Statistical Evaluation of the Jason-1 Operational Sensor Data Record

The Jason-1 satellite altimeter mission represents a first step towards operational oceanography from satellite altimeter missions. An operational data product, the Operational Sensor Data Record (OSDR), provides measurements from the on-board altimeter and radiometer within 3-5 h of real time. This data product is a wind and wave product that is aimed towards near-real-time meteorological applications. A higher accuracy and more detailed data product, the Interim Geophysical Data Record (IGDR), that is better suited to detailed scientific studies of ocean topography, is available no sooner than 2-3 days from real time. The measurements reported on the OSDR primarily differ from those on the IGDR in that the OSDR reports measurements derived from on-board processing of the altimeter waveforms, while ground retracking of the waveforms is performed for the IGDR. The altimeter-derived measurements on the OSDR are validated through a statistical evaluation of the differences between data on the OSDR and IGDR. In doing so, the impact of ground retracking of the altimeter waveforms is also illustrated.