Provides swap observer/target and improved light time correction. More...

#include <SpacecraftPosition.h>

Inheritance diagram for Isis::SpacecraftPosition:

Collaboration diagram for Isis::SpacecraftPosition:

Public Types
enum	Source { Spice , Memcache , HermiteCache , PolyFunction , PolyFunctionOverHermiteConstant }
	This enum indicates the status of the object. More...

enum	PartialType { WRT_X , WRT_Y , WRT_Z }

enum	OverrideType { NoOverrides , ScaleOnly , BaseAndScale }

Public Member Functions
	SpacecraftPosition (int targetCode, int observerCode, const LightTimeCorrectionState &ltState=LightTimeCorrectionState(), const Distance &radius=Distance(0.0, Distance::Meters))
	constructor for swapping observer/target parameters

virtual	~SpacecraftPosition ()

double	getRadiusLightTime () const
	Returns the time it takes for light to travel the radius of the target.

virtual void	SetAberrationCorrection (const QString &correction)
	Set aberration correction value for determining positions.

virtual QString	GetAberrationCorrection () const
	Returns the stellr aberration correction applied.

virtual void	SetEphemerisTimeSpice ()
	Determine accurate position of target w.r.t.

const LightTimeCorrectionState &	getLightTimeState () const
	Return the state of light time correction parameters.

void	SetTimeBias (double timeBias)
	Apply a time bias when invoking SetEphemerisTime method.

double	GetTimeBias () const
	Returns the value of the time bias added to ET.

double	GetLightTime () const
	Return the light time coorection value.

virtual const std::vector< double > &	SetEphemerisTime (double et)
	Return J2000 coordinate at given time.

virtual double	EphemerisTime () const
	Return the current ephemeris time.

double	scaledTime () const
	Return the scaled time.

const std::vector< double > &	GetCenterCoordinate ()
	Compute and return the coordinate at the center time.

virtual const std::vector< double > &	Coordinate ()
	Return the current J2000 position.

const std::vector< double > &	Velocity ()
	Return the current J2000 velocity.

bool	HasVelocity ()
	Return the flag indicating whether the velocity exists.

void	LoadCache (double startTime, double endTime, int size)
	Cache J2000 position over a time range.

void	LoadCache (double time)
	Cache J2000 position for a time.

void	LoadCache (Table &table)
	Cache J2000 positions using a table file.

void	LoadCache (nlohmann::json &isd)
	Load the cached data from an ALE ISD.

Table	LineCache (const QString &tableName)
	Return a table with J2000 to reference positions.

Table	LoadHermiteCache (const QString &tableName)
	Cache J2000 position over existing cached time range using polynomials stored as Hermite cubic spline knots.

void	ReloadCache ()
	Cache J2000 positions over existing cached time range using polynomials.

void	ReloadCache (Table &table)
	Cache J2000 position over existing cached time range using table.

Table	Cache (const QString &tableName)
	Return a table with J2000 positions.

bool	IsCached () const
	Is this position cached.

int	cacheSize () const
	Get the size of the current cached positions.

void	SetPolynomial (const Source type=PolyFunction)
	Set the coefficients of a polynomial fit to each of the components (X, Y, Z) of the position vector for the time period covered by the cache, component = c0 + c1t + c2t*2 + ... + cnt**n, where t = (time - p_baseTime) / p_timeScale.

void	SetPolynomial (const std::vector< double > &XC, const std::vector< double > &YC, const std::vector< double > &ZC, const Source type=PolyFunction)
	Set the coefficients of a polynomial (parabola) fit to each of the three coordinates of the position vector for the time period covered by the cache, coord = c0 + c1t + c2t*2 + ... + cnt**n, where t = (time - p_baseTime) / p_timeScale.

void	GetPolynomial (std::vector< double > &XC, std::vector< double > &YC, std::vector< double > &ZC)
	Return the coefficients of a polynomial fit to each of the three coordinates of the position for the time period covered by the cache, angle = c0 + c1t + c2t*2 + ... + cnt**n, where t = (time - p_basetime) / p_timeScale.

void	SetPolynomialDegree (int degree)
	Set the polynomial degree.

Source	GetSource ()
	Return the source of the position.

void	ComputeBaseTime ()
	Compute the base time using cached times.

double	GetBaseTime ()
	Return the base time for the position.

void	SetOverrideBaseTime (double baseTime, double timeScale)
	Set an override base time to be used with observations on scanners to allow all images in an observation to use the same base time and polynomials for the positions.

double	GetTimeScale ()
	Return the time scale for the position.

double	DPolynomial (const int coeffIndex)
	Evaluate the derivative of the fit polynomial (parabola) defined by the given coefficients with respect to the coefficient at the given index, at the current time.

std::vector< double >	CoordinatePartial (SpicePosition::PartialType partialVar, int coeffIndex)
	Set the coefficients of a polynomial fit to each of the three coordinates of the position vector for the time period covered by the cache,.

std::vector< double >	VelocityPartial (SpicePosition::PartialType partialVar, int coeffIndex)
	Compute the derivative of the velocity with respect to the specified variable.

void	Memcache2HermiteCache (double tolerance)
	This method reduces the cache for position, time and velocity to the minimum number of values needed to interpolate the J2000 coordinates using a Hermite spline, given a tolerance of deviation from the NAIF values.

std::vector< double >	Extrapolate (double timeEt)
	Extrapolate position for a given time assuming a constant velocity.

std::vector< double >	HermiteCoordinate ()
	This method returns the Hermite coordinate for the current time for PolyFunctionOverHermiteConstant functions.

