His research is focused on improving our understanding of geologic, hydrodynamic and ecologic processes on planets. He is currently studying large lakes, wildfires and mineral distributions on Earth. He has also applied his knowledge of terrestrial geologic processes to other planets, in particular Mars.

Simon’s passion is research and mission development in the optical domain, particularly the thermal infrared, he is an expert on optical radiometry and thermal infrared spectroscopy and member of several instrument teams. The instrument teams include ASTER, MODIS, SNPP, Landsat and AATSR. He has developed validation sites at Lake Tahoe, CA/NV and several other sites in California including Salton Sea, Russel Ranch, and Tonzi Ranch, for determining the absolute radiometry of airborne and spaceborne mid and thermal infrared radiometers and developing surface temperature and emissivity retrieval algorithms. The measurements at the sites are used as an absolute reference standard for multiple instruments developed by both domestic and foreign space agencies. The Lake Tahoe site was established in 1999 and has been operational for over 20 years measuring the surface temperature and other meteorological and radiation variables at 4 locations every few minutes. The Tahoe data are primarily used to calibrate and validate satellite sensors, but are also used to develop surface temperature retrieval algorithms and help understand hydrodynamic and limnological processes.