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 58865. 1.875 0.181 -1.789
aji 58866. 1.885 -0.762 -1.764
aji 58867. 1.869 -2.247 -1.565
aji 58868. 1.663 -3.600 -1.278
Ajisai ITT - JAX
aji 58865. -1.902 -0.478 1.871
aji 58866. -1.913 0.409 1.807
aji 58867. -1.924 1.825 1.618
Ajisai JAX - SGF
aji 58865. 0.027 0.297 -0.082
aji 58866. 0.028 0.353 -0.043
aji 58867. 0.055 0.421 -0.053
Beacon-C SGF - ITT
bec 58865. 0.325 -5.223 -2.113
bec 58866. -1.221 -11.018 -1.340
bec 58867. -1.783 -22.092 -2.027
bec 58868. -1.485 -35.644 -2.646
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 58865. -22.615 24.176 -131.925
eta 58866. 35.144 84.253 -126.474
eta 58867. 48.158 118.219 -133.092
eta 58868. 69.797 153.753 -137.344
Etalon-2 SGF - ITT
etb 58865. -1.213 14.440 -1.022
etb 58866. 0.647 15.599 -4.755
etb 58867. 5.615 18.570 -9.653
etb 58868. 12.679 26.493 -13.483
Jason-2 SGF - ITT
Jason-2 ITT - CNES
Jason-2 CNES - SGF
Larets SGF - ITT
lar 58865. 2.187 1.055 -1.465
lar 58866. 2.464 0.301 -2.059
lar 58867. 2.342 -0.808 -2.188
lar 58868. 3.121 -2.047 -3.438
LARES SGF - ITT
las 58865. 1.325 1.146 -0.532
las 58866. 1.234 0.988 -0.927
las 58867. 1.306 0.210 -1.388
las 58868. 1.331 -0.343 -1.923
LAGEOS-1 SGF - ITT
lga 58865. 2.605 3.458 -1.093
lga 58866. 2.691 3.397 -1.840
lga 58867. 2.647 3.898 -1.674
lga 58868. 2.379 3.886 -2.137
LAGEOS-1 ITT - JAX
lga 58865. -2.645 -3.534 1.098
lga 58866. -2.690 -3.585 1.797
lga 58867. -2.678 -3.980 1.935
LAGEOS-1 JAX - SGF
lga 58865. 0.040 0.076 -0.004
lga 58866. -0.001 0.188 0.043
lga 58867. -0.040 0.273 0.014
LAGEOS-2 SGF - ITT
lgb 58865. 1.662 -1.004 -1.623
lgb 58866. 3.101 -2.989 -3.564
lgb 58867. 0.523 -6.118 -1.562
lgb 58868. 3.949 -8.865 -3.973
LAGEOS-2 ITT - JAX
lgb 58865. -1.659 1.105 1.477
lgb 58866. -3.139 3.172 3.399
lgb 58867. -0.580 6.394 2.340
LAGEOS-2 JAX - SGF
lgb 58865. -0.004 -0.101 0.146
lgb 58866. 0.038 -0.184 0.165
lgb 58867. -0.047 -0.374 0.201
Stella SGF - ITT
ste 58865. 1.345 1.691 -0.637
ste 58866. 1.004 0.693 -0.442
ste 58867. 0.809 -0.978 -0.470
ste 58868. 0.491 -3.708 -0.329
Starlette SGF - ITT
str 58865. 1.665 -0.833 -3.520
str 58866. 1.452 -2.919 -3.168
str 58867. 1.445 -6.301 -3.842
str 58868. 1.403 -11.718 -4.313