Java tutorial
/* Copyright 2002-2015 CS Systmes d'Information * Licensed to CS Systmes 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. */ import org.apache.commons.math3.geometry.euclidean.threed.Vector3D; import org.apache.commons.math3.util.FastMath; import org.orekit.bodies.BodyShape; import org.orekit.bodies.CelestialBody; import org.orekit.bodies.GeodeticPoint; import org.orekit.bodies.OneAxisEllipsoid; import org.orekit.errors.OrekitException; import org.orekit.frames.Frame; import org.orekit.frames.FramesFactory; import org.orekit.frames.TopocentricFrame; import org.orekit.orbits.KeplerianOrbit; import org.orekit.orbits.Orbit; import org.orekit.propagation.Propagator; import org.orekit.propagation.SpacecraftState; import org.orekit.propagation.analytical.KeplerianPropagator; import org.orekit.propagation.analytical.tle.TLE; import org.orekit.propagation.analytical.tle.TLEPropagator; import org.orekit.propagation.events.ElevationDetector; import org.orekit.propagation.events.EventDetector; import org.orekit.propagation.events.handlers.EventHandler; import org.orekit.time.AbsoluteDate; import org.orekit.time.TimeScalesFactory; import org.orekit.utils.Constants; import org.orekit.utils.IERSConventions; import org.orekit.utils.PVCoordinates; import Quick_Copy_Files.AutoconfigurationCustom; /* Orekit tutorial for special event detection. * <p>This tutorial shows how to easily check for visibility between a satellite and a ground station.<p> * @author Pascal Parraud */ public class Satellite { //inputs //AbsoluteDate now; //AbsoluteDate endDate; String line1; String line2; //outputs String satName; //printed String satID; //printed AbsoluteDate localRise; //printed //Rise location AbsoluteDate localSet; //printed //Set location double maxElevation; //printed AbsoluteDate maxElevationTime; //printed public Satellite(String name, String line1, String line2) { this.satName = name; this.line1 = line1; this.line2 = line2; this.satID = (line2.split(" "))[1]; } public boolean quickCheck(AbsoluteDate endDate, CelestialBody sun) throws OrekitException { // Initial TLE orbit data TLE TLEdata = new TLE(line1, line2); // Propagator : using TLE elements Propagator TLEProp = TLEPropagator.selectExtrapolator(TLEdata); Vector3D posVec = TLEProp.propagate(endDate) .getPVCoordinates(FramesFactory.getITRF(IERSConventions.IERS_2010, true)).getPosition(); double[] posLatLong = Convert_To_Lat_Long(posVec); System.out.format("Latitude %.8f N%n", posLatLong[0]); System.out.format("Longitude %.8f E%n", posLatLong[1]); System.out.format("Altitude %.0f m %n", posLatLong[2]); return true; } //PRINTABLE_RISETIME = localRise.getComponents(TimeScalesFactory.getUTC()).getTime().toString(); public static double[] Convert_To_Lat_Long(Vector3D posVec) { double Xcomp = posVec.getX(); double Ycomp = posVec.getY(); double Zcomp = posVec.getZ(); double longitude; double latitude; double altitude; //Done so all cases of longitudes are right if (Ycomp > 0) { if (Xcomp > 0) { longitude = Math.toDegrees(Math.atan(Ycomp / Xcomp)); } else { longitude = 180 - Math.toDegrees(Math.atan(Math.abs(Ycomp / Xcomp))); } } else { if (Xcomp > 0) { longitude = -1 * Math.toDegrees(Math.atan(Math.abs(Ycomp / Xcomp))); } else { longitude = -1 * (180 - Math.toDegrees(Math.atan(Ycomp / Xcomp))); } } //Calculate latitude latitude = Math.toDegrees(Math.atan(Zcomp / Math.sqrt(Xcomp * Xcomp + Ycomp * Ycomp))); //Calculate radius and altitude double EER = Constants.WGS84_EARTH_EQUATORIAL_RADIUS; //Earth Equator Radius in meters double EPR = EER - EER * Constants.WGS84_EARTH_FLATTENING; //Earth Polar Radius in meters double earthRadius = Math .sqrt((Math.pow(EPR * EPR * Math.cos(latitude), 2) + Math.pow(EER * EER * Math.cos(latitude), 2)) / (Math.pow(EPR * Math.cos(latitude), 2) + Math.pow(EER * Math.cos(latitude), 2))); double orbitRadius = Math.sqrt(Xcomp * Xcomp + Ycomp * Ycomp + Zcomp * Zcomp); altitude = orbitRadius - earthRadius; return new double[] { latitude, longitude, altitude }; } /** Handler for visibility event. */ private static class VisibilityHandler implements EventHandler<ElevationDetector> { public Action eventOccurred(final SpacecraftState s, final ElevationDetector detector, final boolean increasing) { if (increasing) { System.out.println( " Visibility on " + detector.getTopocentricFrame().getName() + " begins at " + s.getDate()); return Action.CONTINUE; } else { System.out.println( " Visibility on " + detector.getTopocentricFrame().getName() + " ends at " + s.getDate()); return Action.STOP; } } public SpacecraftState resetState(final ElevationDetector detector, final SpacecraftState oldState) { return oldState; } } }