Improve surface status decoding

Author: Douglasdc3

src/main/java/aero/t2s/modes/Track.java

@@ -67,6 +67,7 @@ public class Track {
     private String wtc = "";
     private String registration;
     private String operator;
+    private Angle horizontalSource = Angle.UNAVAILABLE;
 
     public Track(String icao) {
         this.icao = icao;
@@ -548,4 +549,12 @@ public String toString() {
             lon
         );
     }
+
+    public void setHorizontalSource(Angle horizontalSource) {
+        this.horizontalSource = horizontalSource;
+    }
+
+    public Angle getHorizontalSource() {
+        return horizontalSource;
+    }
 }

src/main/java/aero/t2s/modes/decoder/df/df17/AircraftOperationalStatusVersion2Surface.java

@@ -21,23 +21,27 @@ public AircraftOperationalStatusVersion2Surface(short[] data) {
 
     @Override
     public AircraftOperationalStatusVersion2Surface decode() {
-        verison = Version.VERSION2;
-        surfaceCapability = new SurfaceCapability((data[5] << 4) | (data[6] & 0b11110000) >>> 4, verison);
+        version = Version.VERSION2;
+        surfaceCapability = new SurfaceCapability((data[5] << 4) | (data[6] & 0b11110000) >>> 4, version);
         lengthWidthCode = LengthWidthCode.from(data[6] & 0b00001111);
         operationalMode = new SurfaceOperationalMode((data[7] << 8) | data[8]);
 
-        SIL = SourceIntegrityLevel.from((data[10] & 0b000110000) >>> 4);
-        SILsupp = SourceIntegrityLevelSupplement.from((data[10] & 0b00000010) >>> 1);
-
         int NICsuppA = (data[9] & 0b00010000) >>> 4;
         int NACp = (data[9] & 0b00001111);
-        NICp = NavigationIntegrityCategory.surface(NACp, NICsuppA);
+        int GVA = (data[10] & 0b11000000) >>> 6;
+        int SIL = (data[10] & 0b00110000) >>> 4;
+
+        int SILsupp = (data[10] & 0b00000010) >>> 1;
+
+        this.SIL = SourceIntegrityLevel.from(SIL);
+        this.SILsupp = SourceIntegrityLevelSupplement.from(SILsupp);
+        this.NICp = NavigationIntegrityCategory.surface(NACp, NICsuppA);
 
         if ((data[10] & 0b00001000) != 0) {
             if ((data[10] & 0b00000100) != 0)  {
-                horizontalSource = Angle.TRUE_TRACK;
-            } else {
                 horizontalSource = Angle.MAGNETIC_TRACK;
+            } else {
+                horizontalSource = Angle.TRUE_TRACK;
             }
         } else {
             if ((data[10] & 0b00000100) != 0)  {
@@ -53,6 +57,7 @@ public AircraftOperationalStatusVersion2Surface decode() {
     @Override
     public void apply(Track track) {
         track.setVersion(Version.VERSION2);
+        track.setHorizontalSource(horizontalSource);
     }
 
     public SurfaceCapability getSurfaceCapability() {

src/main/java/aero/t2s/modes/decoder/df/df17/SurfacePosition.java

@@ -2,6 +2,7 @@
 
 import aero.t2s.modes.CprPosition;
 import aero.t2s.modes.Track;
+import aero.t2s.modes.constants.Angle;
 
 public class SurfacePosition extends ExtendedSquitter {
     private final String address;
@@ -69,7 +70,14 @@ public void apply(Track track) {
         }
 
         if (trackAvailable) {
-            track.setTrueHeading(this.track);
+            if (track.getHorizontalSource() == Angle.TRUE_TRACK) {
+                track.setTrueHeading(this.track);
+            } else if (track.getHorizontalSource() == Angle.MAGNETIC_HEADING) {
+                track.setMagneticHeading(this.track);
+            } else {
+                track.setTrueHeading(this.track);
+                track.setMagneticHeading(this.track);
+            }
         }
     }
 

src/test/java/aero/t2s/modes/decoder/df/df17/AircraftOperationalStatusMessageTest.java

@@ -0,0 +1,43 @@
+package aero.t2s.modes.decoder.df.df17;
+
+import aero.t2s.modes.BinaryHelper;
+import aero.t2s.modes.constants.*;
+import aero.t2s.modes.decoder.df.df17.data.SurfaceOperationalMode;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class AircraftOperationalStatusMessageTest {
+    @Test
+    public void it_decodes_surface_version1_message() {
+        AircraftOperationalStatusMessage message = new AircraftOperationalStatusMessage(BinaryHelper.stringToByteArray("8F40622DF900260283493839FD1F")).decode();
+
+        Assertions.assertInstanceOf(AircraftOperationalStatusVersion2.class, message);
+        Assertions.assertInstanceOf(AircraftOperationalStatusVersion2Surface.class, message);
+
+        AircraftOperationalStatusVersion2Surface surface = (AircraftOperationalStatusVersion2Surface) message;
+        Assertions.assertEquals(Version.VERSION2, surface.getVersion());
+        Assertions.assertEquals(LengthWidthCode.CAT6, surface.getLengthWidthCode());
+
+        Assertions.assertFalse(surface.getSurfaceCapability().isCockpitDisplayOfTraffic());
+        Assertions.assertFalse(surface.getSurfaceCapability().isUatReceive());
+        Assertions.assertFalse(surface.getSurfaceCapability().isLowB2Power());
+        Assertions.assertFalse(surface.getSurfaceCapability().isPositionOffsetApplied());
+        Assertions.assertFalse(surface.getSurfaceCapability().isReceive1090ES());
+        Assertions.assertEquals(NavigationUncertaintyCategory.NUC1, surface.getSurfaceCapability().getNACv());
+        Assertions.assertEquals(0, surface.getSurfaceCapability().getNICsuppC());
+
+        Assertions.assertFalse(surface.getOperationalMode().isAcasIdent());
+        Assertions.assertTrue(surface.getOperationalMode().isGpsLateralOffsetAvailable());
+        Assertions.assertFalse(surface.getOperationalMode().isSingleAntennaFlag());
+        Assertions.assertTrue(surface.getOperationalMode().isGpsLongitudinalOffsetAvailable());
+        Assertions.assertFalse(surface.getOperationalMode().isGpsLongitudinalOffsetAppliedBySensor());
+        Assertions.assertEquals(AcasState.RA_NOT_ACTIVE, surface.getOperationalMode().getAcasRA());
+        Assertions.assertEquals(0, surface.getOperationalMode().getGpsLateralOffset());
+        Assertions.assertEquals(0, surface.getOperationalMode().getGpsLateralOffset());
+        Assertions.assertEquals(4, surface.getOperationalMode().getGpsLongitudinalOffset());
+        Assertions.assertEquals(SourceIntegrityLevel.LESS_THEN_ONE_PER_HUNDRED_THOUSAND, surface.getOperationalMode().getSystemDesignAssurance());
+
+        Assertions.assertEquals(NavigationIntegrityCategory.RC_75_M, surface.getNICp());
+        Assertions.assertEquals(Angle.TRUE_TRACK, surface.getHorizontalSource());
+    }
+}