ENVISAT S-Band Altimeter Calibration and Validation
Michiel Otten(1) , Rene Zandbergen(1) , and John Dow(1)
As a principal investigator for the Envisat RA-2 Altimeter the Navigation Office at ESOC has been actively involved in the Calibration and Validation phase of the Altimeter. After the Cal/Val phase ESOC has continued monitoring the performance of the altimeter as a member of the Quality Working Group (QWG) of the ENVISAT Altimeter. All the major effort during the Cal/Val phase and the ensuing routine monitoring phase has focused on the Ku-Band of the Altimeter. Very little work so far has been done to correctly estimate the S-Band range and time bias of the Altimeter. This paper will describe the results of the detailed study performed on the S-band range and time bias. Further the impact of the range bias on the dual-frequency ionosphere correction as it is currently present on the GDR product will be illustrated.