SIMT(NIST) versus SIMT(ICE) 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 2Instituto Costarricense de Electridad (ICE), Costa RicaID Number011Baseline3874.561 km
Latitude 9° 55 min 52.809 s NCounter Delay 0.28 nsReference SourceSIMT(ICE)
Longitude 84° 3 min 22.568 s WREF Delay 30.7 nsMask Angle10°
Altitude1247.76 mReceiver Delay238.2 nsReceiver Temp.25 °C

Hours in
Common-View		 Mean Time
Offset (ns)		 Range (ns) Frequency Offset Confidence (r)
24 41.49 14.21 +1.30 x 10-15 +0.01




Allan Deviation
Averaging Period ()
(hours, minutes)		 Samples Frequency
Stability
0 h, 10 min 142 3.24 x 10-12
0 h, 20 min 140 1.91 x 10-12
0 h, 40 min 136 1.13 x 10-12
1 h, 20 min 128 8.12 x 10-13
2 h, 40 min 112 3.94 x 10-13
5 h, 20 min 80 2.55 x 10-13


Time Deviation
Averaging Period ()
(hours, minutes)		 Samples Time
Stability (ns)
0 h, 10 min 142 1.12
0 h, 20 min 139 1.01
0 h, 40 min 133 1.01
1 h, 20 min 121 1.57
2 h, 40 min 97 1.53
5 h, 20 min 49 3.34


SIMT(NIST) - SIMT(ICE)
(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
1 410 220 26.52 2.30 +6.04 x 10-13 +0.91 View
2 350 350 12.08 2.68 -1.67 x 10-13 -0.31 View
3 380 200 21.55 1.38 +1.81 x 10-13 +0.31 View
4 370 240 9.65 2.17 -2.72 x 10-13 -0.45 View
5 320 320 18.13 1.91 -4.80 x 10-13 -0.59 View
6 320 300 15.96 3.19 -2.99 x 10-13 -0.43 View
7 390 220 13.06 1.97 +4.34 x 10-13 +0.71 View
8 380 150 11.98 2.49 +9.85 x 10-13 +0.75 View
9 330 220 8.99 1.83 +2.19 x 10-13 +0.34 View
10 340 310 16.35 2.74 -3.24 x 10-13 -0.39 View
11 --- --- ---------- ------- -------------- ------ ----
12 300 150 10.38 2.03 -8.24 x 10-13 -0.76 View
13 340 190 9.50 1.74 -3.45 x 10-13 -0.43 View
14 380 360 15.23 2.19 +4.12 x 10-13 +0.69 View
15 320 190 7.62 1.87 +3.29 x 10-13 +0.63 View
16 380 240 16.74 1.56 +7.40 x 10-13 +0.83 View
17 350 270 13.85 3.22 -8.47 x 10-14 -0.15 View
18 390 220 27.03 2.13 -1.38 x 10-12 -0.92 View
19 350 240 21.13 2.59 -3.22 x 10-13 -0.37 View
20 340 260 10.53 2.39 +1.66 x 10-13 +0.33 View
21 370 190 25.06 2.52 -2.33 x 10-14 -0.11 View
22 330 180 16.63 1.78 -1.49 x 10-12 -0.94 View
23 370 330 17.70 1.92 -3.35 x 10-13 -0.48 View
24 420 260 19.60 2.33 -1.45 x 10-13 -0.43 View
25 360 170 18.15 2.21 -1.94 x 10-13 -0.56 View
26 360 230 18.07 3.02 +6.73 x 10-14 +0.29 View
27 410 190 19.13 2.22 +1.28 x 10-12 +0.89 View
28 --- --- ---------- ------- -------------- ------ ----
29 330 170 18.32 1.39 -1.14 x 10-12 -0.88 View
30 320 160 16.15 1.04 +7.67 x 10-13 +0.84 View
31 320 280 30.87 2.75 -2.59 x 10-14 -0.12 View
32 320 320 19.25 3.60 +5.13 x 10-14 +0.30 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.