SIMT(NIST) versus SIMT(IBM) via Common-View GPS
1 Day Averages 1 Hour Averages 10 Minute Averages Next Date Last Date Flip    

Laboratory 1National Institute of Standards and TechnologyID Number006End Date2021-09-13
Latitude 39° 59 min 44.579 s NCounter Delay 0.42 nsReference SourceSIMT(NIST)
Longitude105° 15 min 43.185 s WREF Delay 433.4 nsMask Angle10°
Altitude1646.72 mReceiver Delay-5.4 nsReceiver Temp.28 °C
Laboratory 2IBMETRO Bolivia ID Number025Baseline6944.015 km
Latitude 16° 30 min 1.070 s SCounter Delay 0.01 nsReference SourceSIMT(IBM)
Longitude 68° 7 min 56.998 s WREF Delay 2.9 nsMask Angle10°
Altitude3648.75 mReceiver Delay103.0 nsReceiver Temp.41 °C

Hours in
Common-View		 Mean Time
Offset (ns)		 Range (ns) Frequency Offset Confidence (r)
24 68.72 23.62 +9.00 x 10-14 +0.38




Allan Deviation
Averaging Period ()
(hours, minutes)		 Samples Frequency
Stability
0 h, 10 min 141 8.73 x 10-12
0 h, 20 min 139 5.15 x 10-12
0 h, 40 min 135 3.23 x 10-12
1 h, 20 min 127 1.72 x 10-12
2 h, 40 min 111 7.70 x 10-13
5 h, 20 min 79 3.95 x 10-13


Time Deviation
Averaging Period ()
(hours, minutes)		 Samples Time
Stability (ns)
0 h, 10 min 141 3.03
0 h, 20 min 138 2.79
0 h, 40 min 132 3.03
1 h, 20 min 120 2.85
2 h, 40 min 96 2.15
5 h, 20 min 48 4.18


SIMT(NIST) - SIMT(IBM)
(common-view tracks from individual GPS satellites)
GPS
PRN		 Minutes
(In-View)		 Minutes
(Common-View)		 Range (ns) Time
Deviation		 Frequency Offset Confidence (r) View
Detail
1 410 120 13.90 2.39 +1.06 x 10-12 +0.56 View
2 350 90 25.68 2.99 -5.03 x 10-13 -0.59 View
3 380 70 18.38 5.18 -3.86 x 10-12 -0.77 View
4 370 130 14.55 1.45 -1.62 x 10-12 -0.90 View
5 320 140 10.79 2.80 +9.03 x 10-13 +0.64 View
6 320 110 26.85 2.89 +2.63 x 10-12 +0.73 View
7 390 140 14.05 2.21 -1.68 x 10-12 -0.88 View
8 380 160 21.44 3.10 +2.00 x 10-12 +0.91 View
9 330 100 32.92 3.06 +2.86 x 10-12 +0.56 View
10 340 100 14.08 1.60 -2.59 x 10-12 -0.89 View
11 --- --- ---------- ------- -------------- ------ ----
12 300 60 10.86 2.98 +2.06 x 10-13 +0.07 View
13 340 140 17.68 3.81 +1.69 x 10-12 +0.83 View
14 380 140 17.44 1.27 -2.07 x 10-12 -0.86 View
15 320 140 22.04 1.20 +3.03 x 10-12 +0.99 View
16 380 160 20.05 1.74 +2.27 x 10-12 +0.93 View
17 350 70 10.91 3.67 -3.38 x 10-13 -0.69 View
18 390 140 26.02 1.18 -3.50 x 10-12 -0.98 View
19 350 90 23.00 2.56 -2.71 x 10-12 -0.67 View
20 340 190 17.44 1.91 +1.58 x 10-12 +0.88 View
21 370 40 15.45 0.00 +2.64 x 10-12 +0.96 View
22 330 50 10.51 5.91 -3.57 x 10-12 -0.64 View
23 370 120 29.47 2.63 -3.39 x 10-12 -0.82 View
24 420 70 22.72 1.21 +4.91 x 10-12 +0.98 View
25 360 60 19.37 9.74 -3.41 x 10-12 -0.44 View
26 360 150 22.59 2.36 +2.79 x 10-14 +0.08 View
27 410 140 24.38 1.34 +3.08 x 10-12 +0.98 View
28 --- --- ---------- ------- -------------- ------ ----
29 330 100 16.87 1.24 -2.72 x 10-12 -0.90 View
30 320 90 10.24 0.81 -1.24 x 10-12 -0.87 View
31 320 90 12.90 2.28 +1.56 x 10-12 +0.82 View
32 320 60 27.18 5.28 +2.30 x 10-13 +0.86 View


Legend
GPS PRNThe unique pseudo random noise (PRN) code (1 to 32) used to identify each satellite. If no satellite is assigned to a given PRN code, then no data are shown.
Minutes
(In-View)		The number of minutes when the satellite was visible at laboratory 1. During this period, the time difference between the satellite clock and the laboratory reference is measured every second, and 10 minute averages are stored. Since data is recorded in 10 minute segments, the values are even multiples of 10 minutes.
Minutes
(Common-View)		The number of minutes when the satellite was visible at both sites involved in the common-view comparison.
RangeThe difference between the maximum and minimum time offset values (nanoseconds).
Time
Deviation		The time deviation (TDEV) of the 10-minute averages (nanoseconds).
Frequency
Offset		The estimated frequency offset of laboratory 1 relative to laboratory 2 based on a common-view observation of the satellite. This estimate is obtained by fitting a least squares line to all of the recorded data.
Confidence
Level (r)		The confidence level of the estimated frequency offset. The confidence level is the correlation coefficient (r) of the least squares line fitted to the data.
View
Track		Clicking on the View link displays a common-view track from the selected satellite. The number of previous days shown equals the number of previous days shown on this page, up to a maximum of 30 days.