historical packets

assets/css/app.css

@@ -181,8 +181,22 @@ body.home-page main > div {
 
 /* Trail polyline hover effect */
 .leaflet-interactive:hover {
-    stroke-width: 4;
+    stroke-width: 5;
+    stroke-opacity: 1 !important;
+}
+
+/* Historical trail lines */
+.leaflet-interactive[stroke="#1E90FF"] {
+    stroke-width: 3;
     stroke-opacity: 0.8;
+    stroke-linecap: round;
+    stroke-linejoin: round;
+}
+
+.leaflet-interactive[stroke="#1E90FF"]:hover {
+    stroke-width: 5;
+    stroke-opacity: 1;
+    filter: drop-shadow(0 0 4px #1e90ff);
 }
 
 /* Position dot hover effect */
@@ -210,3 +224,52 @@ body.home-page main > div {
     background-color: #1e90ff;
     color: white;
 }
+
+/* Historical dot marker styles */
+.historical-dot-marker {
+    cursor: pointer;
+    transition: transform 0.2s ease-out;
+}
+
+.historical-dot-marker:hover {
+    transform: scale(1.5);
+    z-index: 1000 !important;
+}
+
+.historical-dot-marker div {
+    box-shadow: 0 0 4px rgba(0, 0, 0, 0.4);
+    transition: all 0.2s ease-out;
+}
+
+.historical-dot-marker:hover div {
+    box-shadow: 0 0 8px rgba(255, 107, 107, 0.8);
+    border-color: #ff6b6b !important;
+}
+
+/* Historical trail line styling */
+.historical-trail-line {
+    stroke: #1e90ff;
+    stroke-width: 3;
+    stroke-opacity: 0.8;
+    stroke-linecap: round;
+    stroke-linejoin: round;
+    fill: none;
+    transition: all 0.2s ease-out;
+    z-index: 1;
+}
+
+.historical-trail-line:hover {
+    stroke-width: 5;
+    stroke-opacity: 1;
+    filter: drop-shadow(0 0 4px #1e90ff);
+    z-index: 2;
+}
+
+/* Ensure markers are above trail lines */
+.leaflet-marker-icon {
+    z-index: 10 !important;
+}
+
+.historical-dot-marker {
+    z-index: 15 !important;
+}

assets/js/features/trail_manager.ts

@@ -32,29 +32,62 @@ export class TrailManager {
     }
   }
 
-  addPosition(markerId: string, lat: number, lng: number, timestamp: number) {
+  addPosition(
+    markerId: string,
+    lat: number,
+    lng: number,
+    timestamp: number,
+    isHistoricalDot: boolean = false,
+  ) {
     if (!this.showTrails) return;
 
-    let trailState = this.trails.get(markerId);
+    // Extract base callsign from markerId to group positions by callsign
+    const baseCallsign = this.extractBaseCallsign(markerId);
+
+    let trailState = this.trails.get(baseCallsign);
     if (!trailState) {
       trailState = { positions: [] };
-      this.trails.set(markerId, trailState);
+      this.trails.set(baseCallsign, trailState);
     }
 
-    // Only add if position is different from the last one
+    // Only add if position is different from the last one (more than ~1 meter)
     const lastPos = trailState.positions[trailState.positions.length - 1];
-    if (!lastPos || Math.abs(lastPos.lat - lat) > 0.0001 || Math.abs(lastPos.lng - lng) > 0.0001) {
+    if (
+      !lastPos ||
+      Math.abs(lastPos.lat - lat) > 0.00001 ||
+      Math.abs(lastPos.lng - lng) > 0.00001
+    ) {
       trailState.positions.push({ lat, lng, timestamp });
     }
 
-    // Filter positions to keep only recent ones
-    const cutoffTime = Date.now() - this.trailDuration;
-    trailState.positions = trailState.positions.filter((pos) => pos.timestamp >= cutoffTime);
+    // For historical dots, keep all positions. For live positions, filter by time.
+    if (!isHistoricalDot) {
+      const cutoffTime = Date.now() - this.trailDuration;
+      trailState.positions = trailState.positions.filter((pos) => {
+        // Ensure timestamp is a number for comparison
+        const posTimestamp =
+          typeof pos.timestamp === "string" ? new Date(pos.timestamp).getTime() : pos.timestamp;
+        return posTimestamp >= cutoffTime;
+      });
+    }
 
-    this.updateTrailVisualization(markerId, trailState);
+    // Always update trail visualization
+    this.updateTrailVisualization(baseCallsign, trailState);
   }
 