Static Public Member Functions
static double	getDistanceLightTime (const Distance &distance)
	Returns the time it takes for light to travel a given distance.

Protected Member Functions
void	SetEphemerisTimeMemcache ()
	This is a protected method that is called by SetEphemerisTime() when Source type is Memcache.

void	SetEphemerisTimeHermiteCache ()
	This is a protected method that is called by SetEphemerisTime() when Source type is HermiteCache.

void	SetEphemerisTimePolyFunction ()
	This is a protected method that is called by SetEphemerisTime() when Source type is PolyFunction.

void	SetEphemerisTimePolyFunctionOverHermiteConstant ()
	This is a protected method that is called by SetEphemerisTime() when Source type is PolyFunctionOverHermiteConstant.

int	getObserverCode () const
	Returns observer code.

int	getTargetCode () const
	Returns target code.

double	getAdjustedEphemerisTime () const
	Returns adjusted ephemeris time.

void	computeStateVector (double et, int target, int observer, const QString &refFrame, const QString &abcorr, double state[6], bool &hasVelocity, double &lightTime) const
	Computes the state vector of the target w.r.t observer.

void	setStateVector (const double state[6], const bool &hasVelocity)
	Sets the state of target relative to observer.

void	setLightTime (const double &lightTime)
	Inheritors can set the light time if indicated.

Detailed Description

Provides swap observer/target and improved light time correction.

The process by which ISIS has determined the position of the spacecraft w.r.t a target body is by utilizing the NAIF spkez_c/spkezp_c routines. Recently it has been determined that the parameters for observer (or spacecraft) and target (typically a planet) has been swapped. This results in a slightly different location of the s/c. This class provides programmers with a way to swap these parameters at runtime by providing a different instantiation option.

This implementation was chosen to mostly hide this option as it the full impact of this chage is still being evaluated for all supported instruments in ISIS.

This implementation provides the ability to swap observer/target parameters selectively as deemed appropriate by API developers. See the Spice class for how this class is being utilized.

In addition, this class provides the ability to correct for stellar aberration and light time to the target body surface (via a reimplementation of SetEphemerisSpiceTime()). This mostly fixes the problem of accurate light time correction. What remains is applying this fix on a per pixel basis. It is most accurate at the subspacecraft lat/lon point on the target body surface.

See also: Spice; LightTimeCorrectionState; SpicePosition

Author: 2012-10-11 Kris Becker

Member Enumeration Documentation

◆ OverrideType

enum Isis::SpicePosition::OverrideType

inherited

Enumerator
NoOverrides
ScaleOnly
BaseAndScale

◆ PartialType

enum Isis::SpicePosition::PartialType

inherited

Enumerator
WRT_X
WRT_Y
WRT_Z

◆ Source

enum Isis::SpicePosition::Source

inherited

This enum indicates the status of the object.

The class expects functions to be after MemCache in the list.

Enumerator
Spice	Object is reading directly from the kernels.
Memcache	Object is reading from cached table.
HermiteCache	Object is reading from splined table.
PolyFunction	Object is calculated from nth degree polynomial.
PolyFunctionOverHermiteConstant	Object is reading from splined.

Constructor & Destructor Documentation

◆ SpacecraftPosition()

Isis::SpacecraftPosition::SpacecraftPosition	(	int	targetCode,
		int	observerCode,
		const LightTimeCorrectionState &	ltState = LightTimeCorrectionState(),
		const Distance &	radius = Distance(0.0, Distance::Meters) )

constructor for swapping observer/target parameters

This constructor utlizes a protected constructor in the SpicePosition class specially designed to handle this option. Passing false into this constructor results in preexisting behavior. True will swap observer/target when determining the s/c position.

It is critical that the targetCode and observerCode be of the same exact order as they are in preexisting code. This is consistent with the current SpicePosition constructor with an additional boolean parameter that indicates to treat the targetCode as the observer and the observerCode as the target.

Author: 2012-10-11 Kris Becker

Parameters

targetCode	NAIF code for target
observerCode	NAIF code for observer
swapObserverTarget	Boolean to specify swap

◆ ~SpacecraftPosition()

virtual Isis::SpacecraftPosition::~SpacecraftPosition ( )

inlinevirtual

Member Function Documentation

◆ Cache()

Table Isis::SpicePosition::Cache ( const QString & tableName )

inherited

Return a table with J2000 positions.

Return a table containg the cached coordinates with the given name. The table will have four or seven columns, J2000 x,y,z (optionally vx,vy,vx) and the ephemeris time.

Parameters

tableName Name of the table to create and return

References _FILEINFO_, Isis::TableField::Double, Isis::IException::Io, Isis::SpicePosition::LineCache(), Isis::SpicePosition::Memcache2HermiteCache(), Isis::SpicePosition::PolyFunction, and Isis::SpicePosition::PolyFunctionOverHermiteConstant.

