Waveform characteristics of the AltiKa altimeter
Event: 2014 SARAL/AltiKa workshop
Session: Instrument processing
Presentation type: Type Oral
The AltiKa altimeter has a mode enabling the download of individual echoes, which are provided as a burst of typically 4032 returns in a little over one second. Not only are these waveforms more frequent, but they are of a longer extent (more waveform bins) and higher precision (i.e. no rounding prior to transmission to the ground). These features allow a more complete examination of both the on-board processing and the the statistics of surface reflections from the ocean.. An unexplained trend in the power in the thermal noise region is identified, and the wrap-round effect shown to affect the last 12 waveform bins. This supports the decision for the first and last 12 bins being removed in the processing to produce the standard waveform product. Phase information is also provided with these individual echoes, which permits the investigation of opportunities for coherent processing of Ka-band altimetry. Initial evaluation of lagged covariances reveal some changes at the beginning of the leading edge, but also show further peculiarities in the thermal noise region. However, none of these artefacts appear to detract from the overall excellent performance of the AltiKa altimeter.