Package SatStress :: Module GridCalc :: Class Grid
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Class Grid

source code

A container class defining the temporal and geographic range and resolution of the calculation.

The parameters defining the calculation grid are read in from a name value file, parsed into a Python dictionary using SatStress.nvf2dict, and used to set the data attributes of the Grid object.

The geographic extent of the calculation is specified by minimum and maximum values for latitude and longitude.

The geographic resolution of the calculation is defined by an angular separation between calculations. This angular separation is the same in the north-south and the east-west direction.

The temporal range and resolution of the calculation can be specified either in terms of actual time units (seconds) or in terms of the satellite's orbital position (in degrees). In both cases, time=0 is taken to occur at periapse.

Δ is a measure of how viscous or elastic the response of the body is. It's equal to (μ)/(ηω) where μ and η are the shear modulus and viscosity of the surface layer, respectively, and ω is the forcing frequency to which the body is subjected (see Wahr et al. (2008) for a detailed discussion). It is a logarithmic parameter, so its bounds are specified as powers of 10, e.g. if the minimum value is -3, the initial Δ is 10^-3 = 0.001.

Instance Methods
 
__init__(self, gridFile, satellite=None)
Initialize the Grid object from a gridFile.
source code
Instance Variables
str grid_id
A string identifying the grid
float lat_max
Northern bound, degrees (north positive).
float lat_min
Southern bound, degrees (north positive).
float latlon_step
Angular separation between calculations.
float lon_max
Eastern bound, degrees (east positive).
float lon_min
Western bound, degrees (east positive).
float nsr_delta_max
Final Δ = 10^(nsr_delta_max)
float nsr_delta_min
Initial Δ = 10^(nsr_delta_min)
int nsr_delta_numsteps
How many Δ values to calculate total
float orbit_max
Final orbital position in degrees (0 = periapse)
float orbit_min
Initial orbital position in degrees (0 = periapse)
float orbit_step
Orbital angular separation between calculations in degrees
float time_max
Final time at which calculation ends.
float time_min
Initial time at which calculation begins (0 = periapse).
float time_step
Seconds between subsequent calculations.