1   /* Copyright 2002-2018 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.estimation.sequential;
18  
19  import org.hipparchus.linear.RealMatrix;
20  import org.orekit.propagation.SpacecraftState;
21  
22  /** Abstract provider handling a predefined initial covariance matrix.
23   * <p>
24   * This class always provides a predefined initial noise matrix.
25   * </p>
26   * @author Luc Maisonobe
27   * @since 9.2
28   */
29  public abstract class AbstractCovarianceMatrixProvider implements CovarianceMatrixProvider {
30  
31      /** Initial process noise. */
32      private final RealMatrix initialNoiseMatrix;
33  
34      /** Simple constructor.
35       * @param initialNoiseMatrix initial process noise
36       */
37      protected AbstractCovarianceMatrixProvider(final RealMatrix initialNoiseMatrix) {
38          this.initialNoiseMatrix = initialNoiseMatrix;
39      }
40  
41      /** {@inheritDoc} */
42      @Override
43      public RealMatrix getInitialCovarianceMatrix(final SpacecraftState initial) {
44          return initialNoiseMatrix;
45      }
46  
47  }