added new filtration and fixed processing parameters

data_acq_and_processing/common_cpp/ipc/src/shm_ring.cpp

@@ -188,7 +188,7 @@ auto ShmRing::open_or_create(
             const bool geometry_ok = header->capacity == capacity && header->slot_size_bytes == slot_size_bytes;
 
             if (magic_ok && version_ok && geometry_ok) {
-                // Fix #50: the requested mapped_size matched the header geometry, but the
+                // the requested mapped_size matched the header geometry, but the
                 // backing file may have been created undersized by another process. Confirm
                 // st_size covers the geometry before trusting the mapping.
                 struct stat info {};
@@ -257,7 +257,7 @@ auto ShmRing::open_existing(const std::string& name) -> ShmRing {
     if (header->version != kRingVersion) {
         throw std::runtime_error("Shared memory ring version mismatch for " + name);
     }
-    // Fix #50: ensure the mapping actually spans every slot the header describes.
+    // ensure the mapping actually spans every slot the header describes.
     validate_geometry(*header, mapped_size, name);
 
     ShmRing ring{};
@@ -411,7 +411,7 @@ void ShmRing::validate_name(const std::string& name) {
 }
 
 void ShmRing::validate_geometry(const Header& header, std::size_t mapped_size, const std::string& name) {
-    // Fix #50: derive the expected size from the header's own geometry fields and
+    // derive the expected size from the header's own geometry fields and
     // require the real mapping to cover it. A bogus capacity/slot_size or a truncated
     // mapping would otherwise yield out-of-bounds slot offsets and a SIGSEGV.
     const std::uint32_t capacity = header.capacity;

data_acq_and_processing/processing/data_processor/include/processing_live_config.hpp

@@ -45,8 +45,10 @@ struct ProcessingLiveConfig {
     float gpr_min_depth_m = 2.0F;
     float gpr_max_depth_m = 14.0F;
     float gpr_range_comp_power = 0.1F;
-    float gpr_angle_comp_power = 0.0F;
     float gpr_comp_power = 0.2F;
+    // BP object-detection stop level, as a fraction of the global peak (Python
+    // Horns_motion_3libre.py BP_OBJECT_MIN_FRAC); peaks below it are not objects.
+    float gpr_object_min_frac = 0.7F;
     std::string gpr_score_mode = "combined";
     // Backprojection intra-sweep speed-correction mode: "int_minus" (full
     // correction) or "int_focus" (focusing residual only). Mirrors the Python
@@ -73,13 +75,15 @@ struct ProcessingLiveConfig {
     // BP image is computed in the y=imaging_plane_y_m slice of the 3D grid.
     // Default 0 keeps legacy 1D antenna layouts imaging in the antenna plane.
     float gpr_imaging_plane_y_m = 0.0F;
-    // Locator filter parameters. Mode-dependent threshold (legacy_gpr uses
+    // Coherent BP object visibility (window + the draw limits below) is applied in
-    // `legacy_gpr_min_visible_pair_count`, everything else uses
+    // the processor itself, matching Horns_motion_3libre.py — there is NO score
-    // `gpr_min_visible_score`). Draw limits apply only to non-legacy modes.
+    // threshold for it. Only legacy GPR still thresholds, on a pair count.
-    float gpr_min_visible_score = 0.0F;
     float legacy_gpr_min_visible_pair_count = 0.0F;
     std::uint32_t gpr_max_detected_objects_to_draw = 0;
     std::uint32_t gpr_draw_top_m_objects = 0;
+    // Cross-frame approach filter: an object is shown only once it persists as a
+    // motion-consistent track over this many consecutive frames (<= 1 disables it).
+    std::uint32_t gpr_object_approach_min_frames = 3;
     // Visible X/Z window (metres). The locator clips broadcast objects to this
     // window so the socket emits only what the desktop plot actually shows.
     float gpr_visible_x_min_m = -2.0F;

data_acq_and_processing/processing/data_processor/src/data_processor.cpp

@@ -65,7 +65,7 @@ void DataProcessor::run(const std::atomic<bool>& stop_requested) {
     std::uint64_t last_applied_history_command_seq = 0;
     std::uint64_t error_count = 0;
     std::uint64_t consecutive_errors = 0;
-    // Fix #55: track the socket-fed speed used for the last reprocess so a change
+    // track the socket-fed speed used for the last reprocess so a change
     // arriving without a live-config revision bump still triggers a reprocess of
     // the current result (gated below by reprocess_current_result).
     std::optional<double> last_reprocessed_socket_speed = std::nullopt;
@@ -124,7 +124,7 @@ void DataProcessor::run(const std::atomic<bool>& stop_requested) {
                     publish_locator(replay_result, live_config);
                 }
                 last_replayed_revision = live_revision;
-                // Fix #55: record the speed we just reprocessed with so an
+                //record the speed we just reprocessed with so an
                 // unchanged socket value does not retrigger every iteration.
                 last_reprocessed_socket_speed = current_socket_speed;
             }
@@ -232,29 +232,23 @@ auto DataProcessor::build_locator_filter(const ProcessingLiveConfig& live_config
         live_config.processor_mode.empty() ? default_processor_mode_ : live_config.processor_mode;
 
     radar::locator::FilterParams filter{};
-    // Clip broadcast objects to the same visible X/Z window the desktop plot uses,
-    // so the socket emits only the objects the operator actually sees.
-    filter.visible_bounds = radar::locator::VisibleBounds{
-        .x_min = live_config.gpr_visible_x_min_m,
-        .x_max = live_config.gpr_visible_x_max_m,
-        .z_min = live_config.gpr_visible_z_min_m,
-        .z_max = live_config.gpr_visible_z_max_m,
-    };
     if (requested_mode == "legacy_gpr") {
+        // Legacy GPR emits its objects unfiltered, so the socket applies the legacy
+        // rule here: clip to the visible window and threshold on the pair count. The
+        // GUI disables "draw top N" for legacy, so we skip it on the wire to match.
+        filter.visible_bounds = radar::locator::VisibleBounds{
+            .x_min = live_config.gpr_visible_x_min_m,
+            .x_max = live_config.gpr_visible_x_max_m,
+            .z_min = live_config.gpr_visible_z_min_m,
+            .z_max = live_config.gpr_visible_z_max_m,
+        };
         filter.min_score = live_config.legacy_gpr_min_visible_pair_count;
-        // The GUI deliberately disables the "draw top N" capping for legacy
-        // GPR, so we also skip it on the wire to match observation semantics.
         filter.draw_limits.reset();
-    } else {
-        filter.min_score = live_config.gpr_min_visible_score;
-        if (live_config.gpr_max_detected_objects_to_draw > 0U
-            && live_config.gpr_draw_top_m_objects > 0U) {
-            filter.draw_limits = radar::locator::DrawLimits{
-                .max_detected_objects = live_config.gpr_max_detected_objects_to_draw,
-                .draw_top_objects = live_config.gpr_draw_top_m_objects,
-            };
-        }
     }
+    // Coherent BP already emits the FINAL visible object set from the processor
+    // (window + N/M, no score threshold — matching Horns_motion_3libre.py), so the
+    // socket forwards it verbatim. The default FilterParams passes everything through
+    // (it only drops non-finite rows), keeping the filtering logic in one place.
     return filter;
 }
 

