Field of View (Satellite)

Field of view is the angular extent a satellite sensor observes, which sets the ground footprint and swath. The instantaneous field of view, IFOV, is the solid angle of a single detector and fixes the pixel size: MODIS resolves 250 m to 1 km, VIIRS 375 m to 750 m, while a nadir radar altimeter footprint spans a few kilometers. A wide field of view gives broad swath and frequent revisit at coarser resolution; a narrow one gives fine detail over a thin strip. The trade governs how often a given patch of ocean is seen, which in turn drives the temporal aliasing that altimetry must correct.