Who uses NASA Earth Science Data?
Dr. Xiaofeng Li, Scientist; National Oceanic and Atmospheric Administration (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS)
Research Interests:Using remote sensing data, primarily synthetic aperture radar (SAR) data, to study atmospheric and oceanic processes.
Research Highlights: Radar is a simple concept—radio waves are sent out and their time and power of return are calculated to determine the range, angle, velocity, and characteristics of objects off of which the radar beam bounces. Synthetic aperture radar, or SAR, bounces a microwave radar signal off Earth’s surface to detect physical properties. While the word “aperture” when used in reference to an optical instrument like a film camera refers to the size of an opening in a lens that lets light in, the term “aperture” in radar use refers to the antenna generating the microwave pulses. In general, the larger the radar antenna, the more information and better surface resolution the radar can produce. Since antenna size is limited on satellite instruments, scientists use the spacecraft’s motion along with advanced signal-processing techniques to simulate a larger antenna and create high resolution images. This is where the “synthetic aperture” comes from. Significant advantages of SAR are that it can create high resolution images without the need for illumination (such as from the sun) and can penetrate clouds, fog, tree canopies, or other obstructions to create these images. This makes SAR ideal for use in Earth observing satellites.
Dr. Xiaofeng Li uses SAR data to study a wide range of processes occurring in the atmosphere and ocean, including air-sea interactions, ocean surface winds, waves, coastal upwelling, oil seeps, and tropical cyclones. In fact, SAR has been used to observe tropical cyclones since the launch of the first satellite-borne SAR aboard NASA’s Seasat mission in 1978. SAR reveals visible tropical cyclone features like eye structure, rain bands, and arc clouds, as well as features that may not be visible, such as the presence of high winds within a cyclone’s eye. Dr. Li and his colleagues use SAR to better understand tropical cyclone morphology as well as to help determine physical parameters including wind speed and direction, rain rate, and eye location, all of which help improve cyclone tracking and intensity predictions.
To read his full profile,
https://earthdata.nasa.gov/user-resources/who-uses-nasa-earth-science-data-user-profiles/user-profile-dr-xiaofeng-li