Tools for manipulating and analysing GRACE level-2 data

**balaji devaraju**

```
devaraju at ife uni-hannover de
```

`klm2sc` | Rearranges the output of KLMTSRSMAT back in the format provided by READGRC |

`klmtsrsmat` | Rearranges the GRACE SH coefficients in order to perform time-series analysis. |

`prpfltr` | Arranges the filter matrices in the required format (required by MASSESTMTR). |

`colombo` | Arranging [l m Clm Slm] in order-leading format |

`colomboQ` | Arranging a filter/covariance matrix in order-leading format |

`degordrngvec` | Arranging [l m Clm Slm] in degree-leading format |

`degordrngQ` | Arranging a filter/covariance matrix in degree-leading format |

`vcm2vec` | Extract the diagonal elements of a degree-leading filter/covariance matrix and arrange it in [l m Clm Slm] format |

`rotklm` | Rotating an SH spectrum of a field to a given location |

`rotspkcov` | Rotating the spectrum of a filter to the desired location |

`degvar` | Same as SHbundle/degreeinfo but only provides degree variances |

`lombscargle` | Periodogram analysis of time-series (spectrum and space). |

`lssa` | Least-squares spectral analysis of time-series. |

`intannum` | Gives information about longest contiguous part of the time-series. |

`monthfix` | Fills data gaps in the time-series with NaN values. |

`daysinmonth ` | Provides the number of days in a month depending on the year. |

`daysinyear ` | Provides the number of days in the year. |

`dayofyear ` | Provides the day of the year for a given date. |

`doymonth ` | Provides the month for a given day of the year |

`doy2cal ` | Provides calendar date for a given day of the year |

`grctimetag ` | Provides the appropriate time-tag in days for every GRACE monthly solution. |

`isleap ` | Determines if a given year is a leap year or not |

`monthnames ` | Provides names of months in different formats |

I/O functions | |
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`readgrace ` | Read GRACE SH coefficients provided in text files by CSR,GFZ and JPL in ICGEM format |

`rdslrc20 ` | Read SLR C20 values from technical note 7 |

`readgrccov ` | Read GRACE variance-covariance matrices provided on request by GFZ |

Compute from GRACE SH data | |
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`dealias ` | Tide de-aliasing of GRACE time-series of coefficients as well as grid points |

`detrendgrc ` | De-trending the GRACE coefficients as well as grid points |

`getgracemean` | Computes the mean of the SH data given a start and end date |

`massestmtr ` | Converts GRACE time-series of SH coefficients to spatial grids |

`monthlyres ` | Computes the difference between the time-series and its mean-annual cycle. |

`remgracemonths ` | Removes GRACE months that are regularized and are flagged '2' by GFZ |

NOTE: The following programs require the GRACE L1b position data.

`blddsgn ` | Build the design matrix for computing the GRACE normal matrices |

`blockinv ` | Block inversion of GRACE normal matrices via Schur complement method |

`grcnrml ` | Simulates the normal matrix for a GRACE monthly solution. |

`grccvrnc ` | Wrapper function for GRCNRML to simulate covariance matrices recursively for the whole time-series. |

`prpcoord ` | Prepares GRACE-A GRACE-B positions for GRCNRML |

`catchagg ` | Aggregates mass values over a given catchments. |

`catchleak ` | Computes the leakage into all the catchments for a given filter. |

`catchtsrs ` | Rearranges the aggregated mass values from MASSESTMTR for performing time-series analysis. |

`cindxcoord ` | Provides the coordinates of the pixels of a given catchment. |

`ctchmntcov ` | Propagates the GRACE covariance to the catchments. |

`ctchmntdsgn ` | Provides a spherical harmonic design matrix for the aggregated catchments. |

`fillcatch ` | Fill a particular catchment pixels with a given value. |

`findindx ` | Retrieves time-series of specified catchments. |

`ctchnms.mat ` | MAT-file containing the catchment names, their area and identification numbers. |

`ctchmntindx.mat ` | MAT-file containing the catchment boundaries in a 0.5 x 0.5 degree raster grid. |

`ctchmntindx3.mat ` | Same as ctchmntindx.mat but includes Greenland and Antarctica. |

`bttrwrth ` | Butterworth filter defined for the spectrum |

`diffusionfil ` | Diffusion filter |

`gaussian ` | Gaussian filter |

`gaussfltr ` | Replacement for gaussian. Uses numerical quadrature |

` ` | instead of recursion formula |

`pellinen ` | Pellinen coefficients of the box-car filter on the sphere |

`spkcosine ` | Spectral cosine filter |

`sptbttrwrth ` | Spatial Butterworth filter |

`sptcosine ` | Spatial cosine filter |

`sptgauss ` | Generates the spatial weights of the Gaussian filter directly. |

`vonhann ` | von Hann filter (2nd order spatial cosine filter) |

`hannoniso ` | Anisotropic Gaussian filter proposed by S-C Han et al 2005 |

`fanfilter ` | Anisotropic filter named 'Fan' designed by Zhang et al 2009 |

`dstrpngmtrx ` | Destriping filter of Swenson & Wahr 2006 |

`spt2spk ` | Analysis function for the Legendre transform |

`spk2spt ` | Synthesis function for the Legendre transform |

`anifperf ` | Analyses the performance of inhomgeneous (an)isotropic filters |

`isofperf ` | Analyses the performance of homogeneous isotropic filters |

`hisospvar ` | Spatial variance of the homogeneous isotropic filters |

`mtfhiso ` | Modulation transfer function of the homogeneous isotropic filters |

`mapfield ` | Maps a grid of mass estimates or other quantities. |

`sctriplot ` | Plots the spherical harmonic coefficients as a triangle (SC-format). |

`tsplot ` | Plots the time-series from multiple datasets for specified catchments, and also for specified time periods. |