HalfTrackSampler.java
- /* Copyright 2002-2024 CS GROUP
- * Licensed to CS GROUP (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.models.earth.tessellation;
- import java.util.ArrayList;
- import java.util.List;
- import org.hipparchus.util.Pair;
- import org.orekit.bodies.GeodeticPoint;
- import org.orekit.bodies.OneAxisEllipsoid;
- import org.orekit.propagation.SpacecraftState;
- import org.orekit.propagation.sampling.OrekitFixedStepHandler;
- import org.orekit.utils.TimeStampedPVCoordinates;
- /** Sampler for half track span.
- * @since 7.1
- * @see AlongTrackAiming
- * @author Luc Maisonobe
- */
- class HalfTrackSampler implements OrekitFixedStepHandler {
- /** Ellipsoid over which track is sampled. */
- private final OneAxisEllipsoid ellipsoid;
- /** Half track sample. */
- private final List<Pair<GeodeticPoint, TimeStampedPVCoordinates>> halfTrack;
- /** Simple constructor.
- * @param ellipsoid ellipsoid over which track is sampled
- */
- HalfTrackSampler(final OneAxisEllipsoid ellipsoid) {
- this.ellipsoid = ellipsoid;
- this.halfTrack = new ArrayList<Pair<GeodeticPoint, TimeStampedPVCoordinates>>();
- }
- /** Get half track sample.
- * @return half track sample
- */
- public List<Pair<GeodeticPoint, TimeStampedPVCoordinates>> getHalfTrack() {
- return halfTrack;
- }
- /** {@inheritDoc} */
- @Override
- public void handleStep(final SpacecraftState currentState) {
- // find the sliding ground point below spacecraft
- final TimeStampedPVCoordinates pv = currentState.getPVCoordinates(ellipsoid.getBodyFrame());
- final TimeStampedPVCoordinates groundPV = ellipsoid.projectToGround(pv, ellipsoid.getBodyFrame());
- // geodetic coordinates
- final GeodeticPoint gp =
- ellipsoid.transform(groundPV.getPosition(), ellipsoid.getBodyFrame(), currentState.getDate());
- halfTrack.add(new Pair<GeodeticPoint, TimeStampedPVCoordinates>(gp, groundPV));
- }
- }