Media type: E-Article Title: Characterization of Nadir Echoes in Multiple-Elevation-Beam SAR With Constant and Variable Pulse Repetition Interval Contributor: Villano, Michelangelo; Peixoto, Maxwell Nogueira imprint: Institute of Electrical and Electronics Engineers (IEEE), 2022 Published in: IEEE Transactions on Geoscience and Remote Sensing Language: Not determined DOI: 10.1109/tgrs.2021.3103266 ISSN: 0196-2892; 1558-0644 Keywords: General Earth and Planetary Sciences ; Electrical and Electronic Engineering Origination: Footnote: