Calibration of atmospheric effects on SAR interferograms by GPS and local atmosphere models: first results

A comparison between the zenith path delay (ZPD), obtained from CPS measure ments, and the expected delay, derived from models used to compensate tropo spheric effects on SAR interferograms, is made. The results of the two meth ods are comparable, though the available data set is not large enough for a complete statistical validation of the methods. The results of this prelim inary study suggest a possible integration of GPS-based ZPD data with cheap and standard meteorological data, since the estimated atmospheric componen t proved to be similar. Furthermore, the impact on volcanology of the effec ts measured by CPS, and in particular on the determination of the depth of the volcanic sources, is discussed. (C) 2001 Elsevier Science Ltd. All righ ts reserved.