Class TDOA

  • All Implemented Interfaces:
    Comparable<ComparableMeasurement>, ComparableMeasurement, ObservedMeasurement<TDOA>, TimeStamped, ParameterDriversProvider

    public class TDOA
    extends GroundReceiverMeasurement<TDOA>
    Class modeling a Time Difference of Arrival measurement with a satellite as emitter and two ground stations as receivers.

    TDOA measures the difference in signal arrival time between the emitter and receivers, corresponding to a difference in ranges from the two receivers to the emitter.

    The date of the measurement corresponds to the reception of the signal by the prime station. The measurement corresponds to the date of the measurement minus the date of reception of the signal by the second station: tdoa = tr1 - tr2

    The motion of the stations and the satellite during the signal flight time are taken into account.

    Since:
    11.2
    Author:
    Pascal Parraud
    • Constructor Detail

      • TDOA

        public TDOA​(GroundStation primeStation,
                    GroundStation secondStation,
                    AbsoluteDate date,
                    double tdoa,
                    double sigma,
                    double baseWeight,
                    ObservableSatellite satellite)
        Simple constructor.
        Parameters:
        primeStation - ground station that gives the date of the measurement
        secondStation - ground station that gives the measurement
        date - date of the measurement
        tdoa - observed value (s)
        sigma - theoretical standard deviation
        baseWeight - base weight
        satellite - satellite related to this measurement
    • Method Detail

      • getPrimeStation

        public GroundStation getPrimeStation()
        Get the prime ground station, the one that gives the date of the measurement.
        Returns:
        prime ground station
      • getSecondStation

        public GroundStation getSecondStation()
        Get the second ground station, the one that gives the measurement.
        Returns:
        second ground station
      • forwardSignalTimeOfFlight

        public static double forwardSignalTimeOfFlight​(TimeStampedPVCoordinates adjustableEmitterPV,
                                                       Vector3D receiverPosition,
                                                       AbsoluteDate signalArrivalDate)
        Compute propagation delay on a link leg (typically downlink or uplink). This differs from signalTimeOfFlight through advancing rather than delaying the emitter.
        Parameters:
        adjustableEmitterPV - position/velocity of emitter that may be adjusted
        receiverPosition - fixed position of receiver at signalArrivalDate, in the same frame as adjustableEmitterPV
        signalArrivalDate - date at which the signal arrives to receiver
        Returns:
        positive delay between signal emission and signal reception dates
      • forwardSignalTimeOfFlight

        public static <T extends CalculusFieldElement<T>> T forwardSignalTimeOfFlight​(TimeStampedFieldPVCoordinates<T> adjustableEmitterPV,
                                                                                      FieldVector3D<T> receiverPosition,
                                                                                      FieldAbsoluteDate<T> signalArrivalDate)
        Compute propagation delay on a link leg (typically downlink or uplink).This differs from signalTimeOfFlight through advancing rather than delaying the emitter.
        Type Parameters:
        T - the type of the components
        Parameters:
        adjustableEmitterPV - position/velocity of emitter that may be adjusted
        receiverPosition - fixed position of receiver at signalArrivalDate, in the same frame as adjustableEmitterPV
        signalArrivalDate - date at which the signal arrives to receiver
        Returns:
        positive delay between signal emission and signal reception dates