From c0d7ab98bc724a6590fdfe1efe02498da83d9058 Mon Sep 17 00:00:00 2001
From: Luc Maisonobe <luc@orekit.org>
Date: Tue, 21 Oct 2014 14:28:02 +0200
Subject: [PATCH] Added a protection against los parallel to the DEM last
row/column.
---
.../duvenhage/DuvenhageAlgorithm.java | 90 +++++++++++++------
1 file changed, 64 insertions(+), 26 deletions(-)
diff --git a/core/src/main/java/org/orekit/rugged/intersection/duvenhage/DuvenhageAlgorithm.java b/core/src/main/java/org/orekit/rugged/intersection/duvenhage/DuvenhageAlgorithm.java
index 9d3e5d45..ec96a6ff 100644
--- a/core/src/main/java/org/orekit/rugged/intersection/duvenhage/DuvenhageAlgorithm.java
+++ b/core/src/main/java/org/orekit/rugged/intersection/duvenhage/DuvenhageAlgorithm.java
@@ -397,50 +397,50 @@ public class DuvenhageAlgorithm implements IntersectionAlgorithm {
throws RuggedException, OrekitException {
// look for an exit at bottom
- final Vector3D exitP = ellipsoid.pointAtAltitude(position, los, tile.getMinElevation() - STEP);
- final NormalizedGeodeticPoint exitGP = ellipsoid.transform(exitP, ellipsoid.getBodyFrame(), null,
- tile.getMinimumLongitude());
+ final double reference = tile.getMinimumLongitude();
+ final Vector3D exitP = ellipsoid.pointAtAltitude(position, los, tile.getMinElevation() - STEP);
+ final NormalizedGeodeticPoint exitGP = ellipsoid.transform(exitP, ellipsoid.getBodyFrame(), null, reference);
switch (tile.getLocation(exitGP.getLatitude(), exitGP.getLongitude())) {
case SOUTH_WEST :
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- selectClosest(ellipsoid.pointAtLatitude(position, los, tile.getMinimumLatitude(), exitP),
- ellipsoid.pointAtLongitude(position, los, tile.getMinimumLongitude()),
+ return new LimitPoint(ellipsoid, reference,
+ selectClosest(latitudeCrossing(ellipsoid, position, los, tile.getMinimumLatitude(), exitP),
+ longitudeCrossing(ellipsoid, position, los, tile.getMinimumLongitude(), exitP),
position),
true);
case WEST :
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- ellipsoid.pointAtLongitude(position, los, tile.getMinimumLongitude()),
+ return new LimitPoint(ellipsoid, reference,
+ longitudeCrossing(ellipsoid, position, los, tile.getMinimumLongitude(), exitP),
true);
case NORTH_WEST:
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- selectClosest(ellipsoid.pointAtLatitude(position, los, tile.getMaximumLatitude(), exitP),
- ellipsoid.pointAtLongitude(position, los, tile.getMinimumLongitude()),
+ return new LimitPoint(ellipsoid, reference,
+ selectClosest(latitudeCrossing(ellipsoid, position, los, tile.getMaximumLatitude(), exitP),
+ longitudeCrossing(ellipsoid, position, los, tile.getMinimumLongitude(), exitP),
position),
true);
case NORTH :
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- ellipsoid.pointAtLatitude(position, los, tile.getMaximumLatitude(), exitP),
+ return new LimitPoint(ellipsoid, reference,
+ latitudeCrossing(ellipsoid, position, los, tile.getMaximumLatitude(), exitP),
true);
case NORTH_EAST :
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- selectClosest(ellipsoid.pointAtLatitude(position, los, tile.getMaximumLatitude(), exitP),
- ellipsoid.pointAtLongitude(position, los, tile.getMaximumLongitude()),
+ return new LimitPoint(ellipsoid, reference,
+ selectClosest(latitudeCrossing(ellipsoid, position, los, tile.getMaximumLatitude(), exitP),
+ longitudeCrossing(ellipsoid, position, los, tile.getMaximumLongitude(), exitP),
position),
true);
case EAST :
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- ellipsoid.pointAtLongitude(position, los, tile.getMaximumLongitude()),
+ return new LimitPoint(ellipsoid, reference,
+ longitudeCrossing(ellipsoid, position, los, tile.getMaximumLongitude(), exitP),
true);
case SOUTH_EAST :
