New scientific applications for ocean, land and ice remote sensing with ENVISAT altimeter individual echoes.
Christine Gommenginger(1) , Peter Challenor(1) , Jesus Gomez-Enri(1) , Graham Quartly(1) , Meric Srokosz(1) , Philippa Berry(2) , James Garlick(2) , David Cotton(3) , David Carter(3) , Catherine Rogers(4) , Sally Haynes(4) , Iain LeDuc(4) , Maria Pilar Milagro(5) , and Jerome Benveniste(5)
National Oceanography Centre, Southampton,
SO14 3ZH Southampton,
(2) De Montfort University, The Gateway, LE1 9BH,Leicester, United Kingdom
(3) Satellite Observing Systems, 15 Church Street, Godalming, GU7 1EL, United Kingdom
(4) SciSys (Space & Defence) Ltd, Methuen Park, Chippenham, SN14 0GB, United Kingdom
(5) ESA/ESRIN, Via Galileo Galilei, 00044 Frascati, Italy
The Radar Altimeter on ENVISAT (RA-2) is the first space borne altimeter to provide average waveforms at two radar frequencies as well as bursts of up to 2000 individual echo samples at Ku band, in addition to standard altimeter geophysical products. This paper presents results of a recent study which investigates new scientific applications for ocean, land and ice remote sensing using ENVISAT RA-2 individual echoes. Examples of new applications include the possible use of RA-2 individual waveforms phase measurements to derive new ocean wave spectrum information and the development of improved re-tracking algorithms for rapidly varying land and ice surfaces. Analyses of bursts of individual echoes indicate much greater information content and that higher spatial resolution can be obtained over non-ocean surfaces than previously thought possible. Averaged waveform data at Ku and S band serve also to examine the change of response of ocean and land/ice surfaces with radar wavelength, with implications for a wide range of applications including vegetation and texture studies over land/ice, and rain cell and improved sea state measurements over the ocean and the coastal zone.