data_acq_and_processing/processing/data_processor/src/processing_live_config.cpp

@@ -255,11 +255,11 @@ void apply_legacy_gpr_algorithm_alias(ProcessingLiveConfig& config, const std::s
         }
         config.gpr_range_comp_power = static_cast<float>(found->get<double>());
     }
-    if (const auto found = root.find("gpr_angle_comp_power"); found != root.end()) {
+    if (const auto found = root.find("gpr_object_min_frac"); found != root.end()) {
         if (!found->is_number()) {
-            throw std::runtime_error("processing.gpr_angle_comp_power must be number");
+            throw std::runtime_error("processing.gpr_object_min_frac must be number");
         }
-        config.gpr_angle_comp_power = static_cast<float>(found->get<double>());
+        config.gpr_object_min_frac = static_cast<float>(found->get<double>());
     }
     if (const auto found = root.find("gpr_comp_power"); found != root.end()) {
         if (!found->is_number()) {
@@ -355,12 +355,6 @@ void apply_legacy_gpr_algorithm_alias(ProcessingLiveConfig& config, const std::s
         }
         config.gpr_imaging_plane_y_m = static_cast<float>(found->get<double>());
     }
-    if (const auto found = root.find("gpr_min_visible_score"); found != root.end()) {
-        if (!found->is_number()) {
-            throw std::runtime_error("processing.gpr_min_visible_score must be number");
-        }
-        config.gpr_min_visible_score = static_cast<float>(found->get<double>());
-    }
     for (const auto& [key, target] : {
              std::pair{"gpr_visible_x_min_m", &config.gpr_visible_x_min_m},
              std::pair{"gpr_visible_x_max_m", &config.gpr_visible_x_max_m},
@@ -388,6 +382,10 @@ void apply_legacy_gpr_algorithm_alias(ProcessingLiveConfig& config, const std::s
         config.gpr_draw_top_m_objects =
             parse_u32_number(*found, "processing.gpr_draw_top_m_objects");
     }
+    if (const auto found = root.find("gpr_object_approach_min_frames"); found != root.end()) {
+        config.gpr_object_approach_min_frames =
+            parse_u32_number(*found, "processing.gpr_object_approach_min_frames");
+    }
     if (const auto found = root.find("ignore_socket_speed"); found != root.end()) {
         if (!found->is_boolean()) {
             throw std::runtime_error("processing.ignore_socket_speed must be bool");

data_acq_and_processing/processing/processors/include/gpr_processor.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "object_approach_filter.hpp"
 #include "processor_interface.hpp"
 
 namespace radar::processing {
@@ -13,6 +14,11 @@ class GprProcessor final : public ProcessorInterface {
         std::span<const ipc::PreprocessedCollection> previous_collections,
         const ProcessingLiveConfig& live_config
     ) -> ipc::ResultCollection override;
+
+  private:
+    // Cross-frame "approach" track filter. Persists across collections because the
+    // owning processor instance is long-lived (one per data_processor run).
+    ObjectApproachFilter approach_filter_{};
 };
 
 class LegacyGprProcessor final : public ProcessorInterface {

data_acq_and_processing/processing/processors/include/object_approach_filter.hpp

@@ -0,0 +1,172 @@
+#pragma once
+
+#include <algorithm>
+#include <cmath>
+#include <cstddef>
+#include <cstdint>
+#include <deque>
+#include <limits>
+#include <vector>
+
+namespace radar::processing {
+
+// Temporal "approach" filter for coherent-BP detections — a port of the objects-only
+// filter in Horns_motion_3libre's demonstrate notebook.
+//
+// It keeps only objects that persist as a *motion-consistent track* across at least
+// `min_frames` consecutive frames: as the radar moves, a real target reappears at a
+// predictable, shifting (x, z), whereas a one-frame noise spike forms no track and is
+// dropped. The expected per-frame change in range is `speed * dt * cos(look_angle)`,
+// where `dt` is the real interval between consecutive frames (so dropped frames and a
+// varying frame period are handled naturally).
+//
+// CAUSAL: unlike the offline notebook (which can look forward over the whole sequence),
+// this confirms a track by looking *backward* — an object is kept once it ends a track
+// of `min_frames` frames seen so far. A target therefore first appears after it has
+// persisted `min_frames` frames; the early frames of its track are not shown
+// retroactively.
+//
+// Stateless across pipeline restarts is approximated by breaking tracks across a large
+// inter-frame gap (`kMaxFrameGapSeconds`), so a stale history from a previous run cannot
+// spuriously confirm objects.
+//
+// IDEMPOTENT under reprocessing: the data_processor re-runs the last collection (or
+// replays the whole window) whenever live settings or the socket speed change, with no
+// new sweep. The history is therefore keyed by `frame_id` (the strictly increasing
+// collection id): the same id replaces its entry (reprocess of the current frame), a
+// smaller id rebuilds from scratch (a replay restart), so repeated reprocessing never
+// duplicates frames or falsely confirms a track.
+class ObjectApproachFilter {
+  public:
+    struct Point {
+        double x_m;
+        double z_m;
+    };
+
+    // Record `objects` as frame `frame_id` and return, per object, whether it is
+    // confirmed (ends a >= `min_frames` motion-consistent track). `frame_id` is the
+    // collection id (identity/order, survives reprocessing); `frame_time_seconds` is the
+    // frame's wall-clock timestamp (drives the inter-frame interval); `speed_m_s`/
+    // `look_angle_deg` are the live motion estimate. `min_frames <= 1` disables filtering.
+    [[nodiscard]] auto confirm(
+        const std::vector<Point>& objects,
+        std::uint64_t frame_id,
+        double frame_time_seconds,
+        double speed_m_s,
+        double look_angle_deg,
+        std::size_t min_frames
+    ) -> std::vector<bool> {
+        record_frame(Frame{frame_id, frame_time_seconds, objects});
+        const std::size_t history_depth = std::max<std::size_t>(min_frames, 1U);
+        while (history_.size() > history_depth) {
+            history_.pop_front();
+        }
+
+        std::vector<bool> confirmed(objects.size(), min_frames <= 1U);
+        if (min_frames <= 1U || history_.size() < min_frames) {
+            return confirmed;  // disabled, or not enough history yet to confirm anything
+        }
+
+        const double range_step_per_second = std::abs(speed_m_s) * std::cos(to_radians(look_angle_deg));
+        for (std::size_t object_index = 0U; object_index < objects.size(); ++object_index) {
+            confirmed[object_index] = has_backward_track(objects[object_index], min_frames, range_step_per_second);
+        }
+        return confirmed;
+    }
+
+    void reset() { history_.clear(); }
+
+  private:
+    struct Frame {
+        std::uint64_t id;
+        double time_seconds;
+        std::vector<Point> objects;
+    };
+
+    // Append a genuinely new frame, replace the current one on reprocessing (same id),
+    // or rebuild from scratch when the id steps backward (a replay restart). This keeps
+    // the history one entry per distinct collection no matter how often settings change.
+    void record_frame(Frame frame) {
+        if (history_.empty() || frame.id > history_.back().id) {
+            history_.push_back(std::move(frame));
+        } else if (frame.id == history_.back().id) {
+            history_.back() = std::move(frame);
+        } else {
+            history_.clear();
+            history_.push_back(std::move(frame));
+        }
+    }
+
+    // Fixed matching tolerances (Horns_motion notebook 0.2 block). Range decreases as the
+    // radar approaches the target, hence the negative Z sign.
+    static constexpr double kXToleranceM = 0.45;
+    static constexpr double kRangeToleranceFraction = 0.85;
+    static constexpr double kRangeToleranceFloorM = 0.12;
+    static constexpr double kRangeSign = -1.0;
+    static constexpr double kMaxFrameGapSeconds = 2.0;
+
+    [[nodiscard]] static auto to_radians(double degrees) -> double {
+        return degrees * (M_PI / 180.0);
+    }
+
+    // Walk back from the current object through the history, matching a motion-consistent
+    // predecessor in each earlier frame. Confirmed iff a full chain of `min_frames` frames
+    // (the current one plus `min_frames - 1` predecessors) is found.
+    [[nodiscard]] auto has_backward_track(
+        const Point& object,
+        std::size_t min_frames,
+        double range_step_per_second
+    ) const -> bool {
+        const std::size_t newest = history_.size() - 1U;
+        Point current = object;
+        for (std::size_t step = 1U; step < min_frames; ++step) {
+            const std::size_t earlier_index = newest - step;
+            const Frame& earlier = history_[earlier_index];
+            const double dt = history_[earlier_index + 1U].time_seconds - earlier.time_seconds;
+            if (!(dt > 0.0) || dt > kMaxFrameGapSeconds) {
+                return false;  // non-monotonic time, or a gap that breaks the track
+            }
+            const double expected_range_shift = range_step_per_second * dt;
+            const Point* predecessor = match_predecessor(current, earlier.objects, expected_range_shift);
+            if (predecessor == nullptr) {
+                return false;
+            }
+            current = *predecessor;
+        }
+        return true;
+    }
+
+    // The best earlier-frame object consistent with `object` having moved by one frame:
+    // its range was larger by `expected_range_shift` (radar since approached), within the
+    // cross-range and range tolerances. Returns nullptr when nothing matches.
+    [[nodiscard]] static auto match_predecessor(
+        const Point& object,
+        const std::vector<Point>& candidates,
+        double expected_range_shift
+    ) -> const Point* {
+        const double target_z = object.z_m - (kRangeSign * expected_range_shift);
+        const double range_tolerance =
+            std::max(kRangeToleranceFloorM, kRangeToleranceFraction * expected_range_shift);
+
+        const Point* best = nullptr;
+        double best_cost = std::numeric_limits<double>::infinity();
+        for (const Point& candidate : candidates) {
+            const double dx = std::abs(candidate.x_m - object.x_m);
+            const double dz = std::abs(candidate.z_m - target_z);
+            if (dx > kXToleranceM || dz > range_tolerance) {
+                continue;
+            }
+            const double cost = (dx / kXToleranceM) * (dx / kXToleranceM)
+                + (dz / range_tolerance) * (dz / range_tolerance);
+            if (cost < best_cost) {
+                best = &candidate;
+                best_cost = cost;
+            }
+        }
+        return best;
+    }
+
+    std::deque<Frame> history_{};  // recent frames, newest at the back; capped to min_frames
+};
+
+}  // namespace radar::processing

