There appears to be much more research on Indoor Positioning Systems than Outdoor Systems. A search on Google and Google Scholar will yield significantly more results on research papers related to Indoor Positioning Systems. Gartner made a report on Indoor Positioning Systems, but there is nothing on Outdoor ones.
Why do you think this is? Is the trend towards building more indoor solutions? Is it just trivial to build an outdoor positioning system?
submitted by /u/departedquantities
Original article: There appears to be much more research on Indoor Positioning Systems than Outdoor Systems.