MONITORING RIVERWATER LEVELS FROM SPACE : QUALITY ASSESSMENT OF 20 YEARS OF SATELLITE ALTIMETRY DATA

摘要

This paper presents the results of 20 years of validation of altimetry data for the monitoring of river water levels using a standardized method. The method was initially developed by Cemagref (2006-2011, [5, 6, 3]), now Irstéa, its implementation is now pursued at LEGOS. Our initial statement was: “what if someone1 wants to use satellite measurements of river water levels ?” The obvious question that comes to mind is “what the quality of the data ?”. Moreover, there’s also a need - a demand from data producers, to monitor products quality in a standardized fashion. We addressed such questions and have developped a method to assess the quality of, so called, “Alti-Hydro Products”. The method was implemented for the following Alti-Hydro products (and automatically derived from a L2 product~*) : AVISO~* (Topex/Poseidon, Jason- 2), CASH project (Topex/Poseidon), HydroWeb (Topex/ Poseidon, ENVISAT), River & Lake Hydrology (ERS-2, ENVISAT) and PISTACH~* (Jason-2).