Referenced by Isis::SpicePosition::LineCache(), and Isis::SpicePosition::LoadHermiteCache().

◆ cacheSize()

int Isis::SpicePosition::cacheSize ( ) const

inlineinherited

Get the size of the current cached positions.

Referenced by Isis::Spice::createCache().

◆ ComputeBaseTime()

void Isis::SpicePosition::ComputeBaseTime ( )

inherited

Compute the base time using cached times.

References Isis::SpicePosition::NoOverrides, and Isis::SpicePosition::ScaleOnly.

Referenced by Isis::SpicePosition::SetPolynomial(), and Isis::SpicePosition::SetPolynomial().

◆ computeStateVector()

void Isis::SpicePosition::computeStateVector	(	double	et,
		int	target,
		int	observer,
		const QString &	refFrame,
		const QString &	abcorr,
		double	state[6],
		bool &	hasVelocity,
		double &	lightTime ) const

protectedinherited

Computes the state vector of the target w.r.t observer.

This method computes the state vector of the target that is relative of the observer. It first attempts to retrieve with velocity vectors. If that fails, it makes an additional attempt to get the state w/o velocity vectors. The final result is indicated by the hasVelocity parameter.

The parameters to this routine are the same as the NAIF spkez_c/spkezp_c routines. See http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/spkez_c.html for complete description.

Note that this routine does not actually affect the internals of this object (hence the constness of the method). It is up to the caller to apply the results and potentially handle swapping of observer/target and light time correction. See SpacecraftPosition for additional details on this application of the results.

Author: 2012-10-29 Kris Becker

Parameters

et	Time to compute state vector for
target	NAIF target code
observer	NAIF observer code
refFrame	Reference frame to express coordinates in (e.g., J2000)
abcorr	Stellar aberration correction option
state	Returns the 6-element state vector in target body fixed coordinates
hasVelocity	Returns knowledge of whether the velocity vector is valid
lightTime	Returns the light time correct resulting from the request if applicable

References Isis::NaifStatus::CheckErrors().

Referenced by SetEphemerisTimeSpice(), and Isis::SpicePosition::SetEphemerisTimeSpice().

◆ Coordinate()

virtual const std::vector< double > & Isis::SpicePosition::Coordinate ( )

inlinevirtualinherited

Return the current J2000 position.

Referenced by Isis::Spice::computeSolarLongitude(), Isis::SpicePosition::GetCenterCoordinate(), Isis::Spice::instrumentBodyFixedPosition(), Isis::Spice::instrumentBodyFixedVelocity(), Isis::IsisIlluminator::position(), Isis::Spice::setTime(), Isis::Spice::subSpacecraftPoint(), Isis::Spice::sunToBodyDist(), and Isis::Spice::targetCenterDistance().

◆ CoordinatePartial()

std::vector< double > Isis::SpicePosition::CoordinatePartial	(	SpicePosition::PartialType	partialVar,
		int	coeffIndex )

inherited

Set the coefficients of a polynomial fit to each of the three coordinates of the position vector for the time period covered by the cache,.

coordinate = c0 + c1*t + c2*t**2 + ... cn*t**n, where t = (time - p_basetime) / p_timeScale.

Parameters

partialVar Designated variable of the partial derivative

Returns: Derivative of j2000 vector calculated with polynomial with respect to partialVar

References Isis::SpicePosition::DPolynomial().

◆ DPolynomial()

double Isis::SpicePosition::DPolynomial ( const int coeffIndex )

inherited

Evaluate the derivative of the fit polynomial (parabola) defined by the given coefficients with respect to the coefficient at the given index, at the current time.

Parameters

coeffIndex Index of coefficient to differentiate with respect to

Returns: The derivative evaluated at the current time

References _FILEINFO_, Isis::IException::Programmer, and Isis::toString().

Referenced by Isis::SpicePosition::CoordinatePartial().

◆ EphemerisTime()

virtual double Isis::SpicePosition::EphemerisTime ( ) const

inlinevirtualinherited

Return the current ephemeris time.

Referenced by Isis::SpicePosition::getAdjustedEphemerisTime(), Isis::IsisIlluminator::position(), and Isis::IsisIlluminator::velocity().

◆ Extrapolate()

std::vector< double > Isis::SpicePosition::Extrapolate ( double timeEt )

inherited

Extrapolate position for a given time assuming a constant velocity.

The position and velocity at the current time will be used to extrapolate position at the input time. If velocity does not exist, the value at the current time will be output. The caller must make sure to call SetEphemerisTime to set the time to the time to be used for the extrapolation.

Parameters

[in]	timeEt	The time of the position to be extrapolated
[out]	An	extrapolated position at the input time

◆ GetAberrationCorrection()

QString Isis::SpacecraftPosition::GetAberrationCorrection ( ) const

virtual

Returns the stellr aberration correction applied.

Author: 2012-10-29 Kris Becker

Reimplemented from Isis::SpicePosition.

References Isis::LightTimeCorrectionState::getAberrationCorrection().

Referenced by SetEphemerisTimeSpice().

◆ getAdjustedEphemerisTime()

double Isis::SpicePosition::getAdjustedEphemerisTime ( ) const

protectedinherited

Returns adjusted ephemeris time.

