MiscAccelerations

This class gives the non conservative forces acting on satellites.

Relativistic effect

The relativistic effect to the acceleration of an artificial Earth satellite according to IERS2010 conventions.

The macro model and the attitude of the satellite is not needed.

Name	Type	Annotation
beta	double	PPN (parameterized post-Newtonian) parameter
gamma	double	PPN (parameterized post-Newtonian) parameter
J	double	Earth’s angular momentum per unit mass [m**2/s]
GM	double	Geocentric gravitational constant
factor	double	the result is multiplied by this factor

RadiationPressure

This class computes acceleration acting on a satellite caused by Solar and Earth radiation pressure and thermal radiation.

Solar radiation pressure: The solar constant at 1 AU can be set via solarFlux. The factorSolarRadation can be used to scale the computed acceleration of the direct solar radiation.

Earth radiation pressure: Input are a time series of gridded albedo values (unitless) as inputfileAlbedoTimeSeries and a time series of gridded longwave flux (W/m$^2$) as inputfileLongwaveFluxTimeSeries. Both files are optional and if not specified, the respective effect on the acceleration is not computed. The factorEarthRadation can be used to scale the computed acceleration of the earth radiation.

The thermal radiation (TRP) of the satellite itself is either computed as direct re-emission or based on the actual temperature of the satellite surfaces, depending on the seetings of the satellite macro model. The second one uses a transient temperature model with a temporal differential equation which disallows parallel computing. The factorThermalRadiation can be used to scale the computed acceleration of the TRP.

The algorithms are described in:

Woeske et. al. (2019), GRACE accelerometer calibration by high precision non-gravitational force modeling, Advances in Space Research, https://doi.org/10.1016/j.asr.2018.10.025.

Name	Type	Annotation
solarflux	double	solar flux constant in 1 AU [W/m^2]
eclipse	eclipse
inputfileAlbedoTimeSeries	filename	GriddedDataTimeSeries of albedo values (unitless)
inputfileLongwaveFluxTimeSeries	filename	GriddedDataTimeSeries of longwave flux values [W/m^2]
factorSolarRadation	double	Solar radiation pressure is multiplied by this factor
factorEarthRadation	double	Earth radiation preussure is multiplied by this factor
factorThermalRadiation	double	Thermal (re-)radiation is multiplied by this factor

AtmosphericDrag

Atmospheric drag model. Algorithm for the atmospheric drag modelling is based on the free molecule flow theory by Sentman 1961. An analytical expression of this treatise is given in Moe and Moe 2005.

Sentman L. (1961), Free molecule flow theory and its application to the determination of aerodynamic forces, Technical report.

Moe K., Moe M. M. (2005), Gas-surface interactions and satellite drag coefficients, Planetary and Space Science 53(8), 793-801, doi:10.1016/j.pss.2005.03.005.

Optional determination steps: Turn temperature on or off. In the first case, the model mentioned above is applied, which estimates variable drag and lift coefficients - in the latter case a constant drag coefficient can be specified.

Turn wind on/off: It enables the usage of the Horizontal Wind Model 2014 to add additional thermospheric winds in the calculation process.

Name	Type	Annotation
thermosphere	thermosphere
earthRotation	double	[rad/s]
considerTemperature	boolean	compute drag and lift, otherwise simple drag coefficient is used
considerWind	boolean
factor	double	the result is multiplied by this factor

AtmosphericDragFromDensityFile

Atmospheric drag computed from thermospheric density along the orbit (inputfileDensity, MISCVALUE). The thermosphere is used to to compute temperature and wind. For further details see atmosphericDrag.

Name	Type	Annotation
inputfileDensity	filename	density along orbit, MISCVALUE (kg/m^3)
thermosphere	thermosphere	used to compute temperature and wind
earthRotation	double	[rad/s]
considerTemperature	boolean	compute drag and lift, otherwise simple drag coefficient is used
considerWind	boolean
factor	double	the result is multiplied by this factor

Antenna thrust

The thrust (acceleration) in the opposite direction the antenna is facing which is generated by satellite antenna broadcasts. The thrust is defined in the satellite macro model.

Name	Type	Annotation
factor	double	the result is multiplied by this factor

FromParametrization

Reads a solution vector from file inputfileSolution which may be computed by a least squares adjustment (e.g. by NormalsSolverVCE). The coefficients of the vector are interpreted from position indexStart (counting from zero) with help of parametrization. If the solution file contains solution of several right hand sides you can choose one with number rightSide (counting from zero).

The computed result is multiplied with factor.

Name	Type	Annotation
parametrization	parametrizationAcceleration
inputfileSolution	filename	solution vector
indexStart	uint	position in the solution vector
rightSide	uint	if solution contains several right hand sides, select one
factor	double	the result is multiplied by this factor, set -1 to subtract the field

Group

Groups a set of miscAccelerations and has no further effect itself.

Name	Type	Annotation
miscAccelerations	miscAccelerations
factor	double	the result is multiplied by this factor

SolarRadiationPressure

DEPRECATED. Use radiationPressure instead.

Name	Type	Annotation
solarflux	double	solar flux constant in 1 AU [W/m**2]
eclipse	eclipse
factor	double	the result is multiplied by this factor, set -1 to subtract the field

Albedo

DEPRECATED. Use radiationPressure instead.

Name	Type	Annotation
inputfileReflectivity	filename
inputfileEmissivity	filename
solarflux	double	solar flux constant in 1 AU [W/m**2]
factor	double	the result is multiplied by this factor, set -1 to subtract the field