TV Antenna User Manual

A-66 Acutime 2000 Synchronization Kit User Guide
Trimble Standard Interface Protocol
A
Time of measurement
The time of measurement (Byte 17) is the center of the sample
interval adjusted by adding the receiver-supplied codephase
(modulo mS) to a user-determined integer number of mS between
user and satellite.
The receiver codephase resolution is 1/16th of a C/A code chip.
This corresponds to:
The integer millisecond portion of the pseudo-range must then be
derived by utilizing the approximate user and satellite positions.
Rough user position (within a few hundred kilometers) must be
known; the satellite position can be found in its almanac/ephemeris
data.
Each mS integer corresponds to:
The satellite time-of-transmission for a measurement can be
reconstructed using the code phase, the time of measurement, and the
user-determined integer number of milliseconds.
0x5B Report Packet 5B
Satellite Ephemeris Status Report
This packet is sent in response to packet 3B and optionally, when a
new ephemeris (based on IODE) is received. It contains information
1/16 × C/A code chip
≈
977.517ns/16 ≈ 61.0948 ns
≈ 61.0948 × speed of light, m/s
≈ 18.3158 meters
C/A code epoch
× speed of light
=
1 ms × speed of light m/s
≈ 300 km (approximate)
≈ 299.792458 km (precise)