A often overlooked feature of GPS is that it actually gives you line of sight information to all satellites of the constellation not only a position. So pretty

A often overlooked feature of GPS is that it actually gives you line of sight information to all satellites of the constellation not only a position. So pretty amazing extraction techniques and 3D reconstructions are possible. http://www.cc.gatech.edu/~summetj/papers/kim_iswc_08.pdf http://www.cc.gatech.edu/~summetj/papers/kim_iswc_08.pdf http://www.cs.technion.ac.il/RESEARCH_DAY_13/POSTERS/nir_hershko.pdf http://www.cs.technion.ac.il/RESEARCH_DAY_13/POSTERS/nir_her... (quite big poster) And in the reverse use case this enables shadow forecasting and faster positioning based on known environment and shadow maps: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3574707/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3574707/ http://www-user.tu-chemnitz.de/~maob/nt/paper/Bauer2013.pdf http://www-user.tu-chemnitz.de/~maob/nt/paper/Bauer2013.pdf