NASA\u2019s C-20A aircraft completed a series of flights on April 29 over Central California to contribute new data to improve the accuracy of the region\u2019s earthquake models and support NISAR (NASA-ISRO Synthetic Aperture Radar), the U.S.-India satellite mission launched last year to track hazards, monitor ecosystems and crops, and measure change in ice sheets and glaciers. The flights \u2014 part of an ongoing campaign that began Sept. 30, 2025, will include additional flights this year to build a longer time series \u2014 used airborne radar to measure ground movement along the San Andreas fault.<\/p>\n
The C-20A<\/a>, based at NASA\u2019s Armstrong Flight Research Center<\/a> in Edwards, California, carries the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), an instrument developed at NASA\u2019s Jet Propulsion Laboratory in Southern California. The UAVSAR flights were coordinated with NISAR\u2019s orbit. Data from UAVSAR can help improve scientists\u2019 understanding of how Earth\u2019s atmosphere affects NISAR\u2019s measurements.<\/p>\n During the flights, UAVSAR recorded surface motion driven by crustal deformation on the San Andreas fault and mapped land subsidence in the Central Valley caused by groundwater withdrawal. The campaign was part of a six-month effort to calibrate NISAR\u2019s L-band radar and validate the instrument\u2019s measurements, which will cover nearly all the planet\u2019s land and ice surfaces twice every 12 days. A joint mission between NASA and ISRO (Indian Space Research Organisation), NISAR was designed to study Earth\u2019s most complex natural processes, including the subtle motions and deformation of the land around faults that can help researchers assess the likelihood of earthquakes.<\/p>\n ~Jay Levine<\/em><\/p>\n![](\"https:\/\/secure.gravatar.com\/avatar\/ce0a319da5474ce754922fa466fa4134b65201985bc6ae807cd37369af5be284?s=300&d=https%3A%2F%2Fassets.science.nasa.gov%2Fdynamicimage%2Fassets%2Fscience%2Fpsd%2Fsolar%2Fbosf%2Fimages%2Feditor-page-nasa-logo-250s.png%3Fw%3D250%26h%3D250%26fit%3Dclip%26crop%3Dfaces%252Cfocalpoint&r=g\"\/){kind=logo}
<\/div>\n