The Planet Properties node contains the parameters for the definition of the mass, radius, and radiative properties.
The Planet Properties list is set to
Earth by default. Selecting this option is equivalent to the
User defined option with the following settings (
Ref. 48):
The position of the planet at t = 0 s can be defined from different parameters depending on the selected option for
Planet longitude at start time. When
Determined from GMT at start time is selected, define the Greenwich Mean Time (GMT) that correspond to the planet position at
t = 0 s. Select
Longitude at subspacecraft point to define the initial planet position from the spacecraft position at
t = 0 s. Choose
Longitude facing Vernal point to define the initial planet position from the position of the Sun at
t = 0 s.
Set Geographic position dependence to
Constant when the radiative properties are assumed to be uniform all around the planet. In case they depend on the location on the planet, select the
Latitude and longitude option.
When User-defined distribution option is selected for
Albedo or
Planet radiative flux, the expression is assumed to be a function of
otl.lambda, where otl is the name of the physics interface. This distribution is integrated on each spectral band to obtain the albedo and planet radiative flux for each spectral band.
When Albedo or
Planet radiative flux is set to
User defined for each band, enter a value for each spectral band. Within a spectral band, each value is assumed to be independent of wavelength.
When User defined distribution option is selected for
Albedo or
Planet radiative flux, select a two argument function to define the corresponding property for each spectral band.
If the Wavelength dependence of radiative properties is set to
Constant in the interface node, then the radiative properties are given as expressions or latitude and longitude functions that do not depend on the wavelength
otl.lambda.
The planet is approximated via a set of radiation sources on a spherical cap representing the part of the planet that can be seen from the spacecraft. Under Planet discretization, set the
Number of rings (default value 5) and the number of
Points per ring (default value 10) to define the total number of points that should be used to discretize the planet and how they should be placed. The total number of points used is
where
Nm is the number of ring and
Nn is the number of points per ring. If the radiative properties of the planet depend on the geographic position and an accurate interpretation of the data is expected, the number of points can be increased. Increasing the total number of points
N, also increases the computational time.
