Module: chebyPosEphem¶

This module allows the user to specify a set of Chebyshev coefficients to fit a space ephemeris trajectory. Next the input time is used to determine where a given body is in space.

Defines

MAX_CHEB_COEFF¶

MAX_CHEB_RECORDS¶

Functions

void SelfInit_chebyPosEphem(ChebyPosEphemData *configData, int64_t moduleID)¶

This method creates the output navigation message (translation only) for the ephemeris model

Return

void

Parameters

configData: The configuration data associated with the ephemeris model

void CrossInit_chebyPosEphem(ChebyPosEphemData *configData, int64_t moduleID)¶

This method initializes the input time correlation factor structure

Return

void

Parameters

configData: The configuration data associated with the ephemeris model

void Update_chebyPosEphem(ChebyPosEphemData *configData, uint64_t callTime, int64_t moduleID)¶

This method takes the current time and computes the state of the object using that time and the stored Chebyshev coefficients. If the time provided is outside the specified range, the position vectors rail high/low appropriately.

Return

void

Parameters

configData: The configuration data associated with the ephemeris model
callTime: The clock time at which the function was called (nanoseconds)

void Reset_chebyPosEphem(ChebyPosEphemData *configData, uint64_t callTime, int64_t moduleID)¶

This method takes the chebyshev coefficients loaded for the position estimator and computes the coefficients needed to estimate the time derivative of that position vector (velocity).

Return

void

Parameters

configData: The configuration data associated with the ephemeris model
callTime: The clock time at which the function was called (nanoseconds)

struct ChebyEphemRecord¶

#include <chebyPosEphem.h>

Structure that defines the layout of an Ephemeris “record.” This is basically the set of coefficients for the body x/y/z positions and the time factors associated with those coefficients.

Public Members

uint32_t nChebCoeff¶: [-] Number chebyshev coefficients loaded into record

double ephemTimeMid¶: [s] Ephemeris time (TDB) associated with the mid-point of the curve

double ephemTimeRad¶: [s] “Radius” of time that curve is valid for (half of total range

double posChebyCoeff[3 * MAX_CHEB_COEFF]¶: [-] Set of chebyshev coefficients for position

double velChebyCoeff[3 * MAX_CHEB_COEFF]¶: [-] Set of coefficients for the velocity estimate

struct ChebyPosEphemData¶

#include <chebyPosEphem.h>

Top level structure for the Chebyshev position ephemeris fit system. e.

Public Members

char posFitOutMsgName[MAX_STAT_MSG_LENGTH]¶: [-] The name of the output navigation message for pos/vel

char clockCorrInMsgName[MAX_STAT_MSG_LENGTH]¶: The name of the clock correlation message

ChebyEphemRecord ephArray[MAX_CHEB_RECORDS]¶

int32_t posFitOutMsgID¶: [-] Array of Chebyshev records for ephemeris [-] The ID associated with the outgoing message

int32_t clockCorrInMsgID¶: [-] The ID associated with the incoming clock correlation

uint32_t coeffSelector¶: [-] Index in the ephArray that we are currently using

EphemerisIntMsg outputState¶: [-] The local storage of the outgoing message data

BSKLogger *bskLogger¶: BSK Logging.