Wave vertical orbital velocity effects on Doppler Altimeter waveform and SSH measurement

Eugenio Pugliese Carratelli (CUGRI, Italy)

CoAuthors

Ferdinando Reale (CUGRI, Italy); Fabio Dentale (University of Salerno, Italy)

Event: 2016 SAR Altimetry Workshop

Session: Applications, SAR for science

Presentation type: Type Poster

The resolution of Doppler altimeters is based on the Doppler shift caused by the movement of the antenna relative to the earth. Such an effect depends on the vertical component of the satellite velocity, which is very small near the zenith, i.e. a few metres per second at the border of the first Doppler beam for the Cryosat DDA.

(FIG 1)
Vertical components of the sea waves orbital velocity can easily reach such values and in principle they might interfere with the along-track positioning of the return beam. This interference (“Reale effect”) normally does not constitute a problem when the wavelength of sea waves is much smaller than resolution of the altimeter; however, swell over the ocean may reach wavelengths of the same order as the Doppler beam length (a few hundred meters).

The paper will present the results of simulations aimed at assessing the effect of R-effect on the waveform formation as well as on the SSH values, with special regard to long wave sea states (swell),

Basic references:


Fenoglio Marc, L, Dinardo, S., Scharroo, R., Roland, A., Dutour, M., Lucas, B., Becker, M., Benveniste, J., Weiss, R. (2015). The German Bight: a validation of CryoSat altimeter data in SAR mode,

Gommenginger C, Cipollini P., Snaith H., West L.& Passaro M. SAR altimetry over the open and coastal ocean: Status and Open issues

Gommenginger Christine, Cristina Martin‐Puig, Laiba Amarouche & R. Keith Raney, Review Of State Of Knowledge For SAR Altimetry Over Ocean EUMETSAT REFERENCE: EUM/RSP/REP/14/749304 2013

Halimi A.,C. Mailhes, J.-Y. Tourneret, P. Thibaut, and F. Boy, A semi-analytical model for delay/Doppler altimetry and its estimation algorithm, IEEE Trans. Geosci. and Remote Sensing, 52 (7), 4248 - 4258, July 2014. DOI: 10.1109/TGRS.2013.2280595

Martin-Puig, G. Ruffini, J. Marquez, D. Cotton, M. Srokosz, P. Challenor, R. K. Raney, and J. Benveniste,
“Theoretical model of SAR altimeter over water surfaces,” Proc. IEEE Int. Conf. Geosci. Remote Sens. (IGARSS) Boston, U.S.A., July 7-11, 200

Raney R. K. The Delay-Doppler Altimeter 200 Briefing for the Coastal Altimetry Workshop

Reale F., F. Dentale, E. Pugliese Carratelli On the effect of wave vertical orbital velocity on Doppler Radar Altimetry, 2016 EUMETSAT Conference 2016, Darmstadt, Germany,
 
Wave vertical orbital velocity effects on Doppler Altimeter waveform and SSH measurement

Poster show times:

RoomStart DateEnd Date
Grande Halle Mon, Oct 31 2016,18:30 Mon, Oct 31 2016,19:30
Eugenio Pugliese Carratelli
CUGRI
Italy
epc@unisa.it