better distance estimation, altitude filter, web output

main/traffic.go

@@ -190,6 +190,12 @@ func sendTrafficUpdates() {
 		}
 	}
 
+	var currAlt float32
+	currAlt = mySituation.BaroPressureAltitude
+	if currAlt == 99999 {   // no valid BaroAlt, take GPS instead, better than nothing
+		currAlt = mySituation.GPSAltitudeMSL
+	}
+
 	msgs := make([][]byte, 1)
 	msgFLARM := ""
 	msgFlarmCount := 0
@@ -212,10 +218,12 @@ func sendTrafficUpdates() {
 			ti.Bearing = 0
 			ti.BearingDist_valid = false
 		}
-
+		
 		// TODO: also filter by altitude. +- >2000ft is not relevant
 		if !ti.Position_valid && (bestEstimate.DistanceEstimated == 0 || ti.DistanceEstimated < bestEstimate.DistanceEstimated) {
-			bestEstimate = ti
+			if bestEstimate.Alt > 0 && math.Abs(bestEstimate.Alt - currAlt) < 2000 {
+				bestEstimate = ti
+			}
 		}
 
 		ti.Age = stratuxClock.Since(ti.Last_seen).Seconds()
@@ -235,11 +243,6 @@ func sendTrafficUpdates() {
 		//log.Printf("Traffic age of %X is %f seconds\n",icao,ti.Age)
 		if ti.Age > 2 { // if nothing polls an inactive ti, it won't push to the webUI, and its Age won't update.
 			trafficUpdate.SendJSON(ti)
-			var currAlt float32
-			currAlt = mySituation.BaroPressureAltitude
-			if currAlt == 99999 {   // no valid BaroAlt, take GPS instead, better than nothing
-				currAlt = mySituation.GPSAltitudeMSL
-			}
 			if float32(ti.Alt) <= currAlt + float32(globalSettings.RadarLimits) * 1.3 {   //take 30% more to see moving outs
 				// altitude lower than upper boundary
 				if float32(ti.Alt) >= currAlt - float32(globalSettings.RadarLimits) * 1.3 { 
@@ -312,9 +315,9 @@ func sendTrafficUpdates() {
 
 // Used to tune to our radios. We compare our estimate to real values for ADS-B Traffic.
 // If we tend to estimate too high, we reduce this value, otherwise we increase it
-var estimatedDistFactor = 100.0
+var estimatedDistFactor = 3000.0
 func estimateDistance(ti *TrafficInfo) {
-	dist := (-ti.SignalLevel - 6) * (-ti.SignalLevel - 6) * estimatedDistFactor;  //distance approx. in nm, 6dB for double distance
+	dist := math.Pow(2.0, -ti.SignalLevel / 6.0) * estimatedDistFactor;  // distance approx. in meters, 6dB for double distance
 
 	lambda := 0.2;
 	timeDiff := ti.Timestamp.Sub(ti.DistanceEstimatedLastTs).Seconds() * 1000

web/plates/js/traffic.js

@@ -83,6 +83,7 @@ function TrafficCtrl($rootScope, $scope, $state, $http, $interval) {
 		new_traffic.src = obj.Last_source; // 1=ES, 2=UAT
 		new_traffic.bearing = Math.round(obj.Bearing); // degrees true 
 		new_traffic.dist = (obj.Distance/1852); // nautical miles
+		new_traffic.distEst = obj.DistanceEstimated / 1852;
 		// return new_aircraft;
 	}
 

web/plates/traffic.html

@@ -14,7 +14,7 @@
 					<span class="col-xs-2" ng-hide="showSquawk"><strong>Code</strong></span>
 					<span class="col-xs-2" ng-show="showSquawk"><strong>Squawk</strong></span>
 					<span class="col-xs-5 text-right" ng-hide="GPS_connected && RelDist"><strong>Location</strong></span>
-					<span class="col-xs-3 text-right" ng-show="GPS_connected && RelDist"><strong>Dist</strong></span>
+					<span class="col-xs-3 text-right" ng-show="GPS_connected && RelDist"><strong>Dist (estimated)</strong></span>
 					<span class="col-xs-2 text-right" ng-show="GPS_connected && RelDist"><strong>Bearing</strong></span>
 				</div>
 				
@@ -44,7 +44,7 @@
 						<span ng-show="showSquawk"><span ng-show="aircraft.squawk < 1000">0</span><span ng-show="aircraft.squawk < 100">0</span><span ng-show="aircraft.squawk < 10">0</span>{{aircraft.squawk}}</span>
 					</span>
 					<span class="col-xs-5 text-right" ng-hide="GPS_connected && RelDist">{{aircraft.lat}} {{aircraft.lon}}</span>
-					<span class="col-xs-3 text-right" ng-show="GPS_connected && RelDist">{{aircraft.dist.toFixed(1)}}<span style="font-size:50%">NM</span></span>
+					<span class="col-xs-3 text-right" ng-show="GPS_connected && RelDist">{{aircraft.dist.toFixed(1)}} ({{aircraft.distEst.toFixed(1)}})<span style="font-size:50%">NM</span></span>
 					<span class="col-xs-2 text-right" ng-show="GPS_connected && RelDist">{{aircraft.bearing}}&deg;</span>
 
 				</div>
@@ -99,8 +99,9 @@
 				<div class="col-sm-6">
 					<span class="col-xs-4" ng-hide="showReg"><strong>Callsign</strong></span>
 					<span class="col-xs-4" ng-show="showReg"><strong>Tail Num</strong></span>
-					<span class="col-xs-3"><strong>Code</strong></span>
+					<span class="col-xs-2"><strong>Code</strong></span>
-					<span class="col-xs-3"><strong>Squawk</strong></span>
+					<span class="col-xs-2"><strong>Squawk</strong></span>
+					<span class="col-xs-2"><strong>Dist est.</strong></span>
 				</div>
 				
 				<div class="col-sm-6">
@@ -123,8 +124,9 @@
 						<span ng-show="aircraft.reg" ng-class="'label traffic-style'+aircraft.src+aircraft.targettype">{{aircraft.addr_symb}}<strong>&nbsp;{{aircraft.reg}}</strong></span>
 						<span ng-hide="aircraft.reg" ng-class="'label traffic-style'+aircraft.src+aircraft.targettype">{{aircraft.addr_symb}}<strong>&nbsp;[--N/A--]</strong></span>
 					</span>
-					<span class="col-xs-3" style="font-size:80%">{{aircraft.icao}}<span style="font-size:50%">{{aircraft.addr_type == 3 ? "&nbsp;(TFID)" : ""}}</span></span>
+					<span class="col-xs-2" style="font-size:80%">{{aircraft.icao}}<span style="font-size:50%">{{aircraft.addr_type == 3 ? "&nbsp;(TFID)" : ""}}</span></span>
-					<span class="col-xs-3"><span ng-show="aircraft.squawk < 1000">0</span><span ng-show="aircraft.squawk < 100">0</span><span ng-show="aircraft.squawk < 10">0</span>{{aircraft.squawk}}</span>
+					<span class="col-xs-2"><span ng-show="aircraft.squawk < 1000">0</span><span ng-show="aircraft.squawk < 100">0</span><span ng-show="aircraft.squawk < 10">0</span>{{aircraft.squawk}}</span>
+					<span class="col-xs-2">{{aircraft.distEst.toFixed(1)}}<span style="font-size:50%">NM</span></span>
 				</div>
 
 				<div class="col-sm-6">