datum

Gravitational and ellipsoidal parameters [1] [2]

Source code

General Attributes and Methods

class SMBcorr.datum(ellipsoid: str = 'WGS84', units: str = 'MKS')[source]

Class for gravitational and ellipsoidal parameters

Parameters:
ellipsoid: str, default ‘WGS84’

Reference ellipsoid name

  • 'CLK66': Clarke 1866

  • 'GRS67': Geodetic Reference System 1967

  • 'GRS80': Geodetic Reference System 1980

  • 'HGH80': Hughes 1980 Ellipsoid

  • 'WGS72': World Geodetic System 1972

  • 'WGS84': World Geodetic System 1984

  • 'ATS77': Quasi-earth centred ellipsoid for ATS77

  • 'NAD27': North American Datum 1927

  • 'NAD83': North American Datum 1983

  • 'INTER': International

  • 'KRASS': Krassovsky (USSR)

  • 'MAIRY': Modified Airy (Ireland 1965/1975)

  • 'TOPEX': TOPEX/POSEIDON ellipsoid

  • 'EGM96': EGM 1996 gravity model

  • 'IERS': IERS Numerical Standards (2010)

units: str, default `MKS`

Output units

  • 'MKS': meters, kilograms, seconds

  • 'CGS': centimeters, grams, seconds

Attributes:
a_axis: float

Semi-major axis of the ellipsoid

flat: float

Flattening of the ellipsoid

omega: float

Angular velocity of the Earth

GM: float

Geocentric gravitational constant

property rad_e: float

Average radius of the Earth with same volume as ellipsoid

property b_axis: float

Semi-minor axis of the ellipsoid

property ratio: float

Ratio between ellipsoidal axes

property rad_p: float

Polar radius of curvature

property ecc: float

Linear eccentricity

property ecc1: float

First numerical eccentricity

property ecc2: float

Second numerical eccentricity

property m: float

m Parameter

property f2: float

f2 component

property f4: float

f4 component

property q: float

q Parameter

property q0: float

q0 Parameter

property J2: float

Oblateness coefficient

property C20: float

Normalized C20 harmonic

property gamma_a: float

Normal gravity at the equator

property gamma_b: float

Normal gravity at the pole

gamma_0(theta) → float[source]

Normal gravity at colatitudes

Parameters:
theta: float

Colatitudes in radians

gamma_h(theta, height) → float[source]

Normal gravity at colatitudes and heights

Parameters:
theta: float

Colatitudes in radians

height: float

Height above ellipsoid

property dk: float

Ratio between gravity at pole versus gravity at equator

property U0: float

Normal potential at the ellipsoid

property area: float

Surface area of the ellipsoid

property volume: float

Volume of the ellipsoid

property rho_e: float

Average density

References