Examples with Frame org.orekit.frames.Frame used on opensource projects

Example 46 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class OrekitStepHandlerTest method testIsInterpolated.

/**
 * Check {@link OrekitStepInterpolator#isPreviousStateInterpolated()} and {@link
 * OrekitStepInterpolator#isCurrentStateInterpolated()}.
 *
 * @throws OrekitException on error.
 */
@Test
public void testIsInterpolated() throws OrekitException {
    // setup
    NumericalPropagator propagator = new NumericalPropagator(new ClassicalRungeKuttaIntegrator(60));
    AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
    Frame eci = FramesFactory.getGCRF();
    SpacecraftState ic = new SpacecraftState(new KeplerianOrbit(6378137 + 500e3, 1e-3, 0, 0, 0, 0, PositionAngle.TRUE, eci, date, Constants.EIGEN5C_EARTH_MU));
    propagator.setInitialState(ic);
    propagator.setOrbitType(OrbitType.CARTESIAN);
    // detector triggers half way through second step
    DateDetector detector = new DateDetector(date.shiftedBy(90)).withHandler(new ContinueOnEvent<>());
    propagator.addEventDetector(detector);
    // action and verify
    Queue<Boolean> expected = new ArrayDeque<>(Arrays.asList(false, false, false, true, true, false));
    propagator.setMasterMode(new OrekitStepHandler() {

        @Override
        public void handleStep(OrekitStepInterpolator interpolator, boolean isLast) {
            assertEquals(expected.poll(), interpolator.isPreviousStateInterpolated());
            assertEquals(expected.poll(), interpolator.isCurrentStateInterpolated());
        }
    });
    final AbsoluteDate end = date.shiftedBy(120);
    assertEquals(end, propagator.propagate(end).getDate());
}

Example 47 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class Geoid method getIntersectionPoint.

/**
 * {@inheritDoc}
 *
 * <p> The intersection point is computed using a line search along the
 * specified line. This is accurate when the geoid is slowly varying.
 */
@Override
public GeodeticPoint getIntersectionPoint(final Line lineInFrame, final Vector3D closeInFrame, final Frame frame, final AbsoluteDate date) throws OrekitException {
    /*
         * It is assumed that the geoid is slowly varying over it's entire
         * surface. Therefore there will one local intersection.
         */
    // transform to body frame
    final Frame bodyFrame = this.getBodyFrame();
    final Transform frameToBody = frame.getTransformTo(bodyFrame, date);
    final Vector3D close = frameToBody.transformPosition(closeInFrame);
    final Line lineInBodyFrame = frameToBody.transformLine(lineInFrame);
    // set the line's direction so the solved for value is always positive
    final Line line;
    if (lineInBodyFrame.getAbscissa(close) < 0) {
        line = lineInBodyFrame.revert();
    } else {
        line = lineInBodyFrame;
    }
    final ReferenceEllipsoid ellipsoid = this.getEllipsoid();
    // calculate end points
    // distance from line to center of earth, squared
    final double d2 = line.pointAt(0.0).getNormSq();
    // the minimum abscissa, squared
    final double n = ellipsoid.getPolarRadius() + MIN_UNDULATION;
    final double minAbscissa2 = n * n - d2;
    // smaller end point of the interval = 0.0 or intersection with
    // min_undulation sphere
    final double lowPoint = FastMath.sqrt(FastMath.max(minAbscissa2, 0.0));
    // the maximum abscissa, squared
    final double x = ellipsoid.getEquatorialRadius() + MAX_UNDULATION;
    final double maxAbscissa2 = x * x - d2;
    // larger end point of the interval
    final double highPoint = FastMath.sqrt(maxAbscissa2);
    // line search function
    final UnivariateFunction heightFunction = new UnivariateFunction() {

        @Override
        public double value(final double x) {
            try {
                final GeodeticPoint geodetic = transform(line.pointAt(x), bodyFrame, date);
                return geodetic.getAltitude();
            } catch (OrekitException e) {
                // due to frame transform -> re-throw
                throw new RuntimeException(e);
            }
        }
    };
    // compute answer
    if (maxAbscissa2 < 0) {
        // ray does not pierce bounding sphere -> no possible intersection
        return null;
    }
    // solve line search problem to find the intersection
    final UnivariateSolver solver = new BracketingNthOrderBrentSolver();
    try {
        final double abscissa = solver.solve(MAX_EVALUATIONS, heightFunction, lowPoint, highPoint);
        // return intersection point
        return this.transform(line.pointAt(abscissa), bodyFrame, date);
    } catch (MathRuntimeException e) {
        // no intersection
        return null;
    }
}

Example 48 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class Geoid method getIntersectionPoint.