data_acq_and_processing/processing/processors/src/gpr_backprojection_processor.ipp

@@ -21,7 +21,6 @@ constexpr double kSmoothSigma = 1.5;
 // same default 'reflect' (half-sample symmetric) extension — see reflect_index.
 constexpr double kGaussianTruncate = 4.0;
 constexpr std::size_t kMaxObjects = 10U;
-constexpr double kObjectMinFrac = 0.7;
 constexpr double kRegionThresholdFrac = 0.75;
 constexpr double kSuppressThresholdFrac = 0.20;
 constexpr double kSuppressRadiusXM = 0.80;
@@ -1405,7 +1404,8 @@ void apply_depth_gate(
 
 [[nodiscard]] auto find_bp_objects(
     const std::vector<double>& bp_image,
-    const GridDefinition& grid
+    const GridDefinition& grid,
+    double min_frac
 ) -> std::vector<ObjectRecord> {
     std::vector<ObjectRecord> objects{};
     if (bp_image.empty() || grid.x_grid.size() < 2U || grid.z_grid.size() < 2U) {
@@ -1414,7 +1414,7 @@ void apply_depth_gate(
 
     std::vector<double> work = bp_image;
     const double global_peak = max_value(work);
-    const double stop_level = kObjectMinFrac * global_peak;
+    const double stop_level = min_frac * global_peak;
     if (!(global_peak > 0.0)) {
         return objects;
     }
@@ -1740,7 +1740,15 @@ void add_bp_score_metrics(
     }
 }
 
-[[nodiscard]] auto output_objects_sorted(
+// Select the FINAL visible objects exactly as Horns_motion_3libre.py does, so the
+// processor is the single source of truth: the GUI plot and the locator socket both
+// consume this set verbatim (no second, duplicated filter). Steps, in order:
+//   1. drop sidelobe candidates (when enabled), then sort by score (peak tie-break);
+//   2. clip to the visible X/Z window (display window doubles as an object gate);
+//   3. apply the N/M draw rule (BP_MAX_DETECTED_OBJECTS_TO_DRAW / BP_DRAW_TOP_M_OBJECTS):
+//      if more than N survive, show none; otherwise keep the top M.
+// There is deliberately NO score threshold (the Python reference has none).
+[[nodiscard]] auto select_visible_objects(
     const std::vector<ObjectRecord>& objects,
     const ProcessingLiveConfig& live_config
 ) -> std::vector<const ObjectRecord*> {
@@ -1750,6 +1758,12 @@ void add_bp_score_metrics(
         if (live_config.gpr_remove_sidelobe_objects_enabled && object.sidelobe_candidate) {
             continue;
         }
+        if (object.x_m < live_config.gpr_visible_x_min_m
+            || object.x_m > live_config.gpr_visible_x_max_m
+            || object.z_m < live_config.gpr_visible_z_min_m
+            || object.z_m > live_config.gpr_visible_z_max_m) {
+            continue;
+        }
         visible.push_back(&object);
     }
 
@@ -1759,6 +1773,17 @@ void add_bp_score_metrics(
         }
         return left->selected_score > right->selected_score;
     });
+
+    // N/M draw rule (0 on either disables limiting, mirroring the GUI/locator default).
+    const auto max_detected = live_config.gpr_max_detected_objects_to_draw;
+    const auto draw_top = live_config.gpr_draw_top_m_objects;
+    if (max_detected > 0U && draw_top > 0U) {
+        if (visible.size() > max_detected) {
+            visible.clear();
+        } else if (visible.size() > draw_top) {
+            visible.resize(draw_top);
+        }
+    }
     return visible;
 }
 
@@ -1815,7 +1840,8 @@ void add_bp_score_metrics(
     const config::RunConfig& run_config,
     const ipc::PreprocessedCollection& collection,
     std::span<const ipc::PreprocessedCollection> previous_collections,
-    const ProcessingLiveConfig& live_config
+    const ProcessingLiveConfig& live_config,
+    ObjectApproachFilter& approach_filter
 ) -> ipc::ResultCollection {
     ipc::ResultCollection results{};
     results.collection_id = collection.collection_id;
@@ -1833,8 +1859,10 @@ void add_bp_score_metrics(
         return results;
     }
 
