The C-band synthetic aperture radar on Sentinel-1 operates in four acquisition modes, the primary two being Interferometric Wide swath and Wave. Interferometric Wide swath mode has a swath width of 250 km and a ground resolution of 5m by 20 m. Wave mode acquisitions – which can help determine the direction, wavelength and heights of waves on the open oceans – are 20 km by 20 km, acquired alternately on two different incidence angles every 100 km.