altosui: Require 4 sats for 'good' GPS data

[fw/altos] / ao-tools / altosui / AltosState.java

diff --git a/ao-tools/altosui/AltosState.java b/ao-tools/altosui/AltosState.java
index 3ef00f35d7d87375cf4967553f5e28c3bdd6edd6..1048bb51b09ca8faee0dccb4c4953850d135c2cf 100644 (file)
--- a/ao-tools/altosui/AltosState.java
+++ b/ao-tools/altosui/AltosState.java
@@ -60,6 +60,7 @@ public class AltosState {
        static final int MIN_PAD_SAMPLES = 10;
 
        int     npad;
+       int     ngps;
        int     gps_waiting;
        boolean gps_ready;
 
@@ -80,7 +81,7 @@ public class AltosState {
                data = cur;
 
                ground_altitude = data.ground_altitude();
-               height = data.altitude() - ground_altitude;
+               height = data.filtered_altitude() - ground_altitude;
 
                report_time = System.currentTimeMillis();
 
@@ -97,6 +98,7 @@ public class AltosState {
 
                        /* Preserve any existing gps data */
                        npad = prev_state.npad;
+                       ngps = prev_state.ngps;
                        gps = prev_state.gps;
                        pad_lat = prev_state.pad_lat;
                        pad_lon = prev_state.pad_lon;
@@ -120,15 +122,23 @@ public class AltosState {
                                baro_speed = prev_state.baro_speed;
                } else {
                        npad = 0;
+                       ngps = 0;
                        gps = null;
                        baro_speed = 0;
                        time_change = 0;
                }
 
                if (state == Altos.ao_flight_pad) {
-                       if (data.gps != null && data.gps.locked) {
+
+                       /* Track consecutive 'good' gps reports, waiting for 10 of them */
+                       if (data.gps != null && data.gps.locked && data.gps.nsat >= 4)
                                npad++;
-                               if (npad > 1) {
+                       else
+                               npad = 0;
+
+                       /* Average GPS data while on the pad */
+                       if (data.gps != null && data.gps.locked && data.gps.nsat >= 4) {
+                               if (ngps > 1) {
                                        /* filter pad position */
                                        pad_lat = (pad_lat * 31.0 + data.gps.lat) / 32.0;
                                        pad_lon = (pad_lon * 31.0 + data.gps.lon) / 32.0;
@@ -138,8 +148,7 @@ public class AltosState {
                                        pad_lon = data.gps.lon;
                                        pad_alt = data.gps.alt;
                                }
-                       } else {
-                               npad = 0;
+                               ngps++;
                        }
                }
 
@@ -163,13 +172,13 @@ public class AltosState {
                if (data.gps != null) {
                        if (gps == null || !gps.locked || data.gps.locked)
                                gps = data.gps;
-                       if (npad > 0 && gps.locked) {
+                       if (ngps > 0 && gps.locked) {
                                from_pad = new AltosGreatCircle(pad_lat, pad_lon, gps.lat, gps.lon);
                        }
                }
                elevation = 0;
                range = -1;
-               if (npad > 0) {
+               if (ngps > 0) {
                        gps_height = gps.alt - pad_alt;
                        if (from_pad != null) {
                                elevation = Math.atan2(height, from_pad.distance) * 180 / Math.PI;