Script output images: color phase products for each swath F1, F2, F3. Contains modified Copernicus Sentinel data (2015) processed by ESA.

How to Configure AWS for Running the GMT5SAR InSAR Recipe

Script output images: color phase products for each swath F1, F2, F3. Contains modified Copernicus Sentinel data (2015) processed by ESA.

Adapted from instructions prepared by C. Stoner, ASF

Easy (AWS sign-up and configuration)

In this document you will find:

Background

Steps

Background

After logging-in the user must make some choices before creating their InSAR products. These steps guide you through that process, with recommended settings.

Steps

Start an EC2 Instance

    1. Sign in to your AWS account, or create one now.
AWS Management Console
    1. In AWS Services, under Compute, click on EC2.
Navigate to EC2

Select an Amazon Machine Image (AMI) — i.e., the software package you want

    1. At the right on the top menu bar, set the Region to US East (N. Virginia) by selecting from the drop-down menu. 
    2. Under Create Instance, click on the Launch Instance button.
Select the Region and Launch Instance
    1. Choose an Amazon Machine Instance (AMI) — Step 1
      • (1) Under Quick Start, click on Community AMIs.
      • (2) In the Search community AMIs box, type “asf-insar-gmt5sar” and press Enter.
      • (3) Click the Select button next to ASF-INSAR-GMT5SAR
Search Community AMIs for asf-insar-gmt5sar
Select the ASF-INSAR-GMT5SAR AMI

Configure the EC2 Resources

    1. Choose an Instance Type — Step 2
      • Scroll down the table of available instances and choose: m4.xlarge.
        • Then click on the Next: Configure Instance Details button.
    2. Configure Instance Details — Step 3
      • Nothing needs to be changed here, so click on the Next: Add Storage button.
Choose Instance Type m4.xlarge
View Instance Details
    1. Add Storage — Step 4
      • The volume storage size is preset, so confirm that the Size (GiB) value is 230 and then click on the Next: Add Tags button.
Set Size value, then click Next: Add Tags
    1. Add Tags — Step 5
      • (1) Click on the Add Tag button.
      • (2) Under Key, type “Name.”
      • (3) Under Value, type a description; for example, “asf-insar-tutorial.”
      • Click on the Next: Configure Security Group button.
Click Add Tag
Enter text for the Key and Value entries
    1. Configure Security Group — Step 6
      • This step allows you to set access permissions for your instance. We will create a setting so that only your computer can access your instance.
      • In the Security group name box, type a name.
      • Under Source, click on Custom and select and click on My IP.
      • The IP address of your computer is automatically selected.
      • Click on the Review and Launch button.
Enter a Security group name and choose a Source
Select My IP as a Source
    1. Review Instance Launch — Step 7
      • This last step allows you to review the details of your configuration before activating your new instance.
        • A warning is displayed at the top of the screen that can be ignored. The “free usage tier” AMIs offered in AWS are not powerful enough to process the GMT5SAR InSAR recipe.
      • Click on the Launch button.
Review the details of your configuration

Create a Key Pair (.pem file)

    1. Create a key pair for authentication and encryption when connecting to your running EC2 Instance. Read more on information about key pairs.
      • Click on Choose an existing key pair and select Create a new key pair.
      • Name the key pair; for example, asf_tutorial_keypair.
      • Click on the Download Key Pair button.

Note: The key pair file will download to your default Download directory as filename.pem and can be moved to a directory of your choice. The .pem file is required to connect to your EC2 Instance and to transfer data between your computer and your EC2 Instance.

Select Create a new key pair
Download your Key Pair

Launch the Instance

    1. After creating the key pair, click on the Launch Instances button.
    2. The Launch Status window provides information on your new EC2 Instance. To view your instance, scroll to the bottom of the page and click on the View Instances button.
View Launch Status
View your EC2 Instance's details

Terminate the Instance

Important: Do not terminate your EC2 Instance until you have finished processing and moved any files you want to save from your instance to your computer. To connect to your EC2 Instance and move files in or out, refer to the ASF Data Recipes: How to Connect to an AWS EC2 Instance — OS X and How to Connect to an AWS EC2 Instance using PuTTY v1.1 (Windows)

    1. Once you have launched your instance, you will start incurring charges on your account.
    2. When you have finished processing, you need to terminate the EC2 instance to avoid incurring additional charges.
      • From the EC2 Dashboard, navigate to Actions > Instance State.
        • Click on Terminate and confirm.
        • This deletes the instance and all data stored on the instance; a new AMI will need to be configured for any future processing.

Important: Selecting Stop will shut the instance down and stop further EC2 charges from accruing. But you will continue to be charged for the data left in the instance EBS storage volume (e.g., the GMT5SAR script, granule files, PRODUCT files, etc.) The advantage of this option is that you can restart the instance and avoid configuring a new one for additional processing. 

Note: Each time an instance is started, a minimum one minute is charged. After one minute, you are charged by the seconds used.

