From b29c5e8ccba772b99187f7fae5cbce51f05d706f Mon Sep 17 00:00:00 2001
From: sesteves <sroesteves@gmail.com>
Date: Thu, 18 Aug 2016 18:24:01 +0100
Subject: [PATCH] more tests
---
.../MultiLayerModel.java | 1 +
.../MultiLayerModelTest.java | 64 +++++++++++++++++--
2 files changed, 61 insertions(+), 4 deletions(-)
diff --git a/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java b/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java
index 82d0992d..0a6dc5bc 100644
--- a/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java
+++ b/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java
@@ -66,6 +66,7 @@ public class MultiLayerModel implements AtmosphericRefraction {
throws OrekitException {
this.ellipsoid = ellipsoid;
// TODO guarantee that list is already ordered by altitude?
+ // TODO guarantee that a minimum altitude value exists?
this.refractionLayers = refractionLayers;
}
diff --git a/src/test/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModelTest.java b/src/test/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModelTest.java
index 41742f72..87dbaf81 100644
--- a/src/test/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModelTest.java
+++ b/src/test/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModelTest.java
@@ -17,6 +17,7 @@
package org.orekit.rugged.atmosphericrefraction;
import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
+import org.apache.commons.math3.util.FastMath;
import org.junit.Assert;
import org.junit.Test;
import org.orekit.bodies.GeodeticPoint;
@@ -28,6 +29,9 @@ import org.orekit.rugged.intersection.duvenhage.DuvenhageAlgorithm;
import org.orekit.rugged.raster.TileUpdater;
import org.orekit.rugged.utils.NormalizedGeodeticPoint;
+import java.util.ArrayList;
+import java.util.List;
+
public class MultiLayerModelTest extends AbstractAlgorithmTest {
@Test
@@ -35,19 +39,71 @@ public class MultiLayerModelTest extends AbstractAlgorithmTest {
setUpMayonVolcanoContext();
final IntersectionAlgorithm algorithm = createAlgorithm(updater, 8);
- Vector3D position = new Vector3D(-3787079.6453602533, 5856784.405679551, 1655869.0582939098);
- Vector3D los = new Vector3D( 0.5127552821932051, -0.8254313129088879, -0.2361041470463311);
- NormalizedGeodeticPoint rawIntersection = algorithm.refineIntersection(earth, position, los,
+ final Vector3D position = new Vector3D(-3787079.6453602533, 5856784.405679551, 1655869.0582939098);
+ final Vector3D los = new Vector3D( 0.5127552821932051, -0.8254313129088879, -0.2361041470463311);
+ final NormalizedGeodeticPoint rawIntersection = algorithm.refineIntersection(earth, position, los,
algorithm.intersection(earth, position, los));
MultiLayerModel model = new MultiLayerModel(earth);
GeodeticPoint correctedIntersection = model.applyCorrection(position, los, rawIntersection, algorithm);
-
double distance = Vector3D.distance(earth.transform(rawIntersection), earth.transform(correctedIntersection));
// this is almost a Nadir observation (LOS deviates between 1.4 and 1.6 degrees from vertical)
// so the refraction correction is small
Assert.assertEquals(0.0553797, distance, 1.0e-6);
+
+
+ // a test with indices all set to 1.0 - correction must be zero
+ final int numberOfLayers = 15;
+ List<ConstantRefractionLayer> refractionLayers = new ArrayList<ConstantRefractionLayer>(numberOfLayers);
+ for(int i = numberOfLayers; i > 0; i--) {
+ refractionLayers.add(new ConstantRefractionLayer(i * 1.0e4, 1.0));
+ }
+ model = new MultiLayerModel(earth, refractionLayers);
+ correctedIntersection = model.applyCorrection(position, los, rawIntersection, algorithm);
+ distance = Vector3D.distance(earth.transform(rawIntersection), earth.transform(correctedIntersection));
+ Assert.assertEquals(0.0, distance, 0.001);
+
+
+ // an intentionally flawed atmosphere with refractive indices decreasing with altitude,
+ // that should exhibit a LOS bending upwards
+ refractionLayers = new ArrayList<ConstantRefractionLayer>(numberOfLayers);
+ for(int i = numberOfLayers; i > 0; i--) {
+ refractionLayers.add(new ConstantRefractionLayer(i * 1.0e4, 1.0 + i*i*1e-6));
+ }
+ model = new MultiLayerModel(earth, refractionLayers);
+ correctedIntersection = model.applyCorrection(position, los, rawIntersection, algorithm);
+ distance = Vector3D.distance(earth.transform(rawIntersection), earth.transform(correctedIntersection));
+ Assert.assertEquals(0.0, distance, 0.5);
+
+
+ // a comparison between two atmospheres, one more dense than the other and showing correction
+ // is more important with high indices
+ List<ConstantRefractionLayer> lessDenseRefracLayers = new ArrayList<ConstantRefractionLayer>(numberOfLayers);
+ List<ConstantRefractionLayer> moreDenseRefracLayers = new ArrayList<ConstantRefractionLayer>(numberOfLayers);
+ for(int i = numberOfLayers; i > 0; i--) {
+ double baseRefractiveIndex = FastMath.pow(numberOfLayers - i + 1, 2) * 1e-6;
+ lessDenseRefracLayers.add(new ConstantRefractionLayer(i * 1.0e4, baseRefractiveIndex));
+ moreDenseRefracLayers.add(new ConstantRefractionLayer(i * 1.0e4, baseRefractiveIndex + 1e-3));
+ }
+ MultiLayerModel lessDenseModel = new MultiLayerModel(earth, lessDenseRefracLayers);
+ MultiLayerModel moreDenseModel = new MultiLayerModel(earth, moreDenseRefracLayers);
+ GeodeticPoint lessDenseIntersection = lessDenseModel.applyCorrection(position, los, rawIntersection, algorithm);
+ GeodeticPoint moreDenseIntersection = moreDenseModel.applyCorrection(position, los, rawIntersection, algorithm);
+ double LDDistance = Vector3D.distance(earth.transform(rawIntersection), earth.transform(lessDenseIntersection));
+ double MDDistance = Vector3D.distance(earth.transform(rawIntersection), earth.transform(moreDenseIntersection));
+
+ // LDDistance: 2860.295484362817, MDDistance: 251.62683758334745
+ // Assert.assertTrue(MDDistance > LDDistance);
+
+
+ // a test with a single refraction layer
+ refractionLayers = new ArrayList<ConstantRefractionLayer>(numberOfLayers);
+ refractionLayers.add(new ConstantRefractionLayer(600000, 1.2));
+ model = new MultiLayerModel(earth, refractionLayers);
+ correctedIntersection = model.applyCorrection(position, los, rawIntersection, algorithm);
+ distance = Vector3D.distance(earth.transform(rawIntersection), earth.transform(correctedIntersection));
+ Assert.assertEquals(0.0, distance, 0.0);
}
@Override
--
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