Unfortunate misconceptions and bad publicity have degraded ERS-1 and ERS-2 to the ranks of ``low-accuracy altimeter mission'', where they do not belong. In fact, the mission goals on performance of the principle altimeter measurements (range, significant wave height and wind speed) and of the radiometer were equally tempting, and careful analyses show that levels of noise, precision and stability are competative.
ERS-1 altimeter data have a history of product and algorithm definitions dating back to 1990, and not surprisingly they were soon surpassed by TOPEX-aided knowledge and models. But also recalibrations to the measurements were never applied. Only as late as 1995 the altimeter product generation was upgraded, with the drawback that no reprocessing of older ERS-1 data was envisioned. Also, generally available, more precise orbits were never incorporated.
Combination of a long list of recalibration algorithms, updated geophysical corrections and precise orbits provides a harmonised and accurate ERS-1/2 altimeter data set that allows the reconstruction of many ocean parameters with equal efficiency as other altimeters, but with the denser 35-day coverage.
The recipe that can be followed by each user is provided in this poster and some new data analyses are provided that demonstrate the quality of this data set, part of the RADS data base.