Navigate to terminate the EC2 Instance

InSAR – Collaboration

InSAR Access — API

Among ASF’s many collaborations, University NAVSTAR Consortium (UNAVCO)/Western North American InSAR (WInSAR), the Alaska Satellite Facility (ASF), and the Jet Propulsion Laboratory (JPL) worked on an information technology and data-management development project to design and implement a seamless distributed access system for synthetic aperture radar (SAR) data and derived interferometric data products. The seamless SAR archive increases the accessibility and the utility of SAR science data to solid Earth and cryospheric science researchers.

An example of the Vertex baseline plot. Users are provided with the capability to observe the perpendicular and temporal baseline distribution of an InSAR stack based on the selection of a desired master, filter granules, and select granules to download.

Specifically, the project will provide simple web services tools to more seamlessly and effectively exchange and share SAR metadata, data and archived and on-demand derived products between the distributed archives, individual users, and key information technology development systems such as the NASA/JPL Advanced Rapid Imaging and Analysis (ARIA) projects that provide higher level resources for geodetic data processing, data assimilation and modeling, and integrative analysis for scientific research and hazards applications. The proposed seamless SAR archive will significantly enhance mature IT capabilities at ASF’s NASA-supported DAAC, the Group on Earth Observations (GEO) Supersites archive, supported operationally by UNAVCO, and UNAVCO’s WInSAR and EarthScope archives that are supported by NASA, the National Science Foundation (NSF), and the United States Geological Survey (USGS) in close collaboration with the European Space Agency (ESA)/European Space Research Institute (ESRIN).

ALOS-PALSAR amplitude image, coherence image, interferogram, and interferogram overlaid on the amplitude of the master image (left to right). Master image: acquired 2006-11-05. Paired image acquired 2008- 11-10 over Baja, California, Mexico. The copyright for the scenes used to create this image (and those below) is held by the Japan Aerospace Exploration Agency/Ministry of Economy, Trade and Industry.

As part of the proposed effort, data/product standard formats and new QC/QA definitions will be developed and implemented to streamline data usage and enable advanced query capability. The seamless SAR archive will provide users with simple browser and web service API access tools to view and retrieve SAR data from multiple archives, to place their tasking requests, to order data, and to report results back to data providers; to make a larger pool of data available to scientific data users; and to encourage broader national and international use of SAR data. The new Advancing Collaborative Connections for Earth System Science (ACCESS)-developed tools will help overcome current obstacles including heterogeneous archive access protocols and data/product formats, data provider access policy constraints, and an increasingly broad and diverse selection of SAR data that now includes ESA/European Remote Sensing Satellite (ERS)/Environmental Satellite (ENVISAT) (and upcoming Sentinel mission), the Canadian Space Agency (CSA)/Radarsat, the Japan Aerospace Exploration Agency (JAXA)/Advanced Land Observation Satellite Phased Array type L-band Synthetic Aperture Radar (ALOS-PALSAR), German Aero-Space Research Establishment (DLR)/TerraSAR-X satellite data and NASA/Uninhabited Aerial Vehicle SAR (UAVSAR) data. The list will continue to expand with NASA/Deformation, Ecosystem Structure and Dynamics of Ice (DESDynI) further increasing the need to efficiently discover, access, retrieve, distribute, and process huge quantities of new and diverse data.

To facilitate terrain corrections, the proposed NASA SAR (NSAR) project will provide InSAR-ready topographic data through OpenTopography. Shown in (a) above is the terrain correction (EGM96 removed) via Generic Mapping Tools (GMT) SAR (GMTSAR) from NASA SRTM data. The terrain-corrected differential interferogram unwrapped phase in (b) from the same ALOS PALSAR pair was processed using ROI_PAC. Red star shows epicenter of April 2010 Mw 7.2 earthquake. The apparent range change variation is 30 cm. (c) shows the zenith path delay difference from Online Services for Correcting Atmosphere in Radar (OSCAR) Modeling, Data and Information Systems (MODIS) zenith path delay maps. The path delay difference map shows no large gradient due to the troposphere in this case. The NSAR project will standardize product and corrections/QC formats and facilitate this type of product quality evaluation and access to products critical to the interpretation of interferograms for earth surface motions and deformation.

Project Objectives:

  • Develop and implement a federated metadata query and product-download capability from distributed airborne (NASA UAVSAR) and spaceborne SAR archives at ASF and UNAVCO/WInSAR.
  • Define and make available new QC parameters and products that will enhance the usability of data and data products from these existing NASA-funded collections.
  • Implement a web services enabled terrain correction service for interferometry (InSAR) using NASA Shuttle Radar Topography Mission (SRTM) data at the San Diego Supercomputer Center (SDSC).
  • Enhance ASF InSAR processing service to access distributed data collections, utilize terrain correction service, and generate enhanced QC products.
  • Establish processed data products archive.