-  private updateTrailVisualization(markerId: string, trailState: TrailState) {
+  private extractBaseCallsign(markerId: string | any): string {
+    // Ensure markerId is a string
+    const id = typeof markerId === "string" ? markerId : String(markerId);
+
+    // Extract base callsign from various ID formats
+    if (id.startsWith("hist_")) {
+      // Remove hist_ prefix and any trailing index
+      return id.replace(/^hist_/, "").replace(/_\d+$/, "");
+    }
+    return id;
+  }
+
+  private updateTrailVisualization(baseCallsign: string, trailState: TrailState) {
     // Remove old trail and dots
     if (trailState.trail) {
       this.trailLayer.removeLayer(trailState.trail);
@@ -69,45 +102,25 @@ export class TrailManager {
       const L = (window as any).L;
       const latLngs = trailState.positions.map((pos) => [pos.lat, pos.lng]);
 
-      // Create polyline for the trail
+      // Create blue polyline connecting the historical position dots
       trailState.trail = L.polyline(latLngs, {
         color: "#1E90FF",
         weight: 3,
-        opacity: 0.5,
+        opacity: 0.8,
         smoothFactor: 1,
+        lineCap: "round",
+        lineJoin: "round",
+        className: "historical-trail-line",
       }).addTo(this.trailLayer);
 
-      // Create dots for each position
-      trailState.dots = trailState.positions.map((pos, index) => {
-        const age = (Date.now() - pos.timestamp) / this.trailDuration;
-        const opacity = Math.max(0.4, 1 - age * 0.6);
-        const isCurrentPosition = index === trailState.positions.length - 1;
-        const radius = isCurrentPosition ? 5 : 3;
-
-        const dot = L.circleMarker([pos.lat, pos.lng], {
-          radius: radius,
-          fillColor: "#FF4500",
-          color: "#8B0000",
-          weight: 1,
-          opacity: opacity,
-          fillOpacity: opacity * 0.8,
-        });
-
-        // Add tooltip with timestamp
-        const time = new Date(pos.timestamp);
-        dot.bindTooltip(time.toLocaleTimeString(), {
-          permanent: false,
-          direction: "top",
-          className: "trail-tooltip",
-        });
-
-        return dot.addTo(this.trailLayer);
-      });
+      // Don't create additional dots here since historical positions are now shown as markers
+      trailState.dots = [];
     }
   }
 
   removeTrail(markerId: string) {
-    const trailState = this.trails.get(markerId);
+    const baseCallsign = this.extractBaseCallsign(markerId);
+    const trailState = this.trails.get(baseCallsign);
     if (trailState) {
       if (trailState.trail) {
         this.trailLayer.removeLayer(trailState.trail);
@@ -115,7 +128,7 @@ export class TrailManager {
       if (trailState.dots) {
         trailState.dots.forEach((dot) => this.trailLayer.removeLayer(dot));
       }
-      this.trails.delete(markerId);
+      this.trails.delete(baseCallsign);
     }
   }
 
@@ -126,12 +139,21 @@ export class TrailManager {
   }
 
   cleanupOldPositions() {
-    const cutoffTime = Date.now() - this.trailDuration;
+    // Don't clean up historical positions - only clean up very old live positions
+    const veryOldCutoff = Date.now() - 24 * 60 * 60 * 1000; // 24 hours
     this.trails.forEach((trailState, markerId) => {
-      trailState.positions = trailState.positions.filter((pos) => pos.timestamp >= cutoffTime);
+      const originalLength = trailState.positions.length;
+      trailState.positions = trailState.positions.filter((pos) => {
+        // Ensure timestamp is a number for comparison
+        const posTimestamp =
+          typeof pos.timestamp === "string" ? new Date(pos.timestamp).getTime() : pos.timestamp;
+        // Keep all positions newer than 24 hours (includes all historical data we care about)
+        return posTimestamp >= veryOldCutoff;
+      });
+
       if (trailState.positions.length === 0) {
         this.removeTrail(markerId);
-      } else {
+      } else if (trailState.positions.length !== originalLength) {
         this.updateTrailVisualization(markerId, trailState);
       }
     });

assets/js/map.ts

@@ -39,6 +39,8 @@ interface MarkerData {
   historical?: boolean;
   color?: string;
   timestamp?: number;
+  is_most_recent_for_callsign?: boolean;
+  callsign_group?: string;
 }
 