This method returns the actual ephemeris time adjusted by a specifed time bias. The bias typically comes explicitly from the camera model but could be adjusted by the environment they are utlized in.

Author: 2012-10-29 Kris Becker

Returns: double Adjusted ephemeris time with time bias applied

References Isis::SpicePosition::EphemerisTime(), and Isis::SpicePosition::GetTimeBias().

Referenced by SetEphemerisTimeSpice(), and Isis::SpicePosition::SetEphemerisTimeSpice().

◆ GetBaseTime()

double Isis::SpicePosition::GetBaseTime ( )

inlineinherited

Return the base time for the position.

Referenced by Isis::IsisBundleObservation::initializeExteriorOrientation().

◆ GetCenterCoordinate()

const std::vector< double > & Isis::SpicePosition::GetCenterCoordinate ( )

inherited

Compute and return the coordinate at the center time.

References Isis::SpicePosition::Coordinate(), and Isis::SpicePosition::SetEphemerisTime().

Referenced by Isis::IsisBundleObservation::bundleOutputFetchData().

◆ getDistanceLightTime()

double Isis::SpacecraftPosition::getDistanceLightTime ( const Distance & distance )

static

Returns the time it takes for light to travel a given distance.

Author: 2012-10-23 Kris Becker

Parameters

radius Distance to compute light time travel for

Returns: double Time in seconds it takes light to travel given distance

References Isis::Distance::kilometers().

◆ GetLightTime()

double Isis::SpicePosition::GetLightTime ( ) const

inherited

Return the light time coorection value.

This method returns the light time correction of the last call to SetEphemerisTimeSpice. This is the actual time after adjustments that has resulting int the adjustment of the target body. The observer position should be unchanged.

Author: 2012-10-29 Kris Becker

Returns: double Returns the light time determined from the last call to SetEphemerisTime[Spice].

◆ getLightTimeState()

const LightTimeCorrectionState & Isis::SpacecraftPosition::getLightTimeState ( ) const

Return the state of light time correction parameters.

Author: Kris Becker - 10/23/2012

Returns: LightTimeCorrectionState Light time state

◆ getObserverCode()

int Isis::SpicePosition::getObserverCode ( ) const

protectedinherited

Returns observer code.

This methods returns the proper observer code as specified in constructor. Code has been subjected to swapping if requested.

Author: 2012-10-29 Kris Becker

Returns: int NAIF code of observer

Referenced by SetEphemerisTimeSpice(), and Isis::SpicePosition::SetEphemerisTimeSpice().

◆ GetPolynomial()

void Isis::SpicePosition::GetPolynomial	(	std::vector< double > &	XC,
		std::vector< double > &	YC,
		std::vector< double > &	ZC )

inherited

Return the coefficients of a polynomial fit to each of the three coordinates of the position for the time period covered by the cache, angle = c0 + c1*t + c2*t**2 + ... + cn*t**n, where t = (time - p_basetime) / p_timeScale.

Parameters

[out]	XC	Coefficients of fit to first coordinate of position
[out]	YC	Coefficients of fit to second coordinate of position
[out]	ZC	Coefficients of fit to third coordinate of position

Referenced by Isis::IsisBundleObservation::applyParameterCorrections(), Isis::IsisBundleObservation::bundleOutputFetchData(), and Isis::IsisBundleObservation::initializeExteriorOrientation().

◆ getRadiusLightTime()

double Isis::SpacecraftPosition::getRadiusLightTime ( ) const

Returns the time it takes for light to travel the radius of the target.

This method returns the time in seconds it takes to travel the distance of the radius of the target body. This is a function of the Distance parameter provided at the time this object was constructed.

Author: 2012-10-23 Kris Becker

Returns: double Time in seconds it takes light to travel the distance of the radius provided/set in the object

References Isis::Distance::kilometers().

Referenced by SetEphemerisTimeSpice().

◆ GetSource()

Source Isis::SpicePosition::GetSource ( )

inlineinherited

Return the source of the position.

Referenced by Isis::Spice::createCache().

◆ getTargetCode()

int Isis::SpicePosition::getTargetCode ( ) const

protectedinherited

Returns target code.

This methods returns the proper target code as specified in constructor. Code has been subjected to swapping if requested.

Author: 2012-10-29 Kris Becker

Returns: int NAIF code for target body

Referenced by SetEphemerisTimeSpice(), and Isis::SpicePosition::SetEphemerisTimeSpice().

◆ GetTimeBias()

double Isis::SpicePosition::GetTimeBias ( ) const

inherited

Returns the value of the time bias added to ET.

Author: 2012-10-29 Kris Becker

Returns: double Returns time bias for current object

Referenced by Isis::SpicePosition::getAdjustedEphemerisTime().

◆ GetTimeScale()

double Isis::SpicePosition::GetTimeScale ( )

inlineinherited

Return the time scale for the position.

Referenced by Isis::IsisBundleObservation::initializeExteriorOrientation().

◆ HasVelocity()

bool Isis::SpicePosition::HasVelocity ( )

inlineinherited

Return the flag indicating whether the velocity exists.

Referenced by Isis::Spice::createCache().