-    const double velocity_mps =
+    // Coherent BP fixes the medium to vacuum/air (eps_r = 1), matching the Python
-        kSpeedOfLightMetersPerSec / std::sqrt(std::max(1e-6, static_cast<double>(run_config.gpr.relative_permittivity)));
+    // reference Horns_motion_3libre.py (its 0.3 block hardcodes eps_r = 1.0). The
+    // configurable relative_permittivity stays a legacy-GPR-only knob.
+    const double velocity_mps = kSpeedOfLightMetersPerSec;
     const double start_hz = static_cast<double>(live_config.gpr_start_freq_mhz) * 1'000'000.0;
     const double stop_hz = static_cast<double>(live_config.gpr_stop_freq_mhz) * 1'000'000.0;
     const double min_depth_m = static_cast<double>(live_config.gpr_min_depth_m);
@@ -1920,7 +1948,7 @@ void add_bp_score_metrics(
         min_depth_m,
         max_depth_m,
         std::max(0.0, static_cast<double>(live_config.gpr_range_comp_power)),
-        std::max(0.0, static_cast<double>(live_config.gpr_angle_comp_power))
+        0.0  // angle compensation fixed off (Python Horns_motion_3libre.py COMP_ANGLE_POWER = 0.0)
     );
     if (bp.image.empty()) {
         return results;
@@ -1930,7 +1958,7 @@ void add_bp_score_metrics(
     const auto incoherent_display_map =
         normalize_bp_map(bp.incoherent, grid, min_depth_m, max_depth_m, kSmoothSigma);
 
-    auto objects = find_bp_objects(display_map, grid);
+    auto objects = find_bp_objects(display_map, grid, static_cast<double>(live_config.gpr_object_min_frac));
     add_local_prominence_metrics(objects, display_map, grid, min_depth_m, max_depth_m);
     add_incoherent_support_metrics(objects, incoherent_display_map, bp.coherence_factor);
     mark_sidelobe_candidates(objects, selected_traces, selection, imaging_plane_y_m);
@@ -1951,14 +1979,34 @@ void add_bp_score_metrics(
 
     results.collection_payloads.push_back(build_image_payload("gpr_accumulator", grid.x_grid, grid.z_grid, display_map));
 
+    // Final visible set (window + N/M), then the cross-frame approach filter: keep only
+    // objects confirmed as a >= min_frames motion-consistent track (Horns_motion notebook).
+    const auto visible = select_visible_objects(objects, live_config);
+    std::vector<ObjectApproachFilter::Point> visible_points{};
+    visible_points.reserve(visible.size());
+    for (const auto* object : visible) {
+        visible_points.push_back({object->x_m, object->z_m});
+    }
+    const auto confirmed = approach_filter.confirm(
+        visible_points,
+        collection.collection_id,
+        static_cast<double>(collection.monotonic_ns) * 1e-9,
+        static_cast<double>(live_config.gpr_speed_m_s),
+        static_cast<double>(live_config.gpr_look_angle_deg),
+        static_cast<std::size_t>(live_config.gpr_object_approach_min_frames)
+    );
+
     std::vector<std::vector<float>> point_rows{};
-    point_rows.reserve(objects.size());
+    point_rows.reserve(visible.size());
-    for (const auto* object : output_objects_sorted(objects, live_config)) {
+    for (std::size_t index = 0U; index < visible.size(); ++index) {
+        if (!confirmed[index]) {
+            continue;
+        }
         point_rows.push_back(
             {
-                static_cast<float>(object->x_m),
+                static_cast<float>(visible[index]->x_m),
-                static_cast<float>(object->z_m),
+                static_cast<float>(visible[index]->z_m),
-                static_cast<float>(object->selected_score),
+                static_cast<float>(visible[index]->selected_score),
             }
         );
     }

data_acq_and_processing/processing/processors/src/gpr_processor.cpp

@@ -36,7 +36,7 @@ auto GprProcessor::process_collection(
     std::span<const ipc::PreprocessedCollection> previous_collections,
     const ProcessingLiveConfig& live_config
 ) -> ipc::ResultCollection {
-    return process_backprojection_gpr(run_config, collection, previous_collections, live_config);
+    return process_backprojection_gpr(run_config, collection, previous_collections, live_config, approach_filter_);
 }
 
 auto LegacyGprProcessor::name() const -> std::string {

data_acq_and_processing/sweep_orchestrator/src/sweep_orchestrator.cpp

@@ -207,7 +207,7 @@ SweepOrchestrator::SweepOrchestrator(
 void SweepOrchestrator::run(const std::atomic<bool>& stop_requested) {
     // Fail fast on a config error: a slot that is too small for the worst-case payload can
     // never carry a full collection, so report it clearly at startup instead of dropping
-    // every collection at runtime (fix #27).
+    // every collection at runtime.
     const auto worst_case_bytes = worst_case_serialized_bytes(config_.run_combos.size(), config_.radar.sweep.points);
     if (worst_case_bytes > raw_ring_.slot_size_bytes()) {
         throw std::runtime_error(
@@ -219,7 +219,7 @@ void SweepOrchestrator::run(const std::atomic<bool>& stop_requested) {
     }
 
     DriverLifecycleGuard lifecycle_guard(radar_driver_, input_switch_driver_, output_switch_driver_);
-    // Wait for the devices to become available before starting (fix #8/#9): an absent device
+    // Wait for the devices to become available before starting: an absent device
     // makes the orchestrator wait, not exit.
     if (!lifecycle_guard.open_all_with_retry(stop_requested)) {
         return;  // stop requested before any device became available

python_app/gui/controllers/app_window_config/live_processing_mixin.py

@@ -58,14 +58,14 @@ _WEB_LIVE_SCHEMA = [
     ("gpr_stop_freq_mhz", "Geometry & depth", _GPR_MODES, _dual("_gpr_stop_freq_mhz", "_legacy_gpr_stop_freq_mhz")),
     ("gpr_imaging_plane_y_m", "Geometry & depth", ("gpr",), _attr("_gpr_imaging_plane_y_m")),
     ("gpr_range_comp_power", "Imaging", ("gpr",), _attr("_gpr_range_comp_power")),
-    ("gpr_angle_comp_power", "Imaging", ("gpr",), _attr("_gpr_angle_comp_power")),
     ("gpr_score_mode", "Imaging", ("gpr",), _attr("_gpr_score_mode")),
     ("gpr_background_subtract_enabled", "Imaging", _GPR_MODES, _dual("_gpr_background_subtract_enabled", "_legacy_gpr_background_subtract_enabled")),
     ("gpr_background_mean_count", "Imaging", _GPR_MODES, _dual("_gpr_background_mean_count", "_legacy_gpr_background_mean_count")),
     ("gpr_remove_sidelobe_objects_enabled", "Imaging", ("gpr",), _attr("_gpr_remove_sidelobe_objects_enabled")),
-    ("gpr_min_visible_score", "Detection", ("gpr",), _attr("_gpr_min_visible_score")),
+    ("gpr_object_min_frac", "Detection", ("gpr",), _attr("_gpr_object_min_frac")),
     ("gpr_max_detected_objects_to_draw", "Detection", ("gpr",), _attr("_gpr_max_detected_objects_to_draw")),
     ("gpr_draw_top_m_objects", "Detection", ("gpr",), _attr("_gpr_draw_top_m_objects")),
+    ("gpr_object_approach_min_frames", "Detection", ("gpr",), _attr("_gpr_object_approach_min_frames")),
     ("gpr_comp_power", "Detection", ("legacy_gpr",), _attr("_legacy_gpr_comp_power")),
     ("gpr_snr_thresh", "Detection", ("legacy_gpr",), _attr("_legacy_gpr_snr_thresh")),
     ("gpr_snr_comp_max", "Detection", ("legacy_gpr",), _attr("_legacy_gpr_snr_comp_max")),
@@ -110,7 +110,9 @@ _WEB_DISPLAY_SCHEMA = [
 # take effect only when the pipeline (re)starts — not hot-reloaded — so the web marks them
 # "applies on Start" and editing them just updates the widget for the next start.
 _WEB_STABLE_SCHEMA = [
-    ("relative_permittivity", "Geometry & medium", _GPR_MODES, _attr("_gpr_relative_permittivity")),
+    # Coherent BP fixes the medium to eps_r = 1 (Horns_motion_3libre.py), so relative
+    # permittivity is a legacy-GPR-only knob; BP ignores it.
+    ("relative_permittivity", "Geometry & medium", ("legacy_gpr",), _attr("_gpr_relative_permittivity")),
     ("tx_geometry", "Geometry & medium", _GPR_MODES, _attr("_gpr_tx_geometry_input")),
     ("rx_geometry", "Geometry & medium", _GPR_MODES, _attr("_gpr_rx_geometry_input")),
 ]
@@ -475,14 +477,13 @@ class AppWindowLiveProcessingMixin:
                 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"object_min_frac={self._gpr_object_min_frac.value():g}, "
                 f"score_mode={self._gpr_score_mode.currentText()}, "
                 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"imaging_plane_y={self._gpr_imaging_plane_y_m.value():g} m, "
                 f"render_mode={self._gpr_render_mode.currentText()}, "
-                f"min_score={self._gpr_min_visible_score.value():g}, "
                 f"max_draw={self._gpr_max_detected_objects_to_draw.value()}, "
                 f"draw_top={self._gpr_draw_top_m_objects.value()})"
             )

