 +13,9 @@ enum class HistoryCommand {
     ClearAll,
 };
 
-enum class GprAlgorithm {
-    Backprojection,
-    LegacyPoint,
-    LegacyExtended,
+enum class LegacyGprMode {
+    Point,
+    Extended,
 };
 
 struct ProcessingLiveConfig {
@@ -32,7 +31,7 @@ struct ProcessingLiveConfig {
     float bscan_gain = 1.0F;
     float bscan_start_freq_mhz = 100.0F;
     float bscan_stop_freq_mhz = 8800.0F;
-    GprAlgorithm gpr_algorithm = GprAlgorithm::Backprojection;
+    LegacyGprMode legacy_gpr_mode = LegacyGprMode::Point;
     std::vector<std::uint32_t> gpr_input_positions{};
     std::vector<std::uint32_t> gpr_output_positions{};
     float gpr_min_depth_m = 2.0F;
diff --git a/data_acq_and_processing/processing/data_processor/src/data_processor.cpp b/data_acq_and_processing/processing/data_processor/src/data_processor.cpp
index 8d261fc..80f2277 100644
--- a/data_acq_and_processing/processing/data_processor/src/data_processor.cpp
+++ b/data_acq_and_processing/processing/data_processor/src/data_processor.cpp
@@ -162,6 +162,10 @@ auto create_default_processors() -> ProcessorRegistry {
         auto processor = std::make_unique<GprProcessor>();
         processors.emplace(processor->name(), std::move(processor));
     }
+    {
+        auto processor = std::make_unique<LegacyGprProcessor>();
+        processors.emplace(processor->name(), std::move(processor));
+    }
     return processors;
 }
 
diff --git a/data_acq_and_processing/processing/data_processor/src/processing_live_config.cpp b/data_acq_and_processing/processing/data_processor/src/processing_live_config.cpp
index 438524e..3d0aaf3 100644
--- a/data_acq_and_processing/processing/data_processor/src/processing_live_config.cpp
+++ b/data_acq_and_processing/processing/data_processor/src/processing_live_config.cpp
@@ -31,19 +31,32 @@ using Json = nlohmann::json;
     throw std::runtime_error("processing.history_command must be one of: none, remove_last, clear_all");
 }
 
-[[nodiscard]] auto parse_gpr_algorithm(const std::string& value) -> GprAlgorithm {
+[[nodiscard]] auto parse_legacy_gpr_mode(const std::string& value, const std::string& field_name) -> LegacyGprMode {
+    if (value == "point") {
+        return LegacyGprMode::Point;
+    }
+    if (value == "extended") {
+        return LegacyGprMode::Extended;
+    }
+    throw std::runtime_error(field_name + " must be one of: point, extended");
+}
+
+void apply_legacy_gpr_algorithm_alias(ProcessingLiveConfig& config, const std::string& value) {
     if (value == "backprojection") {
-        return GprAlgorithm::Backprojection;
+        return;
     }
     if (value == "legacy_point") {
-        return GprAlgorithm::LegacyPoint;
+        config.legacy_gpr_mode = LegacyGprMode::Point;
+    } else if (value == "legacy_extended") {
+        config.legacy_gpr_mode = LegacyGprMode::Extended;
+    } else {
+        throw std::runtime_error(
+            "processing.gpr_algorithm must be one of: backprojection, legacy_point, legacy_extended"
+        );
     }
-    if (value == "legacy_extended") {
-        return GprAlgorithm::LegacyExtended;
+    if (config.processor_mode.empty() || config.processor_mode == "gpr") {
+        config.processor_mode = "legacy_gpr";
     }
-    throw std::runtime_error(
-        "processing.gpr_algorithm must be one of: backprojection, legacy_point, legacy_extended"
-    );
 }
 
 [[nodiscard]] auto parse_s_parameter_channel(const std::string& value, const std::string& field_name) -> std::string {
@@ -179,11 +192,18 @@ using Json = nlohmann::json;
         }
         config.bscan_stop_freq_mhz = static_cast<float>(found->get<double>());
     }
+    if (const auto found = root.find("legacy_gpr_mode"); found != root.end()) {
+        if (!found->is_string()) {
+            throw std::runtime_error("processing.legacy_gpr_mode must be string");
+        }
+        config.legacy_gpr_mode =
+            parse_legacy_gpr_mode(found->get<std::string>(), "processing.legacy_gpr_mode");
+    }
     if (const auto found = root.find("gpr_algorithm"); found != root.end()) {
         if (!found->is_string()) {
             throw std::runtime_error("processing.gpr_algorithm must be string");
         }
-        config.gpr_algorithm = parse_gpr_algorithm(found->get<std::string>());
+        apply_legacy_gpr_algorithm_alias(config, found->get<std::string>());
     }
     if (const auto found = root.find("gpr_input_positions"); found != root.end()) {
         config.gpr_input_positions = parse_u32_array(*found, "processing.gpr_input_positions");
diff --git a/data_acq_and_processing/processing/processors/include/gpr_processor.hpp b/data_acq_and_processing/processing/processors/include/gpr_processor.hpp
index bc06471..dc8a9ed 100644
--- a/data_acq_and_processing/processing/processors/include/gpr_processor.hpp
+++ b/data_acq_and_processing/processing/processors/include/gpr_processor.hpp
@@ -15,4 +15,15 @@ class GprProcessor final : public ProcessorInterface {
     ) -> ipc::ResultCollection override;
 };
 
+class LegacyGprProcessor final : public ProcessorInterface {
+  public:
+    [[nodiscard]] auto name() const -> std::string override;
+    [[nodiscard]] auto process_collection(
+        const config::RunConfig& run_config,
+        const ipc::PreprocessedCollection& collection,
+        std::span<const ipc::PreprocessedCollection> previous_collections,
+        const ProcessingLiveConfig& live_config
+    ) -> ipc::ResultCollection override;
+};
+
 }  // namespace radar::processing
diff --git a/data_acq_and_processing/processing/processors/src/gpr_legacy_processor.ipp b/data_acq_and_processing/processing/processors/src/gpr_legacy_processor.ipp
index 57833b0..4970af3 100644
--- a/data_acq_and_processing/processing/processors/src/gpr_legacy_processor.ipp
+++ b/data_acq_and_processing/processing/processors/src/gpr_legacy_processor.ipp
@@ -750,7 +750,7 @@ void apply_legacy_motion_correction(
         return results;
     }
 
-    if (live_config.gpr_algorithm == GprAlgorithm::LegacyExtended) {
+    if (live_config.legacy_gpr_mode == LegacyGprMode::Extended) {
         const auto [regions, smoothed_accumulator] = extended_legacy_find_regions(
             grid,
             peaks_by_pair,
diff --git a/data_acq_and_processing/processing/processors/src/gpr_processor.cpp b/data_acq_and_processing/processing/processors/src/gpr_processor.cpp
index c8a87cb..5c3ea80 100644
--- a/data_acq_and_processing/processing/processors/src/gpr_processor.cpp
+++ b/data_acq_and_processing/processing/processors/src/gpr_processor.cpp
@@ -35,10 +35,20 @@ auto GprProcessor::process_collection(
     std::span<const ipc::PreprocessedCollection> previous_collections,
     const ProcessingLiveConfig& live_config
 ) -> ipc::ResultCollection {
-    if (live_config.gpr_algorithm != GprAlgorithm::Backprojection) {
-        return process_legacy_gpr(run_config, collection, previous_collections, live_config);
-    }
     return process_backprojection_gpr(run_config, collection, previous_collections, live_config);
 }
 
+auto LegacyGprProcessor::name() const -> std::string {
+    return "legacy_gpr";
+}
+
+auto LegacyGprProcessor::process_collection(
+    const config::RunConfig& run_config,
+    const ipc::PreprocessedCollection& collection,
+    std::span<const ipc::PreprocessedCollection> previous_collections,
+    const ProcessingLiveConfig& live_config
+) -> ipc::ResultCollection {
+    return process_legacy_gpr(run_config, collection, previous_collections, live_config);
+}
+
 }  // namespace radar::processing
diff --git a/python_app/gui/controllers/app_window_config/live_processing_mixin.py b/python_app/gui/controllers/app_window_config/live_processing_mixin.py
index 9788a1e..3ecd16c 100644
--- a/python_app/gui/controllers/app_window_config/live_processing_mixin.py
+++ b/python_app/gui/controllers/app_window_config/live_processing_mixin.py
@@ -11,6 +11,11 @@ from python_app.orchestration.live_processing_config import ProcessingLiveConfig
 class AppWindowLiveProcessingMixin:
     """Handle live processing updates, redraws, and locator republishing."""
 
+    @staticmethod
+    def _is_gpr_processing_mode(mode: str) -> bool:
+        """Return whether a mode uses GPR result payloads and plot surface."""
+        return mode in {"gpr", "legacy_gpr"}
+
     def _validate_processing_mode_selection(self, mode: str) -> None:
         """Validate requested processing mode against current stable/live GUI state."""
         validate_processing_mode_constraints(
@@ -23,10 +28,30 @@ class AppWindowLiveProcessingMixin:
         """Build live processing config from current processing widgets."""
         self._sync_bscan_frequency_limits_with_radar()
         self._sync_gpr_frequency_limits_with_radar()
+        mode = self._processing_mode.currentText()
+        if mode == "legacy_gpr":
+            gpr_input_positions_text = self._legacy_gpr_input_positions_input.text()
+            gpr_output_positions_text = self._legacy_gpr_output_positions_input.text()
+            gpr_min_depth_m = float(self._legacy_gpr_min_depth_m.value())
+            gpr_max_depth_m = float(self._legacy_gpr_max_depth_m.value())
+            gpr_start_freq_mhz = float(self._legacy_gpr_start_freq_mhz.value())
+            gpr_stop_freq_mhz = float(self._legacy_gpr_stop_freq_mhz.value())
+            gpr_background_enabled = bool(self._legacy_gpr_background_subtract_enabled.isChecked())
+            gpr_background_mean_count = int(self._legacy_gpr_background_mean_count.value())
+        else:
+            gpr_input_positions_text = self._gpr_input_positions_input.text()
+            gpr_output_positions_text = 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_start_freq_mhz = float(self._gpr_start_freq_mhz.value())
+            gpr_stop_freq_mhz = float(self._gpr_stop_freq_mhz.value())
+            gpr_background_enabled = bool(self._gpr_background_subtract_enabled.isChecked())
+            gpr_background_mean_count = int(self._gpr_background_mean_count.value())
+
         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(),
+            processor_mode=mode,
             pass_through_channel="s21",
             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),
@@ -38,22 +63,22 @@ class AppWindowLiveProcessingMixin:
             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_algorithm=self._gpr_algorithm.currentText(),
-            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()),
+            legacy_gpr_mode=self._legacy_gpr_config_mode.currentText(),
+            gpr_input_positions=self._parse_csv_int_list(gpr_input_positions_text),
+            gpr_output_positions=self._parse_csv_int_list(gpr_output_positions_text),
+            gpr_min_depth_m=gpr_min_depth_m,
+            gpr_max_depth_m=gpr_max_depth_m,
             gpr_range_comp_power=float(self._gpr_range_comp_power.value()),
             gpr_angle_comp_power=float(self._gpr_angle_comp_power.value()),
-            gpr_comp_power=float(self._gpr_comp_power.value()),
-            gpr_speed_m_s=float(self._gpr_speed_m_s.value()),
-            gpr_look_angle_deg=float(self._gpr_look_angle_deg.value()),
-            gpr_snr_thresh=float(self._gpr_snr_thresh.value()),
-            gpr_snr_comp_max=float(self._gpr_snr_comp_max.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()),
+            gpr_comp_power=float(self._legacy_gpr_comp_power.value()),
+            gpr_speed_m_s=float(self._legacy_gpr_speed_m_s.value()),
+            gpr_look_angle_deg=float(self._legacy_gpr_look_angle_deg.value()),
+            gpr_snr_thresh=float(self._legacy_gpr_snr_thresh.value()),
+            gpr_snr_comp_max=float(self._legacy_gpr_snr_comp_max.value()),
+            gpr_start_freq_mhz=gpr_start_freq_mhz,
+            gpr_stop_freq_mhz=gpr_stop_freq_mhz,
+            gpr_background_subtract_enabled=gpr_background_enabled,
+            gpr_background_mean_count=gpr_background_mean_count,
             gpr_remove_sidelobe_objects_enabled=bool(self._gpr_remove_sidelobe_objects_enabled.isChecked()),
             history_command_seq=int(self._history_command_seq),
             history_command=str(history_command),
@@ -69,7 +94,7 @@ class AppWindowLiveProcessingMixin:
         """Handle live-processing setting changes and trigger redraw when needed."""
         try:
             current_mode = self._processing_mode.currentText()
-            if current_mode == "gpr":
+            if self._is_gpr_processing_mode(current_mode):
                 self._drain_results_until_quiet(timeout_s=0.05, poll_s=0.005)
 
