cunluo/osaris

Scripts to facilitate analysis of large stacks of SAR data (e.g. Sentinel 1) on SLURM-based HPC environments basing on GMTSAR.

OSARIS

Open Source SAR Investigation System

OSARIS provides a framework to process large stack of synthetic aperture radar (SAR) data in High Performance Computing (HPC) environments.

REQUIREMENTS:

1. A working installation of GMT5SAR, further info and installation instructions at http://gmt.soest.hawaii.edu/projects/gmt5sar/wiki
2. A working SLURM environment, further info and installation instructions at https://slurm.schedmd.com/

DOWNLOAD / INSTALLATION

Clone the OSARIS repository: git clone https://github.com/cryotools/osaris.git

PREPARATION

• Provide DEM data. You may use the DEM generator: http://topex.ucsd.edu/gmtsar/demgen/

• In the OSARIS folder, copy configuration templates to config folder

cp ./templates/config.template ./config/my_study.config cp ./templates/GMTSAR.template ./config/GMTSAR_my_study_.config

• Edit new config files to fit your needs and local configuration. See comments in template files for details.

• Make sure .sh files are executable (chmod +x )

LAUNCH

Go to the OSARIS folder. Launch your run with ./osaris.sh ./config/my_config.config

TIPPS

• Launch OSARIS from within a tmux or screen session to detach your terminal session from the process. Doing this will prevent the OSARIS processing to fail in case you lose connection, your terminal crashes, etc. (besides numerous other advantages of using tmux/screen).

• Start with relatively few scenes and optimize your configuration. When the basic processing results fit your needs, use the options to turn off pre- and interferometric preocesing to work on module configuration in detail.

• Keep an eye on the log files during processing. In your procesing directory, use 'tail -f Log/logfile_name' to monitor what is going on.

• After processing, take a look at the reports in 'Output/Reports'.

• Use the 'create_pdf_summary' module to get an overview of the interferometric processing results.

• Make sure the DEM extent is not much bigger than the extent of the scenes you actually want to process. A big DEM will need a lot of extra processing time.

MODULES

Ping

Wake up sleeping nodes Status: beta

Simple PSI

Identify persistent scatterers by finding data points of consitently high coherences. Status: beta

Homogenize interferograms

Shift unwrapped interferograms and LOS relatively to 'stable ground points'. Status: beta

Grid difference

Calculate the difference between OSARIS result grid files throughout the timeseries. Status: beta

Unstable Coherence Metric

Identify regions where high coherence values drop substantially between two data takes. Status: beta

Timeseries xy

Extract values for particular coordinates throughout a series of grids (e.g. coherence, phase). Status: beta

Create PDF Summary

Preview key processing results in a single graphic overview. Requires ImageMagick. Status: beta

GETTING INVOLVED

Your participation in the development of OSARIS is strongly encouraged! In case you want to add a feature, module, etc., please fork your copy, code your additions, and open a merge request when finished. If you are interested in joining the development team please get in touch: https://hu.berlin/davidloibl .

CREDITING

As stated in the license file, you are free to use OSARIS in whatever way you like. If you publish OSARIS results, e.g. in scientific publications, please credit the website cryo-tools.org/tools/osaris .

Acknowledgements

Thanks to Ziyadin Cakir who supported the conception of OSARIS with thoughtful comments and by sharing scripts.