python_app/gui/controllers/app_window_config/profile_io_mixin.py

@@ -291,7 +291,7 @@ class AppWindowConfigProfileIOMixin:
             self._gpr_min_depth_m,
             self._gpr_max_depth_m,
             self._gpr_range_comp_power,
-            self._gpr_angle_comp_power,
+            self._gpr_object_min_frac,
             self._gpr_score_mode,
             self._gpr_motion_mode,
             self._gpr_look_angle_deg,
@@ -300,6 +300,7 @@ class AppWindowConfigProfileIOMixin:
             self._gpr_speed_m_s,
             self._gpr_max_detected_objects_to_draw,
             self._gpr_draw_top_m_objects,
+            self._gpr_object_approach_min_frames,
             self._gpr_start_freq_mhz,
             self._gpr_stop_freq_mhz,
             self._gpr_background_subtract_enabled,
@@ -307,7 +308,6 @@ class AppWindowConfigProfileIOMixin:
             self._gpr_remove_sidelobe_objects_enabled,
             self._gpr_imaging_plane_y_m,
             self._gpr_render_mode,
-            self._gpr_min_visible_score,
             self._gpr_visible_x_min_m,
             self._gpr_visible_x_max_m,
             self._gpr_visible_z_min_m,
@@ -457,7 +457,7 @@ class AppWindowConfigProfileIOMixin:
             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_object_min_frac.setValue(float(gui_state.processing.gpr.object_min_frac))
             self._set_combo_current_text(self._gpr_score_mode, gui_state.processing.gpr.score_mode)
             self._set_combo_current_text(self._gpr_motion_mode, gui_state.processing.gpr.motion_mode)
             self._gpr_look_angle_deg.setValue(float(gui_state.processing.gpr.look_angle_deg))
@@ -470,6 +470,7 @@ class AppWindowConfigProfileIOMixin:
                 int(gui_state.processing.gpr.max_detected_objects_to_draw)
             )
             self._gpr_draw_top_m_objects.setValue(int(gui_state.processing.gpr.draw_top_m_objects))
+            self._gpr_object_approach_min_frames.setValue(int(gui_state.processing.gpr.object_approach_min_frames))
             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(
@@ -481,7 +482,6 @@ class AppWindowConfigProfileIOMixin:
             )
             self._gpr_imaging_plane_y_m.setValue(float(gui_state.processing.gpr.imaging_plane_y_m))
             self._set_combo_current_text(self._gpr_render_mode, gui_state.processing.gpr.render_mode)
-            self._gpr_min_visible_score.setValue(float(gui_state.processing.gpr.min_visible_score))
             self._gpr_visible_x_min_m.setValue(float(gui_state.processing.gpr.visible_x_min_m))
             self._gpr_visible_x_max_m.setValue(float(gui_state.processing.gpr.visible_x_max_m))
             self._gpr_visible_z_min_m.setValue(float(gui_state.processing.gpr.visible_z_min_m))

python_app/gui/controllers/app_window_config/state_builders.py

@@ -224,7 +224,7 @@ class AppWindowConfigStateBuildersMixin:
                     min_depth_m=2.0,
                     max_depth_m=14.0,
                     range_comp_power=0.1,
-                    angle_comp_power=0.0,
+                    object_min_frac=0.7,
                     score_mode="combined",
                     motion_mode="int_minus",
                     look_angle_deg=0.0,
@@ -233,6 +233,7 @@ class AppWindowConfigStateBuildersMixin:
                     ignore_socket_speed_enabled=False,
                     max_detected_objects_to_draw=5,
                     draw_top_m_objects=2,
+                    object_approach_min_frames=3,
                     start_freq_mhz=3000.0,
                     stop_freq_mhz=6000.0,
                     background_subtract_enabled=True,
@@ -240,7 +241,6 @@ class AppWindowConfigStateBuildersMixin:
                     remove_sidelobe_objects_enabled=True,
                     imaging_plane_y_m=0.0,
                     render_mode="heatmap",
-                    min_visible_score=0.0,
                     visible_x_min_m=default_gpr_x_min_m,
                     visible_x_max_m=default_gpr_x_max_m,
                     visible_z_min_m=0.0,
@@ -351,7 +351,7 @@ class AppWindowConfigStateBuildersMixin:
                     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()),
+                    object_min_frac=float(self._gpr_object_min_frac.value()),
                     score_mode=self._gpr_score_mode.currentText(),
                     motion_mode=self._gpr_motion_mode.currentText(),
                     look_angle_deg=float(self._gpr_look_angle_deg.value()),
@@ -360,6 +360,7 @@ class AppWindowConfigStateBuildersMixin:
                     ignore_socket_speed_enabled=bool(self._gpr_ignore_socket_speed_enabled.isChecked()),
                     max_detected_objects_to_draw=int(self._gpr_max_detected_objects_to_draw.value()),
                     draw_top_m_objects=int(self._gpr_draw_top_m_objects.value()),
+                    object_approach_min_frames=int(self._gpr_object_approach_min_frames.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()),
@@ -367,7 +368,6 @@ class AppWindowConfigStateBuildersMixin:
                     remove_sidelobe_objects_enabled=bool(self._gpr_remove_sidelobe_objects_enabled.isChecked()),
                     imaging_plane_y_m=float(self._gpr_imaging_plane_y_m.value()),
                     render_mode=self._gpr_render_mode.currentText(),
-                    min_visible_score=float(self._gpr_min_visible_score.value()),
                     visible_x_min_m=float(self._gpr_visible_x_min_m.value()),
                     visible_x_max_m=float(self._gpr_visible_x_max_m.value()),
                     visible_z_min_m=float(self._gpr_visible_z_min_m.value()),

