1. University of Potsdam; Institute of Earth and Environmental Sciences; Karl-Liebknecht-Str. 24/25; D-14476; Potsdam; Germany
2. German Research Centre for Geosciences; Department of Geodesy and Remote Sensing; Telegrafenberg; 14473; Potsdam; Germany
3. Federal University of Ceará; Department of Agricultural Engineering; Bloco 804-Campus do Pici; CEP 60 455-970; Fortaleza; CE; Brazil