◆ HermiteCoordinate()

std::vector< double > Isis::SpicePosition::HermiteCoordinate ( )

inherited

This method returns the Hermite coordinate for the current time for PolyFunctionOverHermiteConstant functions.

See also: SetEphemerisTime()

References _FILEINFO_, Isis::SpicePosition::PolyFunctionOverHermiteConstant, Isis::IException::Programmer, and Isis::SpicePosition::SetEphemerisTimeHermiteCache().

◆ IsCached()

bool Isis::SpicePosition::IsCached ( ) const

inlineinherited

Is this position cached.

Referenced by Isis::Spice::createCache().

◆ LineCache()

Table Isis::SpicePosition::LineCache ( const QString & tableName )

inherited

Return a table with J2000 to reference positions.

Return a table containing the cached positions with the given name. The table will have seven columns, positionX, positionY, positionZ, angular velocity X, angular velocity Y, angular velocity Z, and time of J2000 position.

Parameters

tableName Name of the table to create and return

References _FILEINFO_, Isis::SpicePosition::Cache(), Isis::SpicePosition::HermiteCache, Isis::SpicePosition::Memcache, Isis::IException::Programmer, and Isis::SpicePosition::ReloadCache().

Referenced by Isis::SpicePosition::Cache().

◆ LoadCache() [1/4]

void Isis::SpicePosition::LoadCache	(	double	startTime,
		double	endTime,
		int	size )

inherited

Cache J2000 position over a time range.

This method will load an internal cache with coordinates over a time range. This prevents the NAIF kernels from being read over-and-over again and slowing a application down due to I/O performance. Once the cache has been loaded then the kernels can be unloaded from the NAIF system.

Parameters

startTime	Starting ephemeris time in seconds for the cache
endTime	Ending ephemeris time in seconds for the cache
size	Number of coordinates/positions to keep in the cache

References _FILEINFO_, Isis::SpicePosition::HermiteCache, Isis::SpicePosition::Memcache, Isis::IException::Programmer, and Isis::SpicePosition::SetEphemerisTime().

Referenced by Isis::Spice::createCache(), Isis::SpicePosition::LoadCache(), and Isis::SpicePosition::ReloadCache().

◆ LoadCache() [2/4]

void Isis::SpicePosition::LoadCache ( double time )

inherited

Cache J2000 position for a time.

This method will load an internal cache with coordinates for a single time (e.g. useful for framing cameras). This prevents the NAIF kernels from being read over-and-over again and slowing a application down due to I/O performance. Once the cache has been loaded then the kernels can be unloaded from the NAIF system. This calls the LoadCache(stime,etime,size) method using the time as both the starting and ending time with a size of 1.

Parameters

time	single ephemeris time in seconds to cache

References Isis::SpicePosition::LoadCache().

◆ LoadCache() [3/4]

void Isis::SpicePosition::LoadCache ( nlohmann::json & isd )

inherited

Load the cached data from an ALE ISD.

The SpicePosition object must be set to a SPICE source before loading the cache.

Parameters

isdPos The ALE ISD as a JSON object.

References _FILEINFO_, Isis::SpicePosition::Memcache, Isis::IException::Programmer, and Isis::SpicePosition::SetEphemerisTime().

◆ LoadCache() [4/4]

void Isis::SpicePosition::LoadCache ( Table & table )

inherited

Cache J2000 positions using a table file.

This method will load an internal cache with coordinates from an ISIS table file. The table must have 4 columns, or 7 (if velocity) is included, and at least one row. The 4 columns contain the following information, body position x,y,z in J2000 and the ephemeris time of that position. If there are multiple rows it is assumed you can interpolate position at times in between the rows.

Parameters

table An ISIS table blob containing valid J2000 coordinate/time values

References _FILEINFO_, Isis::PvlObject::findKeyword(), Isis::PvlObject::hasKeyword(), Isis::SpicePosition::HermiteCache, Isis::IException::Io, Isis::Table::Label(), Isis::SpicePosition::Memcache, Isis::Table::Name(), Isis::SpicePosition::PolyFunction, Isis::IException::Programmer, Isis::Table::Records(), Isis::SpicePosition::ScaleOnly, Isis::SpicePosition::SetOverrideBaseTime(), Isis::SpicePosition::SetPolynomial(), Isis::SpicePosition::SetPolynomialDegree(), and Isis::toDouble().

◆ LoadHermiteCache()

Table Isis::SpicePosition::LoadHermiteCache ( const QString & tableName )

inherited

Cache J2000 position over existing cached time range using polynomials stored as Hermite cubic spline knots.

This method will reload an internal cache with positions formed from a cubic Hermite spline over a time range. The method assumes a polynomial function has been fit to the coordinates of the positions and calculates the spline from the polynomial function.

References _FILEINFO_, Isis::SpicePosition::Cache(), Isis::SpicePosition::HermiteCache, Isis::SpicePosition::PolyFunction, Isis::IException::Programmer, and Isis::SpicePosition::SetEphemerisTime().

◆ Memcache2HermiteCache()

void Isis::SpicePosition::Memcache2HermiteCache ( double tolerance )

inherited

This method reduces the cache for position, time and velocity to the minimum number of values needed to interpolate the J2000 coordinates using a Hermite spline, given a tolerance of deviation from the NAIF values.