             self._write_live_processing_config()
@@ -77,7 +102,7 @@ class AppWindowLiveProcessingMixin:
                 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":
+            elif self._is_gpr_processing_mode(current_mode):
                 latest = self._drain_results_until_quiet(timeout_s=0.8, poll_s=0.02)
                 collection = latest
                 if collection is None and self._result_history:
@@ -96,7 +121,7 @@ class AppWindowLiveProcessingMixin:
 
     def _on_gpr_visual_settings_changed(self, *_args) -> None:
         """Redraw current GPR result using updated GUI-only render settings."""
-        if self._processing_mode.currentText() != "gpr":
+        if not self._is_gpr_processing_mode(self._processing_mode.currentText()):
             return
         try:
             if self._result_history and self._draw_results(self._result_history[-1]):
@@ -108,7 +133,7 @@ class AppWindowLiveProcessingMixin:
     def _on_gpr_locator_threshold_changed(self, *_args) -> None:
         """Redraw GPR view and republish locator snapshot after threshold changes."""
         self._on_gpr_visual_settings_changed()
-        if self._processing_mode.currentText() != "gpr":
+        if not self._is_gpr_processing_mode(self._processing_mode.currentText()):
             return
         try:
             self._publish_locator_snapshot_from_latest_result()
@@ -118,7 +143,7 @@ class AppWindowLiveProcessingMixin:
     def _on_gpr_locator_window_changed(self, *_args) -> None:
         """Redraw GPR view and republish locator snapshot after visible X/Z changes."""
         self._on_gpr_visual_settings_changed()
-        if self._processing_mode.currentText() != "gpr":
+        if not self._is_gpr_processing_mode(self._processing_mode.currentText()):
             return
         try:
             self._publish_locator_snapshot_from_latest_result()
@@ -131,8 +156,10 @@ class AppWindowLiveProcessingMixin:
             "pass_through": 0,
             "bscan": 1,
             "gpr": 2,
+            "legacy_gpr": 3,
         }
         self._processing_mode_pages.setCurrentIndex(mode_to_page.get(mode, 0))
+        self._gpr_common_page.setVisible(self._is_gpr_processing_mode(mode))
         current_page = self._processing_mode_pages.currentWidget()
         if current_page is not None:
             self._processing_mode_pages.setFixedHeight(current_page.sizeHint().height())
@@ -157,9 +184,9 @@ class AppWindowLiveProcessingMixin:
         self._set_plot_mode(mode)
         self._set_processing_mode_page(mode)
         self._on_processing_live_settings_changed()
-        if mode == "gpr":
+        if self._is_gpr_processing_mode(mode):
             self._publish_locator_snapshot_from_latest_result()
-        elif previous_mode == "gpr" and self._locator_service is not None:
+        elif self._is_gpr_processing_mode(previous_mode) and self._locator_service is not None:
             self._locator_service.publish_empty()
         if mode == "pass_through":
             self._log(
@@ -182,21 +209,36 @@ class AppWindowLiveProcessingMixin:
         elif mode == "gpr":
             self._log(
                 "Processing mode selected: gpr "
-                f"(algorithm={self._gpr_algorithm.currentText()}, "
-                f"inputs={self._gpr_input_positions_input.text().strip() or '<all>'}, "
+                f"(inputs={self._gpr_input_positions_input.text().strip() or '<all>'}, "
                 f"outputs={self._gpr_output_positions_input.text().strip() or '<all>'}, "
                 f"depth={self._gpr_min_depth_m.value():g}..{self._gpr_max_depth_m.value():g} m, "
                 f"freq={self._gpr_start_freq_mhz.value():g}..{self._gpr_stop_freq_mhz.value():g} MHz, "
                 f"range_comp={self._gpr_range_comp_power.value():g}, "
                 f"angle_comp={self._gpr_angle_comp_power.value():g}, "
-                f"comp={self._gpr_comp_power.value():g}, "
-                f"snr={self._gpr_snr_thresh.value():g}, "
                 f"background_subtract={self._gpr_background_subtract_enabled.isChecked()}, "
                 f"mean_count={self._gpr_background_mean_count.value()}, "
                 f"remove_sidelobes={self._gpr_remove_sidelobe_objects_enabled.isChecked()}, "
                 f"render_mode={self._gpr_render_mode.currentText()}, "
                 f"min_score={self._gpr_min_visible_score.value():g})"
             )
+        elif mode == "legacy_gpr":
+            self._log(
+                "Processing mode selected: legacy_gpr "
+                f"(mode={self._legacy_gpr_config_mode.currentText()}, "
+                f"inputs={self._legacy_gpr_input_positions_input.text().strip() or '<all>'}, "
+                f"outputs={self._legacy_gpr_output_positions_input.text().strip() or '<all>'}, "
+                f"depth={self._legacy_gpr_min_depth_m.value():g}..{self._legacy_gpr_max_depth_m.value():g} m, "
+                f"freq={self._legacy_gpr_start_freq_mhz.value():g}..{self._legacy_gpr_stop_freq_mhz.value():g} MHz, "
+                f"comp={self._legacy_gpr_comp_power.value():g}, "
+                f"snr={self._legacy_gpr_snr_thresh.value():g}, "
+                f"snr_comp_max={self._legacy_gpr_snr_comp_max.value():g}, "
+                f"speed={self._legacy_gpr_speed_m_s.value():g} m/s, "
+                f"look_angle={self._legacy_gpr_look_angle_deg.value():g} deg, "
+                f"background_subtract={self._legacy_gpr_background_subtract_enabled.isChecked()}, "
+                f"mean_count={self._legacy_gpr_background_mean_count.value()}, "
+                f"render_mode={self._legacy_gpr_render_mode.currentText()}, "
+                f"min_pairs={self._legacy_gpr_min_visible_pair_count.value()})"
+            )
 
     def _clear_history_mode_caches(self) -> None:
         """Drop cached render state for pass-through, B-scan, and GPR views."""
@@ -218,7 +260,7 @@ class AppWindowLiveProcessingMixin:
                 self._bscan_plot.clear()
                 self._configure_bscan_plot_axes()
             return
-        if self._processing_mode.currentText() == "gpr":
+        if self._is_gpr_processing_mode(self._processing_mode.currentText()):
             if self._result_history and self._draw_results(self._result_history[-1]):
                 return
             self._clear_gpr_plot()
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 3964101..f429285 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
@@ -70,25 +70,6 @@ class AppWindowConfigProfileIOMixin:
         self._pass_through_y_min_db.setEnabled(enabled)
         self._pass_through_y_max_db.setEnabled(enabled)
 
-    def _sync_gpr_algorithm_controls(self) -> None:
-        """Enable only controls that affect the selected GPR algorithm."""
-        backprojection_enabled = self._gpr_algorithm.currentText() == "backprojection"
-        for widget in (
-            self._gpr_range_comp_power,
-            self._gpr_angle_comp_power,
-            self._gpr_remove_sidelobe_objects_enabled,
-        ):
-            widget.setEnabled(backprojection_enabled)
-
-        for widget in (
-            self._gpr_comp_power,
-            self._gpr_speed_m_s,
-            self._gpr_look_angle_deg,
-            self._gpr_snr_thresh,
-            self._gpr_snr_comp_max,
-        ):
-            widget.setEnabled(not backprojection_enabled)
-
     def _apply_history_limit_from_config(self, config) -> None:
         """Resize in-memory history buffers to match the loaded config."""
         history_limit = self._history_limit_for_config(config)
@@ -213,7 +194,6 @@ class AppWindowConfigProfileIOMixin:
             self._bscan_start_freq_mhz,
             self._bscan_stop_freq_mhz,
             self._bscan_subtract_mean_ascan,
-            self._gpr_algorithm,
             self._gpr_relative_permittivity,
             self._gpr_tx_geometry_input,
             self._gpr_rx_geometry_input,
@@ -223,11 +203,6 @@ class AppWindowConfigProfileIOMixin:
             self._gpr_max_depth_m,
             self._gpr_range_comp_power,
             self._gpr_angle_comp_power,
-            self._gpr_comp_power,
-            self._gpr_speed_m_s,
-            self._gpr_look_angle_deg,
-            self._gpr_snr_thresh,
-            self._gpr_snr_comp_max,
             self._gpr_start_freq_mhz,
             self._gpr_stop_freq_mhz,
             self._gpr_background_subtract_enabled,
@@ -239,6 +214,26 @@ class AppWindowConfigProfileIOMixin:
             self._gpr_visible_x_max_m,
             self._gpr_visible_z_min_m,
             self._gpr_visible_z_max_m,
+            self._legacy_gpr_config_mode,
+            self._legacy_gpr_input_positions_input,
+            self._legacy_gpr_output_positions_input,
+            self._legacy_gpr_min_depth_m,
+            self._legacy_gpr_max_depth_m,
+            self._legacy_gpr_comp_power,
+            self._legacy_gpr_snr_thresh,
+            self._legacy_gpr_snr_comp_max,
+            self._legacy_gpr_start_freq_mhz,
+            self._legacy_gpr_stop_freq_mhz,
+            self._legacy_gpr_speed_m_s,
+            self._legacy_gpr_look_angle_deg,
+            self._legacy_gpr_background_subtract_enabled,
+            self._legacy_gpr_background_mean_count,
+            self._legacy_gpr_render_mode,
+            self._legacy_gpr_min_visible_pair_count,
+            self._legacy_gpr_visible_x_min_m,
+            self._legacy_gpr_visible_x_max_m,
+            self._legacy_gpr_visible_z_min_m,
+            self._legacy_gpr_visible_z_max_m,
             self._save_count,
             self._save_path_input,
             self._save_name_input,
@@ -290,16 +285,10 @@ class AppWindowConfigProfileIOMixin:
             )
             self._gpr_input_positions_input.setText(str(gui_state.processing.gpr.input_positions))
             self._gpr_output_positions_input.setText(str(gui_state.processing.gpr.output_positions))
-            self._set_combo_current_text(self._gpr_algorithm, gui_state.processing.gpr.algorithm)
             self._gpr_min_depth_m.setValue(float(gui_state.processing.gpr.min_depth_m))
             self._gpr_max_depth_m.setValue(float(gui_state.processing.gpr.max_depth_m))
             self._gpr_range_comp_power.setValue(float(gui_state.processing.gpr.range_comp_power))
             self._gpr_angle_comp_power.setValue(float(gui_state.processing.gpr.angle_comp_power))
-            self._gpr_comp_power.setValue(float(gui_state.processing.gpr.comp_power))
-            self._gpr_speed_m_s.setValue(float(gui_state.processing.gpr.speed_m_s))
-            self._gpr_look_angle_deg.setValue(float(gui_state.processing.gpr.look_angle_deg))
-            self._gpr_snr_thresh.setValue(float(gui_state.processing.gpr.snr_thresh))
-            self._gpr_snr_comp_max.setValue(float(gui_state.processing.gpr.snr_comp_max))
             self._gpr_start_freq_mhz.setValue(float(gui_state.processing.gpr.start_freq_mhz))
             self._gpr_stop_freq_mhz.setValue(float(gui_state.processing.gpr.stop_freq_mhz))
             self._gpr_background_subtract_enabled.setChecked(
@@ -316,6 +305,29 @@ class AppWindowConfigProfileIOMixin:
             self._gpr_visible_z_min_m.setValue(float(gui_state.processing.gpr.visible_z_min_m))
             self._gpr_visible_z_max_m.setValue(float(gui_state.processing.gpr.visible_z_max_m))
 