python_app/gui/controllers/app_window_plot/gpr_plot_mixin.py

@@ -8,7 +8,6 @@ import pyqtgraph as pg
 
 from python_app.models.dataset_model import ResultCollection
 from python_app.orchestration.gpr_locator import (
-    apply_object_draw_limits as gpr_apply_object_draw_limits,
     collection_payload_by_name as gpr_collection_payload_by_name,
     collection_payloads_by_prefix as gpr_collection_payloads_by_prefix,
     filter_object_rows as gpr_filter_object_rows,
@@ -371,26 +370,6 @@ class AppWindowGprPlotMixin:
             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())
-
-    def _gpr_draw_limits(self) -> tuple[int, int] | None:
-        """Return GPR object draw limits, or None for legacy GPR."""
-        if self._processing_mode.currentText() == "legacy_gpr":
-            return None
-        return (
-            int(self._gpr_max_detected_objects_to_draw.value()),
-            int(self._gpr_draw_top_m_objects.value()),
-        )
-
-    @staticmethod
-    def _apply_object_draw_limits(rows: np.ndarray, limits: tuple[int, int] | None) -> np.ndarray:
-        """Apply object count/top-M drawing rules to already-filtered rows."""
-        return gpr_apply_object_draw_limits(rows, limits)
-
     @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."""
@@ -506,18 +485,24 @@ class AppWindowGprPlotMixin:
         return extract_gpr_object_rows(collection)
 
     def _filtered_gpr_object_rows(self, collection: ResultCollection) -> np.ndarray:
-        """Return object rows filtered by threshold, visible X/Z bounds, and active GPR draw limits."""
+        """Return the object rows to draw for the active GPR mode.
+
+        Coherent BP is already finalized by the processor (visible window + N/M draw
+        limits, no score threshold — exactly Horns_motion_3libre.py), so its rows are
+        drawn verbatim. Legacy GPR is still filtered here by its pair-count threshold
+        and the visible window.
+        """
         rows = self._gpr_object_rows(collection)
-        if rows.size == 0:
+        if rows.size == 0 or self._processing_mode.currentText() != "legacy_gpr":
             return rows
 
         x_min, x_max, z_min, z_max = self._gpr_visible_object_bounds()
         return gpr_filter_object_rows(
             rows,
-            min_score=self._gpr_locator_threshold(),
+            min_score=float(self._legacy_gpr_min_visible_pair_count.value()),
             x_bounds=(x_min, x_max),
             z_bounds=(z_min, z_max),
-            draw_limits=self._gpr_draw_limits(),
+            draw_limits=None,
         )
 
     def _draw_gpr_objects_only(self, collection: ResultCollection) -> bool:

python_app/gui/controllers/sections/processing_section.py

@@ -177,10 +177,14 @@ def build_processing_group(owner) -> QGroupBox:
 
     gpr_defaults = owner._defaults_config.gpr
 
+    # Medium permittivity is a legacy-GPR-only knob (shown on the legacy page below).
+    # Coherent BP fixes the medium to eps_r = 1 (Horns_motion_3libre.py), so it is not
+    # offered there. Applies on the next pipeline start (a run_config field).
     owner._gpr_relative_permittivity = QDoubleSpinBox()
     owner._gpr_relative_permittivity.setDecimals(4)
     owner._gpr_relative_permittivity.setRange(0.0001, 1000.0)
     owner._gpr_relative_permittivity.setSingleStep(0.05)
+    owner._gpr_relative_permittivity.setToolTip("Applied on the next pipeline start (Save Config and restart).")
     owner._gpr_relative_permittivity.setValue(float(gpr_defaults.relative_permittivity))
 
     owner._gpr_tx_geometry_input = QPlainTextEdit(_format_tx_geometry(owner))
@@ -194,14 +198,13 @@ def build_processing_group(owner) -> QGroupBox:
     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_geometry_hint = QLabel("To apply Tx/Rx geometry or permittivity changes: Save Config and restart the app")
+    owner._gpr_geometry_hint = QLabel("To apply Tx/Rx geometry changes: Save Config and restart the app")
     owner._gpr_geometry_hint.setWordWrap(True)
     owner._gpr_common_page.layout().addWidget(owner._gpr_geometry_hint)
 
@@ -229,11 +232,15 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_range_comp_power.setSingleStep(0.01)
     owner._gpr_range_comp_power.setValue(float(gpr_live_defaults.range_comp_power))
 
-    owner._gpr_angle_comp_power = QDoubleSpinBox()
+    owner._gpr_object_min_frac = QDoubleSpinBox()
-    owner._gpr_angle_comp_power.setDecimals(3)
+    owner._gpr_object_min_frac.setDecimals(2)
-    owner._gpr_angle_comp_power.setRange(0.0, 5.0)
+    owner._gpr_object_min_frac.setRange(0.0, 1.0)
-    owner._gpr_angle_comp_power.setSingleStep(0.01)
+    owner._gpr_object_min_frac.setSingleStep(0.05)
-    owner._gpr_angle_comp_power.setValue(float(gpr_live_defaults.angle_comp_power))
+    owner._gpr_object_min_frac.setToolTip(
+        "Object detection stops once a peak falls below this fraction of the global "
+        "maximum (Horns_motion_3libre.py BP_OBJECT_MIN_FRAC)."
+    )
+    owner._gpr_object_min_frac.setValue(float(gpr_live_defaults.object_min_frac))
 
     owner._gpr_score_mode = QComboBox()
     owner._gpr_score_mode.addItems(["peak", "combined"])
@@ -289,6 +296,14 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_draw_top_m_objects.setRange(0, 10_000)
     owner._gpr_draw_top_m_objects.setValue(int(gpr_live_defaults.draw_top_m_objects))
 
+    owner._gpr_object_approach_min_frames = QSpinBox()
+    owner._gpr_object_approach_min_frames.setRange(1, 100)
+    owner._gpr_object_approach_min_frames.setToolTip(
+        "Show an object only after it persists as a motion-consistent track this many "
+        "consecutive frames (1 disables the approach filter)."
+    )
+    owner._gpr_object_approach_min_frames.setValue(int(gpr_live_defaults.object_approach_min_frames))
+
     owner._gpr_start_freq_mhz = QDoubleSpinBox()
     owner._gpr_start_freq_mhz.setDecimals(1)
     owner._gpr_start_freq_mhz.setRange(100.0, 8800.0)
@@ -315,12 +330,6 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_render_mode.addItems(["heatmap", "objects_only"])
     owner._set_combo_current_text(owner._gpr_render_mode, gpr_live_defaults.render_mode)
 