Parameters

tolerance Maximum error allowed between NAIF kernel coordinate values and values interpolated by the Hermite spline.

References _FILEINFO_, Isis::SpicePosition::HermiteCache, Isis::SpicePosition::Memcache, and Isis::IException::Programmer.

Referenced by Isis::SpicePosition::Cache(), and Isis::Spice::createCache().

◆ ReloadCache() [1/2]

void Isis::SpicePosition::ReloadCache ( )

inherited

Cache J2000 positions over existing cached time range using polynomials.

This method will reload an internal cache with positions calculated from functions fit to the coordinates of the position over a time range.

References _FILEINFO_, Isis::NaifStatus::CheckErrors(), Isis::SpicePosition::HermiteCache, Isis::SpicePosition::Memcache, Isis::IException::Programmer, and Isis::SpicePosition::SetEphemerisTime().

Referenced by Isis::SpicePosition::LineCache().

◆ ReloadCache() [2/2]

void Isis::SpicePosition::ReloadCache ( Table & table )

inherited

Cache J2000 position over existing cached time range using table.

This method will reload an internal cache with positions formed from coordinates in a table

Parameters

table An ISIS table blob containing valid J2000 coordinate/time values.

References Isis::SpicePosition::LoadCache(), and Isis::SpicePosition::Spice.

◆ scaledTime()

double Isis::SpicePosition::scaledTime ( ) const

inherited

Return the scaled time.

Returns: Scaled time.

◆ SetAberrationCorrection()

void Isis::SpacecraftPosition::SetAberrationCorrection ( const QString & correction )

virtual

Set aberration correction value for determining positions.

Author: 2012-10-29 Kris Becker

Parameters

correction Type of stellar aberration correction to apply

Reimplemented from Isis::SpicePosition.

References Isis::LightTimeCorrectionState::setAberrationCorrection(), and Isis::SpicePosition::SetAberrationCorrection().

◆ SetEphemerisTime()

const std::vector< double > & Isis::SpicePosition::SetEphemerisTime ( double et )

virtualinherited

Return J2000 coordinate at given time.

This method returns the J2000 coordinates (x,y,z) of the body at a given et in seconds. The coordinates are obtained from either a valid NAIF spk kernel, or alternatively from an internal cache loaded from an ISIS Table object. In the first case, the SPK kernel must contain positions for the body code specified in the constructor at the given time and it must be loaded using the SpiceKernel class.

Parameters

et	ephemeris time in seconds

References Isis::NaifStatus::CheckErrors(), Isis::SpicePosition::HermiteCache, Isis::SpicePosition::Memcache, Isis::SpicePosition::PolyFunction, Isis::SpicePosition::PolyFunctionOverHermiteConstant, Isis::SpicePosition::SetEphemerisTimeHermiteCache(), Isis::SpicePosition::SetEphemerisTimeMemcache(), Isis::SpicePosition::SetEphemerisTimePolyFunction(), Isis::SpicePosition::SetEphemerisTimePolyFunctionOverHermiteConstant(), and Isis::SpicePosition::SetEphemerisTimeSpice().

Referenced by Isis::Spice::computeSolarLongitude(), Isis::SpicePosition::GetCenterCoordinate(), Isis::SpicePosition::LoadCache(), Isis::SpicePosition::LoadCache(), Isis::SpicePosition::LoadHermiteCache(), Isis::IsisIlluminator::position(), Isis::SpicePosition::ReloadCache(), Isis::SpicePosition::SetPolynomial(), Isis::SpicePosition::SetPolynomial(), Isis::Spice::setTime(), and Isis::IsisIlluminator::velocity().

◆ SetEphemerisTimeHermiteCache()

void Isis::SpicePosition::SetEphemerisTimeHermiteCache ( )

protectedinherited

This is a protected method that is called by SetEphemerisTime() when Source type is HermiteCache.

It calculates J2000 coordinates (x,y,z) of the body that correspond to a given et in seconds. These coordinates are obtained by using a Hermite spline to interpolate values from an internal reduced cache loaded from an ISIS Table object.

See also: SetEphemerisTime()

References _FILEINFO_, and Isis::IException::Io.

Referenced by Isis::SpicePosition::HermiteCoordinate(), Isis::SpicePosition::SetEphemerisTime(), and Isis::SpicePosition::SetEphemerisTimePolyFunctionOverHermiteConstant().

◆ SetEphemerisTimeMemcache()

void Isis::SpicePosition::SetEphemerisTimeMemcache ( )

protectedinherited

This is a protected method that is called by SetEphemerisTime() when Source type is Memcache.

It calculates J2000 coordinates (x,y,z) of the body that correspond to a given et in seconds. These coordinates are obtained from an internal cache loaded from an ISIS Table object.

See also: SetEphemerisTime()

Referenced by Isis::SpicePosition::SetEphemerisTime().

◆ SetEphemerisTimePolyFunction()

void Isis::SpicePosition::SetEphemerisTimePolyFunction ( )

protectedinherited

This is a protected method that is called by SetEphemerisTime() when Source type is PolyFunction.

It calculates J2000 coordinates (x,y,z) of the body that correspond to a given et in seconds. These coordinates are obtained by using an nth degree polynomial function fit to each coordinate of the position vector.