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- selectClosest(ellipsoid.pointAtLatitude(position, los, tile.getMinimumLatitude(), exitP),
- ellipsoid.pointAtLongitude(position, los, tile.getMaximumLongitude()),
+ return new LimitPoint(ellipsoid, reference,
+ selectClosest(latitudeCrossing(ellipsoid, position, los, tile.getMinimumLatitude(), exitP),
+ longitudeCrossing(ellipsoid, position, los, tile.getMaximumLongitude(), exitP),
position),
true);
case SOUTH :
- return new LimitPoint(ellipsoid, tile.getMinimumLongitude(),
- ellipsoid.pointAtLatitude(position, los, tile.getMinimumLatitude(), exitP),
+ return new LimitPoint(ellipsoid, reference,
+ latitudeCrossing(ellipsoid, position, los, tile.getMinimumLatitude(), exitP),
true);
case HAS_INTERPOLATION_NEIGHBORS :
return new LimitPoint(exitGP, false);
@@ -463,6 +463,44 @@ public class DuvenhageAlgorithm implements IntersectionAlgorithm {
return Vector3D.distance(p1, position) <= Vector3D.distance(p2, position) ? p1 : p2;
}
+ /** Get point at some latitude along a pixel line of sight.
+ * @param ellipsoid reference ellipsoid
+ * @param position pixel position (in body frame)
+ * @param los pixel line-of-sight, not necessarily normalized (in body frame)
+ * @param latitude latitude with respect to ellipsoid
+ * @param closeReference reference point used to select the closest solution
+ * when there are two points at the desired latitude along the line
+ * @return point at altitude, or closeReference if no such point can be found
+ */
+ private Vector3D latitudeCrossing(final ExtendedEllipsoid ellipsoid,
+ final Vector3D position, final Vector3D los,
+ final double latitude, final Vector3D closeReference) {
+ try {
+ return ellipsoid.pointAtLatitude(position, los, latitude, closeReference);
+ } catch (RuggedException re) {
+ return closeReference;
+ }
+ }
+
+ /** Get point at some latitude along a pixel line of sight.
+ * @param ellipsoid reference ellipsoid
+ * @param position pixel position (in body frame)
+ * @param los pixel line-of-sight, not necessarily normalized (in body frame)
+ * @param longitude longitude with respect to ellipsoid
+ * @param closeReference reference point used to select the closest solution
+ * when there are two points at the desired latitude along the line
+ * @return point at altitude, or closeReference if no such point can be found
+ */
+ private Vector3D longitudeCrossing(final ExtendedEllipsoid ellipsoid,
+ final Vector3D position, final Vector3D los,
+ final double longitude, final Vector3D closeReference) {
+ try {
+ return ellipsoid.pointAtLongitude(position, los, longitude);
+ } catch (RuggedException re) {
+ return closeReference;
+ }
+ }
+
/** Point at tile boundary. */
private static class LimitPoint {
@@ -474,17 +512,17 @@ public class DuvenhageAlgorithm implements IntersectionAlgorithm {
/** Simple constructor.
* @param ellipsoid reference ellipsoid
- * @param centralLongitude reference longitude lc such that the point longitude will
+ * @param referenceLongitude reference longitude lc such that the point longitude will
* be normalized between lc-Ï€ and lc+Ï€
* @param cartesian Cartesian point
* @param side if true, the point is on a side limit, otherwise
* it is on a top/bottom limit
* @exception OrekitException if geodetic coordinates cannot be computed
*/
- public LimitPoint(final ExtendedEllipsoid ellipsoid, final double centralLongitude,
+ public LimitPoint(final ExtendedEllipsoid ellipsoid, final double referenceLongitude,
final Vector3D cartesian, final boolean side)
throws OrekitException {
- this(ellipsoid.transform(cartesian, ellipsoid.getBodyFrame(), null, centralLongitude), side);
+ this(ellipsoid.transform(cartesian, ellipsoid.getBodyFrame(), null, referenceLongitude), side);
}
/** Simple constructor.
--
GitLab