 interface BoundsData {
@@ -60,6 +62,8 @@ interface MarkerState {
   symbol_code: string;
   popup?: string;
   historical?: boolean;
+  is_most_recent_for_callsign?: boolean;
+  callsign_group?: string;
 }
 
 interface MapEventData {
@@ -536,11 +540,41 @@ let MapAPRSMap = {
     // Handle bulk loading of historical packets
     self.handleEvent("add_historical_packets", (data: { packets: MarkerData[] }) => {
       if (data.packets && Array.isArray(data.packets)) {
+        // Group packets by callsign to process them in chronological order for proper trail drawing
+        const packetsByCallsign = new Map<string, MarkerData[]>();
+
         data.packets.forEach((packet) => {
-          self.addMarker({
-            ...packet,
-            historical: true,
-            popup: self.buildPopupContent(packet),
+          const callsign = packet.callsign_group || packet.callsign || packet.id;
+          if (!packetsByCallsign.has(callsign)) {
+            packetsByCallsign.set(callsign, []);
+          }
+          packetsByCallsign.get(callsign)!.push(packet);
+        });
+
+        // Process each callsign group in chronological order (oldest first)
+        packetsByCallsign.forEach((packets, callsign) => {
+          // Sort by timestamp (oldest first) to ensure proper trail line drawing
+          const sortedPackets = packets.sort((a, b) => {
+            const timeA = a.timestamp
+              ? typeof a.timestamp === "number"
+                ? a.timestamp
+                : new Date(a.timestamp).getTime()
+              : 0;
+            const timeB = b.timestamp
+              ? typeof b.timestamp === "number"
+                ? b.timestamp
+                : new Date(b.timestamp).getTime()
+              : 0;
+            return timeA - timeB;
+          });
+
+          // Add markers in chronological order
+          sortedPackets.forEach((packet) => {
+            self.addMarker({
+              ...packet,
+              historical: true,
+              popup: self.buildPopupContent(packet),
+            });
           });
         });
       }
@@ -561,7 +595,7 @@ let MapAPRSMap = {
       const markersToRemove: string[] = [];
       self.markers!.forEach((marker: any, id: any) => {
         if ((marker as any)._isHistorical) {
-          markersToRemove.push(id);
+          markersToRemove.push(String(id));
         }
       });
       markersToRemove.forEach((id) => self.removeMarker(id));
@@ -643,7 +677,13 @@ let MapAPRSMap = {
 
       if (positionChanged && self.trailManager) {
         // Position changed, update trail
-        self.trailManager.addPosition(data.id, lat, lng, data.timestamp || Date.now());
+        const isHistoricalDot = data.historical && !data.is_most_recent_for_callsign;
+        const timestamp = data.timestamp
+          ? typeof data.timestamp === "string"
+            ? new Date(data.timestamp).getTime()
+            : data.timestamp
+          : Date.now();
+        self.trailManager.addPosition(data.id, lat, lng, timestamp, isHistoricalDot);
       }
 
       if (!positionChanged && !dataChanged) {
@@ -659,7 +699,7 @@ let MapAPRSMap = {
     // Remove existing marker if it exists
     self.removeMarker(data.id);
 
-    // Create marker using APRS symbol icon
+    // Create marker - use simple dot for older historical positions, APRS icon for most recent
     const marker = L.marker([lat, lng], {
       icon: self.createMarkerIcon(data),
     });
@@ -697,11 +737,19 @@ let MapAPRSMap = {
       symbol_code: data.symbol_code || ">",
       popup: data.popup,
       historical: data.historical,
+      is_most_recent_for_callsign: data.is_most_recent_for_callsign,
+      callsign_group: data.callsign_group,
     });
 
-    // Initialize trail for new marker
+    // Initialize trail for new marker - always add to trail for line drawing
     if (self.trailManager) {
-      self.trailManager.addPosition(data.id, lat, lng, data.timestamp || Date.now());
+      const isHistoricalDot = data.historical && !data.is_most_recent_for_callsign;
+      const timestamp = data.timestamp
+        ? typeof data.timestamp === "string"
+          ? new Date(data.timestamp).getTime()
+          : data.timestamp
+        : Date.now();
+      self.trailManager.addPosition(data.id, lat, lng, timestamp, isHistoricalDot);
     }
 
