gen_point_load

  • Calculates gravitational spherical harmonic coefficients for point masses

Calling Sequence

from gravity_toolkit.gen_point_load import gen_point_load
Ylms = gen_point_load(data, lon, lat, UNITS=1, LMAX=LMAX, LOVE=(hl,kl,ll))

Source code

gravity_toolkit.gen_point_load(data, lon, lat, LMAX=60, MMAX=None, UNITS=1, LOVE=None)[source]

Calculates spherical harmonic coefficients for point masses [19, 40, 50]

Parameters:
data: np.ndarray

data magnitude

lon: np.ndarray

longitude of points

lat: np.ndarray

latitude of points

LMAX: int, default 60

Upper bound of Spherical Harmonic Degrees

MMAX: int or NoneType, default None

Upper bound of Spherical Harmonic Orders

UNITS: int, default 1

Input data units

  • 1: grams of mass (g)

  • 2: gigatonnes of mass (Gt)

  • list: custom degree-dependent unit conversion factor

LOVE: tuple or NoneType, default None

Input load Love numbers up to degree LMAX (hl, kl, ll)

Returns:
clm: np.ndarray

cosine spherical harmonic coefficients

slm: np.ndarray

sine spherical harmonic coefficients

l: np.ndarray

spherical harmonic degree to LMAX

m: np.ndarray

spherical harmonic order to MMAX

gravity_toolkit.gen_point_load.spherical_harmonic_matrix(l, data, phi, theta, coeff)[source]

Calculates the spherical harmonics for a particular degree evaluated from data at coordinates

Parameters:
l: int

spherical harmonic degree

data: np.ndarray

data magnitude in grams

phi: np.ndarray

longitude of points in radians

theta: np.ndarray

colatitude of points in radians

coeff: np.ndarray

degree-dependent factor for converting units

Returns:
Ylms: np.ndarray

spherical harmonic coefficients in Eulerian form