Examples with DOPComputer org.orekit.gnss.DOPComputer used on opensource projects

Example 1 with DOPComputer

use of org.orekit.gnss.DOPComputer in project Orekit by CS-SI.

the class DOPComputation method run.

private void run(final OneAxisEllipsoid shape, final List<GeodeticPoint> zone, final double meshSize, final double minElevation, final AbsoluteDate tStart, final AbsoluteDate tStop, final double tStep) throws IOException, OrekitException, ParseException {
    // Gets the GPS almanacs from the SEM file
    final SEMParser reader = new SEMParser(null);
    reader.loadData();
    final List<GPSAlmanac> almanacs = reader.getAlmanacs();
    // Creates the GPS propagators from the almanacs
    final List<Propagator> propagators = new ArrayList<Propagator>();
    for (GPSAlmanac almanac : almanacs) {
        // Only keeps almanac with health status ok
        if (almanac.getHealth() == 0) {
            propagators.add(new GPSPropagator.Builder(almanac).build());
        } else {
            System.out.println("GPS PRN " + almanac.getPRN() + " is not OK (Health status = " + almanac.getHealth() + ").");
        }
    }
    // Meshes the area of interest into a grid of geodetic points.
    final List<List<GeodeticPoint>> points = sample(shape, zone, meshSize);
    // Creates the DOP computers for all the locations of the sampled geographic zone
    final List<DOPComputer> computers = new ArrayList<DOPComputer>();
    for (List<GeodeticPoint> row : points) {
        for (GeodeticPoint point : row) {
            computers.add(DOPComputer.create(shape, point).withMinElevation(minElevation));
        }
    }
    // Computes the DOP for each point over the period
    final List<List<DOP>> allDop = new ArrayList<List<DOP>>();
    // Loops on the period
    AbsoluteDate tc = tStart;
    while (tc.compareTo(tStop) != 1) {
        // Loops on the grid points
        final List<DOP> dopAtDate = new ArrayList<DOP>();
        for (DOPComputer computer : computers) {
            try {
                final DOP dop = computer.compute(tc, propagators);
                dopAtDate.add(dop);
            } catch (OrekitException oe) {
                System.out.println(oe.getLocalizedMessage());
            }
        }
        allDop.add(dopAtDate);
        tc = tc.shiftedBy(tStep);
    }
    // Post-processing: gets the statistics of PDOP over the zone at each time
    System.out.println("                           PDOP");
    System.out.println("          Date           min  max");
    for (List<DOP> dopAtDate : allDop) {
        final StreamingStatistics pDoP = new StreamingStatistics();
        for (DOP dopAtLoc : dopAtDate) {
            pDoP.addValue(dopAtLoc.getPdop());
        }
        final AbsoluteDate date = dopAtDate.get(0).getDate();
        System.out.format(Locale.ENGLISH, "%s %.2f %.2f%n", date.toString(), pDoP.getMin(), pDoP.getMax());
    }
}