1   /* Copyright 2013-2016 CS Systèmes d'Information
2    * Licensed to CS Systèmes d'Information (CS) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * CS licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *   http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.orekit.rugged.los;
18  
19  import org.apache.commons.math3.analysis.differentiation.DerivativeStructure;
20  import org.apache.commons.math3.geometry.euclidean.threed.FieldVector3D;
21  import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
22  import org.orekit.rugged.utils.ParametricModel;
23  import org.orekit.time.AbsoluteDate;
24  
25  /** Interface representing a line-of-sight which depends on time.
26   * @see org.orekit.rugged.linesensor.LineSensor
27   * @author Luc Maisonobe
28   */
29  public interface TimeDependentLOS extends ParametricModel {
30  
31      /** Get the number of pixels.
32       * @return number of pixels
33       */
34      int getNbPixels();
35  
36      /** Get the line of sight for a given date.
37       * @param index los pixel index
38       * @param date date
39       * @return line of sight
40       */
41      Vector3D getLOS(int index, AbsoluteDate date);
42  
43      /** Get the line of sight and its partial derivatives for a given date.
44       * <p>
45       * This method is used for LOS calibration purposes. It allows to compute
46       * the Jacobian matrix of the LOS with respect to the parameters, which
47       * are typically polynomials coefficients representing rotation angles.
48       * These polynomials can be used for example to model thermo-elastic effects.
49       * </p>
50       * <p>
51       * Note that in order for the partial derivatives to be properly set up, the
52       * {@link #setEstimatedParameters(double[], int, int) setEstimatedParameters}
53       * <em>must</em> have been called at least once before this method and its
54       * {@code start} parameter will be used to ensure the partial derivatives are
55       * ordered in the same way in the returned vector as they were in the set
56       * parameters.
57       * </p>
58       * @param index los pixel index
59       * @param date date
60       * @param parameters current estimate of the adjusted parameters
61       * @return line of sight, and its first partial derivatives with respect to the parameters
62       */
63      FieldVector3D<DerivativeStructure> getLOS(int index, AbsoluteDate date, double[] parameters);
64  
65  }