Geolocation Technologies

• There are usually many limitations when doing "position determination based on Low Earth Orbit (LEO) satellites signal of opportunity" in exposed and remote GNSS areas such as oceanic areas, northern territories, and desert regions.
• To reach these seemingly unreachable areas, a new Search and Rescue (SAR) positioning configuration was created.
• Through this new configuration the position and speed of the tranceiver can be gauged using the distributed Doppler data capture from LEO sattelites.  
• The Iridium Next LEO constellation can overcome the challenges that are usually encountered when tracking moving objects such as airplanes. The signal from this system can also work around obstructions.
• Through various coupling, filtering, and PNT resiliency combinations, the signals from Iridium sattelites can even yield more accurate results.
• The solution can be used to locate stationary objects as well as moving targets. It can be applied to track flights over oceanic regions and help in aircraft navigation safety in locations that are not typically covered by satellite signals.
• With regard to traditional GPS, this tracking technology has more limitations compared to geolocation using an Iridium satellite network.
• GPS will not usually work in indoor areas where there are solid obstructions such as walls, furniture, and other objects.
• Furthermore, low-level GPS are not capable of locating objects at over 3-m accuracy.
• Because of these constraints, GPS will not be effective in tracking the flow of people inside structures such as retail stores.
• GPS is also not useful in the Arctic regions because of the orbital angle of the satellites used and the high latitude of the Arctic circle.
• GPS satellites are also more prone to ionospheric currents. This can then cause signal timing lags, resulting in positioning calculation inaccuracies.

Summary of Findings:

• Our one hour of research provided a comparative analysis between geolocation (including altitude) provided by the Iridium satellite network versus traditional GPS.
• As there was no geographic focus provided to us, we are assuming a global focus. If a more targeted approach is desired, for example, the United States, this would have to be clearly communicated to us in any reply.