See also: SetEphemerisTime()

References Isis::SpicePosition::WRT_X, Isis::SpicePosition::WRT_Y, and Isis::SpicePosition::WRT_Z.

Referenced by Isis::SpicePosition::SetEphemerisTime(), and Isis::SpicePosition::SetEphemerisTimePolyFunctionOverHermiteConstant().

◆ SetEphemerisTimePolyFunctionOverHermiteConstant()

void Isis::SpicePosition::SetEphemerisTimePolyFunctionOverHermiteConstant ( )

protectedinherited

This is a protected method that is called by SetEphemerisTime() when Source type is PolyFunctionOverHermiteConstant.

It calculates J2000 coordinates (x,y,z) of the body that correspond to a given et in seconds. These coordinates are obtained by adding a constant cubic Hermite spline added to an nth degree polynomial function fit to each coordinate of the position vector.

See also: SetEphemerisTime()

References Isis::SpicePosition::SetEphemerisTimeHermiteCache(), and Isis::SpicePosition::SetEphemerisTimePolyFunction().

Referenced by Isis::SpicePosition::SetEphemerisTime().

◆ SetEphemerisTimeSpice()

void Isis::SpacecraftPosition::SetEphemerisTimeSpice ( )

virtual

Determine accurate position of target w.r.t.

observer

This method computes the position of the target w.r.t. the observer with additional specialized light time position of target and to a more accurate correction to the surface.

NAIF routines are used to compute state vectors that have optional light time correction applied. However, this uses the center of the body as the reference

Author: 2012-10-29 Kris Becker

Reimplemented from Isis::SpicePosition.

References Isis::SpicePosition::computeStateVector(), GetAberrationCorrection(), Isis::SpicePosition::getAdjustedEphemerisTime(), Isis::SpicePosition::getObserverCode(), getRadiusLightTime(), Isis::SpicePosition::getTargetCode(), Isis::LightTimeCorrectionState::isLightTimeCorrected(), Isis::LightTimeCorrectionState::isLightTimeToSurfaceCorrected(), Isis::SpicePosition::SetEphemerisTimeSpice(), Isis::SpicePosition::setLightTime(), and Isis::SpicePosition::setStateVector().

◆ setLightTime()

void Isis::SpicePosition::setLightTime ( const double & lightTime )

protectedinherited

Inheritors can set the light time if indicated.

Referenced by SetEphemerisTimeSpice(), and Isis::SpicePosition::SetEphemerisTimeSpice().

◆ SetOverrideBaseTime()

void Isis::SpicePosition::SetOverrideBaseTime	(	double	baseTime,
		double	timeScale )

inherited

Set an override base time to be used with observations on scanners to allow all images in an observation to use the same base time and polynomials for the positions.

Parameters

[in] baseTime The baseTime to use and override the computed base time

References Isis::SpicePosition::BaseAndScale.

Referenced by Isis::IsisBundleObservation::initializeExteriorOrientation(), and Isis::SpicePosition::LoadCache().

◆ SetPolynomial() [1/2]

void Isis::SpicePosition::SetPolynomial ( const Source type = PolyFunction )

inherited

Set the coefficients of a polynomial fit to each of the components (X, Y, Z) of the position vector for the time period covered by the cache, component = c0 + c1*t + c2*t**2 + ... + cn*t**n, where t = (time - p_baseTime) / p_timeScale.

References Isis::SpicePosition::ComputeBaseTime(), Isis::SpicePosition::PolyFunction, Isis::SpicePosition::PolyFunctionOverHermiteConstant, Isis::SpicePosition::SetEphemerisTime(), and Isis::SpicePosition::SetPolynomial().

Referenced by Isis::IsisBundleObservation::initializeExteriorOrientation(), Isis::SpicePosition::LoadCache(), Isis::SpicePosition::SetPolynomial(), and Isis::SpicePosition::SetPolynomialDegree().

◆ SetPolynomial() [2/2]

void Isis::SpicePosition::SetPolynomial	(	const std::vector< double > &	XC,
		const std::vector< double > &	YC,
		const std::vector< double > &	ZC,
		const Source	type = PolyFunction )

inherited

Set the coefficients of a polynomial (parabola) fit to each of the three coordinates of the position vector for the time period covered by the cache, coord = c0 + c1*t + c2*t**2 + ... + cn*t**n, where t = (time - p_baseTime) / p_timeScale.

Parameters

[in]	XC	Coefficients of fit to X coordinate
[in]	YC	Coefficients of fit to Y coordinate
[in]	ZC	Coefficients of fit to Z coordinate

References Isis::SpicePosition::ComputeBaseTime(), and Isis::SpicePosition::SetEphemerisTime().

◆ SetPolynomialDegree()

void Isis::SpicePosition::SetPolynomialDegree ( int degree )

inherited

Set the polynomial degree.

Set the degree of the polynomials to be fit to the three position coordinates for the time period covered by the cache, coordinate = c0 + c1*t + c2*t**2 + ... + cn*t**n, where t = (time - p_baseTime) / p_timeScale, and n = p_degree.

Parameters

[in] degree Degree of the polynomial to be fit

References Isis::SpicePosition::SetPolynomial().

