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 58827. 2.609 1.774 -3.333
aji 58828. 2.764 1.068 -3.775
aji 58829. 2.435 0.400 -3.159
aji 58830. 2.756 -0.806 -4.076
Ajisai ITT - JAX
aji 58827. -2.604 -0.957 3.091
aji 58828. -2.870 0.608 3.566
aji 58829. -2.727 2.411 3.400
Ajisai JAX - SGF
aji 58827. -0.006 -0.817 0.242
aji 58828. 0.106 -1.676 0.209
aji 58829. 0.016 -2.633 0.261
Beacon-C SGF - ITT
bec 58827. 1.824 -1.793 -4.056
bec 58828. 2.367 -7.304 -4.482
bec 58829. 2.598 -16.397 -4.132
bec 58830. 1.909 -30.854 -2.828
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 58827. 8.317 7.008 0.035
eta 58828. 7.381 6.387 -0.860
eta 58829. 7.125 6.435 -1.229
eta 58830. 6.870 6.608 -1.976
Etalon-2 SGF - ITT
etb 58827. 10.859 131.284 -2.595
etb 58828. 15.159 141.205 -20.928
etb 58829. 56.674 160.445 -0.717
etb 58830. 5.323 166.470 -66.192
Jason-2 SGF - ITT
Jason-2 ITT - CNES
Jason-2 CNES - SGF
Larets SGF - ITT
lar 58827. 2.908 1.933 -0.765
lar 58828. 2.672 1.070 -0.710
lar 58829. 2.584 -0.069 -0.754
lar 58830. 2.269 -1.637 -0.534
LARES SGF - ITT
las 58827. 3.390 2.639 -2.510
las 58828. 3.579 2.007 -2.949
las 58829. 3.906 0.996 -3.933
las 58830. 3.692 -0.012 -4.308
LAGEOS-1 SGF - ITT
lga 58827. 4.408 4.736 -0.398
lga 58828. 4.102 5.461 -0.458
lga 58829. 4.754 6.442 0.159
lga 58830. 3.786 7.123 0.658
LAGEOS-1 ITT - JAX
lga 58827. -4.428 -4.694 0.393
lga 58828. -4.117 -5.406 0.415
lga 58829. -4.726 -6.358 -0.181
LAGEOS-1 JAX - SGF
lga 58827. 0.020 -0.042 0.006
lga 58828. 0.014 -0.055 0.043
lga 58829. -0.028 -0.084 0.022
LAGEOS-2 SGF - ITT
lgb 58827. 3.666 0.767 -2.504
lgb 58828. 4.393 -0.025 -3.463
lgb 58829. 3.318 -3.557 -2.219
lgb 58830. 5.013 -4.035 -3.780
LAGEOS-2 ITT - JAX
lgb 58827. -3.604 -1.334 2.433
lgb 58828. -4.204 -0.624 3.290
lgb 58829. -3.278 2.318 2.633
LAGEOS-2 JAX - SGF
lgb 58827. -0.062 0.567 0.071
lgb 58828. -0.188 0.649 0.173
lgb 58829. 0.038 1.126 0.095
Stella SGF - ITT
ste 58827. 3.147 3.476 -1.322
ste 58828. 3.399 4.792 -1.639
ste 58829. 3.542 6.125 -1.610
ste 58830. 3.472 7.906 -1.824
Starlette SGF - ITT
str 58827. 2.119 0.936 -2.668
str 58828. 2.149 0.876 -2.914
str 58829. 2.045 0.219 -2.927
str 58830. 2.167 0.699 -2.988