This repository contains the application files and scripts to process a pair of Envisat ASAR data with ROI_PAC (Repeat Orbit Interferometry PACkage), a software package created by the Jet Propulsion Laboratory division of NASA and CalTech for processing SAR images to create InSAR images, named interferograms. Read more about ROI_PAC on Wikipedia.

To run this application, you will need a Developer Cloud Sandbox that can be either requested from the ESA research & service support Portal (http://eogrid.esrin.esa.int/cloudtoolbox/) for ESA G-POD related projects and ESA registered user accounts, or directly from Terradue's Portal (http://www.terradue.com/partners), provided user registration approval.

A Developer Cloud Sandbox provides Earth Science data access services, and assistance tools for a user to implement, test and validate his application. It runs in two different lifecycle modes: sandbox mode and cluster mode. Used in Sandbox mode (single virtual machine), it supports cluster simulation and user assistance functions in building the distributed application. Used in Cluster mode (collections of virtual machines), it supports the deployment and execution of the application with the power of distributed computing processing over large datasets (leveraging the Hadoop Streaming MapReduce technology).

1. Log on the app roi_pac sandbox via SSH

2. Install ROI_PAC

ROI_PAC is installed using yum. It is a package available on the sandbox software repository.

ROI_pac is copyrighted software that requires a license. Licenses are available at no charge for non-commercial use from Open Channel Foundation. Comply with the ROI_PAC license by registering and getting a copy of ROI_PAC.

sudo yum install roi_pac.x86_64

3 Application deployment

Use ciop-github to clone the repository in the application volume:

ciop-github clone -g https://github.com/Terradue/roi_pac.git

We will process an Envisat pair from 2010 Baja California earthquake.

The application is described in the Application Descriptor file (application.xml), it describes two processing nodes:

• processing step dem
• processing step roipac

The processing step dem takes the two Envisat ASAR datasets references:

• http://catalogue.terradue.int/catalogue/search/ASA_IM__0P/ASA_IM__0CNPDE20100502_175016_000000172089_00084_42723_0354.N1/rdf
• http://catalogue.terradue.int/catalogue/search/ASA_IM__0P/ASA_IM__0CNPDE20100328_175019_000000162088_00084_42222_9504.N1/rdf

These products are also available on the European Space Agency (ESA) virtual archive available at http://eo-virtual-archive4.esa.int/search/ASA_IM__0P/html?startIndex=0&start=2010-03-28&stop=2010-05-02&bbox=-116,30,-112,33&track=[084,084] Browsing for data does not require registering while downloading the data requires an ESA UM-SSO account (a few steps starting here http://eosupport.eo.esa.int/sso/registration.php)

The dem processing tasks are:

• invoke the strm dem WPS service with one of the ASAR product reference
• parse the strm dem WPS result to grep the URL to the DEM
• pass the ASAR dataset and DEM references to the roipac processing step

The processing step dem uses the strm dem to generate a DEM spanning 1 degree in all directions from the ASAR product's centroid. The strm dem WPS service access point is defined in the file application.xml.

The processing step dem produces references to

• The ASAR datasets
  • http://catalogue.terradue.int/catalogue/search/ASA_IM__0P/ASA_IM__0CNPDE20100502_175016_000000172089_00084_42723_0354.N1/rdf
  • http://catalogue.terradue.int/catalogue/search/ASA_IM__0P/ASA_IM__0CNPDE20100328_175019_000000162088_00084_42222_9504.N1/rdf
• the DEM

The roipac processing step takes as inputs the references to the dem processing step outputs to generate the interferogram out of the Envisat ASAR pair of products.

The roipac processing tasks are:

• Copy the generated DEM to the working directory
• For each of the Envisat ASAR products:
• Copy the product to the working directory
• Invoke ROI_PAC's make_raw_envi.pl script to convert to the RAW format
• Generate the ROI_PAC proc file
• Invoke ROI_PAC's process_2pass.pl script to generate the interferogramme

From the Sandbox roi_pac shell, to submit the execution of the worklflow node node_dem run:

$ ciop-simjob -f node_dem

Then, with the inputs from the above node_dem execution, the node_roipac can be submitted:

$ ciop-simjob -f node_roipac

$ ciop-simwf

This will submit the complete worflow with nodes node_dem and node_roipac

The Sandbox dashboard allows submitting and monitoring an OGC WPS request with a GUI

On a Browser:

• Type the address http://sandbox_ip/dashboard
• Click the Invoke tab
• Fill the processing request
• Submit the process by clicking "Run"

Using HTTP GET request with curl

curl http://sandbox_ip/wps/?service=WPS&request=Execute&version=1.0.0&Identifier=&storeExecuteResponse=true&status=true&DataInputs=sar1=http://catalogue.terradue.int/catalogue/search/ASA_IM__0P/ASA_IM__0CNPDE20100502_175016_000000172089_00084_42723_0354.N1/rdf;sar2=http://catalogue.terradue.int/catalogue/search/ASA_IM__0P/ASA_IM__0CNPDE20100328_175019_000000162088_00084_42222_9504.N1/rdf

Using HTTP POST request with curl

TBW

ROI_PAC on a Sandbox wiki

• Developer Cloud Sandbox
• ESA Virtual Archive - access SAR data
• ROI_PAC Web Site
• SSEP CloudToolbox to request a Developer Cloud Sandbox PaaS and run this application