From feda26a1151af585a202fb820db489db1d165965 Mon Sep 17 00:00:00 2001
From: sesteves <sroesteves@gmail.com>
Date: Tue, 5 Jul 2016 19:07:18 +0100
Subject: [PATCH] multi layer model
---
.../AtmosphericRefraction.java | 2 +-
.../MultiLayerModel.java | 76 ++++++++++++++-----
2 files changed, 59 insertions(+), 19 deletions(-)
diff --git a/src/main/java/org/orekit/rugged/atmosphericrefraction/AtmosphericRefraction.java b/src/main/java/org/orekit/rugged/atmosphericrefraction/AtmosphericRefraction.java
index d17b112e..05bee9ec 100644
--- a/src/main/java/org/orekit/rugged/atmosphericrefraction/AtmosphericRefraction.java
+++ b/src/main/java/org/orekit/rugged/atmosphericrefraction/AtmosphericRefraction.java
@@ -25,6 +25,6 @@ import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
*/
public interface AtmosphericRefraction {
- long getDeviation(Vector3D pos, Vector3D los, double altitude);
+ double getDeviation(Vector3D pos, Vector3D los, Vector3D zenith, double altitude);
}
diff --git a/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java b/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java
index 0f4151d1..d2b54f90 100644
--- a/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java
+++ b/src/main/java/org/orekit/rugged/atmosphericrefraction/MultiLayerModel.java
@@ -1,9 +1,27 @@
+/* Copyright 2013-2016 CS Systèmes d'Information
+ * Licensed to CS Systèmes d'Information (CS) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * CS licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
package org.orekit.rugged.atmosphericrefraction;
import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
+import org.apache.commons.math3.util.FastMath;
-import java.util.ArrayList;
-import java.util.List;
+import java.util.Collections;
+import java.util.Map;
+import java.util.TreeMap;
/**
* Multi layer model for atmospheric refraction.
@@ -11,28 +29,50 @@ import java.util.List;
*/
public class MultiLayerModel implements AtmosphericRefraction {
- private static final double KARMA_LINE = 1000000;
- private static final double LAYER_SIZE = KARMA_LINE * 0.25;
-
- private List<Double> refractions = new ArrayList<Double>();
-
- private int numberOfLayers = 1;
+ // maps altitude (lower bound) to refraction index
+ private static final Map<Double, Double> meanAtmoshpericRefractions;
- public MultiLayerModel() {
- }
-
- public MultiLayerModel(int numberOfLayers) {
- refractions.add(1.00029);
- this.numberOfLayers = numberOfLayers;
+ static {
+ Map<Double, Double> refractions = new TreeMap(Collections.reverseOrder());
+ refractions.put(-1000.00000000000, 1.00030600000);
+ refractions.put(0.00000000000, 1.00027800000);
+ refractions.put(1000.00000000000, 1.00025200000);
+ refractions.put(3000.00000000000, 1.00020600000);
+ refractions.put(5000.00000000000, 1.00016700000);
+ refractions.put(7000.00000000000, 1.00013400000);
+ refractions.put(9000.00000000000, 1.00010600000);
+ refractions.put(11000.00000000000, 1.00008300000);
+ refractions.put(14000.00000000000, 1.00005200000);
+ refractions.put(18000.00000000000, 1.00002800000);
+ refractions.put(23000.00000000000, 1.00001200000);
+ refractions.put(30000.00000000000, 1.00000400000);
+ refractions.put(40000.00000000000, 1.00000100000);
+ refractions.put(50000.00000000000, 1.00000000000);
+ refractions.put(100000.00000000000, 1.00000000000);
+ meanAtmoshpericRefractions = Collections.unmodifiableMap(refractions);
}
@Override
- public long getDeviation(Vector3D pos, Vector3D los, double altitude) {
-
- double numberOfCrossedLayers = (KARMA_LINE - altitude) / LAYER_SIZE;
+ public double getDeviation(Vector3D pos, Vector3D los, Vector3D zenith, double altitude) {
+ double incidenceAngleSin = FastMath.sin(Vector3D.angle(los, zenith));
+ double previousRefractionIndex = -1;
+ double xDistance = 0;
+ for(Map.Entry<Double, Double> entry : meanAtmoshpericRefractions.entrySet()) {
+ if(pos.getZ() < entry.getKey()) {
+ continue;
+ }
+ if(previousRefractionIndex > 0) {
+ incidenceAngleSin = previousRefractionIndex * incidenceAngleSin / entry.getValue();
+ }
+ xDistance += (pos.getZ() - entry.getKey()) * FastMath.tan(incidenceAngleSin);
+ if(altitude > entry.getKey()) {
+ break;
+ }
+ previousRefractionIndex = entry.getValue();
+ }
- return 0;
+ return pos.getX() + xDistance;
}
}
--
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