From 7938de708b06f1fee24e6921721d023d134c3521 Mon Sep 17 00:00:00 2001
From: Alain Knaff <alain@knaff.lu>
Date: Sat, 16 May 2026 14:11:55 +0200
Subject: [PATCH] Only log point if new point is further away from previous
 than its accuracy

---
 app/src/main/java/net/osmtracker/OSMTracker.java         | 3 +++
 .../main/java/net/osmtracker/service/gps/GPSLogger.java  | 9 +++++++++
 app/src/main/res/values/strings-preferences.xml          | 2 ++
 app/src/main/res/xml/preferences.xml                     | 7 ++++++-
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/net/osmtracker/OSMTracker.java b/app/src/main/java/net/osmtracker/OSMTracker.java
index 3accb77c..8a81ac22 100644
--- a/app/src/main/java/net/osmtracker/OSMTracker.java
+++ b/app/src/main/java/net/osmtracker/OSMTracker.java
@@ -23,6 +23,8 @@ public static final class Preferences {
 		public final static String KEY_GPS_IGNORE_CLOCK = "gps.ignoreclock";
 		public final static String KEY_GPS_LOGGING_INTERVAL = "gps.logging.interval";
 		public final static String KEY_GPS_LOGGING_MIN_DISTANCE = "gps.logging.min_distance";
+		public final static String KEY_GPS_LOGGING_DIST_GT_ACCURACY = "gps.logging.dist_gt_accuracy";
+
 		public final static String KEY_USE_BAROMETER = "gpx.use_barometer";
 		public final static String KEY_USE_NOTES = "gpx.notes";
 		public final static String KEY_OUTPUT_FILENAME = "gpx.filename";
@@ -61,6 +63,7 @@ public static final class Preferences {
 		public final static boolean VAL_GPS_IGNORE_CLOCK = false;
 		public final static String VAL_GPS_LOGGING_INTERVAL = "0";
 		public final static String VAL_GPS_LOGGING_MIN_DISTANCE = "0";
+		public final static boolean VAL_GPS_LOGGING_DIST_GT_ACCURACY = false;
 		public final static boolean VAL_USE_BAROMETER = false;
 		public final static String VAL_USE_NOTES = "both";
 		
diff --git a/app/src/main/java/net/osmtracker/service/gps/GPSLogger.java b/app/src/main/java/net/osmtracker/service/gps/GPSLogger.java
index 901cc5e6..f865cc3d 100644
--- a/app/src/main/java/net/osmtracker/service/gps/GPSLogger.java
+++ b/app/src/main/java/net/osmtracker/service/gps/GPSLogger.java
@@ -98,6 +98,7 @@ public class GPSLogger extends Service implements LocationListener {
 	 */
 	private long gpsLoggingInterval;
 	private long gpsLoggingMinDistance;
+	private boolean gpsLoggingDistGtAccuracy;
 	
 	/**
 	 * sensors for magnetic orientation
@@ -254,6 +255,8 @@ public void onCreate() {
 				OSMTracker.Preferences.KEY_GPS_LOGGING_MIN_DISTANCE, OSMTracker.Preferences.VAL_GPS_LOGGING_MIN_DISTANCE));
 		use_barometer = PreferenceManager.getDefaultSharedPreferences(this.getApplicationContext()).getBoolean(
 				OSMTracker.Preferences.KEY_USE_BAROMETER, OSMTracker.Preferences.VAL_USE_BAROMETER);
+		gpsLoggingDistGtAccuracy = PreferenceManager.getDefaultSharedPreferences(this.getApplicationContext()).getBoolean(
+				OSMTracker.Preferences.KEY_GPS_LOGGING_DIST_GT_ACCURACY, OSMTracker.Preferences.VAL_GPS_LOGGING_DIST_GT_ACCURACY);
 
 		// Register our broadcast receiver
 		IntentFilter filter = new IntentFilter();
@@ -348,6 +351,12 @@ public void onLocationChanged(Location location) {
 		
 		// first of all we check if the time from the last used fix to the current fix is greater than the logging interval
 		if((lastGPSTimestamp + gpsLoggingInterval) < System.currentTimeMillis()){
+			// next check whether distance is greater than accurracy
+			if(gpsLoggingDistGtAccuracy &&
+			   lastLocation != null &&
+			   location.distanceTo(lastLocation) <= location.getAccuracy())
+				return;
+
 			lastGPSTimestamp = System.currentTimeMillis(); // save the time of this fix
 		
 			lastLocation = location;
diff --git a/app/src/main/res/values/strings-preferences.xml b/app/src/main/res/values/strings-preferences.xml
index 88861e3c..a4ecba71 100644
--- a/app/src/main/res/values/strings-preferences.xml
+++ b/app/src/main/res/values/strings-preferences.xml
@@ -26,6 +26,8 @@
   <string name="prefs_gps_logging_min_distance_summary">Min. distance between track points in meters, use 0 for the shortest possible</string>
   <string name="prefs_gps_logging_min_distance_meters">meters</string>
   <string name="prefs_gps_logging_min_distance_empty">Min. distance between track points cannot be empty</string>
+  <string name="prefs_gps_logging_distance_gt_accuracy">Log only pts where dist. &gt; accur.</string>
+  <string name="prefs_gps_logging_distance_gt_accuracy_summary">Log only points which are further away from previous point than GPS accuracy</string>
   <string name="prefs_ui">User interface</string>
   <string name="prefs_ui_picture_source">Default photo source</string>
   <string name="prefs_ui_picture_source_summary">Take photos from camera or gallery?</string>
diff --git a/app/src/main/res/xml/preferences.xml b/app/src/main/res/xml/preferences.xml
index fb05bec8..07d2b719 100644
--- a/app/src/main/res/xml/preferences.xml
+++ b/app/src/main/res/xml/preferences.xml
@@ -67,6 +67,11 @@
             app:key="gps.logging.min_distance"
             app:summary="@string/prefs_gps_logging_min_distance_summary"
             app:title="@string/prefs_gps_logging_min_distance" />
+        <CheckBoxPreference
+            app:defaultValue="false"
+            app:key="gps.logging.dist_gt_accuracy"
+            app:summary="@string/prefs_gps_logging_distance_gt_accuracy_summary"
+            app:title="@string/prefs_gps_logging_distance_gt_accuracy" />
     </PreferenceCategory>
 
     <PreferenceCategory app:title="@string/prefs_output">
@@ -159,4 +164,4 @@
             app:title="@string/prefs_ui_orientation" />
     </PreferenceCategory>
 
-</PreferenceScreen>
\ No newline at end of file
+</PreferenceScreen>