AccelSolRad

class ssapy.accel.AccelSolRad(**defaultkw)[source][source]

Bases: Accel

Acceleration due to solar radiation pressure.

This is a relatively simple model in which the direction of the acceleration is directly away from the sun and the magnitude is modulated by a single solar radiation pressure coefficient CR. The coefficient is 1.0 for purely absorbed light, and 2.0 for purely reflected light. Rough typical values for a variety of different satellite components are

~ 1.2 for solar panels ~ 1.3 for a high gain antenna ~ 1.9 for a aluminum coated mylar solar sail.

Additionally, this class models the Earth’s shadow as a cylinder. Either the satellite is inside the cylinder, in which case the acceleration from this term is 0, or the satellite is outside the cylinder, in which case the full magnitude of the acceleration is computed.

More details can be found in Section 3.4 of Montenbruck and Gill.

Parameters:

defaultkw (dict) – default parameters for kwargs passed to __call__, (area, mass, CR)

Methods Summary

__call__(r, v, t, **kwargs)

Evaluate acceleration at particular place/moment.

Methods Documentation

__call__(r, v, t, **kwargs)[source][source]

Evaluate acceleration at particular place/moment.

Parameters:

  • r (array_like, shape(3, )) – Position in meters in GCRF frame.

  • v (array_like, shape(3, )) – Velocity in meters per second. Unused.

  • t (float) – Time as GPS seconds

  • area (float) – Area in meters^2.

  • mass (flat) – Mass in kg.

  • CR (float) – Radiation pressure coefficient.

Returns:

accel – Acceleration in meters per second^2

Return type:

array_like, shape(3,)