read_SLR_harmonics

  • Reads 5×5 spherical harmonic coefficients with 1 coefficient from degree 6 all calculated from satellite laser ranging (SLR) measurements

  • Calculated by the University of Texas Center for Space Research (CSR) and NASA Goddard Space Flight Center (GSFC)

    • CSR: CSR_Monthly_5x5_Gravity_Harmonics.txt

    • GSFC: gsfc_slr_5x5c61s61.txt

Calling Sequence

from gravity_toolkit.read_SLR_harmonics import read_SLR_harmonics
Ylms = read_SLR_harmonics(input_file)

Source code

gravity_toolkit.read_SLR_harmonics(SLR_file, **kwargs)[source]

Wrapper function for reading spherical harmonic coefficients from Satellite Laser Ranging (SLR) measurements

Parameters:
SLR_file: str

Satellite Laser Ranging file

**kwargs: dict

keyword arguments for input readers

gravity_toolkit.read_SLR_harmonics.read_CSR_monthly_6x1(SLR_file, SCALE=1e-10, HEADER=True)[source]

Reads in monthly low degree and order spherical harmonic coefficients from Satellite Laser Ranging (SLR) measurements [10]

Parameters:
SLR_file: str

Satellite Laser Ranging file from CSR

SCALE: float, default 1e-10

Scale factor for converting to fully-normalized spherical harmonics

HEADER: bool, default True

File contains header text to be skipped

Returns:
clm: np.ndarray

Cosine spherical harmonic coefficients

slm: np.ndarray

Sine spherical harmonic coefficients

error/clm: np.ndarray

Cosine spherical harmonic coefficient uncertainty

error/slm: np.ndarray

Sine spherical harmonic coefficients uncertainty

MJD: np.ndarray

output date as Modified Julian Day

time: np.ndarray

output date in year-decimal

gravity_toolkit.read_SLR_harmonics.read_GSFC_weekly_6x1(SLR_file, SCALE=1.0, HEADER=True)[source]

Reads weekly 5x5 spherical harmonic coefficients with 1 coefficient from degree 6 calculated from satellite laser ranging measurements [41, 42]

Parameters:
SLR_file: str

Satellite laser ranging file from GSFC

SCALE: float, default 1.0

Scale factor for converting to fully-normalized spherical harmonics

HEADER: bool, default True

File contains header text to be skipped

Returns:
clm: np.ndarray

Cosine spherical harmonic coefficients

slm: np.ndarray

Sine spherical harmonic coefficients

MJD: np.ndarray

output date as Modified Julian Day

time: np.ndarray

output date in year-decimal

gravity_toolkit.read_SLR_harmonics.convert_weekly(t_in, d_in, DATE=[], NEIGHBORS=28)[source]

Interpolate harmonics from 7-day to 28-day

Parameters:
t_in: float

Weekly time

d_in: float

Weekly harmonics

DATE: list, default []

Output monthly time for central averages

NEIGHBORS: int, default 28

Number of days to use in average

Returns:
time: np.ndarray

output date in year-decimal

month: np.ndarray

GRACE/GRACE-FO month

data: np.ndarray

monthly spherical harmonic coefficients