Off-nadir radar altimetry

Author

Parsons, Chester L. ; Walsh, Edward J.

Author_Institution

NASA Goddard Space Flight Center, Wallops Island, VA, USA

Volume

27

Issue

2

fYear

1989

fDate

3/1/1989 12:00:00 AM

Firstpage

215

Lastpage

224

Abstract

The characteristics of nadir versus off-nadir altimetry are reviewed and contrasted and a potentially serious problem has been pointed out that has been overlooked by earlier investigators, who focused on the nongeophysical error sources in off-nadir altimetry. Spatial gradients of radar cross section on the sea surface, caused by wind or current gradients or the variation of radar cross section with incidence angle, could introduce significant range errors in off-nadir altimeter. This potentially crippling effect can be overcome by leaving the traditional 13-GHz frequency and implementing the multibeam altimeter at 36 GHz. A multibeam altimeter proposed for the Eos (Earth Observing System) is described as well as a multimode airborne radar altimeter being developed to study problems inherent in off-nadir altimetry

Keywords

height measurement; oceanographic equipment; oceanographic techniques; radar applications; radar cross-sections; radioaltimeters; remote sensing; 36 GHz; EHF; Earth Observing System; Eos; MARA; current gradients; errors; incidence angle; multibeam altimeter; multimode airborne radar altimeter; nadir altimetry; oceanographic techniques; off-nadir altimetry; radar altimetry; radar cross section; remote sensing; sea surface; wind; Altimetry; Earth Observing System; Instruments; NASA; Radar remote sensing; Satellites; Sea surface; Space technology; Spaceborne radar; Surface topography;

fLanguage

English

Journal_Title

Geoscience and Remote Sensing, IEEE Transactions on

Publisher

ieee

ISSN

0196-2892

Type

jour

DOI

10.1109/36.20300

Filename

20300