Design Principles and Considerations for Spaceborne ATI SAR-Based Observations of Ocean Surface Velocity Vectors

Steffen Wollstadt, Paco Lopez-Dekker, Francesco De Zan, Marwan Younis

Research output: Contribution to journalArticleScientificpeer-review

15 Citations (Scopus)


This paper presents a methodology to design a spaceborne dual-beam along-track synthetic aperture radar interferometer to retrieve ocean surface velocity vectors. All related aspects and necessary tradeoffs are identified and discussed or reviewed, respectively. This includes a review of the measurement principle and the relation between baseline and sensitivity, the relation between wind and radar backscatter, a discussion of the observation geometry, including the antenna concept, polarization diversity, and all main error contributions. The design methodology consists of a sensitivity-based derivation of explicit instrument requirements from scientific requirements. In turn, this derivation is based on a statistical model for the interferometric phase error. This allows a quantitative, well-grounded instrument design offering an additional degree of freedom to the approach, which we call ''noise-equivalent-sigma-zero requirement space.'' Crucial tradeoffs for the system design, such as the resolution, the number of independent looks, the minimum wind speed, and the coherence and ambiguities, are pointed out and discussed. Finally, this paper concludes with a single platform system concept operating in Ku-band, which provides the measurement quality needed to achieve a surface velocity estimation accuracy of [5] cm/s, [200]-km swath coverage, for [$4x4$] km² L2-product resolution and winds starting at [3] m/s.

Original languageEnglish
Pages (from-to)4500 - 4519
Number of pages20
JournalIEEE Transactions on Geoscience and Remote Sensing
Issue number8
Publication statusPublished - 19 May 2017

Fingerprint Dive into the research topics of 'Design Principles and Considerations for Spaceborne ATI SAR-Based Observations of Ocean Surface Velocity Vectors'. Together they form a unique fingerprint.

Cite this