Print Email Facebook Twitter Optimal Configuration of Omega-Kappa FF-SAR Processing for Specular and Non-Specular Targets in Altimetric Data: The Sentinel-6 Michael Freilich Study Case Title Optimal Configuration of Omega-Kappa FF-SAR Processing for Specular and Non-Specular Targets in Altimetric Data: The Sentinel-6 Michael Freilich Study Case Author Amraoui, Samira (Collecte Localisation Satellites) Guccione, Pietro (ARESYS SRL) Moreau, Thomas (Collecte Localisation Satellites) Alves, Marta (Collecte Localisation Satellites) Altiparmaki, O. (TU Delft Astrodynamics & Space Missions) Peureux, Charles (Collecte Localisation Satellites) Recchia, Lisa (ARESYS SRL) Maraldi, Claire (Centre National pour l’Etudes Spatiales) Boy, François (CNES Centre National d'Etudes Spatiales) Donlon, Craig (European Space Agency (ESA)) Date 2024 Abstract In this study, the full-focusing (FF) algorithm is reviewed with the objective of optimizing it for processing data from different types of surfaces probed in altimetry. In particular, this work aims to provide a set of optimal FF processing parameters for the Sentinel-6 Michael Freilich (S6-MF) mission. The S6-MF satellite carries an advanced radar altimeter offering a wide range of potential FF-based applications which are just beginning to be explored and require prior optimization of this processing. In S6-MF, the Synthetic Aperture Radar (SAR) altimeter acquisitions are known to be aliased in the along-track direction. Depending on the target, aliasing can be tolerated or may be a severe impairment to provide the level of performance expected from FF processing. Another key aspect to consider in this optimization study is the unprecedented resolution of the FF processing, which results in a higher posting rate than the standard SAR processing. This work investigates the relationship between posting rate and noise levels and provides recommendations for optimal algorithm configurations in various scenarios, including transponder, open ocean, and specular targets like sea-ice and inland water scenes. The Omega–Kappa (WK) algorithm, which has demonstrated superior CPU efficiency compared to the back-projection (BP) algorithm, is considered for this study. But, unlike BP, it operates in the Doppler frequency domain, necessitating further precise spectral and time domain settings. Based on the results of this work, real case studies using S6-MF acquisitions are presented. We first compare S6-MF FF radargrams with Sentinel-1 (S1) images to showcase the potential of optimally configured FF processing. For highly specular surfaces such as sea-ice, distinct techniques are employed for lead signature identification. S1 relies on image-based lineic reconstruction, while S6-MF utilizes phase coherency of focalized pulses for lead detection. The study also delves into two-dimensional wave spectra derived from the amplitude modulation of image/radargrams, with a focus on a coastal example. This case is especially intriguing, as it vividly illustrates different sea states characterized by varying spectral peak positions over time. To reference this document use: http://resolver.tudelft.nl/uuid:5fcc82ce-8371-40fb-a0e8-afa54887def4 DOI https://doi.org/10.3390/rs16061112 ISSN 2072-4292 Source Remote Sensing, 16 (6) Part of collection Institutional Repository Document type journal article Rights © 2024 Samira Amraoui, Pietro Guccione, Thomas Moreau, Marta Alves, O. Altiparmaki, Charles Peureux, Lisa Recchia, Claire Maraldi, François Boy, Craig Donlon Files PDF remotesensing-16-01112-v2.pdf 34.77 MB Close viewer /islandora/object/uuid:5fcc82ce-8371-40fb-a0e8-afa54887def4/datastream/OBJ/view