+            self._set_combo_current_text(self._legacy_gpr_config_mode, gui_state.processing.legacy_gpr.mode)
+            self._legacy_gpr_input_positions_input.setText(str(gui_state.processing.legacy_gpr.input_positions))
+            self._legacy_gpr_output_positions_input.setText(str(gui_state.processing.legacy_gpr.output_positions))
+            self._legacy_gpr_min_depth_m.setValue(float(gui_state.processing.legacy_gpr.min_depth_m))
+            self._legacy_gpr_max_depth_m.setValue(float(gui_state.processing.legacy_gpr.max_depth_m))
+            self._legacy_gpr_comp_power.setValue(float(gui_state.processing.legacy_gpr.comp_power))
+            self._legacy_gpr_snr_thresh.setValue(float(gui_state.processing.legacy_gpr.snr_thresh))
+            self._legacy_gpr_snr_comp_max.setValue(float(gui_state.processing.legacy_gpr.snr_comp_max))
+            self._legacy_gpr_start_freq_mhz.setValue(float(gui_state.processing.legacy_gpr.start_freq_mhz))
+            self._legacy_gpr_stop_freq_mhz.setValue(float(gui_state.processing.legacy_gpr.stop_freq_mhz))
+            self._legacy_gpr_speed_m_s.setValue(float(gui_state.processing.legacy_gpr.speed_m_s))
+            self._legacy_gpr_look_angle_deg.setValue(float(gui_state.processing.legacy_gpr.look_angle_deg))
+            self._legacy_gpr_background_subtract_enabled.setChecked(
+                bool(gui_state.processing.legacy_gpr.background_subtract_enabled)
+            )
+            self._legacy_gpr_background_mean_count.setValue(int(gui_state.processing.legacy_gpr.background_mean_count))
+            self._set_combo_current_text(self._legacy_gpr_render_mode, gui_state.processing.legacy_gpr.render_mode)
+            self._legacy_gpr_min_visible_pair_count.setValue(int(gui_state.processing.legacy_gpr.min_visible_pair_count))
+            self._legacy_gpr_visible_x_min_m.setValue(float(gui_state.processing.legacy_gpr.visible_x_min_m))
+            self._legacy_gpr_visible_x_max_m.setValue(float(gui_state.processing.legacy_gpr.visible_x_max_m))
+            self._legacy_gpr_visible_z_min_m.setValue(float(gui_state.processing.legacy_gpr.visible_z_min_m))
+            self._legacy_gpr_visible_z_max_m.setValue(float(gui_state.processing.legacy_gpr.visible_z_max_m))
+
             self._save_count.setValue(int(gui_state.data_actions.save_count))
             self._save_path_input.setText(str(gui_state.data_actions.save_path))
             self._save_name_input.setText(str(gui_state.data_actions.save_name))
@@ -330,7 +342,7 @@ class AppWindowConfigProfileIOMixin:
         self._gpr_geometry_signature = None
         self._gpr_selected_geometry = None
         self._sync_pass_through_y_controls()
-        self._sync_gpr_algorithm_controls()
+        self._set_processing_mode_page(gui_state.processing.selected_mode)
         self._refresh_preprocess_summary_labels()
 
         if self._preprocess_dialog is not None:
diff --git a/python_app/gui/controllers/app_window_config/radar_limits_mixin.py b/python_app/gui/controllers/app_window_config/radar_limits_mixin.py
index 7cb61b0..ea5076c 100644
--- a/python_app/gui/controllers/app_window_config/radar_limits_mixin.py
+++ b/python_app/gui/controllers/app_window_config/radar_limits_mixin.py
@@ -175,6 +175,8 @@ class AppWindowRadarLimitsMixin:
             "_bscan_stop_freq_mhz": "B-scan Stop MHz",
             "_gpr_start_freq_mhz": "GPR Start MHz",
             "_gpr_stop_freq_mhz": "GPR Stop MHz",
+            "_legacy_gpr_start_freq_mhz": "Legacy GPR Start MHz",
+            "_legacy_gpr_stop_freq_mhz": "Legacy GPR Stop MHz",
         }
         widgets = [getattr(self, widget_name) for widget_name in widget_names]
         previous_values = {widget_name: getattr(self, widget_name).value() for widget_name in widget_names}
@@ -223,5 +225,7 @@ class AppWindowRadarLimitsMixin:
             (
                 "_gpr_start_freq_mhz",
                 "_gpr_stop_freq_mhz",
+                "_legacy_gpr_start_freq_mhz",
+                "_legacy_gpr_stop_freq_mhz",
             )
         )
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 aaf49c8..521749c 100644
--- a/python_app/gui/controllers/app_window_config/state_builders.py
+++ b/python_app/gui/controllers/app_window_config/state_builders.py
@@ -6,6 +6,7 @@ from python_app.models.gui_profile_model import (
     GuiBscanStateModel,
     GuiDataActionsStateModel,
     GuiGprStateModel,
+    GuiLegacyGprStateModel,
     GuiPassThroughStateModel,
     GuiPreprocessDialogStateModel,
     GuiProcessingStateModel,
@@ -183,6 +184,27 @@ class AppWindowConfigStateBuildersMixin:
                     visible_z_min_m=0.0,
                     visible_z_max_m=14.0,
                 ),
+                legacy_gpr=GuiLegacyGprStateModel(
+                    input_positions=self._default_gpr_input_positions_from_config(config),
+                    output_positions=self._default_gpr_output_positions_from_config(config),
+                    min_depth_m=2.0,
+                    max_depth_m=14.0,
+                    comp_power=0.2,
+                    start_freq_mhz=3000.0,
+                    stop_freq_mhz=6000.0,
+                    speed_m_s=0.0,
+                    look_angle_deg=0.0,
+                    snr_thresh=4.5,
+                    snr_comp_max=25.0,
+                    background_subtract_enabled=True,
+                    background_mean_count=10,
+                    render_mode="heatmap",
+                    min_visible_pair_count=1,
+                    visible_x_min_m=default_gpr_x_min_m,
+                    visible_x_max_m=default_gpr_x_max_m,
+                    visible_z_min_m=0.0,
+                    visible_z_max_m=14.0,
+                ),
             ),
             data_actions=GuiDataActionsStateModel(
                 save_count=10,
@@ -252,18 +274,12 @@ class AppWindowConfigStateBuildersMixin:
                     subtract_mean_ascan=bool(self._bscan_subtract_mean_ascan.isChecked()),
                 ),
                 gpr=GuiGprStateModel(
-                    algorithm=self._gpr_algorithm.currentText(),
                     input_positions=self._gpr_input_positions_input.text().strip(),
                     output_positions=self._gpr_output_positions_input.text().strip(),
                     min_depth_m=float(self._gpr_min_depth_m.value()),
                     max_depth_m=float(self._gpr_max_depth_m.value()),
                     range_comp_power=float(self._gpr_range_comp_power.value()),
                     angle_comp_power=float(self._gpr_angle_comp_power.value()),
-                    comp_power=float(self._gpr_comp_power.value()),
-                    speed_m_s=float(self._gpr_speed_m_s.value()),
-                    look_angle_deg=float(self._gpr_look_angle_deg.value()),
-                    snr_thresh=float(self._gpr_snr_thresh.value()),
-                    snr_comp_max=float(self._gpr_snr_comp_max.value()),
                     start_freq_mhz=float(self._gpr_start_freq_mhz.value()),
                     stop_freq_mhz=float(self._gpr_stop_freq_mhz.value()),
                     background_subtract_enabled=bool(self._gpr_background_subtract_enabled.isChecked()),
@@ -276,6 +292,28 @@ class AppWindowConfigStateBuildersMixin:
                     visible_z_min_m=float(self._gpr_visible_z_min_m.value()),
                     visible_z_max_m=float(self._gpr_visible_z_max_m.value()),
                 ),
+                legacy_gpr=GuiLegacyGprStateModel(
+                    mode=self._legacy_gpr_config_mode.currentText(),
+                    input_positions=self._legacy_gpr_input_positions_input.text().strip(),
+                    output_positions=self._legacy_gpr_output_positions_input.text().strip(),
+                    min_depth_m=float(self._legacy_gpr_min_depth_m.value()),
+                    max_depth_m=float(self._legacy_gpr_max_depth_m.value()),
+                    comp_power=float(self._legacy_gpr_comp_power.value()),
+                    start_freq_mhz=float(self._legacy_gpr_start_freq_mhz.value()),
+                    stop_freq_mhz=float(self._legacy_gpr_stop_freq_mhz.value()),
+                    speed_m_s=float(self._legacy_gpr_speed_m_s.value()),
+                    look_angle_deg=float(self._legacy_gpr_look_angle_deg.value()),
+                    snr_thresh=float(self._legacy_gpr_snr_thresh.value()),
+                    snr_comp_max=float(self._legacy_gpr_snr_comp_max.value()),
+                    background_subtract_enabled=bool(self._legacy_gpr_background_subtract_enabled.isChecked()),
+                    background_mean_count=int(self._legacy_gpr_background_mean_count.value()),
+                    render_mode=self._legacy_gpr_render_mode.currentText(),
+                    min_visible_pair_count=int(self._legacy_gpr_min_visible_pair_count.value()),
+                    visible_x_min_m=float(self._legacy_gpr_visible_x_min_m.value()),
+                    visible_x_max_m=float(self._legacy_gpr_visible_x_max_m.value()),
+                    visible_z_min_m=float(self._legacy_gpr_visible_z_min_m.value()),
+                    visible_z_max_m=float(self._legacy_gpr_visible_z_max_m.value()),
+                ),
             ),
             data_actions=GuiDataActionsStateModel(
                 save_count=int(self._save_count.value()),
@@ -325,7 +363,7 @@ class AppWindowConfigStateBuildersMixin:
                 combo_text = self._combos_text.text()
                 config.combos = parse_combos_from_text(combo_text)
                 config.ensure_combos()
-            if self._processing_mode.currentText() != "gpr" and self._switches_are_effectively_static(config):
+            if self._processing_mode.currentText() not in {"gpr", "legacy_gpr"} and self._switches_are_effectively_static(config):
                 config.combos = [ComboModel(input=0, output=0)]
 
         for key in PREPROCESS_ASSET_KEYS:
diff --git a/python_app/gui/controllers/app_window_pipeline_mixin.py b/python_app/gui/controllers/app_window_pipeline_mixin.py
index f094fc4..a8c11cd 100644
--- a/python_app/gui/controllers/app_window_pipeline_mixin.py
+++ b/python_app/gui/controllers/app_window_pipeline_mixin.py
@@ -363,7 +363,7 @@ class AppWindowPipelineMixin:
             if record_result_history(self._result_history, collection):
                 latest = collection
                 if (
-                    self._processing_mode.currentText() == "gpr"
+                    self._is_gpr_processing_mode(self._processing_mode.currentText())
                     and collection_has_gpr_payloads(collection)
                 ):
                     self._publish_locator_snapshot_from_collection(collection)
@@ -478,11 +478,13 @@ class AppWindowPipelineMixin:
         speed_m_s = self._locator_service.drain_speed_updates()
         if speed_m_s is None:
             return
+        if self._processing_mode.currentText() != "legacy_gpr":
+            return
 
