On Sun, 24 Feb 2008 20:56:33 +0100, "Paul B. Andersen"
wrote:
Dr. Henri Wilson skrev:
Of course the bloody rate is changed after launch.
Each clock is software adjusted so that its rate is as close as possible to the
GC...after that, only very small corrections are required.
Actual GPS clock data measured by the ground stations can be found at:
http://tycho.usno.navy.mil/gps_datafiles.html
Below is a tiny excerpt of the data for the last 30 days.
I have shown the first and the last entry for each SV.
The table shows what the clock error is, and how much
it has changed during 30 days.
PRN Julian day clock error
1 54490.06701 -181263.7
1 54519.98368 -187755.1
2 54490.64201 -169105.0
2 54519.79479 -176782.5
3 54490.30035 -177788.4
3 54519.38646 -191137.3
4 54490.58646 57227.6
4 54519.72813 14049.3
5 54490.07813 -661179.4
5 54519.98368 -699917.9
8 54490.42257 138330.7
8 54519.51701 142174.2
9 54490.01146 -107278.9
9 54519.98368 -111959.0
10 54490.73090 222933.3
10 54519.85035 251627.2
11 54490.45590 -27039.0
11 54519.53924 -26982.6
12 54490.07813 354993.0
12 54519.98368 357044.3
13 54490.31146 -236284.6
12 54519.98368 357044.3
13 54490.31146 -236284.6
13 54519.70590 -241797.6
14 54490.01146 302989.6
14 54519.98368 294474.3
15 54490.01146 72735.4
15 54519.93924 79184.7
16 54490.21146 -132329.8
16 54519.33090 -132703.7
17 54490.50868 -43758.3
17 54519.65035 -42076.6
18 54490.01146 209686.4
18 54519.98368 201917.5
19 54490.33368 -18148.0
19 54519.43924 -21843.8
20 54490.20035 -121917.9
20 54519.59479 -119999.1
21 54490.01146 -73032.8
21 54519.98368 -71052.4
22 54490.01146 -207495.1
22 54519.98368 -208856.2
23 54490.25590 -328993.3
23 54519.33090 -336150.2
24 54490.01146 -65090.9
24 54519.93924 -72906.5
25 54490.36701 -503963.0
25 54519.45035 -516635.8
26 54490.83090 -165569.7
26 54519.89479 -191070.1
27 54490.37813 -163211.5
27 54519.48368 -169772.7
28 54490.47813 14182.0
28 54519.59479 15544.0
29 54490.79757 71673.8
29 54519.87257 56322.2
30 54490.14479 -61209.3
30 54519.71701 -65013.3
31 54490.10035 6616.5
31 54519.25313 10205.2
The table below show what the average rate error is
for each satellite clock during the last 30 days.
PRN Rate error
x10^-12
1 -2.51
2 -3.05
3 -5.31
4 -17.15
5 -14.99
8 1.53
9 -1.81
10 11.40
11 0.02
12 0.79
13 -2.17
14 -3.29
15 2.49
16 -0.15
17 0.67
18 -3.00
19 -1.47
20 0.76
21 0.76
22 -0.53
23 -2.85
24 -3.02
25 -5.04
26 -10.15
27 -2.61
28 0.54
29 -6.11
30 -1.49
31 1.42
I leave it to the reader to draw his conclusions.
These are merely recordings of typical clock drift.
Henri Wilson. ASTC,BSc,DSc(T)
www.users.bigpond.com/hewn/index.htm
Einstein's Relativity is easy to understand if one has the IQ of a parrot and a gullibility index 0.95.