From 39ba3e8734ea1c3dd17a232072b26d1f82c4ac69 Mon Sep 17 00:00:00 2001
From: Luc Maisonobe <luc@orekit.org>
Date: Thu, 16 Jul 2015 10:17:42 +0200
Subject: [PATCH] New test and simplified code.
---
.../utils/RoughVisibilityEstimator.java | 17 +++++------
.../utils/RoughVisibilityEstimatorTest.java | 28 +++++++++++++++++++
2 files changed, 37 insertions(+), 8 deletions(-)
diff --git a/src/main/java/org/orekit/rugged/utils/RoughVisibilityEstimator.java b/src/main/java/org/orekit/rugged/utils/RoughVisibilityEstimator.java
index cfd7d055..8c0dbbb9 100644
--- a/src/main/java/org/orekit/rugged/utils/RoughVisibilityEstimator.java
+++ b/src/main/java/org/orekit/rugged/utils/RoughVisibilityEstimator.java
@@ -110,8 +110,8 @@ public class RoughVisibilityEstimator {
final Vector3D point = ellipsoid.transform(groundPoint);
int closeIndex = findClose(last, point);
- // check if there are closer points in previous half periods
- final int repeat = (int) FastMath.rint(FastMath.PI / rateVSIndices);
+ // check if there are closer points in previous periods
+ final int repeat = (int) FastMath.rint(2.0 * FastMath.PI / rateVSIndices);
for (int index = closeIndex - repeat; index > 0; index -= repeat) {
final int otherIndex = findClose(index, point);
if (otherIndex != closeIndex &&
@@ -121,7 +121,7 @@ public class RoughVisibilityEstimator {
}
}
- // check if there are closer points in next half periods
+ // check if there are closer points in next periods
for (int index = closeIndex + repeat; index < pvGround.size(); index += repeat) {
final int otherIndex = findClose(index, point);
if (otherIndex != closeIndex &&
@@ -160,6 +160,10 @@ public class RoughVisibilityEstimator {
}
/** Estimate angular motion needed to go past test point.
+ * <p>
+ * This estimation is quite crude. The sub-satellite point is properly on the
+ * ellipsoid surface, but we compute the angle assuming a spherical shape.
+ * </p>
* @param subSatellite current sub-satellite position-velocity
* @param point test point
* @return angular motion to go past test point (positive is
@@ -170,12 +174,9 @@ public class RoughVisibilityEstimator {
final Vector3D ssP = subSatellite.getPosition();
final Vector3D momentum = subSatellite.getMomentum();
+ final double y = Vector3D.dotProduct(point, Vector3D.crossProduct(momentum, ssP).normalize());
+ final double x = Vector3D.dotProduct(point, ssP.normalize());
- // find phase angle around momentum
- final Vector3D yAxis = Vector3D.crossProduct(momentum, ssP).normalize();
- final Vector3D xAxis = Vector3D.crossProduct(yAxis, momentum).normalize();
- final double y = Vector3D.dotProduct(point, yAxis);
- final double x = Vector3D.dotProduct(point, xAxis);
return FastMath.atan2(y, x);
}
diff --git a/src/test/java/org/orekit/rugged/utils/RoughVisibilityEstimatorTest.java b/src/test/java/org/orekit/rugged/utils/RoughVisibilityEstimatorTest.java
index 2245083c..5858bf5d 100644
--- a/src/test/java/org/orekit/rugged/utils/RoughVisibilityEstimatorTest.java
+++ b/src/test/java/org/orekit/rugged/utils/RoughVisibilityEstimatorTest.java
@@ -88,6 +88,34 @@ public class RoughVisibilityEstimatorTest {
}
+ @Test
+ public void testOneOrbitsSpan()
+ throws RuggedException, OrekitException, URISyntaxException {
+
+ String path = getClass().getClassLoader().getResource("orekit-data").toURI().getPath();
+ DataProvidersManager.getInstance().addProvider(new DirectoryCrawler(new File(path)));
+ BodyShape earth = createEarth();
+ NormalizedSphericalHarmonicsProvider gravityField = createGravityField();
+ Orbit orbit = createOrbit(gravityField.getMu());
+ Propagator propagator = createPropagator(earth, gravityField, orbit);
+ final List<TimeStampedPVCoordinates> pv = new ArrayList<TimeStampedPVCoordinates>();
+ propagator.setMasterMode(1.0, new OrekitFixedStepHandler() {
+ public void init(SpacecraftState s0, AbsoluteDate t) {
+ }
+ public void handleStep(SpacecraftState currentState, boolean isLast) {
+ pv.add(currentState.getPVCoordinates());
+ }
+ });
+ propagator.propagate(orbit.getDate().shiftedBy(orbit.getKeplerianPeriod()));
+
+ RoughVisibilityEstimator estimator = new RoughVisibilityEstimator(ellipsoid, orbit.getFrame(), pv);
+ AbsoluteDate d = estimator.estimateVisibility(new GeodeticPoint(FastMath.toRadians(43.303),
+ FastMath.toRadians(-46.126),
+ 0.0));
+ Assert.assertEquals("2012-01-01T01:02:39.123", d.toString(TimeScalesFactory.getUTC()));
+
+ }
+
private BodyShape createEarth()
throws OrekitException {
return new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS,
--
GitLab