-        previous_speed_m_s = float(self._gpr_speed_m_s.value())
-        with QSignalBlocker(self._gpr_speed_m_s):
-            self._gpr_speed_m_s.setValue(float(speed_m_s))
-        current_speed_m_s = float(self._gpr_speed_m_s.value())
+        previous_speed_m_s = float(self._legacy_gpr_speed_m_s.value())
+        with QSignalBlocker(self._legacy_gpr_speed_m_s):
+            self._legacy_gpr_speed_m_s.setValue(float(speed_m_s))
+        current_speed_m_s = float(self._legacy_gpr_speed_m_s.value())
         if current_speed_m_s == previous_speed_m_s:
             return
 
@@ -494,7 +496,7 @@ class AppWindowPipelineMixin:
             return
         self._locator_service.publish_collection(
             collection,
-            float(self._gpr_min_visible_score.value()),
+            self._gpr_locator_threshold(),
             visible_bounds=self._gpr_visible_object_bounds(),
         )
 
@@ -502,7 +504,7 @@ class AppWindowPipelineMixin:
         """Publish current locator-visible snapshot from latest cached GPR result."""
         if self._locator_service is None:
             return
-        if self._processing_mode.currentText() != "gpr":
+        if not self._is_gpr_processing_mode(self._processing_mode.currentText()):
             self._locator_service.publish_empty()
             return
 
diff --git a/python_app/gui/controllers/app_window_plot/gpr_plot_mixin.py b/python_app/gui/controllers/app_window_plot/gpr_plot_mixin.py
index 198d151..75e1d81 100644
--- a/python_app/gui/controllers/app_window_plot/gpr_plot_mixin.py
+++ b/python_app/gui/controllers/app_window_plot/gpr_plot_mixin.py
@@ -17,6 +17,14 @@ from python_app.orchestration.gpr_locator import (
 class AppWindowGprPlotMixin:
     """Renders GPR accumulator heatmaps and detected object overlays."""
 
+    def _gpr_plot_title(self, *, objects_only: bool = False) -> str:
+        """Return title for the active GPR-like processing mode."""
+        if self._processing_mode.currentText() == "legacy_gpr":
+            title = f"Legacy GPR {self._legacy_gpr_config_mode.currentText()}"
+        else:
+            title = "GPR coherent BP"
+        return f"{title} Objects Only" if objects_only else title
+
     def _clear_gpr_plot(self) -> None:
         """Clear latest GPR plot surface."""
         if not hasattr(self, "_gpr_plot"):
@@ -39,7 +47,7 @@ class AppWindowGprPlotMixin:
         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("GPR coherent BP")
+        self._gpr_plot.setTitle(self._gpr_plot_title())
 
     def _configure_gpr_plot_axes(self) -> None:
         """Apply persistent GPR plot axis labels and base view settings."""
@@ -162,8 +170,14 @@ class AppWindowGprPlotMixin:
 
     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()))
+        if self._processing_mode.currentText() == "legacy_gpr":
+            input_positions_text = self._legacy_gpr_input_positions_input.text()
+            output_positions_text = self._legacy_gpr_output_positions_input.text()
+        else:
+            input_positions_text = self._gpr_input_positions_input.text()
+            output_positions_text = self._gpr_output_positions_input.text()
+        requested_inputs = tuple(self._parse_csv_int_list(input_positions_text))
+        requested_outputs = tuple(self._parse_csv_int_list(output_positions_text))
         signature = (
             self._gpr_tx_geometry_input.toPlainText(),
             self._gpr_rx_geometry_input.toPlainText(),
@@ -193,7 +207,7 @@ class AppWindowGprPlotMixin:
 
     def _draw_gpr_map(self, collection: ResultCollection) -> bool:
         """Draw latest collection-level GPR plot according to current render mode."""
-        if self._gpr_render_mode.currentText() == "objects_only":
+        if self._gpr_render_mode_text() == "objects_only":
             return self._draw_gpr_objects_only(collection)
         return self._draw_gpr_heatmap(collection)
 
@@ -251,7 +265,8 @@ class AppWindowGprPlotMixin:
                 )
                 self._gpr_points_item.show()
                 for x_value, y_value, score in points:
-                    label = pg.TextItem(text=f"{float(score):.2f}", color="#ffffff", anchor=(0.0, 1.0))
+                    label_text = f"{float(score):.0f}" if self._processing_mode.currentText() == "legacy_gpr" else f"{float(score):.2f}"
+                    label = pg.TextItem(text=label_text, color="#ffffff", anchor=(0.0, 1.0))
                     label.setZValue(40)
                     label.setPos(float(x_value), float(y_value))
                     plot.addItem(label)
@@ -297,7 +312,7 @@ class AppWindowGprPlotMixin:
                 self._gpr_region_mask_items.append(mask_image)
                 self._gpr_region_contours.append(contour)
 
-            plot.setTitle("GPR coherent BP")
+            plot.setTitle(self._gpr_plot_title())
         finally:
             plot.setUpdatesEnabled(True)
         return True
@@ -315,14 +330,24 @@ class AppWindowGprPlotMixin:
 
     def _gpr_visible_bounds(self) -> tuple[float, float, float, float]:
         """Return normalized GPR visible X/Z bounds from GUI controls."""
+        if self._processing_mode.currentText() == "legacy_gpr":
+            x_min_widget = self._legacy_gpr_visible_x_min_m
+            x_max_widget = self._legacy_gpr_visible_x_max_m
+            z_min_widget = self._legacy_gpr_visible_z_min_m
+            z_max_widget = self._legacy_gpr_visible_z_max_m
+        else:
+            x_min_widget = self._gpr_visible_x_min_m
+            x_max_widget = self._gpr_visible_x_max_m
+            z_min_widget = self._gpr_visible_z_min_m
+            z_max_widget = self._gpr_visible_z_max_m
         x_min, x_max = self._normalized_display_range(
-            float(self._gpr_visible_x_min_m.value()),
-            float(self._gpr_visible_x_max_m.value()),
+            float(x_min_widget.value()),
+            float(x_max_widget.value()),
             minimum_span=0.1,
         )
         z_min, z_max = self._normalized_display_range(
-            float(self._gpr_visible_z_min_m.value()),
-            float(self._gpr_visible_z_max_m.value()),
+            float(z_min_widget.value()),
+            float(z_max_widget.value()),
             minimum_span=0.1,
         )
         return x_min, x_max, z_min, z_max
@@ -331,6 +356,18 @@ class AppWindowGprPlotMixin:
         """Return normalized object/locator visible X/Z bounds from GUI controls."""
         return self._gpr_visible_bounds()
 
+    def _gpr_render_mode_text(self) -> str:
+        """Return render mode for the active GPR-like processing mode."""
+        if self._processing_mode.currentText() == "legacy_gpr":
+            return self._legacy_gpr_render_mode.currentText()
+        return self._gpr_render_mode.currentText()
+
+    def _gpr_locator_threshold(self) -> float:
+        """Return object threshold using the active GPR mode's score semantics."""
+        if self._processing_mode.currentText() == "legacy_gpr":
+            return float(self._legacy_gpr_min_visible_pair_count.value())
+        return float(self._gpr_min_visible_score.value())
+
     @staticmethod
     def _gpr_display_y_min(z_min: float, z_max: float) -> float:
         """Return lower display bound, preserving surface markers only when surface is visible."""
@@ -372,9 +409,10 @@ class AppWindowGprPlotMixin:
             self._gpr_rx_item.setData(x=[], y=[])
             self._gpr_rx_item.hide()
 
-    @staticmethod
-    def _format_gpr_object_label(x_m: float, z_m: float, score: float) -> str:
+    def _format_gpr_object_label(self, x_m: float, z_m: float, score: float) -> str:
         """Format object-only annotation text with normalized BP score and coordinates."""
+        if self._processing_mode.currentText() == "legacy_gpr":
+            return f"{int(round(score))} | x={x_m:.1f} | z={z_m:.1f}"
         return f"{score:.2f} | x={x_m:.1f} | z={z_m:.1f}"
 
     @staticmethod
@@ -451,7 +489,7 @@ class AppWindowGprPlotMixin:
             return rows
 
         x_min, x_max, z_min, z_max = self._gpr_visible_object_bounds()
-        min_score = float(self._gpr_min_visible_score.value())
+        min_score = self._gpr_locator_threshold()
         finite_mask = np.all(np.isfinite(rows[:, :3]), axis=1)
         visible_mask = (
             finite_mask
@@ -527,7 +565,7 @@ class AppWindowGprPlotMixin:
 
             plot.setXRange(x_min, x_max, padding=0.0)
             plot.setYRange(self._gpr_display_y_min(z_min, z_max), z_max, padding=0.0)
-            plot.setTitle("GPR coherent BP Objects Only")
+            plot.setTitle(self._gpr_plot_title(objects_only=True))
         finally:
             plot.setUpdatesEnabled(True)
         return True
diff --git a/python_app/gui/controllers/app_window_plot/trace_plot_mixin.py b/python_app/gui/controllers/app_window_plot/trace_plot_mixin.py
index e359fde..80b1dd2 100644
--- a/python_app/gui/controllers/app_window_plot/trace_plot_mixin.py
+++ b/python_app/gui/controllers/app_window_plot/trace_plot_mixin.py
@@ -37,7 +37,7 @@ class AppWindowTracePlotMixin:
 
     def _on_trace_visibility_changed(self, *_args) -> None:
         """Redraw pass-through traces when magnitude/phase toggles changed."""
-        if self._processing_mode.currentText() in {"bscan", "gpr"}:
+        if self._processing_mode.currentText() in {"bscan", "gpr", "legacy_gpr"}:
             return
         if self._result_history:
             self._draw_results(self._result_history[-1])
diff --git a/python_app/gui/controllers/app_window_plot_mixin.py b/python_app/gui/controllers/app_window_plot_mixin.py
index 1f23ec1..5d89196 100644
--- a/python_app/gui/controllers/app_window_plot_mixin.py
+++ b/python_app/gui/controllers/app_window_plot_mixin.py
@@ -31,7 +31,7 @@ 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":
+        if self._processing_mode.currentText() in {"gpr", "legacy_gpr"}:
             return self._draw_gpr_map(collection)
         return self._draw_trace_lines(collection)
 
diff --git a/python_app/gui/controllers/app_window_ui_mixin.py b/python_app/gui/controllers/app_window_ui_mixin.py
index 80d0fa8..c5d81bd 100644
--- a/python_app/gui/controllers/app_window_ui_mixin.py
+++ b/python_app/gui/controllers/app_window_ui_mixin.py
@@ -265,13 +265,13 @@ class AppWindowUiMixin:
         """Switch visible plot page according to processing mode.
 
