[PDF] Evaluation of the Potential of Global Navigation Satellite Systems for

Can high altitude missions take advantage of GNSS signals?

NASA is developing capabilities that will allow missions at high altitudes to take advantage of signals from Global Navigation Satellite System (GNSS) constellations — like GPS commonly used in the U.S.

What is Leo enhanced global navigation satellite system (legnss)?

In order to improve the GNSS performance and expand its applications, Low Earth Orbit (LEO) Enhanced Global Navigation Satellite System (LeGNSS) is being vigorously advocated.

Which countries have developed satellite navigation systems based on GPS?

The great success of GPS has made other countries start to develop their own satellite navigation systems, such as Russia’s GLONASS, EU’s Galileo, China’s BDS, Japan’s Quasi-Zenith Satellite System (QZSS), India’s Indian Regional Navigation Satellite System (IRNSS), etc.

Why should we use LEO satellites for Global topside ionospheric map (gtim)?

Therefore, LEO navigation constellation can fill the gaps of the ocean and polar region and further improve the precision and reliability of the global ionosphere map. On the other hand, a large number of LEO satellites also bring opportunities for Global Topside Ionospheric Map (GTIM).