开源软件名称（OpenSource Name）：

开源软件地址(OpenSource Url)：

开源编程语言(OpenSource Language)：

开源软件介绍(OpenSource Introduction)：

slepian_delta

Spatiospectral localization of data from the GRACE/GRACE-FO missions using Slepian functions as originally developed by C. Harig & F. J. Simons. This package is hosted by CSDMS at http://csdms.colorado.edu/wiki/Model:SLEPIAN_Delta

Citation information

Please cite our work as appropriate if you find this package useful.

To cite the method:
Harig, Christopher and Frederik J. Simons. Mapping Greeenland's mass loss in space and time. Proc. Natl. Acad. Sc., 109(49), 19934-19937, 2012. doi:10.1073/pnas.1206785109

To cite the code itself:
Persistent DOI of the latest release:

To cite the application to Greenland:
Harig, Christopher and Frederik J. Simons.
Ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Archipelago: Seasonal cycles and decadal trends.
Geophys. Res. Let., 43 (7), 3150-3159, 2016. http://dx.doi.org/10.1002/2016GL067759

Harig, Christopher and Frederik J. Simons.
Mapping Greeenland's mass loss in space and time.
Proc. Natl. Acad. Sc., 109(49), 19934-19937, 2012. doi:10.1073/pnas.1206785109

To cite the application to Antarctica:
Harig, Christopher and Frederik J. Simons.
Accelerated West Antarctic ice mass loss continues to outpace East Antarctica gains. Earth Planet. Sci. Let., 415, 134-141, 2015. http://dx.doi.org/10.1016/j.epsl.2015.01.029

Latest release hosted on

Where to start? Slepian localization and GRACE: a recipe

Here is a general outline to study regions and signals in GRACE data.

1. Set up your data and directory structure, and then with GRACE2PLMT read in the GRACE data files into a matrix for use in Matlab. This function does corrections for C2,0 from the SLR values of Cheng and Tapley, [2004] and degree 1 values from Swenson, [2008].

2. Decide on your choice of basis, depending on your region of interest and the bandwidth you want. Using GRACE2SLEPT, project the results of GRACE2PLMT into your chosen basis. We recommend that your basis is chosen based on a set of synthetic experiments which estimate the leakage/recovery tradeoffs.

3. Next run SLEPT2RESID to fit a choice of functions (e.g. lines, quadratics, etc.) to the Slepian coefficients. Note: if you want to remove a model of GIA then you should do that before this step, using a function like CORRECT4GIA.

4. If you want to examine the total mass trend in a region, this information is calculated and returned as a result from SLEPT2RESID. To summarize, each Slepian coefficient up to the Shannon truncation is multiplied by the integral (found using INTEGRATEBASIS) of the corresponding function over the region. This total data is then fit with TIMESERIESFIT which allows fitting with a custom data variance.

5. If you want the total map of mass change, multiply the difference between estimated signal coefficients by the corresponding Slepian function, and add them up. Remember the appropriate units. This sum can then be expanded to space using PLM2XYZ By limiting the set of coefficients you use, you can instead make this for any date span, such as for several years or a single year.

Note: The demos above and the package in general expects a couple of environmental variables to be set (e.g. your storage location: $IFILES) and a directory tree for data storage to already be created (i.e. subdirectories in $IFILES). The programs will initially display errors instructing the user to set up these shell variables and folders. Also, if you have an open pool of Matlab workers, a few functions such as KERNELCP will take advantage of the parallel computing resources and run much faster than otherwise.

Function List:

Administrative

Geographic

Analysis

Other important stuff

This software is distributed under the GNU Public License v2, which can be found at http://geoweb.princeton.edu/people/simons/license.html and also copied below.

Copyright (C) 2014. Developer can be contacted by email.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You can receive a copy of the GNU General Public License by writing to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.