Ka-band Radar Interferometer (KaRIn)

KaRIn is the Ka-band Radar Interferometer and primary wide-swath radar payload on SWOT.^[1][2] It is a near-nadir Ka-band radar-interferometer and swath altimeter using two SAR antennae at opposite ends of a 10 m boom.^[2] Its center frequency is 35.75 GHz.^[2] The instrument measures ocean and surface-water levels across a 120 km geometry, described as two 60 km swaths on either side of nadir, from 10 to 70 km cross-track, with a nadir gap.^[1][3][2] KaRIn operates in a low-resolution ocean mode with onboard processing and a high-resolution mode over broad, primarily continental hydrology regions.^[1] Its measurements feed SWOT KaRIn L2 low-rate sea-surface-height products and high-rate water-mask pixel-cloud products.^[3] Radar altimetry is demonstrated on SWOT, which launched on 2022-12-16, and KaRIn data collections run from 2022-12-16 to present.^[1][3]