Calibration and Validation of the Advanced Scatterometer on METOP-B
Anderson, Craig; Bauch, Helmut; Duff, Colin; Figa-Saldana, Julia; Miller, James; Wilson, JJW

The Advanced Scatterometer (ASCAT) is a six beam radar instrument operating at C band with vertical polarisation designed to accurately measure surface backscatter allowing the retrieval of wind fields over the ocean. The data it provides is also used by a number of other applications including sea ice monitoring and soil moisture retrieval. An ASCAT is carried on each of the ESA/EUMETSAT Metop satellites.

The ASCAT on board the Metop-B satellite (ASCAT-B) became operational in 2013 and three ground based transponders have been used to achieve an absolute calibration. A summary of the calibration and validation process is presented along with an analysis of the achieved calibration accuracy.

The ASCAT carried by the Metop-A satellite (ASCAT-A) has been operational since 2007 and operates in the same orbit as ASCAT-A but with a lead of around 50 minutes. A comparison of the data from the two instruments is presented showing that they agree to a very high level.

These results show that that the data from the two ASCAT instruments is of a very high quality and can be used interchangeably for most applications.