- Provided initial real-time RFI and Spoofing analysis tools and visualization (tool efficacy has not yet been evaluated and is based on previously observed EW indicators)

- added a single view "GNSS Risk" meter that provides a simple overall risk level

Author: scottlandis

torgi/build.gradle

@@ -52,6 +52,7 @@ dependencies {
 
     viewerImplementation 'com.github.PhilJay:MPAndroidChart:v3.0.3' //for charts
     viewerImplementation 'org.osmdroid:osmdroid-android:6.0.2'
+    viewerImplementation 'org.apache.commons:commons-math3:3.0' //for statistical analysis
     implementation 'mil.nga.geopackage:geopackage-android:3.0.2'
     implementation 'com.android.support:appcompat-v7:27.1.1'
     viewerImplementation 'com.android.support.constraint:constraint-layout:1.1.3'

torgi/src/main/AndroidManifest.xml

@@ -18,7 +18,8 @@
 
         <activity
             android:name=".ui.MainActivity"
-            android:label="@string/app_name">
+            android:label="@string/app_name"
+            android:launchMode="singleTask">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />

torgi/src/main/java/org/sofwerx/torgi/gnss/Constellation.java

@@ -14,7 +14,9 @@ public enum Constellation {
 
     private int value;
 
-    public static int size() { return Constellation.size(); }
+    private static final int size = values().length;
+
+    public static int size() { return size; }
 
     Constellation(int value) {
         this.value = value;

torgi/src/main/java/org/sofwerx/torgi/gnss/DataPoint.java

@@ -1,11 +1,16 @@
 package org.sofwerx.torgi.gnss;
 
+import android.util.Log;
+
+import org.apache.commons.math3.stat.descriptive.moment.StandardDeviation;
+
 import java.util.ArrayList;
 
 /**
  * Represents relevant EW indicator values at one place in spacetime
  */
 public class DataPoint {
+    private final static String TAG="TORGI.EW";
     private SpaceTime spaceTime;
     private ArrayList<SatMeasurement> measurements = null;
 
@@ -26,15 +31,91 @@ public GNSSEWValues getAverageMeasurements() {
         return SatMeasurement.getAverage(measurements);
     }
 
-    //TODO hey dummy! maybe calculate the difference from baseline as well
+    public ArrayList<GNSSEWValues> getAllGNSSEWValues() {
+        if ((measurements == null) || measurements.isEmpty())
+            return null;
+        ArrayList<GNSSEWValues> valuesList = new ArrayList<>();
+        for (SatMeasurement measurement:measurements) {
+            if (measurement.getValues() != null)
+                valuesList.add(measurement.getValues());
+        }
+        if (valuesList.isEmpty())
+            valuesList = null;
+        return valuesList;
+    }
+
+    /**
+     * Gets the average difference between values and baseline
+     * @return
+     */
+    public GNSSEWValues getAverageDifference() {
+        return SatMeasurement.getAverageDifference(measurements);
+    }
+
+    public ArrayList<SatMeasurement> getMeasurementsByConstellation(Constellation con) {
+        if ((measurements != null) && !measurements.isEmpty() && (con != null)) {
+            ArrayList<SatMeasurement> conMeas = null;
+            for (SatMeasurement measurement:measurements) {
+                if ((measurement.getSat() != null) && (measurement.getSat().getConstellation() == con)) {
+                    if (conMeas == null)
+                        conMeas = new ArrayList<>();
+                    conMeas.add(measurement);
+                }
+            }
+            return conMeas;
+        }
+        return null;
+    }
 
     /**
      * Gets the average GNSSEWValues for each constellation
-     * @return array with index corresponding to the constellation number of the constellation
+     * @return array with the average value with index corresponding to the constellation number of the constellation
      */
     public GNSSEWValues[] getAverageMeasurementsByConstellation() {
         GNSSEWValues[] values = new GNSSEWValues[Constellation.size()];
 
+        if ((measurements != null) && !measurements.isEmpty()) {
+            Constellation con;
+            ArrayList<SatMeasurement> conMeas;
+            for (int i=0;i<values.length;i++) {
+                con = Constellation.get(i);
+                conMeas = getMeasurementsByConstellation(con);
+                values[i] = SatMeasurement.getAverage(conMeas);
+            }
+        }
+
+        return values;
+    }
+
+    public float getAllBaselinesCN0SD() {
+        if ((measurements != null) && !measurements.isEmpty()) {
+            ArrayList<GNSSEWValues> valuesWithCN0s = new ArrayList<>();
+            for (SatMeasurement measurement:measurements) {
+                if ((measurement.getValues() != null) && !Float.isNaN(measurement.getValues().getCn0()))
+                    valuesWithCN0s.add(measurement.getValues());
+            }
+            if (!valuesWithCN0s.isEmpty()) {
+                double[] values = new double[valuesWithCN0s.size()];
+                for (int i=0;i<values.length;i++) {
+                    values[i] = valuesWithCN0s.get(i).getCn0();
+                }
+                StandardDeviation devCal = new StandardDeviation();
+                float stdDev = (float)devCal.evaluate(values);
+                Log.d(TAG,"C/N0 stdDev across all satellites == "+Float.toString(stdDev));
+                return stdDev;
+            }
+        }
+        Log.d(TAG,"Could not compute C/N0 stdDev across all satellites");
+        return Float.NaN;
+    }
+
+    /**
+     * Gets the difference between baseline and current GNSSEWValues for each constellation
+     * @return array with the average difference between value and baseline with index corresponding to the constellation number of the constellation
+     */
+    public GNSSEWValues[] getAverageDifferenceFromBaselineByConstellation() {
+        GNSSEWValues[] values = new GNSSEWValues[Constellation.size()];
+
         if ((measurements != null) && !measurements.isEmpty()) {
             Constellation con;
             ArrayList<SatMeasurement> conMeas;
@@ -48,7 +129,7 @@ public GNSSEWValues[] getAverageMeasurementsByConstellation() {
                         conMeas.add(measurement);
                     }
                 }
-                values[i] = SatMeasurement.getAverage(conMeas);
+                values[i] = SatMeasurement.getAverageDifference(conMeas);
             }
         }