avni.mapping.geodesy module#

avni.mapping.geodesy.getplanetconstants(planet: Union[None, str] = None, configfile: Union[None, str] = None, option=None)[source]#

Load the astronomic-geodetic constraints for a planet from a configuration file.

Parameters

planettp.Union[None,str], optional: _description_, by default None so constants.planetpreferred()
configfiletp.Union[None,str], optional: all the planet configurations are in this file., by default None so read from so get_configdir/constants.planetpreferred()
option: GRS option for constants, by default None so use the default one
:Authors:: Raj Moulik (moulik@caa.columbia.edu)
:Last Modified:: 2023.02.16 5.00

avni.mapping.geodesy.evaluate_grs(GM: Union[None, float] = None, f: Union[None, float] = None, a_e: Union[None, float] = None, omega: Union[None, float] = None, R: Union[None, float] = None, nzo: int = 10, store: bool = False)[source]#

Calculate geopotential constants in a reference earth model.

All the following page numbers and equation numbers refer to the book Physical Geodesy by Hofmann-wellenhof and Moritz [HWM06]

Parameters

GMtp.Union[None,float], optional: Gravitational constant times mass reference, by default None
ftp.Union[None,float], optional: Flattening, by default None
a_etp.Union[None,float], optional: Semi-major axis, by default None
omegatp.Union[None,float], optional: Angular velocity, by default None
Rtp.Union[None,float], optional: _description_, by default None
nzoint, optional: Number of zonal harmonics (2,4,… 2*nzo), by default 10
storebool, optional: Store in constants or return as output if False, by default False

Returns

barC2n: Normalized even zonal harmonics of the corresponding Somigliana-Pizzetti normal field. barC2n(:,1): normalized zonal harmonics barC2n(:,2): degree of the zonal harmonic [2 4 … 2*nzo]
geqt: Normal gravity at the equator
gpol: Normal gravity at the pole
U0: Normal potential at the ellipsoid
m: omega^2*a^2*b/(GM)
ecc: First eccentricity
eccp: Second eccentricity
a_p: Semi-minor axis
E: Linear eccentricity
c: Polar radius of curvature