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Increase GPS drift threshold from 15m to 50m

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Fixed issue where stationary stations like K5SGD-D were showing multiple
positions due to minor GPS accuracy variations. The previous 15-meter
threshold was too strict for typical GPS drift which can vary 5-30 meters.

- Increased default threshold in GeoUtils from 10m to 50m
- Updated packet processor to use 50m threshold for movement detection
- Verified with K5SGD-D showing ~24m variations that are now ignored

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
Graham McIntire 2025-07-21 11:23:37 -05:00
parent 9b034cd211
commit b4206b63d1
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2 changed files with 5 additions and 5 deletions
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4
lib/aprsme/geo_utils.ex
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@ -39,9 +39,9 @@ defmodule Aprsme.GeoUtils do
Check if the distance between two points exceeds a minimum threshold.
This helps filter out GPS drift and insignificant movements.
Default threshold is 10 meters to account for typical GPS accuracy.
Default threshold is 50 meters to account for typical GPS accuracy variations.
"""
def significant_movement?(lat1, lon1, lat2, lon2, threshold_meters \\ 10) do
def significant_movement?(lat1, lon1, lat2, lon2, threshold_meters \\ 50) do
case haversine_distance(lat1, lon1, lat2, lon2) do
nil -> false
distance -> distance > threshold_meters

6
lib/aprsme_web/live/map_live/packet_processor.ex
View file

@ -60,11 +60,11 @@ defmodule AprsmeWeb.MapLive.PacketProcessor do
# Check if we have valid existing coordinates
if is_number(existing_lat) and is_number(existing_lon) and
GeoUtils.significant_movement?(existing_lat, existing_lon, lat, lon, 15) do
# Significant movement detected (more than 15 meters), update the marker
GeoUtils.significant_movement?(existing_lat, existing_lon, lat, lon, 50) do
# Significant movement detected (more than 50 meters), update the marker
handle_valid_postgres_packet(packet, lat, lon, socket)
else
# Just GPS drift or invalid coordinates, update the packet data but don't send visual update
# Just GPS drift (less than 50 meters) or invalid coordinates, update the packet data but don't send visual update
new_visible_packets = Map.put(socket.assigns.visible_packets, callsign_key, packet)
assign(socket, :visible_packets, new_visible_packets)
end