Global Positioning System (GPS)

From Signal Identification Wiki
Jump to: navigation, search

Global Positioning System (GPS)
GPS.png
Frequencies 1176.45 MHz,1227.6 MHz,1381.05 MHz,1379.913 MHz,1575.42 MHz
Frequency Range 1176.45 MHz - 1575.42 MHz
Mode USB
Modulation BPSK,BOC,TMBOC,QAM,DSSS
ACF
Emission Designator
Bandwidth 24 MHz,22 MHz,25 MHz
Location Worldwide
Short Description GPS is the USA's global navigation satellite system which provides precision position, navigation, and timing services to devices around the globe.
I/Q Raw Recording Download file
Audio Sample

The Global Positioning System (GPS) is a global navigation satellite system (GNSS) which provides precision position, navigation, and timing (PNT) services to devices around the globe. It is broken up into the space segment (the constellation formed of 31 active satellites or "space vehicles" that broadcast a precision code and navigation message), the control segment (ground stations which monitor and manage the health of the satellites) and the user segment (the equipment used for receiving and utilizing signals from the space segment). In order to obtain a fix, a receiver must obtain almanac/ephemeris data containing orbit information and decode the precise timing code for at least four space vehicles (a fourth is necessary to determine the receiver's time so it can calculate pseudorange, as the time of the receiver usually not known to the degree of precision required for distance calculations).

Frequencies[edit]

"Space Vehicles" broadcast different signals (some of which are on the same frequency as each other) for various services. Depending on the generation/block of satellites, each space vehicle broadcasts navigation signals on the L1, L2, and L5 bands which contain the satellite's precise time which can then be used in conjunction with orbital ephemeris data (which is also broadcast as "navigation messages" at 50 bits/second) to determine the receiver's position, velocity, and time (PVT). C/A, L2C, and L5 are currently the only publicly-available navigation services available for civilians to use. The L5 band only contains one service,

Band Frequency (MHzMegaHertz (MHz) 10^6 Hz) Bandwidth (MHzMegaHertz (MHz) 10^6 Hz) Usage/Services
L1 Band 1575.42 24 Navigation: C/A, L1C, P(Y) Code, and M-Code Broadcasts
L2 Band 1227.60 22 Navigation: L2C, P(Y) Code and M-Code Broadcasts
L3 Band 1381.05 Nuclear Detonation Detection
L4 Band 1379.913 Ionospheric Correction Studies
L5 Band 1176.45 25 Navigation (Safety-of-Life): L5 Signal

Decoding Software[edit]

Decoding Tutorials[edit]

Additional Links[edit]