     // Open popup if requested
@@ -710,18 +758,21 @@ let MapAPRSMap = {
     }
   },
 
-  removeMarker(id: string) {
+  removeMarker(id: string | any) {
     const self = this as unknown as LiveViewHookContext;
-    const marker = self.markers!.get(id);
+    // Ensure id is a string
+    const markerId = typeof id === "string" ? id : String(id);
+
+    const marker = self.markers!.get(markerId);
     if (marker) {
       self.markerLayer!.removeLayer(marker);
-      self.markers!.delete(id);
-      self.markerStates!.delete(id);
+      self.markers!.delete(markerId);
+      self.markerStates!.delete(markerId);
     }
 
     // Remove trail
     if (self.trailManager) {
-      self.trailManager.removeTrail(id);
+      self.trailManager.removeTrail(markerId);
     }
   },
 
@@ -743,7 +794,13 @@ let MapAPRSMap = {
           if (positionChanged) {
             existingMarker.setLatLng([lat, lng]);
             if (self.trailManager) {
-              self.trailManager.addPosition(data.id, lat, lng, data.timestamp || Date.now());
+              const isHistoricalDot = data.historical && !data.is_most_recent_for_callsign;
+              const timestamp = data.timestamp
+                ? typeof data.timestamp === "string"
+                  ? new Date(data.timestamp).getTime()
+                  : data.timestamp
+                : Date.now();
+              self.trailManager.addPosition(data.id, lat, lng, timestamp, isHistoricalDot);
             }
           }
         }
@@ -802,10 +859,32 @@ let MapAPRSMap = {
     });
 
     // Remove out-of-bounds markers
-    markersToRemove.forEach((id) => self.removeMarker(id));
+    markersToRemove.forEach((id) => self.removeMarker(String(id)));
   },
 
   createMarkerIcon(data: MarkerData): L.DivIcon {
+    // For historical packets that are not the most recent for their callsign,
+    // show a simple red dot (only positions where lat/lon actually changed)
+    if (data.historical && !data.is_most_recent_for_callsign) {
+      const iconHtml = `<div style="
+        width: 8px;
+        height: 8px;
+        background-color: #FF6B6B;
+        border: 2px solid #FFFFFF;
+        border-radius: 50%;
+        opacity: 0.8;
+        box-shadow: 0 0 2px rgba(0,0,0,0.3);
+      " title="Historical position for ${data.callsign} (position changed)"></div>`;
+
+      return L.divIcon({
+        html: iconHtml,
+        className: "historical-dot-marker",
+        iconSize: [12, 12],
+        iconAnchor: [6, 6],
+      });
+    }
+
+    // For current packets or most recent historical packets, show the full APRS symbol icon
     const symbolTableId = data.symbol_table_id || "/";
     const symbolCode = getValidSymbolCode(data.symbol_code, symbolTableId);
 
@@ -841,7 +920,7 @@ let MapAPRSMap = {
       background-size: 512px 192px;
       background-repeat: no-repeat;
       image-rendering: pixelated;
-      opacity: ${data.historical ? "0.7" : "1.0"};
+      opacity: ${data.historical && data.is_most_recent_for_callsign ? "0.9" : "1.0"};
       overflow: hidden;
     " data-symbol-table="${symbolTableId}" data-symbol-code="${symbolCode}" data-sprite-position="${x},${y}" data-expected-index="${index}" title="Symbol: ${symbolCode} (${charCode}) at row ${row}, col ${column}"></div>`;
 

lib/aprs_web/live/map_live/callsign_view.ex

@@ -720,21 +720,94 @@ defmodule AprsWeb.MapLive.CallsignView do
         now
       )
 
