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A comparative analysis of waveform data from seven altimeters

Graham Quartly(1)

(1) National Oceanography Centre, Southampton, Empress Dock, Southampton, SO14 3ZH, United Kingdom


Altimeter waveform data are used for an increasing variety of applications. Their analysis over oceans is being pushed to new levels as investigators study the skewness of sea surface height, and also the structure of storm systems, as revealed by the attenuation caused by rain. Improved tracking algorithms are also being developed for ice and land applications. However, the use of inconsistent datasets could lead to spurious trends within the 15-year series. This poster will examine the waveform data from the ESA satellites, ERS-1, ERS-2 and Envisat, from NASA/CNES's Topex, Poseidon and Jason-1 and from the US Navy's GFO. The shape of the mean waveform, with attendant ripples and spikes, indicates possible power leakages and the quality of the corrections for filter response. The variability about this mean indicates the number of degrees of freedom in each waveform bin, which needs to be known for some waveform-fitting algorithms. Thirdly, the correlation between anomalies in neighbouring bins indicates smoothing or signal leakage within the waveform.



                 Last modified: 07.10.03