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 58902. 0.678 0.528 -0.741
aji 58903. 0.964 0.227 -0.933
aji 58904. 0.715 -0.759 -0.741
aji 58905. 0.893 -1.918 -0.651
Ajisai ITT - JAX
aji 58902. -0.754 -0.353 0.987
aji 58903. -1.023 -0.155 1.243
aji 58904. -0.980 0.474 1.243
Ajisai JAX - SGF
aji 58902. 0.076 -0.175 -0.246
aji 58903. 0.059 -0.071 -0.310
aji 58904. 0.010 0.086 -0.340
Beacon-C SGF - ITT
bec 58902. 0.843 -2.111 -0.008
bec 58903. 1.575 -2.944 0.756
bec 58904. 1.740 -3.487 1.218
bec 58905. 2.026 -2.239 1.317
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 58902. 1.776 4.678 -1.128
eta 58903. 1.073 3.805 -0.631
eta 58904. 2.147 4.707 -0.692
Etalon-2 SGF - ITT
etb 58902. 2.168 3.778 -0.877
etb 58903. 3.665 4.373 -1.848
etb 58904. 3.746 5.911 -1.802
Jason-2 SGF - ITT
Jason-2 ITT - CNES
Jason-2 CNES - SGF
Larets SGF - ITT
lar 58902. 0.927 -0.022 0.926
lar 58903. 0.828 0.061 1.443
lar 58904. 0.763 0.199 1.923
lar 58905. 0.472 0.644 2.681
LARES SGF - ITT
las 58902. 1.018 -0.066 0.141
las 58903. 1.098 -0.879 0.027
las 58904. 1.058 -1.720 -0.059
las 58905. 1.154 -3.376 -0.336
LAGEOS-1 SGF - ITT
lga 58902. 1.416 2.206 0.706
lga 58903. 1.603 2.780 1.081
lga 58904. 1.529 3.305 1.347
lga 58905. 1.241 3.659 1.360
LAGEOS-1 ITT - JAX
lga 58902. -1.424 -1.991 -0.621
lga 58903. -1.609 -2.491 -1.023
lga 58904. -1.451 -3.049 -1.282
LAGEOS-1 JAX - SGF
lga 58902. 0.009 -0.216 -0.084
lga 58903. 0.005 -0.289 -0.058
lga 58904. -0.078 -0.256 -0.065
LAGEOS-2 SGF - ITT
lgb 58902. 1.059 1.333 -0.728
lgb 58903. 1.268 1.594 0.350
lgb 58904. 0.981 1.399 -0.520
lgb 58905. 1.004 1.040 -0.865
LAGEOS-2 ITT - JAX
lgb 58902. -0.988 -2.347 0.893
lgb 58903. -1.587 -2.863 0.059
lgb 58904. -0.881 -3.372 0.684
LAGEOS-2 JAX - SGF
lgb 58902. -0.070 1.015 -0.165
lgb 58903. 0.318 1.269 -0.409
lgb 58904. -0.100 1.974 -0.164
Stella SGF - ITT
ste 58902. 0.878 0.256 0.157
ste 58903. 1.222 -0.059 -0.073
ste 58904. 1.272 0.367 -0.156
ste 58905. 1.305 0.839 -0.211
Starlette SGF - ITT
str 58902. 0.756 -0.162 -1.911
str 58903. 0.839 -0.353 -1.984
str 58904. 0.639 -0.188 -2.025
str 58905. 0.617 -0.259 -1.889