Validation of an airborne ka-band cross-track interferometer; uavsar/glistin-a observations of the 2022 mauna loa eruption

The GLISTIN-A instrument was flown on the NASA/AFRC C-20 (Gulfstream III) in December 2022 to observe the Mauna Loa eruption event in Hawaii, USA. As the volcano was actively erupting, several of the swaths were repeated on both the same and successive days to observe changes in the lava flow thicknesses and lava fronts. These repeated swaths provided a unique opportunity to re-address our understanding of the calibration of GLISTIN-A and its ability to precisely and accurately compute the topography of significantly sloped terrains. After calibration with localized troposphere estimates from nearby GNSS sites, adjustments to the roll from post-processed Applanix data, and applying an empirical temperature model, the average slope difference is 4.3 millidegrees and the average RMS difference is 1.7 meters between overlapping swaths. The slope and RMS differences were computed for look angles from 11 to 52 degrees.