Global Positioning System tracks the entire globe and is maintained by the USA. The constellation requires 24 Satellites to be operational and has around 31 satellites in orbit. All of these are Medium Earth Orbit, which is to say that they are not stationary in space with respect to the revolving earth. GPS also uses a single frequency band and this makes calculations a bit more complex.
India’s Navic has 3 geostationary satellites and 4 geosynchronous satellites, and these satellites are situated in much higher orbit (signal is less prone to obstructions). NavIC satellites use dual frequency bands (L5-band and S-band), which is why the system is relatively more accurate than GPS (that uses a single band and makes compensation for error due to signal deterioration by the atmosphere
Parameter |
NavIC |
GPS |
Accuracy |
Up to 5 meters |
Up to 20-30 meters |
Frequency |
S-band and L-Band |
L- Band |
If the navigation receiver is kept inside a building and the antenna is positioned outside the building some distance away, will the receiver report position of the receiver inside the building correctly?
Any navigation receiver computes the position of the antenna and not the receiver unit itself.
In case the antenna is placed outside the building with sufficient clear view to the sky, and sufficiently less cable length is maintained, the receiver will correctly report position of the antenna.