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Exploring the Applications of Synthetic Aperture Radar (SAR) Data

Access Alaska Satellite Facility Home Page
Order the free CD-Rom Capturing a Dynamic Planet (currently unavailable from the ASF).

This DataSheet was prepared by Aleshia Mueller in collaboration with Charles Burrows, Claude Duguay, Melanie Engram, Carlos Rios, and Anton Sommer.

The Dataset

This image is one of several that rotate as a featured image on the Alaska Satellite Facility (ASF) website.
Synthetic Aperture Radar (SAR) Data is the only satellite imagery that can be acquired at any time of the day or night and during adverse weather conditions. Available SAR products include: full-resolution (25 m) images; low-resolution (240 m) images; complex-format SAR data products which retain amplitude and phase information; geocoded images; and uncorrelated (raw signal) SAR data, representing the original backscattered radar signals.

This data set is called "Capturing a Dynamic Planet" and is available for free on a CD. This remote sensing lesson should be a pre-cursor to other activities using SAR data.


Use and Relevance

SAR's ability to pass relatively unaffected through clouds, illuminate the Earth's surface with its own signals, and precisely measure distances makes it especially useful for the following applications:

Use in Teaching

SAR data can be used to teach or learn the following topics and skills in remote sensing education:

Topics

Skills

Exploring the Data

Data Type and Presentation

Samples of this restricted data are processed and available in a graphic format on the "Capturing a Dynamic Planet" CD-Rom (which contains its own viewer) for educational use. Images are available as JPGs.

Accessing the Data

The Capturing a Dynamic Planet CD is currently unavailable from the ASF, but visit their website for more info.

Manipulating Data and Creating Visualizations

CD-ROM includes an Image Browser. JPG images are also available for viewing within the "assets" folder in the "images" subfolder.

Tools for Data Manipulation

CD-ROM includes an Image Browser. Images can also be used with Google Earth, ImageJ, My World GIS, and any JPG image editing software.

About the Data

Collection Methods

SAR data is collected from polar-orbiting satellites. The SAR instrument is an active microwave sensor that bounces radar off the earth and receives the reflected backscatter. Examples of SAR satellites that are currently acquiring data are Radarsat-1, ERS-2, Envisat and ALOS. The signal data are downlinked to various receiving groundstations and the data must be processed in order to produce an image.

Limitations and Sources of Error

Water on top of ice (lake or sea ice) can cause erroneous image interpretation.

References and Resources

Scientific References that Use this Dataset

Synthetic Aperture Radar (SAR) Applications & Techniques Bibliography

Education Resources that Use this Dataset

How do teachers learn how to look at a SAR image and interpret what the image shows?

Other related Education Resources

The main concern with teaching with SAR amplitude data is that it is represented as grayscale and this lack of color could reduce student interest.

Another concern is "layover" when imaging mountains.

Related Links

Remote Sensing Core Curriculum Homepage (more info)