1   /* Copyright 2002-2021 CS GROUP
2    * Licensed to CS GROUP (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.measurements.generation;
18  
19  import java.util.List;
20  import java.util.SortedSet;
21  
22  import org.orekit.estimation.measurements.ObservedMeasurement;
23  import org.orekit.propagation.sampling.OrekitStepInterpolator;
24  import org.orekit.time.AbsoluteDate;
25  
26  
27  /** Interface for generating {@link ObservedMeasurement measurements} sequences.
28   * @param <T> the type of the measurement
29   * @author Luc Maisonobe
30   * @since 9.3
31   */
32  public interface Scheduler<T extends ObservedMeasurement<T>> {
33  
34      /** Initialize scheduler at the start of a measurements generation.
35       * <p>
36       * This method is called once at the start of the measurements generation. It
37       * may be used by the scheduler to initialize some internal data
38       * if needed, typically {@link MeasurementBuilder#init(AbsoluteDate, AbsoluteDate)
39       * initializing builders}.
40       * </p>
41       * @param start start of the measurements time span
42       * @param end end of the measurements time span
43       */
44      void init(AbsoluteDate start, AbsoluteDate end);
45  
46      /** Generate a sequence of measurements.
47       * @param interpolators interpolators for spacecraft states
48       * @return generated measurements
49       */
50      SortedSet<T> generate(List<OrekitStepInterpolator> interpolators);
51  
52  }