We compare TEC measurements from the NASA Radar Altimeter and DORIS instrument on board TOPEX/POSEIDON with GPS TEC estimates , and evaluate diierent GPS data analysis strategies. We verify that global tomographic GPS analysis using a voxel grid is well suited for ionospheric calibration of altimeters. We show that a 1-day t of 20-second-averaged NRA ionospheric correction data versus GPS tomog...

Active and passive microwave measurements obtained by the dual-frequency Topex–Poseidon radar altimeter from the Northern Great Plains of the United States are used to develop a snow pack radar backscatter model. The model results are compared with daily time series of surface snow observations made by the U.S. National Weather Service. The model results show that Ku-band provides more accurate...

A recently developed multiresolution estimation framework offers the possibility of highly efficient statistical analysis, interpolation, and smoothing of extremely large data sets in a multiscale fashion. This framework enjoys a number of advantages not shared by other statistically-based methods. In particular, the algorithms resulting from this framework have complexity that scales only line...

Continuous monitoring of the range stability is a pre-requisite for sea-level rise and other demanding applications in satellite altimetry. Range stability may be investigated by either absolute or relative calibration techniques. In this study relative calibration is undertaken through intercomparison against TOPEX/Poseidon and absolute calibration undertaken in the vicinity of 8 tide gauges a...

An offline approach is proposed for the estimation of model and data error covariance matrices whereby covariance matrices of model data residuals are ‘‘matched’’ to their theoretical expectations using familiar leastsquares methods. This covariance matching approach is both a powerful diagnostic tool for addressing theoretical questions and an efficient estimator for real data assimilation stu...

†‡ GPS measurements made at Topex/Poseidon and the accompanying ground tracking sites will be affected by the Selective Availability. Although in principle the effects may be removed by differencing between receivers observing the same GPS satellites, this requires accurate synchronization of all receiver clocks. In the case of Topex/Poseidon application, there are two sources of imperfect cloc...

Two years of TOPEX/POSEIDON altimeter data have successfully been used to study the mesoscale field in the Mediterranean and to investigate the seasonal and year-toyear variability of the sea level and eddy statistics in this basin. The mesoscale field described by TOPEX/POSEIDON revealed a strong, but subbasin dependent, seasonal signal. Year-toyear variations are also evident in terms of both...

Near-real time altimetry products from ENVISAT RA2, Jason 1 and Topex/Poseidon tandem mission are validated for the North Sea and Baltic Sea region to assess the feasibility of using the data for operational purposes. The coverage of the satellite data shows that all Jason 1 and Topex/Poseidon observations in the Baltic Sea are currently discarded in the processing of the data. The spatial scal...