Geodesy Tools

import sasktran2 as sk

SASKTRAN2 contains a simple implementation of ellipsoidal implementations. These can be created with the generic sasktran2.Geodetic object which allows the creation of ellipsoids with arbitrary axis lengths and/or flattening factors. Typically it is recommended to use one of the built in specializations,

sasktran2.WGS84()	A geodetic object based upon the standard WGS84 ellipsoid.
sasktran2.SphericalGeoid(radius)	A geoid that is represented as a perfect sphere.

In this guide we will use the sasktran2.WGS84 object.

geodetic = sk.WGS84()

Usage

In the beginning, the geodetic object is in an unitialized state,

print(geodetic)

WGS84 Unitialized

to initialize the object, we use one of the available from_* methods,

geodetic.from_lat_lon_alt(latitude=60, longitude=120, altitude=10000)
print(geodetic)

WGS84 Location:
Latitude: 60.0, Longitude: 120.0, Altitude: 10000.0

Then we can do things such as convert to geocentric cartesian coordinates,

print(geodetic.location)

[-1601052.29346197  2773103.91785082  5509137.38797648]

or access the local right handed coordinate system pointing (up, south, west),

print(f"up: {geodetic.local_up}, south: {geodetic.local_south}, west: {geodetic.local_west}")

up: [-0.25       0.4330127  0.8660254], south: [-0.4330127  0.75      -0.5      ], west: [ 8.66025404e-01  5.00000000e-01 -2.77555756e-17]

Initialization Methods

sasktran2.Geodetic.from_xyz(location)	Initializes the Geodetic from a geocentric location
sasktran2.Geodetic.from_lat_lon_alt(...)	Initializes the Geodetic based on a specifiec latitude, longitude, and altitude.
sasktran2.Geodetic.from_tangent_point(...)	Initializes the Geodetic by calculating the tangent point from an observer position and look vector
sasktran2.Geodetic.from_tangent_altitude(...)	Initialized the Geodetic from a specified tangent altitude, obsever location, and bore sight plane.