Satellite CPF Predictions
The ILRS network uses CPF orbit predictions provided by mission operators and analysis centres.
The SGF calculates precise satellite orbit predictions daily for most of the ILRS targets and makes these orbits available to other SLR stations internationally. These predictions can be compared in advance to those from other CPF providers so that stations and providers can be confident in their accuracy.
The Consolidated Prediction Format (CPF) is the official format used by the ILRS. It consists of geocentric X, Y, and Z positions at different epochs that can be interpolated for very accurate predictions. Accurate prediction of the positions of the full range of laser-tracked satellites is possible in a single, simple format.
The plots below compare the CPFs when there is more than one provider by taking the differences in metres between the orbital X, Y and Z values at zero hours for today and for the next three or four days.
Full residual plot comparisons are plotted here.
Difference between CPF Providers
JD X Y Z
Ajisai SGF - ITT
aji 60856. 2.050 -1.940 -4.250
aji 60857. 2.474 -3.702 -5.126
aji 60858. 2.101 -5.106 -4.906
aji 60859. 2.506 -8.358 -6.034
Ajisai SGF - DGF
Ajisai ITT - DGF
Beacon-C SGF - ITT
bec 60856. -3.734 -55.736 7.555
bec 60857. -7.179 -107.140 15.221
bec 60858. -6.655 -169.018 22.160
bec 60859. 0.185 -247.450 26.600
Etalon-1 SGF - ITT
eta 60856. -53.348 -5.157 -12.581
eta 60857. -63.685 -66.219 67.890
eta 60858. 17.624 -142.257 122.666
eta 60859. 15.040 -135.946 -111.664
Etalon-1 SGF - DGF
eta 60856. 0.056 -0.177 -0.008
eta 60857. 0.071 -0.288 0.028
eta 60858. 0.115 -0.376 0.171
eta 60859. 0.205 -0.335 0.345
eta 60860. 0.235 -0.321 0.446
Etalon-1 ITT - DGF
eta 60856. 53.404 4.979 12.572
eta 60857. 63.756 65.931 -67.862
eta 60858. -17.509 141.881 -122.495
eta 60859. -14.900 135.729 112.013
Etalon-2 SGF - ITT
etb 60856. 14.763 2.512 23.182
etb 60857. 22.839 12.211 28.316
etb 60858. 26.783 27.540 32.676
etb 60859. 20.640 44.116 36.144
Etalon-2 SGF - DGF
etb 60856. -0.056 -0.188 -0.368
etb 60857. -0.049 -0.301 -0.387
etb 60858. -0.076 -0.454 -0.399
etb 60859. -0.007 -0.802 -0.676
etb 60860. 0.111 -0.862 -0.478
Etalon-2 ITT - DGF
etb 60856. -14.819 -2.700 -23.550
etb 60857. -22.889 -12.513 -28.703
etb 60858. -26.860 -27.994 -33.075
etb 60859. -20.714 -44.792 -36.560
Larets SGF - ITT
lar 60856. 3.008 -1.628 -3.955
lar 60857. 2.485 0.296 -3.971
lar 60858. 2.654 4.633 -4.800
lar 60859. 1.100 6.028 -3.710
Larets SGF - DGF
Larets ITT - DGF
LARES SGF - ITT
las 60856. 4.476 -3.197 1.495
las 60857. 4.582 -4.358 2.146
las 60858. 4.721 -6.989 3.362
las 60859. 4.987 -8.864 3.968
LARES SGF - DGF
LARES ITT - DGF
LARES-2 SGF - DGF
LAGEOS-1 SGF - ITT
lga 60856. 6.378 -0.975 1.176
lga 60857. 6.839 -1.669 1.959
lga 60858. 6.589 -0.627 1.674
lga 60859. 6.157 -1.181 3.051
LAGEOS-1 SGF - DGF
LAGEOS-2 SGF - ITT
lgb 60856. 4.255 4.818 -6.542
lgb 60857. 2.278 9.315 -6.585
lgb 60858. 5.213 13.170 -8.694
lgb 60859. 0.573 17.812 -6.127
LAGEOS-2 SGF - DGF
lgb 60856. 0.040 0.021 -0.035
lgb 60857. 0.130 -0.170 -0.140
lgb 60858. 0.039 -0.320 -0.007
lgb 60859. 0.248 -0.631 -0.233
lgb 60860. -0.054 -0.941 -0.136
Stella SGF - ITT
ste 60856. 5.270 1.718 -2.681
ste 60857. 5.458 4.226 -2.901
ste 60858. 6.416 6.748 -3.362
ste 60859. 5.590 11.360 -2.736
Stella SGF - DGF
Stella ITT - DGF
Starlette SGF - ITT
str 60856. 0.869 -13.412 -0.749
str 60857. 1.104 -23.111 -0.855
str 60858. -0.779 -36.499 0.928
str 60859. 0.099 -53.754 0.879
Starlette SGF - DGF
Starlette ITT - DGF