-    socket =
+    if Enum.empty?(packets) do
+      # No historical packets found
+      socket
+    else
+      # Clear any previous historical packets from the map
+      socket = push_event(socket, "clear_historical_packets", %{})
+
+      # Sort packets by inserted_at to identify the most recent
+      # Convert NaiveDateTime to DateTime if needed for proper comparison
+      sorted_packets =
+        Enum.sort_by(
+          packets,
+          fn packet ->
+            case packet.inserted_at do
+              %NaiveDateTime{} = naive_dt ->
+                DateTime.from_naive!(naive_dt, "Etc/UTC")
+
+              %DateTime{} = dt ->
+                dt
+
+              _other ->
+                DateTime.utc_now()
+            end
+          end,
+          {:desc, DateTime}
+        )
+
+      # Filter out packets with unchanged positions (only keep if lat/lon changed)
+      unique_position_packets = filter_unique_positions(sorted_packets)
+
+      # Build packet data for all positions, marking which is the most recent
+      packet_data_list =
+        unique_position_packets
+        |> Enum.with_index()
+        |> Enum.map(fn {packet, index} ->
+          case build_packet_data(packet) do
+            nil ->
+              nil
+
+            packet_data ->
+              # Generate a unique ID for this historical packet
+              packet_id =
+                "hist_#{if Map.has_key?(packet, :id), do: packet.id, else: System.unique_integer([:positive])}_#{index}"
+
+              is_most_recent = index == 0
+              callsign = socket.assigns.callsign
+
+              packet_data
+              |> Map.put("id", packet_id)
+              |> Map.put("is_historical", true)
+              |> Map.put("is_most_recent_for_callsign", is_most_recent)
+              |> Map.put("callsign_group", callsign)
+              |> Map.put(
+                "timestamp",
+                case packet.inserted_at do
+                  %NaiveDateTime{} = naive_dt ->
+                    DateTime.to_unix(DateTime.from_naive!(naive_dt, "Etc/UTC"), :millisecond)
+
+                  %DateTime{} = dt ->
+                    DateTime.to_unix(dt, :millisecond)
+
+                  _other ->
+                    DateTime.to_unix(DateTime.utc_now(), :millisecond)
+                end
+              )
+          end
+        end)
+        |> Enum.filter(& &1)
+
+      # Send all historical packets at once
+      socket = push_event(socket, "add_historical_packets", %{packets: packet_data_list})
+
+      # Store historical packets in assigns for reference
+      historical_packets_map =
+        packet_data_list
+        |> Enum.zip(unique_position_packets)
+        |> Enum.reduce(%{}, fn {packet_data, packet}, acc ->
+          Map.put(acc, packet_data["id"], packet)
+        end)
+
       assign(socket,
-        replay_packets: packets,
+        historical_packets: historical_packets_map,
+        replay_packets: [],
         replay_index: 0,
         replay_start_time: one_hour_ago,
-        replay_end_time: now,
-        historical_packets: %{}
+        replay_end_time: now
       )
-
-    # Start replay immediately if we have packets
-    if length(packets) > 0 do
-      Process.send_after(self(), :replay_next_packet, 100)
     end
-
-    socket
   end
 
   defp fetch_historical_packets_for_callsign(callsign, start_time, end_time) do
@@ -746,6 +819,43 @@ defmodule AprsWeb.MapLive.CallsignView do
     })
   end
 
+  # Filter packets to only include those with unique positions (lat/lon changed)
+  @spec filter_unique_positions([struct()]) :: [struct()]
+  defp filter_unique_positions(packets) do
+    packets
+    |> Enum.reduce([], fn packet, acc ->
+      {lat, lng, _} = MapHelpers.get_coordinates(packet)
+
+      if lat && lng do
+        # Check if this position is different from the last position
+        case acc do
+          [] ->
+            # First packet, always include
+            [packet | acc]
+
+          [last_packet | _] ->
+            if position_changed?(packet, last_packet) do
+              [packet | acc]
+            else
+              acc
+            end
+        end
+      else
+        acc
+      end
+    end)
+    |> Enum.reverse()
+  end
+
+  # Check if position changed significantly between two packets (more than ~1 meter)
+  @spec position_changed?(struct(), struct()) :: boolean()
+  defp position_changed?(packet1, packet2) do
+    {lat1, lng1, _} = MapHelpers.get_coordinates(packet1)
+    {lat2, lng2, _} = MapHelpers.get_coordinates(packet2)
+
+    abs(lat1 - lat2) > 0.00001 || abs(lng1 - lng2) > 0.00001
+  end
+
   defp build_packet_data(packet) do
     {lat, lng, _} = MapHelpers.get_coordinates(packet)
     callsign = Map.get(packet, :base_callsign, Map.get(packet, "base_callsign", ""))

lib/aprs_web/live/map_live/index.ex

@@ -594,43 +594,79 @@ defmodule AprsWeb.MapLive.Index do
         # Clear any previous historical packets from the map
         socket = push_event(socket, "clear_historical_packets", %{})
 
