Preliminary results of the 2013 Ibiza calibration campaign of Jason 2 and Saral altimeters

This study presents the preliminary results of the 2013 Ibiza calibration campaign of Jason-2 and Saral altimeters. It took place from 14 to 16 September 2013 and was composed of two phases: the calibration of the GNSS buoys to estimate the antenna height of each of them and absolute calibration to estimate the altimeter bias (i.e., the difference of sea level measured by radar altimetry and GNSS). The first one was achieved in the Ibiza harbor at a close vicinity of the Ibiza tide gauge and the second one was at ∼ 40 km at the northwest of Ibiza Island at a crossover point of Jason-2 and Saral nominal groundtracks. Five buoys were used to delineate the crossover region and their measurements interpolated at the exact location of each overflight. The overflights occurred two consecutive days: 15 and 16 September 2013 for Jason-2 and Saral respectively. Absolute biases of 0.1 and −4 cm were found for Jason-2 and Saral respectively.