HR: 1340h
AN: SF53A-0722    [Abstracts]
TI: Preliminary Attempts to Connect Ocean Reflected GNSS Signals Detected From Low Earth Orbit With Sea Winds
AU: * Gleason, S
EM: s.gleason@sstl.co.uk
AF: Surrey Satellite Technology Limited, University of Surrey, Guildford, GU2 7XH United Kingdom
AU: * Gleason, S
EM: s.gleason@sstl.co.uk
AF: Surrey Space Centre, University of Surrey, Guildford, GU2 7XH United Kingdom
AU: Sun, Y
EM: y.sun@eim.surrey.ac.uk
AF: Surrey Space Centre, University of Surrey, Guildford, GU2 7XH United Kingdom
AU: Gommenginger, C
EM: cg1@soc.soton.ac.uk
AF: Southampton Oceanography Centre, LSO, Southampton, SO14 3ZH United Kingdom
AU: Unwin, M
EM: m.unwin@sstl.co.uk
AF: Surrey Satellite Technology Limited, University of Surrey, Guildford, GU2 7XH United Kingdom
AU: Mackin, S
EM: s.mackin@eim.surrey.ac.uk
AF: Surrey Space Centre, University of Surrey, Guildford, GU2 7XH United Kingdom
AU: Hodgart, S
EM: s.hodgart@eim.surrey.ac.uk
AF: Surrey Space Centre, University of Surrey, Guildford, GU2 7XH United Kingdom
AU: Adjrad, M
EM: m.adjrad@eim.surrey.ac.uk
AF: Surrey Space Centre, University of Surrey, Guildford, GU2 7XH United Kingdom
AB: Most people are generally aware of the fact that the GPS receivers used on boats and airplanes use signals transmitted by a constellation of satellites to determine their locations. What is less obvious is that the same signals are constantly being scattered off the surrounding seas and land, and these signals contain valuable and varied information on the Earth's environment. The GNSS bi-static radar experiment carried on the UK disaster monitoring constellation satellite has been collecting and down linking raw data containing ocean reflected GPS signals since its successful commissioning in March of 2004. It is our aim to connect the delay and Doppler shapes of the received ocean scattered waveforms to an observable ocean phenomenon. This has been shown to be possible based on numerous ground and aircraft experiments utilising the same concept. In these cases it was important to obtain a truth measurement to coincide with the experiment data, such as collecting data while flying underneath TOPEX/POSIEDEN as it passes overhead. In the case of collecting data on an orbiting satellite it becomes more complicated. Sea wind estimates have been obtained from the QuickSCAT and JASON satellites as well as from buoy's and weather models. To what extent these independent measurements provide a degree of "truth" depends on several factors. The most obvious of these are the spatial and temporal coincidence with the signal detections. These and other issues will be discussed and the steps that have been taken to improve the validation procedure will be presented. Despite the obstacles encountered, it can be shown that ocean reflected signals from the GPS navigation satellite constellation can be tracked from a low-earth orbiting satellite and that these signals show rough correlation with independent measurements of the sea winds. This breakthrough has the potential to influence a wide range of applications including the determination of sea surface roughness, ocean wind speed and potentially sea surface altimetry. From low Earth orbit, these types of measurements could provide high-density sampling over meso-scale ocean features, which could significantly impact global climate modelling. Based on our initial results, satellite ocean remote sensing using passive ocean scattered signals is now possible.
DE: 4200 OCEANOGRAPHY: GENERAL
DE: 4294 Instruments and techniques
DE: 4500 OCEANOGRAPHY: PHYSICAL
SC: Special Focus: Advances in Data Acquisition, Management, Analysis and Display [SF]
MN: 2004 AGU Fall Meeting