ROI_PAC processing for Modern Geodetic Methods (Page 1 of 6)

by Andrew Newman and Jay Jackson

In the following web pages we describe how to compare SAR images from the ERS-2 satellite using interferometric methods in order to determine relative ground deformation from a large surface rupturing earthquake (Hector Mine 10/16/199).

Table of Contents:

1. Introduction and setup (this page)
2. Building a DEM from SRTM data
3. Retrieving SAR data from WInSAR
4. Processing SAR pairs to build interferograms
5. Create InSAR images using GMT
6. Clean Up unnecessary files
7. Appendix: Satellites available for InSAR

Some available sources of information

ROI_PAC software
• ROI_PAC manual: (local pdf) theoretical details of some processing.
  
• ROI_PAC programs: (local) A very out-of-date booklet on some of the ROI_PAC codes.
  
• Getting ROI_PAC
  
• ROI_PAC Wiki
  
• Y. Fialko's ROI_PAC problems/solutions page
  
• M. Pritchard's ROI_PAC processing Pages
  1. A quick introduction
     
  2. Troubleshooting
     
• T. Wright's ROI_PAC processing pages
  1. Running ROI_PAC
     
  2. Making a DEM using ROI_PAC
     
  3. Cleaning_Up afterwards (removing unnecessary files)
     
Data sources and misc.
• A table of SAR satellites suitable for InSAR
  
• Getting DGX and MDX viewers
  
• MDX installation notes for x86-64
  
• MDX Using MDX at GT
  
• ESA Global Data Viewer
  
• WInSAR Consortium
  
• Alaska SAR facility
  
• StaMPS: Persistent Scatterer InSAR Manual (src)
  
• DORIS: Another free set of InSAR processing tools from Delft University
  
• GMTSAR: Yet anoter free set of InSAR tools using GMT natively (I'm intrigued!)
  
• more to come...

Specific initializations:

• Processing will be on Tohoku, a 64-bit 12-processor machine with 24Gb ram. Please log into Tohoku with your current username and password. This is dependent on the machine you are working from. On another Unix-based command-line do the following:

  % ssh -X $USER@tohoku.eas.gatech.edu 

• Now please change your group to MGM by running. Note that upon switching groups a message will be displayed telling you which directory to work in.

  % newgrp MGM   
  % cd MGM       # same as 'cd /home/$USER/MGM' here  
  
  % mkdir HectorMine
  % cd HectorMine
  

Setting up parameters:

• This is done automatically for you once you switch to group MGM. If you are not using MGM (processing on another system, doing non-class related processing, or are not in the MGM group), you will need to source the appropriate ROI_PAC config file. On our system, if you are using the bash shell, you can simply type the following command

  % source /usr/local/geophysics/ROI_PAC/SAR_CONFIG-gfortran_v3_1.txt
  

• Sourcing the above directories set a bunch of environmental variables as well as adding some ROI_PAC directories to your path. You can test to see that you have configured ROI_PAC correctly by checking to see if the pertinent variables are set correctly and that the path includes ROI_PAC:

  % printf " $SAR\n $SAR_PRC_DIR\n $SAR_ODR_DIR\n $ROI_PAC\n $FFTW_LIB_DIR\n"
   /usr/local/geophysics/ROI_PAC/ROI_PAC_3_1beta
   /usr/local/geophysics/ROI_PAC/ORBITS/PRC
   /usr/local/geophysics/ROI_PAC/ORBITS/ERS/Delft
   /usr/local/geophysics/ROI_PAC/ROI_PAC_3_1beta/ROI_PAC
   /usr/local/geophysics/ROI_PAC/ROI_PAC_3_1beta/ROI_PAC/NetInst/fftw-120221-1209/lib 
  
  # the following will check if your PATH is likely to be correctly set.
  % printf "$MY_BIN\n $INT_BIN\n $INT_SCR\n"
   /usr/local/geophysics/ROI_PAC/bin
   /usr/local/geophysics/ROI_PAC/ROI_PAC_3_1beta/ROI_PAC/multibuild-120221-1214/installs/gfortran64/bin
   /usr/local/geophysics/ROI_PAC/ROI_PAC_3_1beta/ROI_PAC/multibuild-120221-1214/installs/share/roi_pac 
  
  # the following will check if your PATH is likely to be correctly set.
  %  if echo $PATH | egrep ROI_PAC >/dev/null ; then 
         echo PATH looks good 
      else echo PATH needs to be set
     fi
  PATH looks good
  

  If your output is similar to this, you are probably ready to start. Otherwise, if your output is either blank or only a fraction of this, you will need to source the SAR_CONFIG file.