         `bscan`   -> show `self._bscan_plot`
-        `gpr`     -> show `self._gpr_plot`
+        `gpr` and `legacy_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":
+        if mode in {"gpr", "legacy_gpr"}:
             self._plot_stack.setCurrentWidget(self._gpr_plot)
             return
         self._plot_stack.setCurrentWidget(self._trace_plots_container)
diff --git a/python_app/gui/controllers/sections/processing_section.py b/python_app/gui/controllers/sections/processing_section.py
index 86f41d9..7d44ad7 100644
--- a/python_app/gui/controllers/sections/processing_section.py
+++ b/python_app/gui/controllers/sections/processing_section.py
@@ -56,9 +56,10 @@ def build_processing_group(owner) -> QGroupBox:
     pass_defaults = processing_defaults.pass_through
     bscan_defaults = processing_defaults.bscan
     gpr_live_defaults = processing_defaults.gpr
+    legacy_gpr_defaults = processing_defaults.legacy_gpr
 
     owner._processing_mode = QComboBox()
-    owner._processing_mode.addItems(["pass_through", "bscan", "gpr"])
+    owner._processing_mode.addItems(["pass_through", "bscan", "gpr", "legacy_gpr"])
     owner._set_combo_current_text(owner._processing_mode, processing_defaults.selected_mode)
 
     owner._processing_mode_pages = QStackedWidget(group)
@@ -154,10 +155,6 @@ def build_processing_group(owner) -> QGroupBox:
 
     gpr_defaults = owner._defaults_config.gpr
 
-    owner._gpr_algorithm = QComboBox()
-    owner._gpr_algorithm.addItems(["backprojection", "legacy_point", "legacy_extended"])
-    owner._set_combo_current_text(owner._gpr_algorithm, gpr_live_defaults.algorithm)
-
     owner._gpr_relative_permittivity = QDoubleSpinBox()
     owner._gpr_relative_permittivity.setDecimals(4)
     owner._gpr_relative_permittivity.setRange(0.0001, 1000.0)
@@ -172,6 +169,16 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_rx_geometry_input.setPlaceholderText("input_pos x_m")
     owner._gpr_rx_geometry_input.setFixedHeight(78)
 
+    owner._gpr_common_page = _build_processing_mode_page(
+        group,
+        [
+            ("Relative permittivity", owner._gpr_relative_permittivity),
+            ("Tx geometry", owner._gpr_tx_geometry_input),
+            ("Rx geometry", owner._gpr_rx_geometry_input),
+        ],
+        split_index=1,
+    )
+
     owner._gpr_input_positions_input = QLineEdit(str(gpr_live_defaults.input_positions))
     owner._gpr_input_positions_input.setPlaceholderText("0,1,2")
 
@@ -202,36 +209,6 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_angle_comp_power.setSingleStep(0.01)
     owner._gpr_angle_comp_power.setValue(float(gpr_live_defaults.angle_comp_power))
 
-    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(float(gpr_live_defaults.comp_power))
-
-    owner._gpr_speed_m_s = QDoubleSpinBox()
-    owner._gpr_speed_m_s.setDecimals(3)
-    owner._gpr_speed_m_s.setRange(-100.0, 100.0)
-    owner._gpr_speed_m_s.setSingleStep(0.01)
-    owner._gpr_speed_m_s.setValue(float(gpr_live_defaults.speed_m_s))
-
-    owner._gpr_look_angle_deg = QDoubleSpinBox()
-    owner._gpr_look_angle_deg.setDecimals(2)
-    owner._gpr_look_angle_deg.setRange(-90.0, 90.0)
-    owner._gpr_look_angle_deg.setSingleStep(0.1)
-    owner._gpr_look_angle_deg.setValue(float(gpr_live_defaults.look_angle_deg))
-
-    owner._gpr_snr_thresh = QDoubleSpinBox()
-    owner._gpr_snr_thresh.setDecimals(2)
-    owner._gpr_snr_thresh.setRange(0.0, 1_000.0)
-    owner._gpr_snr_thresh.setSingleStep(0.1)
-    owner._gpr_snr_thresh.setValue(float(gpr_live_defaults.snr_thresh))
-
-    owner._gpr_snr_comp_max = QDoubleSpinBox()
-    owner._gpr_snr_comp_max.setDecimals(2)
-    owner._gpr_snr_comp_max.setRange(0.0, 1_000.0)
-    owner._gpr_snr_comp_max.setSingleStep(0.5)
-    owner._gpr_snr_comp_max.setValue(float(gpr_live_defaults.snr_comp_max))
-
     owner._gpr_start_freq_mhz = QDoubleSpinBox()
     owner._gpr_start_freq_mhz.setDecimals(1)
     owner._gpr_start_freq_mhz.setRange(100.0, 8800.0)
@@ -254,8 +231,6 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_remove_sidelobe_objects_enabled = QCheckBox("Remove sidelobe objects")
     owner._gpr_remove_sidelobe_objects_enabled.setChecked(bool(gpr_live_defaults.remove_sidelobe_objects_enabled))
 
-    owner._sync_gpr_algorithm_controls()
-
     owner._gpr_render_mode = QComboBox()
     owner._gpr_render_mode.addItems(["heatmap", "objects_only"])
     owner._set_combo_current_text(owner._gpr_render_mode, gpr_live_defaults.render_mode)
@@ -293,25 +268,16 @@ def build_processing_group(owner) -> QGroupBox:
     gpr_page = _build_processing_mode_page(
         owner._processing_mode_pages,
         [
-            ("Algorithm", owner._gpr_algorithm),
-            ("Relative permittivity", owner._gpr_relative_permittivity),
             ("Input positions", owner._gpr_input_positions_input),
             ("Output positions", owner._gpr_output_positions_input),
             ("Min depth m", owner._gpr_min_depth_m),
             ("Max depth m", owner._gpr_max_depth_m),
             ("Range comp power", owner._gpr_range_comp_power),
             ("Angle comp power", owner._gpr_angle_comp_power),
-            ("Comp power", owner._gpr_comp_power),
-            ("SNR thresh", owner._gpr_snr_thresh),
-            ("SNR comp max", owner._gpr_snr_comp_max),
             ("Render mode", owner._gpr_render_mode),
             ("Min visible score", owner._gpr_min_visible_score),
-            ("Tx geometry", owner._gpr_tx_geometry_input),
-            ("Rx geometry", owner._gpr_rx_geometry_input),
             ("Start MHz", owner._gpr_start_freq_mhz),
             ("Stop MHz", owner._gpr_stop_freq_mhz),
-            ("Speed m/s", owner._gpr_speed_m_s),
-            ("Look angle deg", owner._gpr_look_angle_deg),
             ("Visible X min m", owner._gpr_visible_x_min_m),
             ("Visible X max m", owner._gpr_visible_x_max_m),
             ("Visible Z min m", owner._gpr_visible_z_min_m),
@@ -320,10 +286,141 @@ def build_processing_group(owner) -> QGroupBox:
             ("Mean count", owner._gpr_background_mean_count),
             owner._gpr_remove_sidelobe_objects_enabled,
         ],
-        split_index=12,
+        split_index=8,
     )
     owner._processing_mode_pages.addWidget(gpr_page)
 
