NavList:

Why hasn't the Satelles navigation system become popular? As noted on their website, "Satelles delivers a solution for global time and location that is completely independent from GPS, and is available today. Originating from the Iridium constellation of 66 low-earth-orbiting satellites, Satellite Time and Location (STL) is 1000 times stronger than GPS, reaching deep into buildings and penetrating GPS jamming without the aid of local infrastructure. Cryptographic security features of STL also provide exceptional resilience to intentional spoofing. STL perfectly augments GPS and other location-based technologies, and provides the absolute height of security." Read more in articles from GPS World here. My guess is that the answer is simply that they haven't found a partner willing to bring the system to market at a reasonable price. It's worth noting that a system like this will be much easier to create and with lower delay in position-finding when one of the proposed very low LEO satellite constellations is deployed within the next few years. It's going to be a different world for ocean navigation when high-power unjammable satellite navigation is available globally piggybacked on a system which will also deliver high-speed internet access at a greatly reduced price anywhere on the globe.

Frank Reed