Narendra N Das, Jet Propulsion Laboratory, Pasadena, CA, United States, Dara Entekhabi, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Cambridge, MA, United States, Binayak Mohanty, Texas A&M University, Department of Biological and Agricultural Engineering, College Station, TX, United States and Simon H Yueh, JPL, Pasadena, CA, United States