-        # Group packets by callsign and get only the most recent for each
-        latest_packets_by_callsign =
+        # Group packets by callsign-ssid and process all positions
+        packet_data_list =
           historical_packets
           |> Enum.group_by(&generate_callsign/1)
-          |> Enum.map(fn {_callsign, packets} ->
-            # Sort by received_at descending and take the most recent
-            Enum.max_by(packets, & &1.received_at, DateTime)
+          |> Enum.flat_map(fn {callsign, packets} ->
+            # Sort packets by inserted_at to identify the most recent
+            # Convert NaiveDateTime to DateTime if needed for proper comparison
+            sorted_packets =
+              Enum.sort_by(
+                packets,
+                fn packet ->
+                  case packet.inserted_at do
+                    %NaiveDateTime{} = naive_dt ->
+                      DateTime.from_naive!(naive_dt, "Etc/UTC")
+
+                    %DateTime{} = dt ->
+                      dt
+
+                    _other ->
+                      DateTime.utc_now()
+                  end
+                end,
+                {:desc, DateTime}
+              )
+
+            # Filter out packets with unchanged positions (only keep if lat/lon changed)
+            unique_position_packets = filter_unique_positions(sorted_packets)
+
+            # Process all packets with unique positions, marking which is the most recent
+            unique_position_packets
+            |> Enum.with_index()
+            |> Enum.map(fn {packet, index} ->
+              case build_packet_data(packet) do
+                nil ->
+                  nil
+
+                packet_data ->
+                  # Generate a unique ID for this historical packet
+                  packet_id =
+                    "hist_#{if Map.has_key?(packet, :id), do: packet.id, else: System.unique_integer([:positive])}_#{index}"
+
+                  is_most_recent = index == 0
+
+                  packet_data
+                  |> Map.put("id", packet_id)
+                  |> Map.put("is_historical", true)
+                  |> Map.put("is_most_recent_for_callsign", is_most_recent)
+                  |> Map.put("callsign_group", callsign)
+                  |> Map.put(
+                    "timestamp",
+                    case packet.inserted_at do
+                      %NaiveDateTime{} = naive_dt ->
+                        DateTime.to_unix(DateTime.from_naive!(naive_dt, "Etc/UTC"), :millisecond)
+
+                      %DateTime{} = dt ->
+                        DateTime.to_unix(dt, :millisecond)
+
+                      _other ->
+                        DateTime.to_unix(DateTime.utc_now(), :millisecond)
+                    end
+                  )
+              end
+            end)
+            |> Enum.filter(& &1)
           end)
 
-        # Build packet data for all latest packets
-        packet_data_list =
-          latest_packets_by_callsign
-          |> Enum.map(fn packet ->
-            case build_packet_data(packet) do
-              nil ->
-                nil
-
-              packet_data ->
-                # Generate a unique ID for this historical packet
-                packet_id =
-                  "hist_#{if Map.has_key?(packet, :id), do: packet.id, else: System.unique_integer([:positive])}"
-
-                packet_data
-                |> Map.put("id", packet_id)
-                |> Map.put("is_historical", true)
-            end
-          end)
-          # Remove nil values
-          |> Enum.filter(& &1)
-
         # Send all historical packets at once
         socket = push_event(socket, "add_historical_packets", %{packets: packet_data_list})
 
         # Store historical packets in assigns for reference
         historical_packets_map =
           packet_data_list
-          |> Enum.zip(latest_packets_by_callsign)
+          |> Enum.zip(historical_packets)
           |> Enum.reduce(%{}, fn {packet_data, packet}, acc ->
             Map.put(acc, packet_data["id"], packet)
           end)
@@ -645,6 +681,42 @@ defmodule AprsWeb.MapLive.Index do
     end
   end
 
+  # Filter packets to only include those with unique positions (lat/lon changed)
+  @spec filter_unique_positions([struct()]) :: [struct()]
+  defp filter_unique_positions(packets) do
+    packets
+    |> Enum.reduce([], fn packet, acc ->
+      {lat, lng, _} = MapHelpers.get_coordinates(packet)
+
+      if lat && lng do
+        case acc do
+          [] ->
+            # First packet, always include
+            [packet | acc]
+
+          [last_packet | _] ->
+            if position_changed?(packet, last_packet) do
+              [packet | acc]
+            else
+              acc
+            end
+        end
+      else
+        acc
+      end
+    end)
+    |> Enum.reverse()
+  end
+
+  # Check if position changed significantly between two packets (more than ~1 meter)
+  @spec position_changed?(struct(), struct()) :: boolean()
+  defp position_changed?(packet1, packet2) do
+    {lat1, lng1, _} = MapHelpers.get_coordinates(packet1)
+    {lat2, lng2, _} = MapHelpers.get_coordinates(packet2)
+
+    abs(lat1 - lat2) > 0.00001 || abs(lng1 - lng2) > 0.00001
+  end
+
   # Fetch historical packets from the database
   @spec fetch_historical_packets(list(), DateTime.t(), DateTime.t()) :: [struct()]
   defp fetch_historical_packets(bounds, start_time, end_time) do