Referenced by Isis::IsisBundleObservation::initializeExteriorOrientation(), and Isis::SpicePosition::LoadCache().

◆ setStateVector()

void Isis::SpicePosition::setStateVector	(	const double	state[6],
		const bool &	hasVelocity )

protectedinherited

Sets the state of target relative to observer.

This method sets the state of the target (vector) relative to the observer. Note that is the only place where the swap of observer/target adjustment to the state vector is handled. All contributors to this computation must compute the state vector representing the position and velocity of the target relative to the observer where the first three components of state[] are the x-, y- and z-component cartesian coordinates of the target's position; the last three are the corresponding velocity vector.

This routine maintains the directional integrity of the state vector should the observer/target be swapped. See the documentation for the spkez_c at http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/spkez_c.html.

Author: 2012-10-29 Kris Becker

Parameters

state	State vector. First three components of this 6 element array is the body fixed coordinates of the vector from the target to the observer. The last three components are the velocity state.
hasVelocity	If true, then the velocity components of the state vector are valid, otherwise they should be ignored.

Referenced by SetEphemerisTimeSpice(), and Isis::SpicePosition::SetEphemerisTimeSpice().

◆ SetTimeBias()

void Isis::SpicePosition::SetTimeBias ( double timeBias )

inherited

Apply a time bias when invoking SetEphemerisTime method.

The bias is used only when reading from NAIF kernels. It is added to the ephermeris time passed into SetEphemerisTime and then the body position is read from the NAIF kernels and returned. When the cache is loaded from a table the bias is ignored as it is assumed to have already been applied. If this method is never called the default bias is 0.0 seconds.

Parameters

timeBias time bias in seconds

◆ Velocity()

const std::vector< double > & Isis::SpicePosition::Velocity ( )

inherited

Return the current J2000 velocity.

Return the velocity vector if available.

Returns: The velocity vector evaluated at the current time

References _FILEINFO_, and Isis::IException::Programmer.

Referenced by Isis::Spice::computeSolarLongitude(), Isis::Spice::instrumentBodyFixedVelocity(), and Isis::IsisIlluminator::velocity().

◆ VelocityPartial()

std::vector< double > Isis::SpicePosition::VelocityPartial	(	SpicePosition::PartialType	partialVar,
		int	coeffIndex )

inherited

Compute the derivative of the velocity with respect to the specified variable.

The velocity is the derivative of the coordinate with respect to time.

coordinate = C0 + C1*t + C2*t**2 + ... +Cn*t**n , where t = (time - p_basetime) / p_timeScale. velocity = (1/p_timeScale) * (C1 + 2*C2*t + ... + n*Cn*t**(n-1)) partial(velocity) with respect to C0 = 0. partial(velocity) with respect to C1 = 1/p_timeScale. partial(velocity) with respect to C2 = 2*t/p_timeScale partial(velocity) with respect to CN = n*t**(n-1)/p_timeScale

Parameters

partialVar Designated variable of the partial derivative

Returns: Derivative of j2000 velocity vector calculated with respect to partialVar

The documentation for this class was generated from the following files:

/Users/chkim/repos/ISIS3/isis/src/base/objs/Spice/SpacecraftPosition.h
/Users/chkim/repos/ISIS3/isis/src/base/objs/Spice/SpacecraftPosition.cpp

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ OverrideType

◆ PartialType

◆ Source

Constructor & Destructor Documentation

◆ SpacecraftPosition()

◆ ~SpacecraftPosition()

Member Function Documentation

◆ Cache()

◆ cacheSize()

◆ ComputeBaseTime()

◆ computeStateVector()

◆ Coordinate()

◆ CoordinatePartial()

◆ DPolynomial()

◆ EphemerisTime()

◆ Extrapolate()

◆ GetAberrationCorrection()

◆ getAdjustedEphemerisTime()

◆ GetBaseTime()

◆ GetCenterCoordinate()

◆ getDistanceLightTime()

◆ GetLightTime()

◆ getLightTimeState()

◆ getObserverCode()

◆ GetPolynomial()

◆ getRadiusLightTime()

◆ GetSource()

◆ getTargetCode()

◆ GetTimeBias()

◆ GetTimeScale()

◆ HasVelocity()

◆ HermiteCoordinate()

◆ IsCached()

◆ LineCache()

◆ LoadCache() [1/4]

◆ LoadCache() [2/4]

◆ LoadCache() [3/4]

◆ LoadCache() [4/4]

◆ LoadHermiteCache()

◆ Memcache2HermiteCache()

◆ ReloadCache() [1/2]

◆ ReloadCache() [2/2]

◆ scaledTime()

◆ SetAberrationCorrection()

◆ SetEphemerisTime()

◆ SetEphemerisTimeHermiteCache()

◆ SetEphemerisTimeMemcache()

◆ SetEphemerisTimePolyFunction()

◆ SetEphemerisTimePolyFunctionOverHermiteConstant()

◆ SetEphemerisTimeSpice()

◆ setLightTime()

◆ SetOverrideBaseTime()

◆ SetPolynomial() [1/2]

◆ SetPolynomial() [2/2]

◆ SetPolynomialDegree()

◆ setStateVector()

◆ SetTimeBias()

◆ Velocity()

◆ VelocityPartial()