FIRST RESULTS OF RECOVERY OF SHORTWAVELENGTH GRAVITY FIELD SIGNALS FROM CRYOSAT-2 DATA

摘要

A number of geophysical phenomena in the open oceanrnare still unresolved by conventional 1 Hz altimetry, butrncould be observed through the potential improvementsrnoffered by SAR, or Delay-Doppler (DD), altimetry. ThernDD altimeter offers the following benefits with respectrnto conventional satellite altimetry: Factor of 20 improvementsrnin along track resolution, along-track footprintrnlength that does not vary with wave height (sea state),rnand improved precision in sea surface height measurements/rnsea surface slope measurements.rnThese improvements are studied with respect to retrievalrnof short wavelength geophysical signal related to mainlyrnbathymetric features. The combination of upward continuationrnfrom the sea bottom and smoothing the altimeterrnobservations resulted in the best recovery of geophysicalrnsignal for simulated 5-Hz DD observations. The firstrnvalidation of these theoretical modelling results with respectrnto resolution and noise are presented using variousrnCryoSat-2 data and evaluation against conventionalrnRadar altimeter data from older GM missions onboardrnERS-1 is presented.rnA comparison of L2 products for LRM data are carriedrnout with retracked L1b data for the same data types.