perturb::Satellite Class Reference

Represents a specific orbital ephemeris for an Earth-centered trajectory. More...

#include <perturb.hpp>

Public Member Functions
	Satellite (sgp4::elsetrec sat_rec)
	Construct from a raw SGP4 orbital record. More...
	Satellite (const TwoLineElement &tle, GravModel grav_model=GravModel::WGS72)
	Construct and initialize from a pre-parsed TLE record. More...
Sgp4Error	last_error () const
	Return the last recorded error in the internal SGP4 record.
JulianDate	epoch () const
	Return the epoch of the orbital ephemeris, likely from a TLE.
Sgp4Error	propagate_from_epoch (double mins_from_epoch, StateVector &sv)
	Propagate the SGP4 model based on time around the epoch. More...
Sgp4Error	propagate (JulianDate jd, StateVector &sv)
	Propagate the SGP4 model to a specific time point. More...

Static Public Member Functions
static Satellite	from_tle (char *line_1, char *line_2, GravModel grav_model=GravModel::WGS72)
	Construct and initialize a Satellite from a TLE record. More...
static Satellite	from_tle (std::string &line_1, std::string &line_2, GravModel grav_model=GravModel::WGS72)
	Wrapper for Satellite::from_tle that accepts C++ style strings. More...

Public Attributes
sgp4::elsetrec	sat_rec
	Internal SGP4 type.

Detailed Description

Represents a specific orbital ephemeris for an Earth-centered trajectory.

This is the primary type in this library. Wraps the internal SGP4 record type perturb::sgp4::elsetrec. Generally constructed via TLEs through Satellite::from_tle constructors. Of particular importance is the Satellite::last_error method which you can check to determine if there were any issues with TLE initialization or propagation. The primary method of running the SGP4 algorithm is the Satellite::propagate method.

Constructor & Destructor Documentation

Satellite() [1/2]

perturb::Satellite::Satellite ( sgp4::elsetrec  sat_rec )

explicit

Construct from a raw SGP4 orbital record.

Parameters

sat_rec

Pre-initialized SGP4 orbital record

Satellite() [2/2]

perturb::Satellite::Satellite ( const TwoLineElement &  tle, GravModel  grav_model = GravModel::WGS72  )

explicit

Construct and initialize from a pre-parsed TLE record.

Does not require any string parsing, so aight for embedded. Does the same initialization steps as perturb::sgp4::twoline2rv and then uses perturb::sgp4::sgp4init to fully initialize.

You probably don't want to parse a TLE string into a TwoLineElement and then construct a Satellite via this. You should instead use the Satellite::from_tle constructor directly.

This is only useful if you don't want any IO (via the PERTURB_DISABLE_IO flag), because then this and the Satellite(sgp4::elsetrec) constructor are the only way of constructing a Satellite object. It's up to you how you wanna construct the parsed perturb::TwoLineElement object.

Precondition

The TLE must be valid and contain valid values.

Parameters

tle	Parsed and valid TLE
grav_model	Gravity constants to use (default GravModel::WGS72)

Member Function Documentation

from_tle() [1/2]

Satellite perturb::Satellite::from_tle ( char *  line_1, char *  line_2, GravModel  grav_model = GravModel::WGS72  )

static

Construct and initialize a Satellite from a TLE record.

The strings are mutable because the underlying implementation in perturb::sgp4::twoline2rv may modify the string during parsing. Left as mutable instead of internally copying for efficiency reasons as this may be okay for the caller.

Parameters

line_1	First line of TLE as C-string of length perturb::TLE_LINE_LEN
line_2	Second line of TLE as C-string of length perturb::TLE_LINE_LEN
grav_model	Gravity constants to use (default GravModel::WGS72)

Returns

An initialized Satellite

from_tle() [2/2]

Satellite perturb::Satellite::from_tle ( std::string &  line_1, std::string &  line_2, GravModel  grav_model = GravModel::WGS72  )

static

Wrapper for Satellite::from_tle that accepts C++ style strings.

Parameters

line_1	First line of TLE
line_2	Second line of TLE
grav_model	Gravity constants to use (default GravModel::WGS72)

Returns

An initialized Satellite

propagate()

Sgp4Error perturb::Satellite::propagate	(	JulianDate	jd,
		StateVector &	sv
	)

Propagate the SGP4 model to a specific time point.

Parameters

jd	Time point in UTC or UT1
posvel	Returned state vector in the TEME frame

Returns

Issues during propagation, should usually be Sgp4Error::NONE

propagate_from_epoch()

Sgp4Error perturb::Satellite::propagate_from_epoch	(	double	mins_from_epoch,
		StateVector &	sv
	)

Propagate the SGP4 model based on time around the epoch.

Parameters

mins_from_epoch	Offset number of minutes around the epoch
posvel	Returned state vector in the TEME frame

Returns

Issues during propagation, should usually be Sgp4Error::NONE

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

• /github/workspace/include/perturb/perturb.hpp
• /github/workspace/src/perturb.cpp