Summer SAR Class

By David Lokken and Vicky Wolf

This summer’s SAR class, held June 19-23, attracted 10 students, ranging from employees of ASF User Services Office to researchers and graduate students from as far away as Michigan and New Mexico. The class ran the full gamut of experience, from beginners to veteran SAR users.

The class started with an introduction to SAR and SAR phenomenology by Richard Carande, President of Neva Ridge Technologies. Carande, formerly of Vexcel Corporation and Jet Propulsion Laboratory, has over 20 years experience with SAR data. The lecture included an overview of the development of radar imaging, types of SAR systems and their applications, and the equations for range and azimuth resolution. He wrapped up the lecture with a discussion about interferometry and speckle.

The class took a break from the classroom, when Phil Utley, a 7-year veteran of ASF’s Data Quality group, led them on a 4-km walk along the University of Alaska Fairbanks trails to visit a corner reflector. The 2-m wide metal, three-sided corner is used to calibrate SAR data.

Day two started with Carande discussing radar fundamentals, including range and resolution, and the basics of SAR processing. During the afternoon lab, every student tried to create a SAR sensor using Carande’s spreadsheet illustrating the trade-offs involved in designing a satellite-based SAR system, including parameters such as power requirements, peak power, and frequency.

On day three, Dr. Rudi Gens of ASF lectured about geocoding and map projections. During the lab, the class got hands-on practice processing data with the ASF SAR Training Processor (STP), a software program that allows the user to see the results of each of the many intermediate steps that are required to turn raw data into a final product. The training processor is available from ASF via the web at http://www.asf.alaska.edu/softwaretools/.

On day four, the class learned about topics like image filtering and terrain correction and applications of SAR data. UAF researcher, Dr. Matt Nolan, discussed some of his recent work using SAR data, including imaging methane bubbles in lake ice. According to Nolan, SAR’s real power is in revealing change.

Day five, the final day, continued the SAR applications topic with talks by Dr. Martin Jeffries and Dr. Claude Duguay, both research professors with the UAF Geophysical Institute (GI), on interpreting SAR images of snow and ice cover. In the afternoon, the class divided into pairs, and worked on interpreting data and applying the knowledge gained in the preceding days. Each pair presented their conclusions to the rest of the class. All walked away with a greater understanding of SAR systems and data.

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