LOFOffsetAttitudeLaw 4.5.1
Aller à la navigation
Aller à la recherche
public class LOFOffsetAttitudeLaw {
public static void main(String[] args) throws PatriusException, IOException, URISyntaxException {
// Patrius Dataset initialization (needed for example to get the UTC time
PatriusDataset.addResourcesFromPatriusDataset() ;
// Recovery of the UTC time scale using a "factory" (not to duplicate such unique object)
final TimeScale TUC = TimeScalesFactory.getUTC();
// Date of the orbit given in UTC time scale)
final AbsoluteDate date = new AbsoluteDate("2010-01-01T12:00:00.000", TUC);
// Getting the frame with wich will defined the orbit parameters
// As for time scale, we will use also a "factory".
final Frame GCRF = FramesFactory.getGCRF();
// Initial orbit
final double sma = 7200.e+3;
final double exc = 0.01;
final double inc = FastMath.toRadians(98.);
final double pa = FastMath.toRadians(0.);
final double raan = FastMath.toRadians(0.);
final double anm = FastMath.toRadians(0.);
final double MU = Constants.WGS84_EARTH_MU;
final KeplerianParameters par = new KeplerianParameters(sma, exc, inc, pa, raan, anm, PositionAngle.MEAN, MU);
final Orbit iniOrbit = new KeplerianOrbit(par, GCRF, date);
// Building a first attitude law
final AttitudeLaw attitudeLaw0= new LofOffset(LOFType.TNW);
final Attitude att0 = attitudeLaw0.getAttitude(iniOrbit);
// Building a second attitude law with a 45 deg rotation on Z axis
final double psi = FastMath.toRadians(45.);
final double teta = 0.;
final double phi = 0.;
final AttitudeLaw attitudeLaw = new LofOffset(LOFType.TNW, RotationOrder.ZYX, psi, teta, phi);
final Attitude att = attitudeLaw.getAttitude(iniOrbit);
// Rotation of the X axis
Vector3D vec0 = att0.getRotation().applyTo(Vector3D.PLUS_I);
Vector3D vec = att.getRotation().applyTo(Vector3D.PLUS_I);
double cos = vec.dotProduct(vec0);
double ang = FastMath.acos(cos);
System.out.println(FastMath.toDegrees(ang));
// Rotation of the Y axis
vec0 = att0.getRotation().applyTo(Vector3D.PLUS_J);
vec = att.getRotation().applyTo(Vector3D.PLUS_J);
cos = vec.dotProduct(vec0);
ang = FastMath.acos(cos);
System.out.println(FastMath.toDegrees(ang));
// Z axis comparison
vec0 = att0.getRotation().applyTo(Vector3D.PLUS_K);
vec = att.getRotation().applyTo(Vector3D.PLUS_K);
final Vector3D dVec = vec.subtract(vec0);
final double norm = dVec.getNorm();
System.out.println(norm);
}
}