Workflow design

Data

You will use Envisat ASAR Image Mode Level 0: two acquisitions over the Baja area, on before and one after the 2010 Baja California earthquake.

An Advanced Synthetic Aperture Radar (ASAR), operating at C-band, ASAR ensured continuity with the image mode (SAR) and the wave mode of the ERS-1/2 AMI. It featured enhanced capability in terms of coverage, range of incidence angles, polarisation, and modes of operation. This enhanced capability was provided by significant differences in the instrument design: a full active array antenna equipped with distributed transmit/receive modules which provided distinct transmit and receive beams, a digital waveform generation for pulse “chirp” generation, a block adaptive quantisation scheme, and a ScanSAR mode of operation by beam scanning in elevation.

See Data preparation section for details on the Envisat ASAR data used in this guide.

Software and COTS

ROI_PAC

You will use the Repeat Orbit Interferometry PACkage (ROI_PAC) [1], software for processing synthetic aperture radar data to produce differential interferograms. Licenses available at no charge for non-commercial use.

Workflow structure

The workflow contains three processing steps to:

  • Retrieve the Envisat ASAR auxiliary products (ASA_CON_AX, ASA_INS_AX, ASA_XCA_AX, ASA_XCH_AX) and orbital data (DOR_VOR_AX)
  • Retrieve a Digital Elevation Model (DEM) using STRM3 [2] data over the area covered by one of the ASAR acquisitions (the DEM generation application is available at: https://github.com/Terradue/srtm-dem)
  • Invoke the make_raw_envi on each of the ASAR products; create the ROI_PAC proc file and invoke the process_2pass.pl

!define DIAG_NAME Workflow example !include includes/skins.iuml skinparam backgroundColor #FFFFFF skinparam componentStyle uml2 start fork :node_aux; fork again :node_dem; end fork :node_roi_pac; stop

[1]ROI_PAC Website
[2]Shuttle Radar Topography Mission (SRTM)