-    owner._gpr_min_visible_score = QDoubleSpinBox()
-    owner._gpr_min_visible_score.setDecimals(2)
-    owner._gpr_min_visible_score.setRange(0.0, 1.0)
-    owner._gpr_min_visible_score.setSingleStep(0.05)
-    owner._gpr_min_visible_score.setValue(float(gpr_live_defaults.min_visible_score))
-
     owner._gpr_visible_x_min_m = QDoubleSpinBox()
     owner._gpr_visible_x_min_m.setDecimals(2)
     owner._gpr_visible_x_min_m.setRange(-100.0, 100.0)
@@ -362,7 +371,7 @@ def build_processing_group(owner) -> QGroupBox:
             ("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),
+            ("Object min frac", owner._gpr_object_min_frac),
             ("Score mode", owner._gpr_score_mode),
             ("Motion mode", owner._gpr_motion_mode),
             ("Look angle deg", owner._gpr_look_angle_deg),
@@ -370,9 +379,9 @@ def build_processing_group(owner) -> QGroupBox:
             owner._gpr_ignore_socket_speed_enabled,
             ("Speed m/s", owner._gpr_speed_m_s),
             ("Render mode", owner._gpr_render_mode),
-            ("Min visible score", owner._gpr_min_visible_score),
             ("Max detected objects", owner._gpr_max_detected_objects_to_draw),
             ("Draw top M objects", owner._gpr_draw_top_m_objects),
+            ("Approach min frames", owner._gpr_object_approach_min_frames),
             ("Start MHz", owner._gpr_start_freq_mhz),
             ("Stop MHz", owner._gpr_stop_freq_mhz),
             ("Imaging plane Y m", owner._gpr_imaging_plane_y_m),
@@ -522,6 +531,7 @@ def build_processing_group(owner) -> QGroupBox:
         owner._processing_mode_pages,
         [
             ("Config mode", owner._legacy_gpr_config_mode),
+            ("Relative permittivity", owner._gpr_relative_permittivity),
             ("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),
@@ -574,7 +584,7 @@ def build_processing_group(owner) -> QGroupBox:
     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_object_min_frac.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._gpr_score_mode.currentTextChanged.connect(owner._on_processing_live_settings_changed)
     owner._gpr_motion_mode.currentTextChanged.connect(owner._on_processing_live_settings_changed)
     owner._gpr_look_angle_deg.valueChanged.connect(owner._on_processing_live_settings_changed)
@@ -588,9 +598,9 @@ def build_processing_group(owner) -> QGroupBox:
     owner._gpr_remove_sidelobe_objects_enabled.toggled.connect(owner._on_processing_live_settings_changed)
     owner._gpr_imaging_plane_y_m.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._gpr_render_mode.currentTextChanged.connect(owner._on_gpr_visual_settings_changed)
-    owner._gpr_min_visible_score.valueChanged.connect(owner._on_gpr_locator_threshold_changed)
     owner._gpr_max_detected_objects_to_draw.valueChanged.connect(owner._on_gpr_locator_threshold_changed)
     owner._gpr_draw_top_m_objects.valueChanged.connect(owner._on_gpr_locator_threshold_changed)
+    owner._gpr_object_approach_min_frames.valueChanged.connect(owner._on_processing_live_settings_changed)
     owner._gpr_visible_x_min_m.valueChanged.connect(owner._on_gpr_locator_window_changed)
     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)

python_app/models/gui_profile_codec.py

@@ -276,10 +276,10 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
                 gui.processing.gpr.range_comp_power,
                 "gui.processing.gpr",
             ),
-            angle_comp_power=_optional_float(
+            object_min_frac=_optional_float(
                 gpr_object,
-                "angle_comp_power",
+                "object_min_frac",
-                gui.processing.gpr.angle_comp_power,
+                gui.processing.gpr.object_min_frac,
                 "gui.processing.gpr",
             ),
             score_mode=_optional_string(
@@ -330,6 +330,12 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
                 gui.processing.gpr.draw_top_m_objects,
                 "gui.processing.gpr",
             ),
+            object_approach_min_frames=_optional_int(
+                gpr_object,
+                "object_approach_min_frames",
+                gui.processing.gpr.object_approach_min_frames,
+                "gui.processing.gpr",
+            ),
             start_freq_mhz=_optional_float(
                 gpr_object,
                 "start_freq_mhz",
@@ -372,12 +378,6 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
                 gui.processing.gpr.render_mode,
                 "gui.processing.gpr",
             ),
-            min_visible_score=_optional_float(
-                gpr_object,
-                "min_visible_score",
-                gui.processing.gpr.min_visible_score,
-                "gui.processing.gpr",
-            ),
             visible_x_min_m=_optional_float(
                 gpr_object,
                 "visible_x_min_m",
@@ -467,14 +467,14 @@ def gui_profile_from_dict(payload: dict[str, Any]) -> GuiProfileModel:
         )
     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:
+    if not 0.0 <= gui.processing.gpr.object_min_frac <= 1.0:
-        raise ValueError("gui.processing.gpr.angle_comp_power must be >= 0")
+        raise ValueError("gui.processing.gpr.object_min_frac must be within [0, 1]")
-    if gui.processing.gpr.min_visible_score < 0.0:
-        raise ValueError("gui.processing.gpr.min_visible_score must be >= 0")
     if gui.processing.gpr.max_detected_objects_to_draw < 0:
         raise ValueError("gui.processing.gpr.max_detected_objects_to_draw must be >= 0")
     if gui.processing.gpr.draw_top_m_objects < 0:
         raise ValueError("gui.processing.gpr.draw_top_m_objects must be >= 0")
+    if gui.processing.gpr.object_approach_min_frames < 1:
+        raise ValueError("gui.processing.gpr.object_approach_min_frames must be >= 1")
     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:
@@ -586,7 +586,7 @@ def gui_profile_to_dict(model: GuiProfileModel) -> dict[str, Any]:
                 "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,
+                "object_min_frac": gui.processing.gpr.object_min_frac,
                 "score_mode": gui.processing.gpr.score_mode,
                 "motion_mode": gui.processing.gpr.motion_mode,
                 "look_angle_deg": gui.processing.gpr.look_angle_deg,
@@ -595,6 +595,7 @@ def gui_profile_to_dict(model: GuiProfileModel) -> dict[str, Any]:
                 "ignore_socket_speed_enabled": gui.processing.gpr.ignore_socket_speed_enabled,
                 "max_detected_objects_to_draw": gui.processing.gpr.max_detected_objects_to_draw,
                 "draw_top_m_objects": gui.processing.gpr.draw_top_m_objects,
+                "object_approach_min_frames": gui.processing.gpr.object_approach_min_frames,
                 "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,
@@ -602,7 +603,6 @@ def gui_profile_to_dict(model: GuiProfileModel) -> dict[str, Any]:
                 "remove_sidelobe_objects_enabled": gui.processing.gpr.remove_sidelobe_objects_enabled,
                 "imaging_plane_y_m": gui.processing.gpr.imaging_plane_y_m,
                 "render_mode": gui.processing.gpr.render_mode,
-                "min_visible_score": gui.processing.gpr.min_visible_score,
                 "visible_x_min_m": gui.processing.gpr.visible_x_min_m,
                 "visible_x_max_m": gui.processing.gpr.visible_x_max_m,
                 "visible_z_min_m": gui.processing.gpr.visible_z_min_m,

python_app/models/gui_profile_schema.py

@@ -59,7 +59,10 @@ class GuiGprStateModel:
     min_depth_m: float = 2.0
     max_depth_m: float = 14.0
     range_comp_power: float = 0.1
-    angle_comp_power: float = 0.0
+    # BP object-detection stop level, fraction of the global peak (Horns_motion_3libre.py
+    # BP_OBJECT_MIN_FRAC). Angle compensation and permittivity are fixed for coherent BP
+    # (Python 0.3 block), so they are not exposed here.
+    object_min_frac: float = 0.7
     score_mode: str = "combined"
     motion_mode: str = "int_minus"
     # Intra-sweep motion-correction inputs. Sweep time is derived from acquisition
@@ -71,6 +74,9 @@ class GuiGprStateModel:
     ignore_socket_speed_enabled: bool = False
     max_detected_objects_to_draw: int = 5
     draw_top_m_objects: int = 2
+    # Cross-frame approach filter: show an object only after it persists as a
+    # motion-consistent track this many consecutive frames (<= 1 disables it).
+    object_approach_min_frames: int = 3
     start_freq_mhz: float = 3000.0
     stop_freq_mhz: float = 6000.0
     background_subtract_enabled: bool = True
@@ -78,7 +84,6 @@ class GuiGprStateModel:
     remove_sidelobe_objects_enabled: bool = True
     imaging_plane_y_m: float = 0.0
     render_mode: str = "heatmap"
-    min_visible_score: float = 0.0
     visible_x_min_m: float = -2.0
     visible_x_max_m: float = 2.0
     visible_z_min_m: float = 0.0

