GMTSAR: An InSAR Processing System Based on Generic Mapping Tools

Abstract

GMTSAR is an open source (GNU General Public License) InSAR processing system designed for users familiar with Generic Mapping Tools (GMT). The code is written in C and will compile on any computer where GMT and NETCDF are installed. The system has three main components: 1) a preprocessor for each satellite data type (e.g., ERS, Envisat, and ALOS) to convert the native format and orbital information into a generic format; 2) an InSAR processor to focus and align stacks of images, map topography into phase, and form the complex interferogram; 3) a postprocessor, mostly based on GMT, to filter the interferogram and construct interferometric products of phase, coherence, phase gradient, and line-of-sight displacement in both radar and geographic coordinates. GMT is used to display all the products as postscript files and kml-images for Google Earth. A set of C-shell scripts has been developed for standard 2- pass processing as well as image alignment for stacking and time series. ScanSAR processing is also possible but requires a knowledgeable user. Users are welcome to contribute to this effort.