geocenter

Data class for reading and processing geocenter data

Source code

General Attributes and Methods

class gravity_toolkit.geocenter(**kwargs)[source]

Data class for reading and processing geocenter data

Attributes:

C10: np.ndarray: cosine spherical harmonics of degree 1 and order 0
C11: np.ndarray: cosine spherical harmonics of degree 1 and order 1
S11: np.ndarray: sine spherical harmonics of degree 1 and order 1
X: np.ndarray: X-component of Cartesian geocenter coordinates
Y: np.ndarray: Y-component of Cartesian geocenter coordinates
Z: np.ndarray: Z-component of Cartesian geocenter coordinates
time: np.ndarray: time variable of the spherical harmonics
month: np.ndarray: GRACE/GRACE-FO months variable of the spherical harmonics
radius: float, default 6371000.790009159: Average Radius of the Earth [mm]

case_insensitive_filename(filename)[source]

Searches a directory for a filename without case dependence

Parameters:

filename: str, io.IOBase, pathlib.Path or None: input filename

from_AOD1B(release, year, month, product='glo')[source]

Reads monthly non-tidal ocean and atmospheric variation geocenter files

Parameters:

release: str: GRACE/GRACE-FO/Swarm data release for dealiasing product
year: int: calendar year of data
month: int: calendar month of data
product: str, default ‘glo’: GRACE/GRACE-FO/Swarm dealiasing product

from_gravis(geocenter_file, **kwargs)[source]

Reads monthly geocenter spherical harmonic data files from GFZ GravIS calculated using GRACE/GRACE-FO measurements and Ocean Models of degree 1 [13]

Parameters:

geocenter_file: str: degree 1 file
header: bool, default True: file contains header text to be skipped

from_SLR(geocenter_file, **kwargs)[source]

Reads monthly geocenter files from satellite laser ranging corrected for non-tidal ocean and atmospheric variation

Reads monthly geocenter files from satellite laser ranging provided by CSR

RL04: GCN_RL04.txt

RL05: GCN_RL05.txt

New CF-CM geocenter dataset to reflect the true degree-1 mass variations

New geocenter solutions from Minkang Cheng

Parameters:

geocenter_file: str

Satellite Laser Ranging file

AOD: bool, default False

remove Atmospheric and Oceanic Dealiasing products

release: str or NoneType, default None

GRACE/GRACE-FO/Swarm data release for AOD

header: int, default 0

rows of data to skip when importing data

columns: list, default []

column names of ascii file

'time': date in decimal-years

'X': X-component of geocenter variation

'Y': Y-component of geocenter variation

'Z': Z-component of geocenter variation

'X_sigma': X-component uncertainty

'Y_sigma': Y-component uncertainty

'Z_sigma': Z-component uncertainty

from_UCI(geocenter_file, **kwargs)[source]

Reads monthly geocenter files computed using GRACE/GRACE-FO measurements and ocean models [62] [60]

Parameters:

geocenter_file: str: input datafile with geocenter coefficients

from_swenson(geocenter_file, **kwargs)[source]

Reads monthly geocenter coefficients computed by Sean Swenson using GRACE/GRACE-FO measurements and Ocean Models of degree 1 [62]

Parameters:

geocenter_file: str: degree 1 file
header: bool, default True: file contains header text to be skipped

from_tellus(geocenter_file, **kwargs)[source]

Reads monthly geocenter spherical harmonic data files from GRACE Tellus Technical Notes (TN-13) calculated using GRACE/GRACE-FO measurements and Ocean Models of Degree 1 [58, 59, 62]

Datasets distributed by NASA PO.DAAC

Parameters:

geocenter_file: str

degree 1 file

CSR: TN-13_GEOC_CSR_RL06.txt

GFZ: TN-13_GEOC_GFZ_RL06.txt

JPL: TN-13_GEOC_JPL_RL06.txt

header: bool, default True

file contains header text to be skipped

JPL: bool, default True

use JPL TN-13 geocenter files with self-attraction and loading

from_netCDF4(geocenter_file, group=None, **kwargs)[source]

Reads geocenter file and extracts dates and spherical harmonic data from a netCDF4 file [60]

Parameters:

geocenter_file: str: degree 1 netCDF4 file
group: str or NoneType, default None: netCDF4 group name
compression: str or NoneType, default None: file compression type

copy(**kwargs)[source]

Copy a geocenter object to a new geocenter object

Parameters:

fields: list: default keys in geocenter object

from_dict(temp, **kwargs)[source]

Convert a dictionary object to a geocenter object

Parameters:

temp: dict: dictionary object to be converted
fields: list: default keys in dictionary

from_harmonics(temp, **kwargs)[source]

Convert a harmonics object to a geocenter object

Parameters:

temp: obj: harmonics object to be converted
fields: list: default keys in harmonics object

from_matrix(clm, slm)[source]

Converts spherical harmonic matrices to a geocenter object

Parameters:

clm: np.ndarray: cosine spherical harmonics of degree 1
slm: np.ndarray: sine spherical harmonics of degree 1

to_dict(**kwargs)[source]

Convert a geocenter object to a dictionary object

Parameters:

fields: list: default attributes in geocenter object

to_matrix()[source]: Converts a geocenter object to spherical harmonic matrices

to_cartesian(kl=0.0)[source]

Converts normalized spherical harmonics to cartesian geocenter variations

Parameters:

kl: float: gravitational load love number of degree 1

to_cmwe(kl=0.0)[source]

Converts normalized spherical harmonics to centimeters water equivalent

Parameters:

kl: float: gravitational load love number of degree 1

to_mmwe(kl=0.0)[source]

Converts normalized spherical harmonics to millimeters water equivalent

Parameters:

kl: float: gravitational load love number of degree 1

from_cartesian(kl=0.0)[source]

Converts cartesian geocenter variations to normalized spherical harmonics

Parameters:

kl: float: gravitational load love number of degree 1

from_cmwe(kl=0.0)[source]

Normalizes spherical harmonics from centimeters water equivalent (cmwe)

Parameters:

kl: float: gravitational load love number of degree 1

from_mmwe(kl=0.0)[source]

Normalizes spherical harmonics from millimeters water equivalent (mmwe)

Parameters:

kl: float: gravitational load love number of degree 1

mean(apply=False, indices=Ellipsis)[source]

Compute mean gravitational field and remove from data if specified

Parameters:

apply: bool, default False: remove the mean field from the input harmonics
indices: int, default Ellipsis: indices of input geocenter object to compute mean

add(temp)[source]

Add two geocenter objects

Parameters:

temp: obj: geocenter object to be added

subtract(temp)[source]

Subtract one geocenter object from another

Parameters:

temp: obj: geocenter object to be subtracted

multiply(temp)[source]

Multiply two geocenter objects

Parameters:

temp: obj: geocenter object to be multiplied

divide(temp)[source]

Divide one geocenter object from another

Parameters:

temp: obj: geocenter object to be divided

scale(var)[source]

Multiply a geocenter object by a constant

Parameters:

var: float: scalar value to which the geocenter object will be multiplied

power(power)[source]

Raise a geocenter object to a power

Parameters:

power: float: power to which the geocenter object will be raised

get(field: str)[source]

Get a field from the geocenter object

Parameters:

field: str: field name

Returns:

var: np.ndarray: variable for field