[time-nuts] What's the time Mr Wolf...
sam.mosel at baesystems.com
Sun Nov 2 22:21:00 UTC 2008
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Steve Rooke
Sent: Thursday, 30 October 2008 11:16 PM
> 10) If they are geostationary, or move in relation to the ground,
> how are the affects of the Einstein time dilation handled as they
> may be travelling at a different speed than a point on the surface
> of the Earth?
Internally, the GPS satellites have an approximately 10.23 MHz
oscillator which is:
1. multiplied by 120 to generate the L2 carrier (1227.6 MHz),
2. multiplied by 154 to generate the L1 carrier (1575.42 MHz),
2a. Multiplied by 115 to generate the L5 carrier (1176.45 MHz, Block III
3. passed directly to the P(Y) code generator (10.23 MHz symbol rate)
4. divided by 10 to generate the C/A code (1.023 MHz symbol rate), and
5. divided by 20460 to generate the data (50 Hz bit rate).
So everything is derived from this oscillator, which is actually
10.22999999543 MHz. This -4.57 mHz corrects for relativistic effects.
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