HR: 1340h
AN: SF23A-0032    [Abstracts]
TI: GAPS and RADS: International Collaboration in Provision of Altimetry Datasets
AU: * Snaith, H M
EM: h.snaith@soc.soton.ac.uk
AF: Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH United Kingdom
AU: Lillibridge, J L
AF: NOAA Laboratory for Satellite Altimetry, 1335 East-West Hwy #5344, Silver Spring, MD 20910 United States
AU: Scharroo, R
AF: NOAA Laboratory for Satellite Altimetry, 1335 East-West Hwy #5344, Silver Spring, MD 20910 United States
AB: Two existing Altimeter Data services, both with significant numbers of users, have been interlinked to produce a coherent data service with alternative web interfaces and configurable users access. We will discuss issues of migrating users from existing services to new services such as this. The GAPS (Global Altimeter Processing Scheme) database provides collocated ocean altimeter data. The system has several stages: read the incoming Geophysical Data Records and convert to a consistent format, applying all known data updates and corrections; determine and apply a consistent set of geophysical corrections; collocate to an along track grid. The output includes collocated values of applied corrections so they can be removed or replaced. The system has remained relatively static for several years, giving a stable, but dated, product. The RADS (Radar Altimeter Database System) system, at the Technical University of Delft, is a sophisticated database system that is more flexible in its approach. The system carries out the first 2 stages of the GAPS scheme, allowing users to retrieve non-collocated altimetric parameters. The geophysical corrections are applied at the time of extraction via user-defined corrections sets, allowing more frequent updates to the database. A new system uses RADS as the input data source to create a reference GAPS data set, allowing users to easily extract a collocated, internally consistent dataset with recommended geophysical parameters. The extraction process allows any field in the RADS database to be collocated to the reference grid with little additional computational overhead and no storage overhead. Users can also extract their preferred parameters, using their preferred correction set, either with or without collocation, as required. This system is efficient, but requires the database operator to decide which fields to maintain in the database. Additional data fields must be calculated for all available data, even if never used. A further development of this system is now planned, to make use of recent GRID services advances. The source database will be replaced by a system that retrieves source data on request from remote certified sources.
DE: 4275 Remote sensing and electromagnetic processes (0689)
DE: 4500 OCEANOGRAPHY: PHYSICAL
DE: 1200 GEODESY AND GRAVITY
DE: 1635 Oceans (4203)
DE: 1640 Remote sensing
SC: Special Focus: Advances in Data Acquisition, Management, Analysis and Display [SF]
MN: 2004 AGU Fall Meeting