Examples with FieldGeodeticPoint org.orekit.bodies.FieldGeodeticPoint used on opensource projects

Example 1 with FieldGeodeticPoint

use of org.orekit.bodies.FieldGeodeticPoint in project Orekit by CS-SI.

the class DTM2000 method getDensity.

/**
 * {@inheritDoc}
 */
@Override
public <T extends RealFieldElement<T>> T getDensity(final FieldAbsoluteDate<T> date, final FieldVector3D<T> position, final Frame frame) throws OrekitException {
    // check if data are available :
    final AbsoluteDate dateD = date.toAbsoluteDate();
    if ((dateD.compareTo(inputParams.getMaxDate()) > 0) || (dateD.compareTo(inputParams.getMinDate()) < 0)) {
        throw new OrekitException(OrekitMessages.NO_SOLAR_ACTIVITY_AT_DATE, dateD, inputParams.getMinDate(), inputParams.getMaxDate());
    }
    // compute day number in current year
    final Calendar cal = new GregorianCalendar();
    cal.setTime(date.toDate(TimeScalesFactory.getUTC()));
    final int day = cal.get(Calendar.DAY_OF_YEAR);
    // position in ECEF so we only have to do the transform once
    final Frame ecef = earth.getBodyFrame();
    final FieldVector3D<T> pEcef = frame.getTransformTo(ecef, date).transformPosition(position);
    // compute geodetic position
    final FieldGeodeticPoint<T> inBody = earth.transform(pEcef, ecef, date);
    final T alti = inBody.getAltitude();
    final T lon = inBody.getLongitude();
    final T lat = inBody.getLatitude();
    // compute local solar time
    final Vector3D sunPos = sun.getPVCoordinates(dateD, ecef).getPosition();
    final T y = pEcef.getY().multiply(sunPos.getX()).subtract(pEcef.getX().multiply(sunPos.getY()));
    final T x = pEcef.getX().multiply(sunPos.getX()).add(pEcef.getY().multiply(sunPos.getY()));
    final T hl = y.atan2(x).add(FastMath.PI);
    // get current solar activity data and compute
    return getDensity(day, alti, lon, lat, hl, inputParams.getInstantFlux(dateD), inputParams.getMeanFlux(dateD), inputParams.getThreeHourlyKP(dateD), inputParams.get24HoursKp(dateD));
}

Example 2 with FieldGeodeticPoint

use of org.orekit.bodies.FieldGeodeticPoint 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 3 with FieldGeodeticPoint

use of org.orekit.bodies.FieldGeodeticPoint in project Orekit by CS-SI.

the class Geoid method transform.

/**
 * {@inheritDoc}
 *
 * @param point The surface relative point to transform. Altitude is
 *              orthometric height, that is height above the {@link Geoid}.
 *              Latitude and longitude are both geodetic and defined with
 *              respect to the {@link #getEllipsoid() reference ellipsoid}.
 * @param <T> type of the field elements
 * @return point at the same location but as a Cartesian point in the {@link
 * #getBodyFrame() body frame}.
 * @see #transform(Vector3D, Frame, AbsoluteDate)
 * @since 9.0
 */
@Override
public <T extends RealFieldElement<T>> FieldVector3D<T> transform(final FieldGeodeticPoint<T> point) {
    try {
        // convert orthometric height to height above ellipsoid using undulation
        // TODO pass in date to allow user to specify
        final double undulation = this.getUndulation(point.getLatitude().getReal(), point.getLongitude().getReal(), this.defaultDate);
        final FieldGeodeticPoint<T> ellipsoidal = new FieldGeodeticPoint<>(point.getLatitude(), point.getLongitude(), point.getAltitude().add(undulation));
        // transform using reference ellipsoid
        return this.getEllipsoid().transform(ellipsoidal);
    } catch (OrekitException e) {
        // an OrekitException, so wrap in an exception we can throw.
        throw new RuntimeException(e);
    }
}

Example 4 with FieldGeodeticPoint

use of org.orekit.bodies.FieldGeodeticPoint in project Orekit by CS-SI.

the class NRLMSISE00 method getDensity.

/**
 * {@inheritDoc}
 */
@Override
public <T extends RealFieldElement<T>> T getDensity(final FieldAbsoluteDate<T> date, final FieldVector3D<T> position, final Frame frame) throws OrekitException {
    // check if data are available :
    final AbsoluteDate dateD = date.toAbsoluteDate();
    if ((dateD.compareTo(inputParams.getMaxDate()) > 0) || (dateD.compareTo(inputParams.getMinDate()) < 0)) {
        throw new OrekitException(OrekitMessages.NO_SOLAR_ACTIVITY_AT_DATE, dateD, inputParams.getMinDate(), inputParams.getMaxDate());
    }
    // compute day number in current year and the seconds within the day
    final TimeScale ut1 = TimeScalesFactory.getUT1(IERSConventions.IERS_2010, true);
    final DateTimeComponents dtc = dateD.getComponents(ut1);
    final int doy = dtc.getDate().getDayOfYear();
    final T sec = date.durationFrom(new AbsoluteDate(dtc.getDate(), TimeComponents.H00, ut1));
    // compute geodetic position (km and °)
    final FieldGeodeticPoint<T> inBody = earth.transform(position, frame, date);
    final T alt = inBody.getAltitude().divide(1000.);
    final T lon = inBody.getLongitude().multiply(180.0 / FastMath.PI);
    final T lat = inBody.getLatitude().multiply(180.0 / FastMath.PI);
    // compute local solar time
    final T lst = localSolarTime(dateD, position, frame);
    // get solar activity data and compute
    final FieldOutput<T> out = new FieldOutput<>(doy, sec, lat, lon, lst, inputParams.getAverageFlux(dateD), inputParams.getDailyFlux(dateD), inputParams.getAp(dateD));
    out.gtd7d(alt);
    // return the local density
    return out.getDensity(TOTAL_MASS);
}