Added detection of wrong position/line-of-sight that misses the ground.

core/src/main/java/org/orekit/rugged/api/RuggedMessages.java

@@ -57,6 +57,7 @@ public enum RuggedMessages implements Localizable {
     UNINITIALIZED_CONTEXT("general context has not been initialized"),
     EMPTY_TILE("tile is empty: {0} ⨉ {1}"),
     UNKNOWN_SENSOR("unknown sensor {0}"),
+    LINE_OF_SIGHT_DOES_NOT_REACH_GROUND("line-of-sight does not reach ground"),
     LINE_OF_SIGHT_NEVER_CROSSES_LATITUDE("line-of-sight never crosses latitude {0}"),
     LINE_OF_SIGHT_NEVER_CROSSES_LONGITUDE("line-of-sight never crosses longitude {0}"),
     LINE_OF_SIGHT_NEVER_CROSSES_ALTITUDE("line-of-sight never crosses altitude {0}"),

core/src/main/java/org/orekit/rugged/intersection/duvenhage/DuvenhageAlgorithm.java

@@ -72,6 +72,9 @@ public class DuvenhageAlgorithm implements IntersectionAlgorithm {
 
             // compute intersection with ellipsoid
             final GeodeticPoint gp0 = ellipsoid.pointOnGround(position, los);
+            if (gp0 == null) {
+                throw new RuggedException(RuggedMessages.LINE_OF_SIGHT_DOES_NOT_REACH_GROUND);
+            }
 
             // locate the entry tile along the line-of-sight
             MinMaxTreeTile tile = cache.getTile(gp0.getLatitude(), gp0.getLongitude());

core/src/main/resources/assets/org/orekit/rugged/RuggedMessages_en.utf8

@@ -19,6 +19,9 @@ EMPTY_TILE = tile is empty: {0} ⨉ {1}
 # unknown sensor {0}
 UNKNOWN_SENSOR = unknown sensor {0}
 
+# line-of-sight does not reach ground
+LINE_OF_SIGHT_DOES_NOT_REACH_GROUND = line-of-sight does not reach ground
+
 # line-of-sight never crosses latitude {0}
 LINE_OF_SIGHT_NEVER_CROSSES_LATITUDE = line-of-sight never crosses latitude {0}
 

core/src/main/resources/assets/org/orekit/rugged/RuggedMessages_fr.utf8

@@ -19,6 +19,9 @@ EMPTY_TILE = la tuile est vide : {0} ⨉ {1}
 # unknown sensor {0}
 UNKNOWN_SENSOR = capteur {0} inconnu
 
+# line-of-sight does not reach ground
+LINE_OF_SIGHT_DOES_NOT_REACH_GROUND = la ligne de visée n''atteint pas le sol
+
 # line-of-sight never crosses latitude {0}
 LINE_OF_SIGHT_NEVER_CROSSES_LATITUDE = la ligne de visée ne franchit jamais la latitude {0}
 

core/src/test/java/org/orekit/rugged/api/RuggedMessagesTest.java

@@ -29,7 +29,7 @@ public class RuggedMessagesTest {
 
     @Test
     public void testMessageNumber() {
-        Assert.assertEquals(13, RuggedMessages.values().length);
+        Assert.assertEquals(14, RuggedMessages.values().length);
     }
 
     @Test

core/src/test/java/org/orekit/rugged/intersection/duvenhage/DuvenhageAlgorithmTest.java

@@ -18,10 +18,12 @@ package org.orekit.rugged.intersection.duvenhage;
 
 
 import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
+import org.junit.Assert;
 import org.junit.Test;
 import org.orekit.bodies.GeodeticPoint;
 import org.orekit.errors.OrekitException;
 import org.orekit.rugged.api.RuggedException;
+import org.orekit.rugged.api.RuggedMessages;
 import org.orekit.rugged.intersection.AbstractAlgorithmTest;
 import org.orekit.rugged.intersection.IntersectionAlgorithm;
 import org.orekit.rugged.intersection.duvenhage.DuvenhageAlgorithm;
@@ -55,4 +57,18 @@ public class DuvenhageAlgorithmTest extends AbstractAlgorithmTest {
         checkIntersection(position, los, intersection);
     }
 
+    @Test
+    public void testWrongPositionMissesGround() throws RuggedException, OrekitException {
+        setUpMayonVolcanoContext();
+        final IntersectionAlgorithm algorithm = createAlgorithm(updater, 8);
+        Vector3D position = new Vector3D(7.551889113912788E9, -3.173692685491814E10, 1.5727517321541348E9);
+        Vector3D los = new Vector3D(0.010401349221417867, -0.17836068905951286, 0.9839101973923178);
+        try {
+            algorithm.intersection(earth, position, los);
+            Assert.fail("an exception should have been thrown");
+        } catch (RuggedException re) {
+            Assert.assertEquals(RuggedMessages.LINE_OF_SIGHT_DOES_NOT_REACH_GROUND, re.getSpecifier());
+        }
+    }
+
 }

src/site/xdoc/changes.xml

@@ -22,6 +22,9 @@
   <body>
     <release version="1.0" date="TBD"
              description="TBD">
+      <action dev="luc" type="fix">
+        Added detection of wrong position/line-of-sight that misses the ground.
+      </action>
       <action dev="luc" type="add">
         Added a way to reuse transform interpolator from one run to another
         by dumping its state into a file, thus avoiding costly initialization.