+    owner._legacy_gpr_config_mode = QComboBox()
+    owner._legacy_gpr_config_mode.addItems(["point", "extended"])
+    owner._set_combo_current_text(owner._legacy_gpr_config_mode, legacy_gpr_defaults.mode)
+
+    owner._legacy_gpr_input_positions_input = QLineEdit(str(legacy_gpr_defaults.input_positions))
+    owner._legacy_gpr_input_positions_input.setPlaceholderText("0,1,2")
+
+    owner._legacy_gpr_output_positions_input = QLineEdit(str(legacy_gpr_defaults.output_positions))
+    owner._legacy_gpr_output_positions_input.setPlaceholderText("0,1")
+
+    owner._legacy_gpr_min_depth_m = QDoubleSpinBox()
+    owner._legacy_gpr_min_depth_m.setDecimals(2)
+    owner._legacy_gpr_min_depth_m.setRange(0.0, 50.0)
+    owner._legacy_gpr_min_depth_m.setSingleStep(0.1)
+    owner._legacy_gpr_min_depth_m.setValue(float(legacy_gpr_defaults.min_depth_m))
+
+    owner._legacy_gpr_max_depth_m = QDoubleSpinBox()
+    owner._legacy_gpr_max_depth_m.setDecimals(2)
+    owner._legacy_gpr_max_depth_m.setRange(0.1, 50.0)
+    owner._legacy_gpr_max_depth_m.setSingleStep(0.1)
+    owner._legacy_gpr_max_depth_m.setValue(float(legacy_gpr_defaults.max_depth_m))
+
+    owner._legacy_gpr_comp_power = QDoubleSpinBox()
+    owner._legacy_gpr_comp_power.setDecimals(3)
+    owner._legacy_gpr_comp_power.setRange(0.0, 5.0)
+    owner._legacy_gpr_comp_power.setSingleStep(0.05)
+    owner._legacy_gpr_comp_power.setValue(float(legacy_gpr_defaults.comp_power))
+
+    owner._legacy_gpr_snr_thresh = QDoubleSpinBox()
+    owner._legacy_gpr_snr_thresh.setDecimals(2)
+    owner._legacy_gpr_snr_thresh.setRange(0.0, 1_000.0)
+    owner._legacy_gpr_snr_thresh.setSingleStep(0.1)
+    owner._legacy_gpr_snr_thresh.setValue(float(legacy_gpr_defaults.snr_thresh))
+
+    owner._legacy_gpr_snr_comp_max = QDoubleSpinBox()
+    owner._legacy_gpr_snr_comp_max.setDecimals(2)
+    owner._legacy_gpr_snr_comp_max.setRange(0.0, 1_000.0)
+    owner._legacy_gpr_snr_comp_max.setSingleStep(0.5)
+    owner._legacy_gpr_snr_comp_max.setValue(float(legacy_gpr_defaults.snr_comp_max))
+
+    owner._legacy_gpr_start_freq_mhz = QDoubleSpinBox()
+    owner._legacy_gpr_start_freq_mhz.setDecimals(1)
+    owner._legacy_gpr_start_freq_mhz.setRange(100.0, 8800.0)
+    owner._legacy_gpr_start_freq_mhz.setSingleStep(10.0)
+    owner._legacy_gpr_start_freq_mhz.setValue(float(legacy_gpr_defaults.start_freq_mhz))
+
+    owner._legacy_gpr_stop_freq_mhz = QDoubleSpinBox()
+    owner._legacy_gpr_stop_freq_mhz.setDecimals(1)
+    owner._legacy_gpr_stop_freq_mhz.setRange(100.0, 8800.0)
+    owner._legacy_gpr_stop_freq_mhz.setSingleStep(10.0)
+    owner._legacy_gpr_stop_freq_mhz.setValue(float(legacy_gpr_defaults.stop_freq_mhz))
+
+    owner._legacy_gpr_speed_m_s = QDoubleSpinBox()
+    owner._legacy_gpr_speed_m_s.setDecimals(3)
+    owner._legacy_gpr_speed_m_s.setRange(-100.0, 100.0)
+    owner._legacy_gpr_speed_m_s.setSingleStep(0.01)
+    owner._legacy_gpr_speed_m_s.setValue(float(legacy_gpr_defaults.speed_m_s))
+
+    owner._legacy_gpr_look_angle_deg = QDoubleSpinBox()
+    owner._legacy_gpr_look_angle_deg.setDecimals(2)
+    owner._legacy_gpr_look_angle_deg.setRange(-90.0, 90.0)
+    owner._legacy_gpr_look_angle_deg.setSingleStep(0.1)
+    owner._legacy_gpr_look_angle_deg.setValue(float(legacy_gpr_defaults.look_angle_deg))
+
+    owner._legacy_gpr_background_subtract_enabled = QCheckBox("Subtract mean of previous collections")
+    owner._legacy_gpr_background_subtract_enabled.setChecked(bool(legacy_gpr_defaults.background_subtract_enabled))
+
+    owner._legacy_gpr_background_mean_count = QSpinBox()
+    owner._legacy_gpr_background_mean_count.setRange(0, 10_000)
+    owner._legacy_gpr_background_mean_count.setValue(int(legacy_gpr_defaults.background_mean_count))
+
+    owner._legacy_gpr_render_mode = QComboBox()
+    owner._legacy_gpr_render_mode.addItems(["heatmap", "objects_only"])
+    owner._set_combo_current_text(owner._legacy_gpr_render_mode, legacy_gpr_defaults.render_mode)
+
+    owner._legacy_gpr_min_visible_pair_count = QSpinBox()
+    owner._legacy_gpr_min_visible_pair_count.setRange(1, 10_000)
+    owner._legacy_gpr_min_visible_pair_count.setValue(int(legacy_gpr_defaults.min_visible_pair_count))
+
+    owner._legacy_gpr_visible_x_min_m = QDoubleSpinBox()
+    owner._legacy_gpr_visible_x_min_m.setDecimals(2)
+    owner._legacy_gpr_visible_x_min_m.setRange(-100.0, 100.0)
+    owner._legacy_gpr_visible_x_min_m.setSingleStep(0.1)
+    owner._legacy_gpr_visible_x_min_m.setValue(float(legacy_gpr_defaults.visible_x_min_m))
+
+    owner._legacy_gpr_visible_x_max_m = QDoubleSpinBox()
+    owner._legacy_gpr_visible_x_max_m.setDecimals(2)
+    owner._legacy_gpr_visible_x_max_m.setRange(-100.0, 100.0)
+    owner._legacy_gpr_visible_x_max_m.setSingleStep(0.1)
+    owner._legacy_gpr_visible_x_max_m.setValue(float(legacy_gpr_defaults.visible_x_max_m))
+
+    owner._legacy_gpr_visible_z_min_m = QDoubleSpinBox()
+    owner._legacy_gpr_visible_z_min_m.setDecimals(2)
+    owner._legacy_gpr_visible_z_min_m.setRange(0.0, 100.0)
+    owner._legacy_gpr_visible_z_min_m.setSingleStep(0.1)
+    owner._legacy_gpr_visible_z_min_m.setValue(float(legacy_gpr_defaults.visible_z_min_m))
+
+    owner._legacy_gpr_visible_z_max_m = QDoubleSpinBox()
+    owner._legacy_gpr_visible_z_max_m.setDecimals(2)
+    owner._legacy_gpr_visible_z_max_m.setRange(0.0, 100.0)
+    owner._legacy_gpr_visible_z_max_m.setSingleStep(0.1)
+    owner._legacy_gpr_visible_z_max_m.setValue(float(legacy_gpr_defaults.visible_z_max_m))
+
+    legacy_gpr_page = _build_processing_mode_page(
+        owner._processing_mode_pages,
+        [
+            ("Config mode", owner._legacy_gpr_config_mode),
+            ("Input positions", owner._legacy_gpr_input_positions_input),
+            ("Output positions", owner._legacy_gpr_output_positions_input),
+            ("Min depth m", owner._legacy_gpr_min_depth_m),
+            ("Max depth m", owner._legacy_gpr_max_depth_m),
+            ("Comp power", owner._legacy_gpr_comp_power),
+            ("SNR thresh", owner._legacy_gpr_snr_thresh),
+            ("SNR comp max", owner._legacy_gpr_snr_comp_max),
+            ("Speed m/s", owner._legacy_gpr_speed_m_s),
+            ("Render mode", owner._legacy_gpr_render_mode),
+            ("Min visible pairs", owner._legacy_gpr_min_visible_pair_count),
+            ("Start MHz", owner._legacy_gpr_start_freq_mhz),
+            ("Stop MHz", owner._legacy_gpr_stop_freq_mhz),
+            ("Look angle deg", owner._legacy_gpr_look_angle_deg),
+            ("Visible X min m", owner._legacy_gpr_visible_x_min_m),
+            ("Visible X max m", owner._legacy_gpr_visible_x_max_m),
+            ("Visible Z min m", owner._legacy_gpr_visible_z_min_m),
+            ("Visible Z max m", owner._legacy_gpr_visible_z_max_m),
+            owner._legacy_gpr_background_subtract_enabled,
+            ("Mean count", owner._legacy_gpr_background_mean_count),
+        ],
+        split_index=10,
+    )
+    owner._processing_mode_pages.addWidget(legacy_gpr_page)
+
     owner._processing_mode.currentTextChanged.connect(owner._on_processing_mode_changed)
     owner._show_magnitude_checkbox.toggled.connect(owner._on_trace_visibility_changed)
     owner._show_phase_checkbox.toggled.connect(owner._on_trace_visibility_changed)
@@ -333,6 +430,7 @@ def build_processing_group(owner) -> QGroupBox:
     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)
+    form.addRow(owner._gpr_common_page)
 
     owner._bscan_axis.currentTextChanged.connect(owner._on_processing_live_settings_changed)
     owner._bscan_cut_m.valueChanged.connect(owner._on_processing_live_settings_changed)
@@ -341,19 +439,12 @@ def build_processing_group(owner) -> QGroupBox:
     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._bscan_subtract_mean_ascan.toggled.connect(owner._on_processing_live_settings_changed)
-    owner._gpr_algorithm.currentTextChanged.connect(owner._sync_gpr_algorithm_controls)
-    owner._gpr_algorithm.currentTextChanged.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_range_comp_power.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._gpr_angle_comp_power.valueChanged.connect(owner._on_processing_live_settings_changed)
-    owner._gpr_comp_power.valueChanged.connect(owner._on_processing_live_settings_changed)
-    owner._gpr_speed_m_s.valueChanged.connect(owner._on_processing_live_settings_changed)
-    owner._gpr_look_angle_deg.valueChanged.connect(owner._on_processing_live_settings_changed)
-    owner._gpr_snr_thresh.valueChanged.connect(owner._on_processing_live_settings_changed)
-    owner._gpr_snr_comp_max.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)
@@ -365,6 +456,26 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_visible_x_max_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
     owner._gpr_visible_z_min_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
     owner._gpr_visible_z_max_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
+    owner._legacy_gpr_config_mode.currentTextChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_input_positions_input.editingFinished.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_output_positions_input.editingFinished.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_min_depth_m.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_max_depth_m.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_comp_power.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_snr_thresh.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_snr_comp_max.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_start_freq_mhz.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_stop_freq_mhz.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_speed_m_s.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_look_angle_deg.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_background_subtract_enabled.toggled.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_background_mean_count.valueChanged.connect(owner._on_processing_live_settings_changed)
+    owner._legacy_gpr_render_mode.currentTextChanged.connect(owner._on_gpr_visual_settings_changed)
+    owner._legacy_gpr_min_visible_pair_count.valueChanged.connect(owner._on_gpr_locator_threshold_changed)
+    owner._legacy_gpr_visible_x_min_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
+    owner._legacy_gpr_visible_x_max_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
+    owner._legacy_gpr_visible_z_min_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
+    owner._legacy_gpr_visible_z_max_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
 
     owner._set_processing_mode_page(owner._processing_mode.currentText())
     return group
diff --git a/python_app/gui/runtime/constraints.py b/python_app/gui/runtime/constraints.py
index 9eb3a4e..6f8225e 100644
--- a/python_app/gui/runtime/constraints.py
+++ b/python_app/gui/runtime/constraints.py
@@ -24,7 +24,7 @@ def validate_processing_mode_constraints(
             )
         return
 
-    if processing_mode != "gpr":
+    if processing_mode not in {"gpr", "legacy_gpr"}:
         return
 
     configured_combos = {(int(combo.input), int(combo.output)) for combo in config.combos}
diff --git a/python_app/models/gui_profile_codec.py b/python_app/models/gui_profile_codec.py
index ce24f5f..e462a2b 100644
--- a/python_app/models/gui_profile_codec.py
+++ b/python_app/models/gui_profile_codec.py
@@ -8,6 +8,7 @@ from python_app.models.gui_profile_schema import (
     GuiBscanStateModel,
     GuiDataActionsStateModel,
     GuiGprStateModel,
+    GuiLegacyGprStateModel,
     GuiPassThroughStateModel,
     GuiPreprocessDialogStateModel,
     GuiProcessingStateModel,
@@ -59,6 +60,15 @@ def _optional_float(object_payload: dict[str, Any], key: str, fallback: float, c
     return float(raw_value)
 
