User's Manual

LPP0108IG001 56 Version - Preliminary – 06/20/08
8. GPS Performance
Specification Parameter/Conditions Min Typ Max Units
Maximum Update Rate 1 Hz
Accuracy
-130 dBm, Autonomous CEP (50%) 1 3 m
-140 dBm, Autonomous CEP (50%) 1.5 5 m
-150 dBm, Autonomous CEP (50%) 7 10 m
-155 dBm, Autonomous CEP (50%) 18 25 m
-130 dBm, Autonomous CEP (95%) 2.5 5 m
-140 dBm, Autonomous CEP (95%) 3 7 m
-150 dBm, Autonomous CEP (95%) 15 25 m
-155 dBm, Autonomous CEP (95%) 40 50 m
Acquisition Times
-130 dBm, 25 C
Cold Start TTFF 27 35 49 S
Reacquisition 3 5 S
Sensitivity
Tracking - 157.5 -160 dBm
Reacquisition -157 dBm
Cold Start -144 dBm
 CEP (50%): The radius of a horizontal circle centered at
the antenna’s true position that contains
50% of the fixes.
 CEP (95%): The radius of a horizontal circle centered at
the antenna’s true position that contains
95% of the fixes.
 TTFF (Time To First Fix (seconds)): The number of seconds to provide a
position fix (latitude & longitude).
 Cold Start: The GPS receiver does not have valid
almanac or time data.
 Assisted Cold Start: The modem supplies the GPS receiver any
valid time, ephemeris, almanac, and
position data, that the modem might have
stored.
 Reacquisition: The GPS receiver has valid ephemeris,
almanac and time data.