2D Frequency Domain Fully Focused SAR Processing for High PRF Radar Altimeters

• Published in: Remote Sensing
• Main Authors: Pietro Guccione, Michele Scagliola, Davide Giudici
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2018
• Subjects: altimeter; Synthetic Aperture Radar; Delay/Doppler altimeter; Omega-Kappa domain; Science; Q; Sea ice
• Online Access: https://doi.org/10.3390/rs10121943; https://doaj.org/article/13c9fc8cfa434a2c940c67b8403ed713

Fully-focusing of radar altimeters is a recent concept that has been introduced to allow further improvement of along-track resolution in high pulse repetition frequency (PRF) radar altimeters. The straight potentiality of this new perspective reflects into a more accurate estimation of geophysical parameters in some applications such as sea-ice observation. However, as documented in a recent paper, such capability leaves unsolved the problem of the high computational effort required. In this paper, we face the problem of adapting for altimeters the Omega-Kappa SAR focusing algorithm that is performed in the two-dimensional wavenumber domain, accounting for the difference existing between SAR and altimeter from geometry (looking and swath width) and instrument (echoes are deramped onboard on receiving) point of view. Simulations and an application using in-orbit data show the effectiveness of the proposed approach and the highly reduced computational effort.