 
+def _legacy_gpr_mode_from_algorithm(value: str) -> str | None:
+    """Translate the short-lived nested GPR algorithm field into legacy mode."""
+    if value == "legacy_point":
+        return "point"
+    if value == "legacy_extended":
+        return "extended"
+    return None
+
+
 def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
     """Decode JSON-like payload into :class:`GuiProfileModel`."""
     profile = GuiProfileModel(run_config=RunConfigModel.from_dict(payload), gui=None)
@@ -91,20 +101,72 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
     pass_through_object = _as_dict(processing_object.get("pass_through"), "gui.processing.pass_through")
     bscan_object = _as_dict(processing_object.get("bscan"), "gui.processing.bscan")
     gpr_object = _as_dict(processing_object.get("gpr"), "gui.processing.gpr")
+    legacy_gpr_object = _as_dict(processing_object.get("legacy_gpr"), "gui.processing.legacy_gpr")
     root_gpr_object = payload.get("gpr")
-    gpr_algorithm_default = gui.processing.gpr.algorithm
+
+    selected_mode = _optional_string(
+        processing_object,
+        "selected_mode",
+        gui.processing.selected_mode,
+        "gui.processing",
+    )
+    legacy_mode_default = gui.processing.legacy_gpr.mode
     if isinstance(root_gpr_object, dict):
         if root_gpr_object.get("mode") == "point":
-            gpr_algorithm_default = "legacy_point"
+            legacy_mode_default = "point"
         elif root_gpr_object.get("mode") == "extended":
-            gpr_algorithm_default = "legacy_extended"
+            legacy_mode_default = "extended"
+    legacy_algorithm_mode = _legacy_gpr_mode_from_algorithm(str(gpr_object.get("algorithm", "")))
+    if legacy_algorithm_mode is not None:
+        legacy_mode_default = legacy_algorithm_mode
+    has_legacy_root_gpr_mode = (
+        isinstance(root_gpr_object, dict)
+        and root_gpr_object.get("mode") in {"point", "extended"}
+    )
+    if selected_mode == "gpr" and (legacy_algorithm_mode is not None or has_legacy_root_gpr_mode):
+        selected_mode = "legacy_gpr"
+
+    gpr_context = "gui.processing.gpr"
+    legacy_gpr_context = "gui.processing.legacy_gpr"
+
+    def legacy_string(key: str, fallback: str) -> str:
+        """Read a legacy field, falling back to the old nested gpr object."""
+        return _optional_string(
+            legacy_gpr_object,
+            key,
+            _optional_string(gpr_object, key, fallback, gpr_context),
+            legacy_gpr_context,
+        )
+
+    def legacy_bool(key: str, fallback: bool) -> bool:
+        """Read a legacy bool, falling back to the old nested gpr object."""
+        return _optional_bool(
+            legacy_gpr_object,
+            key,
+            _optional_bool(gpr_object, key, fallback, gpr_context),
+            legacy_gpr_context,
+        )
+
+    def legacy_int(key: str, fallback: int) -> int:
+        """Read a legacy integer, falling back to the old nested gpr object."""
+        return _optional_int(
+            legacy_gpr_object,
+            key,
+            _optional_int(gpr_object, key, fallback, gpr_context),
+            legacy_gpr_context,
+        )
+
+    def legacy_float(key: str, fallback: float) -> float:
+        """Read a legacy float, falling back to the old nested gpr object."""
+        return _optional_float(
+            legacy_gpr_object,
+            key,
+            _optional_float(gpr_object, key, fallback, gpr_context),
+            legacy_gpr_context,
+        )
+
     gui.processing = GuiProcessingStateModel(
-        selected_mode=_optional_string(
-            processing_object,
-            "selected_mode",
-            gui.processing.selected_mode,
-            "gui.processing",
-        ),
+        selected_mode=selected_mode,
         pass_through=GuiPassThroughStateModel(
             show_magnitude=_optional_bool(
                 pass_through_object,
@@ -167,12 +229,6 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
             ),
         ),
         gpr=GuiGprStateModel(
-            algorithm=_optional_string(
-                gpr_object,
-                "algorithm",
-                gpr_algorithm_default,
-                "gui.processing.gpr",
-            ),
             input_positions=_optional_string(
                 gpr_object,
                 "input_positions",
@@ -209,36 +265,6 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
                 gui.processing.gpr.angle_comp_power,
                 "gui.processing.gpr",
             ),
-            comp_power=_optional_float(
-                gpr_object,
-                "comp_power",
-                gui.processing.gpr.comp_power,
-                "gui.processing.gpr",
-            ),
-            speed_m_s=_optional_float(
-                gpr_object,
-                "speed_m_s",
-                gui.processing.gpr.speed_m_s,
-                "gui.processing.gpr",
-            ),
-            look_angle_deg=_optional_float(
-                gpr_object,
-                "look_angle_deg",
-                gui.processing.gpr.look_angle_deg,
-                "gui.processing.gpr",
-            ),
-            snr_thresh=_optional_float(
-                gpr_object,
-                "snr_thresh",
-                gui.processing.gpr.snr_thresh,
-                "gui.processing.gpr",
-            ),
-            snr_comp_max=_optional_float(
-                gpr_object,
-                "snr_comp_max",
-                gui.processing.gpr.snr_comp_max,
-                "gui.processing.gpr",
-            ),
             start_freq_mhz=_optional_float(
                 gpr_object,
                 "start_freq_mhz",
@@ -306,27 +332,62 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
                 "gui.processing.gpr",
             ),
         ),
+        legacy_gpr=GuiLegacyGprStateModel(
+            mode=legacy_string("mode", legacy_mode_default),
+            input_positions=legacy_string("input_positions", gui.processing.legacy_gpr.input_positions),
+            output_positions=legacy_string("output_positions", gui.processing.legacy_gpr.output_positions),
+            min_depth_m=legacy_float("min_depth_m", gui.processing.legacy_gpr.min_depth_m),
+            max_depth_m=legacy_float("max_depth_m", gui.processing.legacy_gpr.max_depth_m),
+            comp_power=legacy_float("comp_power", gui.processing.legacy_gpr.comp_power),
+            start_freq_mhz=legacy_float("start_freq_mhz", gui.processing.legacy_gpr.start_freq_mhz),
+            stop_freq_mhz=legacy_float("stop_freq_mhz", gui.processing.legacy_gpr.stop_freq_mhz),
+            speed_m_s=legacy_float("speed_m_s", gui.processing.legacy_gpr.speed_m_s),
+            look_angle_deg=legacy_float("look_angle_deg", gui.processing.legacy_gpr.look_angle_deg),
+            snr_thresh=legacy_float("snr_thresh", gui.processing.legacy_gpr.snr_thresh),
+            snr_comp_max=legacy_float("snr_comp_max", gui.processing.legacy_gpr.snr_comp_max),
+            background_subtract_enabled=legacy_bool(
+                "background_subtract_enabled",
+                gui.processing.legacy_gpr.background_subtract_enabled,
+            ),
+            background_mean_count=legacy_int(
+                "background_mean_count",
+                gui.processing.legacy_gpr.background_mean_count,
+            ),
+            render_mode=legacy_string("render_mode", gui.processing.legacy_gpr.render_mode),
+            min_visible_pair_count=legacy_int(
+                "min_visible_pair_count",
+                gui.processing.legacy_gpr.min_visible_pair_count,
+            ),
+            visible_x_min_m=legacy_float("visible_x_min_m", gui.processing.legacy_gpr.visible_x_min_m),
+            visible_x_max_m=legacy_float("visible_x_max_m", gui.processing.legacy_gpr.visible_x_max_m),
+            visible_z_min_m=legacy_float("visible_z_min_m", gui.processing.legacy_gpr.visible_z_min_m),
+            visible_z_max_m=legacy_float("visible_z_max_m", gui.processing.legacy_gpr.visible_z_max_m),
+        ),
     )
-    if gui.processing.selected_mode not in {"pass_through", "bscan", "gpr"}:
-        raise ValueError("gui.processing.selected_mode must be one of: pass_through, bscan, gpr")
+    if gui.processing.selected_mode not in {"pass_through", "bscan", "gpr", "legacy_gpr"}:
+        raise ValueError("gui.processing.selected_mode must be one of: pass_through, bscan, gpr, legacy_gpr")
     if gui.processing.bscan.axis not in {"abs", "real", "phase"}:
         raise ValueError("gui.processing.bscan.axis must be one of: abs, real, phase")
-    if gui.processing.gpr.algorithm not in {"backprojection", "legacy_point", "legacy_extended"}:
-        raise ValueError("gui.processing.gpr.algorithm must be one of: backprojection, legacy_point, legacy_extended")
     if gui.processing.gpr.render_mode not in {"heatmap", "objects_only"}:
         raise ValueError("gui.processing.gpr.render_mode must be one of: heatmap, objects_only")
+    if gui.processing.legacy_gpr.mode not in {"point", "extended"}:
+        raise ValueError("gui.processing.legacy_gpr.mode must be one of: point, extended")
+    if gui.processing.legacy_gpr.render_mode not in {"heatmap", "objects_only"}:
+        raise ValueError("gui.processing.legacy_gpr.render_mode must be one of: heatmap, objects_only")
     if gui.processing.gpr.range_comp_power < 0.0:
         raise ValueError("gui.processing.gpr.range_comp_power must be >= 0")
     if gui.processing.gpr.angle_comp_power < 0.0:
         raise ValueError("gui.processing.gpr.angle_comp_power must be >= 0")
-    if gui.processing.gpr.comp_power < 0.0:
-        raise ValueError("gui.processing.gpr.comp_power must be >= 0")
-    if gui.processing.gpr.snr_thresh < 0.0:
-        raise ValueError("gui.processing.gpr.snr_thresh must be >= 0")
-    if gui.processing.gpr.snr_comp_max < 0.0:
-        raise ValueError("gui.processing.gpr.snr_comp_max must be >= 0")
     if gui.processing.gpr.min_visible_score < 0.0:
         raise ValueError("gui.processing.gpr.min_visible_score must be >= 0")
+    if gui.processing.legacy_gpr.comp_power < 0.0:
+        raise ValueError("gui.processing.legacy_gpr.comp_power must be >= 0")
+    if gui.processing.legacy_gpr.snr_thresh < 0.0:
+        raise ValueError("gui.processing.legacy_gpr.snr_thresh must be >= 0")
+    if gui.processing.legacy_gpr.snr_comp_max < 0.0:
+        raise ValueError("gui.processing.legacy_gpr.snr_comp_max must be >= 0")
+    if gui.processing.legacy_gpr.min_visible_pair_count < 1:
+        raise ValueError("gui.processing.legacy_gpr.min_visible_pair_count must be >= 1")
 
     data_actions_object = _as_dict(gui_object.get("data_actions"), "gui.data_actions")
     gui.data_actions = GuiDataActionsStateModel(
@@ -407,18 +468,12 @@ def gui_profile_to_dict(model: GuiProfileModel) -> dict[str, Any]:
                 "subtract_mean_ascan": gui.processing.bscan.subtract_mean_ascan,
             },
             "gpr": {
-                "algorithm": gui.processing.gpr.algorithm,
                 "input_positions": gui.processing.gpr.input_positions,
                 "output_positions": gui.processing.gpr.output_positions,
                 "min_depth_m": gui.processing.gpr.min_depth_m,
                 "max_depth_m": gui.processing.gpr.max_depth_m,
                 "range_comp_power": gui.processing.gpr.range_comp_power,
                 "angle_comp_power": gui.processing.gpr.angle_comp_power,
-                "comp_power": gui.processing.gpr.comp_power,
-                "speed_m_s": gui.processing.gpr.speed_m_s,
-                "look_angle_deg": gui.processing.gpr.look_angle_deg,
-                "snr_thresh": gui.processing.gpr.snr_thresh,
-                "snr_comp_max": gui.processing.gpr.snr_comp_max,
                 "start_freq_mhz": gui.processing.gpr.start_freq_mhz,
                 "stop_freq_mhz": gui.processing.gpr.stop_freq_mhz,
                 "background_subtract_enabled": gui.processing.gpr.background_subtract_enabled,
@@ -431,6 +486,28 @@ def gui_profile_to_dict(model: GuiProfileModel) -> dict[str, Any]:
                 "visible_z_min_m": gui.processing.gpr.visible_z_min_m,
                 "visible_z_max_m": gui.processing.gpr.visible_z_max_m,
             },
+            "legacy_gpr": {
+                "mode": gui.processing.legacy_gpr.mode,
+                "input_positions": gui.processing.legacy_gpr.input_positions,
+                "output_positions": gui.processing.legacy_gpr.output_positions,
+                "min_depth_m": gui.processing.legacy_gpr.min_depth_m,
+                "max_depth_m": gui.processing.legacy_gpr.max_depth_m,
+                "comp_power": gui.processing.legacy_gpr.comp_power,
+                "start_freq_mhz": gui.processing.legacy_gpr.start_freq_mhz,
+                "stop_freq_mhz": gui.processing.legacy_gpr.stop_freq_mhz,
+                "speed_m_s": gui.processing.legacy_gpr.speed_m_s,
+                "look_angle_deg": gui.processing.legacy_gpr.look_angle_deg,
+                "snr_thresh": gui.processing.legacy_gpr.snr_thresh,
+                "snr_comp_max": gui.processing.legacy_gpr.snr_comp_max,
+                "background_subtract_enabled": gui.processing.legacy_gpr.background_subtract_enabled,
+                "background_mean_count": gui.processing.legacy_gpr.background_mean_count,
+                "render_mode": gui.processing.legacy_gpr.render_mode,
+                "min_visible_pair_count": gui.processing.legacy_gpr.min_visible_pair_count,
+                "visible_x_min_m": gui.processing.legacy_gpr.visible_x_min_m,
+                "visible_x_max_m": gui.processing.legacy_gpr.visible_x_max_m,
+                "visible_z_min_m": gui.processing.legacy_gpr.visible_z_min_m,
+                "visible_z_max_m": gui.processing.legacy_gpr.visible_z_max_m,
+            },
         },
         "data_actions": {
             "save_count": gui.data_actions.save_count,
diff --git a/python_app/models/gui_profile_model.py b/python_app/models/gui_profile_model.py
index 5dbcb44..bbb4d3a 100644
--- a/python_app/models/gui_profile_model.py
+++ b/python_app/models/gui_profile_model.py
@@ -5,6 +5,7 @@ from python_app.models.gui_profile_schema import (
     GuiBscanStateModel,
     GuiDataActionsStateModel,
     GuiGprStateModel,
+    GuiLegacyGprStateModel,
     GuiPassThroughStateModel,
     GuiPreprocessDialogStateModel,
     GuiProcessingStateModel,
@@ -17,6 +18,7 @@ __all__ = [
     "GuiBscanStateModel",
     "GuiDataActionsStateModel",
     "GuiGprStateModel",
+    "GuiLegacyGprStateModel",
     "GuiPassThroughStateModel",
     "GuiPreprocessDialogStateModel",
     "GuiProcessingStateModel",
diff --git a/python_app/models/gui_profile_schema.py b/python_app/models/gui_profile_schema.py
index c9e4db7..b7d1ae0 100644
--- a/python_app/models/gui_profile_schema.py
+++ b/python_app/models/gui_profile_schema.py
@@ -47,20 +47,14 @@ class GuiBscanStateModel:
 
