Characterization of Nadir Echoes in Multiple-Elevation-Beam SAR With Constant and Variable Pulse Repetition Interval
| Autor: | Michelangelo Villano, Maxwell Nogueira Peixoto |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
high-resolution wide-swath (HRWS) imaging
Synthetic aperture radar Beamforming Pulse repetition frequency nadir echo Image quality fungi Echo (computing) Elevation synthetic aperture radar (SAR) law.invention body regions multiple-elevation-beam SAR law Digital beamforming Tandem-L NASA-ISRO SAR (NISAR) Nadir General Earth and Planetary Sciences staggered SAR Electrical and Electronic Engineering Radar skin and connective tissue diseases Geology Remote sensing |
| Zdroj: | IEEE Transactions on Geoscience and Remote Sensing. 60:1-9 |
| ISSN: | 1558-0644 0196-2892 |
| DOI: | 10.1109/tgrs.2021.3103266 |
| Popis: | Multiple-elevation-beam synthetic aperture radar (SAR) is a concept based on digital beamforming (DBF) in elevation and simultaneous recording of the echoes of multiple transmitted pulses. It enables high-resolution imaging of wide areas and is therefore ideal for the systematic observation of dynamic processes on the Earth's surface. Furthermore, if the pulse repetition interval (PRI) is continuously varied (staggered SAR), it is possible to map a wide continuous swath rather than multiple subswaths separated by ``blind'' ranges. Within the design of multiple-elevation-beam SAR, however, it is fundamental to consider how nadir echoes affect the mapping capabilities of systems with constant PRI and the image quality of staggered SAR systems, where nadir echoes are intrinsically smeared due to the PRI variation. This article addresses the characterization of nadir echoes in multiple-elevation-beam SAR with constant and variable PRI by presenting a parametric model for the nadir echo profile based on real radar measurements, a formulation of the nadir echo location and smearing in staggered SAR, and realistic simulations based on TerraSAR-X data, which show that nadir echo are likely to be barely visible in staggered SAR images. The results of this work are relevant to both the design of future SAR systems and the interpretation of the acquired data. |
| Databáze: | OpenAIRE |
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