/**
 * {@inheritDoc}
 *
 * <p> The intersection point is computed using a line search along the
 * specified line. This is accurate when the geoid is slowly varying.
 */
@Override
public <T extends RealFieldElement<T>> FieldGeodeticPoint<T> getIntersectionPoint(final FieldLine<T> lineInFrame, final FieldVector3D<T> closeInFrame, final Frame frame, final FieldAbsoluteDate<T> date) throws OrekitException {
    final Field<T> field = date.getField();
    /*
         * It is assumed that the geoid is slowly varying over it's entire
         * surface. Therefore there will one local intersection.
         */
    // transform to body frame
    final Frame bodyFrame = this.getBodyFrame();
    final FieldTransform<T> frameToBody = frame.getTransformTo(bodyFrame, date);
    final FieldVector3D<T> close = frameToBody.transformPosition(closeInFrame);
    final FieldLine<T> lineInBodyFrame = frameToBody.transformLine(lineInFrame);
    // set the line's direction so the solved for value is always positive
    final FieldLine<T> line;
    if (lineInBodyFrame.getAbscissa(close).getReal() < 0) {
        line = lineInBodyFrame.revert();
    } else {
        line = lineInBodyFrame;
    }
    final ReferenceEllipsoid ellipsoid = this.getEllipsoid();
    // calculate end points
    // distance from line to center of earth, squared
    final T d2 = line.pointAt(0.0).getNormSq();
    // the minimum abscissa, squared
    final double n = ellipsoid.getPolarRadius() + MIN_UNDULATION;
    final T minAbscissa2 = d2.negate().add(n * n);
    // smaller end point of the interval = 0.0 or intersection with
    // min_undulation sphere
    final T lowPoint = minAbscissa2.getReal() < 0 ? field.getZero() : minAbscissa2.sqrt();
    // the maximum abscissa, squared
    final double x = ellipsoid.getEquatorialRadius() + MAX_UNDULATION;
    final T maxAbscissa2 = d2.negate().add(x * x);
    // larger end point of the interval
    final T highPoint = maxAbscissa2.sqrt();
    // line search function
    final RealFieldUnivariateFunction<T> heightFunction = z -> {
        try {
            final FieldGeodeticPoint<T> geodetic = transform(line.pointAt(z), bodyFrame, date);
            return geodetic.getAltitude();
        } catch (OrekitException e) {
            // due to frame transform -> re-throw
            throw new RuntimeException(e);
        }
    };
    // compute answer
    if (maxAbscissa2.getReal() < 0) {
        // ray does not pierce bounding sphere -> no possible intersection
        return null;
    }
    // solve line search problem to find the intersection
    final FieldBracketingNthOrderBrentSolver<T> solver = new FieldBracketingNthOrderBrentSolver<>(field.getZero().add(1.0e-14), field.getZero().add(1.0e-6), field.getZero().add(1.0e-15), 5);
    try {
        final T abscissa = solver.solve(MAX_EVALUATIONS, heightFunction, lowPoint, highPoint, AllowedSolution.ANY_SIDE);
        // return intersection point
        return this.transform(line.pointAt(abscissa), bodyFrame, date);
    } catch (MathRuntimeException e) {
        // no intersection
        return null;
    }
}

Example 49 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class SolarRadiationPressure method acceleration.

/**
 * {@inheritDoc}
 */
@Override
public Vector3D acceleration(final SpacecraftState s, final double[] parameters) throws OrekitException {
    final AbsoluteDate date = s.getDate();
    final Frame frame = s.getFrame();
    final Vector3D position = s.getPVCoordinates().getPosition();
    final Vector3D sunSatVector = position.subtract(sun.getPVCoordinates(date, frame).getPosition());
    final double r2 = sunSatVector.getNormSq();
    // compute flux
    final double ratio = getLightingRatio(position, frame, date);
    final double rawP = ratio * kRef / r2;
    final Vector3D flux = new Vector3D(rawP / FastMath.sqrt(r2), sunSatVector);
    return spacecraft.radiationPressureAcceleration(date, frame, position, s.getAttitude().getRotation(), s.getMass(), flux, parameters);
}

Example 50 with Frame

use of org.orekit.frames.Frame in project Orekit by CS-SI.

the class AltitudeDetector method g.

/**
 * Compute the value of the switching function.
 * This function measures the difference between the current altitude
 * and the threshold altitude.
 * @param s the current state information: date, kinematics, attitude
 * @return value of the switching function
 * @exception OrekitException if some specific error occurs
 */
public double g(final SpacecraftState s) throws OrekitException {
    final Frame bodyFrame = bodyShape.getBodyFrame();
    final PVCoordinates pvBody = s.getPVCoordinates(bodyFrame);
    final GeodeticPoint point = bodyShape.transform(pvBody.getPosition(), bodyFrame, s.getDate());
    return point.getAltitude() - altitude;
}