 @dataclass(slots=True)
 class GuiGprStateModel:
-    """UI-only defaults for GPR live settings."""
+    """UI-only defaults for coherent backprojection GPR live settings."""
 
-    algorithm: str = "backprojection"
     input_positions: str = ""
     output_positions: str = ""
     min_depth_m: float = 2.0
     max_depth_m: float = 14.0
     range_comp_power: float = 0.28
     angle_comp_power: float = 0.10
-    comp_power: float = 0.2
-    speed_m_s: float = 0.0
-    look_angle_deg: float = 0.0
-    snr_thresh: float = 4.5
-    snr_comp_max: float = 25.0
     start_freq_mhz: float = 3000.0
     stop_freq_mhz: float = 6000.0
     background_subtract_enabled: bool = True
@@ -74,6 +68,32 @@ class GuiGprStateModel:
     visible_z_max_m: float = 14.0
 
 
+@dataclass(slots=True)
+class GuiLegacyGprStateModel:
+    """UI-only defaults for legacy point/extended GPR live settings."""
+
+    mode: str = "point"
+    input_positions: str = ""
+    output_positions: str = ""
+    min_depth_m: float = 2.0
+    max_depth_m: float = 14.0
+    comp_power: float = 0.2
+    start_freq_mhz: float = 3000.0
+    stop_freq_mhz: float = 6000.0
+    speed_m_s: float = 0.0
+    look_angle_deg: float = 0.0
+    snr_thresh: float = 4.5
+    snr_comp_max: float = 25.0
+    background_subtract_enabled: bool = True
+    background_mean_count: int = 10
+    render_mode: str = "heatmap"
+    min_visible_pair_count: int = 1
+    visible_x_min_m: float = -2.0
+    visible_x_max_m: float = 2.0
+    visible_z_min_m: float = 0.0
+    visible_z_max_m: float = 14.0
+
+
 @dataclass(slots=True)
 class GuiProcessingStateModel:
     """UI-only processing-section defaults."""
@@ -82,6 +102,7 @@ class GuiProcessingStateModel:
     pass_through: GuiPassThroughStateModel = field(default_factory=GuiPassThroughStateModel)
     bscan: GuiBscanStateModel = field(default_factory=GuiBscanStateModel)
     gpr: GuiGprStateModel = field(default_factory=GuiGprStateModel)
+    legacy_gpr: GuiLegacyGprStateModel = field(default_factory=GuiLegacyGprStateModel)
 
 
 @dataclass(slots=True)
diff --git a/python_app/orchestration/live_processing_config.py b/python_app/orchestration/live_processing_config.py
index 18212f2..7d4aa0b 100644
--- a/python_app/orchestration/live_processing_config.py
+++ b/python_app/orchestration/live_processing_config.py
@@ -23,7 +23,7 @@ class ProcessingLiveConfig:
     bscan_gain: float = 1.0
     bscan_start_freq_mhz: float = 100.0
     bscan_stop_freq_mhz: float = 8800.0
-    gpr_algorithm: str = "backprojection"
+    legacy_gpr_mode: str = "point"
     gpr_input_positions: list[int] | None = None
     gpr_output_positions: list[int] | None = None
     gpr_min_depth_m: float = 2.0
@@ -69,7 +69,7 @@ class ProcessingLiveConfig:
             "bscan_gain": float(self.bscan_gain),
             "bscan_start_freq_mhz": float(self.bscan_start_freq_mhz),
             "bscan_stop_freq_mhz": float(self.bscan_stop_freq_mhz),
-            "gpr_algorithm": str(self.gpr_algorithm),
+            "legacy_gpr_mode": str(self.legacy_gpr_mode),
             "gpr_input_positions": [int(value) for value in self.gpr_input_positions],
             "gpr_output_positions": [int(value) for value in self.gpr_output_positions],
             "gpr_min_depth_m": float(self.gpr_min_depth_m),
diff --git a/run_config.json b/run_config.json
index 50afb47..ace723b 100644
--- a/run_config.json
+++ b/run_config.json
@@ -215,18 +215,12 @@
         "subtract_mean_ascan": false
       },
       "gpr": {
-        "algorithm": "backprojection",
         "input_positions": "0,1,2,3",
         "output_positions": "0,1",
         "min_depth_m": 2.0,
         "max_depth_m": 14.0,
         "range_comp_power": 0.28,
         "angle_comp_power": 0.1,
-        "comp_power": 0.2,
-        "speed_m_s": 0.0,
-        "look_angle_deg": 0.0,
-        "snr_thresh": 4.5,
-        "snr_comp_max": 25.0,
         "start_freq_mhz": 3000.0,
         "stop_freq_mhz": 6000.0,
         "background_subtract_enabled": true,
@@ -238,6 +232,28 @@
         "visible_x_max_m": 2.0,
         "visible_z_min_m": 0.0,
         "visible_z_max_m": 14.0
+      },
+      "legacy_gpr": {
+        "mode": "point",
+        "input_positions": "0,1,2,3",
+        "output_positions": "0,1",
+        "min_depth_m": 2.0,
+        "max_depth_m": 14.0,
+        "comp_power": 0.2,
+        "start_freq_mhz": 3000.0,
+        "stop_freq_mhz": 6000.0,
+        "speed_m_s": 0.0,
+        "look_angle_deg": 0.0,
+        "snr_thresh": 4.5,
+        "snr_comp_max": 25.0,
+        "background_subtract_enabled": true,
+        "background_mean_count": 10,
+        "render_mode": "heatmap",
+        "min_visible_pair_count": 1,
+        "visible_x_min_m": -2.0,
+        "visible_x_max_m": 2.0,
+        "visible_z_min_m": 0.0,
+        "visible_z_max_m": 14.0
       }
     },
     "data_actions": {
diff --git a/run_config_simulator.example.json b/run_config_simulator.example.json
index 50afb47..ace723b 100644
--- a/run_config_simulator.example.json
+++ b/run_config_simulator.example.json
@@ -215,18 +215,12 @@
         "subtract_mean_ascan": false
       },
       "gpr": {
-        "algorithm": "backprojection",
         "input_positions": "0,1,2,3",
         "output_positions": "0,1",
         "min_depth_m": 2.0,
         "max_depth_m": 14.0,
         "range_comp_power": 0.28,
         "angle_comp_power": 0.1,
-        "comp_power": 0.2,
-        "speed_m_s": 0.0,
-        "look_angle_deg": 0.0,
-        "snr_thresh": 4.5,
-        "snr_comp_max": 25.0,
         "start_freq_mhz": 3000.0,
         "stop_freq_mhz": 6000.0,
         "background_subtract_enabled": true,
@@ -238,6 +232,28 @@
         "visible_x_max_m": 2.0,
         "visible_z_min_m": 0.0,
         "visible_z_max_m": 14.0
+      },
+      "legacy_gpr": {
+        "mode": "point",
+        "input_positions": "0,1,2,3",
+        "output_positions": "0,1",
+        "min_depth_m": 2.0,
+        "max_depth_m": 14.0,
+        "comp_power": 0.2,
+        "start_freq_mhz": 3000.0,
+        "stop_freq_mhz": 6000.0,
+        "speed_m_s": 0.0,
+        "look_angle_deg": 0.0,
+        "snr_thresh": 4.5,
+        "snr_comp_max": 25.0,
+        "background_subtract_enabled": true,
+        "background_mean_count": 10,
+        "render_mode": "heatmap",
+        "min_visible_pair_count": 1,
+        "visible_x_min_m": -2.0,
+        "visible_x_max_m": 2.0,
+        "visible_z_min_m": 0.0,
+        "visible_z_max_m": 14.0
       }
     },
     "data_actions": {
diff --git a/tmp b/tmp
index 8a3798a..6439c3f 100644
--- a/tmp
+++ b/tmp
@@ -1,3 +1,3 @@
 смотри сейчас будем добавлять в проект поддержку еще одного девайса в качестве радара. Когда будешь читать код смотри если есть файлы длинее чем 1300 строк то надо бы будет их грамотно разбить. В целом пиши код как мастер профессионал лучший в мире и самый опытный разработчик, пиши красивейший код, максимально читаемый, грамотный и понятный. Очень внимательнно смотри чтобы не было фолбеков, если в коде уже сейчас видишь какие то фолбеки то скажи где они и что делают, скорее всего будем удалять их в дальнейшем. И когда писать сейчас будешь то не создавай лишнего кода типа фолбеков изза отсутвтивия зависимостей и так далее, лишний код это плохо. объем в идеале уменьшать надо проекта. 
 
-Давай постепенно будем добавлять поддержку нового типа радара в код, для начала - сбор данных свипов. По пути /home/europa/Documents/kamil_adc 
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+Давай постепенно будем добавлять поддержку нового типа радара в код, для начала - сбор данных свипов. По пути /home/europa/Documents/kamil_adc  лежит проект, который собирает свипы с нового девайса (там формат получается вроде бы как 0x0a step data1 data2 где data 1 это действтиельная часть а 2 это мнимая). Вот надо будет драйвер написать для интеграции в проект. как в случае с мультидевайсом можно только питоновский драйвер оставить, то есть будет запускаться код например из проекта kamil_adc а мы поверх него уже пишем нашу прослойку для интеграции в проект radar_system. Вот желательно немного кода добавтиь. И еще у этого девайса своя конфигурация, увидеть как настраивается устройство и какие параметры можно в проекте 
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