python_app/orchestration/live_processing_config.py

@@ -32,8 +32,8 @@ class ProcessingLiveConfig:
     gpr_min_depth_m: float = 2.0
     gpr_max_depth_m: float = 14.0
     gpr_range_comp_power: float = 0.1
-    gpr_angle_comp_power: float = 0.0
     gpr_comp_power: float = 0.2
+    gpr_object_min_frac: float = 0.7
     gpr_score_mode: str = "combined"
     # Backprojection intra-sweep speed-correction mode: "int_minus" (full
     # correction) or "int_focus" (focusing residual only). Mirrors Python
@@ -41,6 +41,7 @@ class ProcessingLiveConfig:
     gpr_motion_mode: str = "int_minus"
     gpr_max_detected_objects_to_draw: int = 5
     gpr_draw_top_m_objects: int = 2
+    gpr_object_approach_min_frames: int = 3
     gpr_speed_m_s: float = 0.0
     gpr_look_angle_deg: float = 0.0
     # Motion-model knobs for the legacy GPR pipeline. `direction_sign` flips
@@ -61,8 +62,9 @@ class ProcessingLiveConfig:
     gpr_background_mean_count: int = 10
     gpr_remove_sidelobe_objects_enabled: bool = True
     gpr_imaging_plane_y_m: float = 0.0
-    # Locator filter parameters consumed by the C++ TCP locator server.
+    # Locator filter parameter consumed by the C++ TCP locator server. Coherent BP
-    gpr_min_visible_score: float = 0.0
+    # objects are already finalized in the processor (no score threshold); only legacy
+    # GPR still thresholds, on a pair count.
     legacy_gpr_min_visible_pair_count: float = 0.0
     # Visible X/Z window (metres). The locator and the desktop plot both clip
     # detected objects to this window, so the socket broadcasts only what is shown.
@@ -109,12 +111,13 @@ class ProcessingLiveConfig:
             "gpr_min_depth_m": float(self.gpr_min_depth_m),
             "gpr_max_depth_m": float(self.gpr_max_depth_m),
             "gpr_range_comp_power": float(self.gpr_range_comp_power),
-            "gpr_angle_comp_power": float(self.gpr_angle_comp_power),
             "gpr_comp_power": float(self.gpr_comp_power),
+            "gpr_object_min_frac": float(self.gpr_object_min_frac),
             "gpr_score_mode": str(self.gpr_score_mode),
             "gpr_motion_mode": str(self.gpr_motion_mode),
             "gpr_max_detected_objects_to_draw": int(self.gpr_max_detected_objects_to_draw),
             "gpr_draw_top_m_objects": int(self.gpr_draw_top_m_objects),
+            "gpr_object_approach_min_frames": int(self.gpr_object_approach_min_frames),
             "gpr_speed_m_s": float(self.gpr_speed_m_s),
             "gpr_look_angle_deg": float(self.gpr_look_angle_deg),
             "gpr_direction_sign": float(self.gpr_direction_sign),
@@ -128,7 +131,6 @@ class ProcessingLiveConfig:
             "gpr_background_mean_count": int(self.gpr_background_mean_count),
             "gpr_remove_sidelobe_objects_enabled": bool(self.gpr_remove_sidelobe_objects_enabled),
             "gpr_imaging_plane_y_m": float(self.gpr_imaging_plane_y_m),
-            "gpr_min_visible_score": float(self.gpr_min_visible_score),
             "legacy_gpr_min_visible_pair_count": float(self.legacy_gpr_min_visible_pair_count),
             "gpr_visible_x_min_m": float(self.gpr_visible_x_min_m),
             "gpr_visible_x_max_m": float(self.gpr_visible_x_max_m),

python_app/tests/test_storage_webui.py

@@ -161,8 +161,8 @@ class WebControllerTest(unittest.TestCase):
     def test_known_field_emits_and_returns_snapshot(self) -> None:
         received: list[dict] = []
         self.controller.apply_settings_requested.connect(received.append)
-        out = self.controller.apply_live_settings({"gpr_min_visible_score": 0.5})
+        out = self.controller.apply_live_settings({"gpr_object_min_frac": 0.5})
-        self.assertEqual(received, [{"gpr_min_visible_score": 0.5}])
+        self.assertEqual(received, [{"gpr_object_min_frac": 0.5}])
         self.assertIsInstance(out, list)
 
     def test_snapshot_is_replaced_and_returned_as_copy(self) -> None:

run_config.json

@@ -282,7 +282,7 @@
         "min_depth_m": 2.0,
         "max_depth_m": 14.0,
         "range_comp_power": 0.1,
-        "angle_comp_power": 0.0,
+        "object_min_frac": 0.7,
         "score_mode": "combined",
         "motion_mode": "int_minus",
         "look_angle_deg": 0.0,
@@ -291,6 +291,7 @@
         "ignore_socket_speed_enabled": false,
         "max_detected_objects_to_draw": 5,
         "draw_top_m_objects": 2,
+        "object_approach_min_frames": 3,
         "start_freq_mhz": 3000.0,
         "stop_freq_mhz": 6000.0,
         "background_subtract_enabled": true,
@@ -298,7 +299,6 @@
         "remove_sidelobe_objects_enabled": false,
         "imaging_plane_y_m": 0.0,
         "render_mode": "heatmap",
-        "min_visible_score": 0.0,
         "visible_x_min_m": -2.0,
         "visible_x_max_m": 2.0,
         "visible_z_min_m": 0.0,

run_config_examples/run_config_simulator.example.json

@@ -282,7 +282,7 @@
         "min_depth_m": 2.0,
         "max_depth_m": 14.0,
         "range_comp_power": 0.1,
-        "angle_comp_power": 0.0,
+        "object_min_frac": 0.7,
         "score_mode": "combined",
         "motion_mode": "int_minus",
         "look_angle_deg": 0.0,
@@ -291,6 +291,7 @@
         "ignore_socket_speed_enabled": false,
         "max_detected_objects_to_draw": 5,
         "draw_top_m_objects": 2,
+        "object_approach_min_frames": 3,
         "start_freq_mhz": 3000.0,
         "stop_freq_mhz": 6000.0,
         "background_subtract_enabled": true,
@@ -298,7 +299,6 @@
         "remove_sidelobe_objects_enabled": false,
         "imaging_plane_y_m": 0.0,
         "render_mode": "heatmap",
-        "min_visible_score": 0.0,
         "visible_x_min_m": -2.0,
         "visible_x_max_m": 2.0,
         "visible_z_min_m": 0.0,

run_configs/run_config.json

@@ -282,7 +282,7 @@
         "min_depth_m": 2.0,
         "max_depth_m": 14.0,
         "range_comp_power": 0.1,
-        "angle_comp_power": 0.0,
+        "object_min_frac": 0.7,
         "score_mode": "combined",
         "motion_mode": "int_minus",
         "look_angle_deg": 0.0,
@@ -291,6 +291,7 @@
         "ignore_socket_speed_enabled": false,
         "max_detected_objects_to_draw": 5,
         "draw_top_m_objects": 2,
+        "object_approach_min_frames": 3,
         "start_freq_mhz": 3000.0,
         "stop_freq_mhz": 6000.0,
         "background_subtract_enabled": true,
@@ -298,7 +299,6 @@
         "remove_sidelobe_objects_enabled": false,
         "imaging_plane_y_m": 0.0,
         "render_mode": "heatmap",
-        "min_visible_score": 0.0,
         "visible_x_min_m": -2.0,
         "visible_x_max_m": 2.0,
         "visible_z_min_m": 0.0,