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 58465. 3.764 -2.085 -4.368
aji 58466. 3.034 -5.249 -4.039
aji 58467. 3.800 -8.816 -4.114
aji 58468. 4.222 -13.099 -4.873
Ajisai ITT - JAX
aji 58465. -3.711 1.371 4.315
aji 58466. -3.016 4.186 3.939
aji 58467. -3.702 7.373 3.988
Ajisai JAX - SGF
aji 58465. -0.053 0.714 0.054
aji 58466. -0.018 1.062 0.100
aji 58467. -0.097 1.443 0.126
Beacon-C SGF - ITT
bec 58465. 0.435 -25.709 -7.797
bec 58466. 1.005 -44.977 -13.662
bec 58467. -0.909 -60.227 -20.616
bec 58468. -4.819 -65.053 -26.522
Cyrosat-2 ESA - ITT
cyb 58465. 251.847 -15.723 -193.461
cyb 58466. 315.262 216.717 -256.147
cyb 58467. 338.994 518.779 -276.124
Etalon-1 SGF - ITT
eta 58465. 9.977 8.523 -6.941
eta 58466. 9.732 10.617 -9.213
eta 58467. 8.674 12.700 -10.908
eta 58468. 8.971 15.925 -12.673
Etalon-2 SGF - ITT
etb 58465. 8.058 7.793 -10.964
etb 58466. 8.390 6.341 -9.947
etb 58467. 9.215 8.977 -13.483
etb 58468. 11.521 10.273 -17.083
Jason-2 SGF - ITT
jsb 58465. 4.302 -5.971 -4.098
jsb 58466. 3.941 -9.830 -5.630
jsb 58467. 4.244 -13.146 -7.779
Jason-2 ITT - CNES
jsb 58465. -3.143 6.281 1.221
jsb 58466. -2.651 11.801 1.769
jsb 58467. -3.050 17.749 2.896
Jason-2 CNES - SGF
jsb 58465. -1.159 -0.310 2.877
jsb 58466. -1.291 -1.971 3.860
jsb 58467. -1.193 -4.603 4.884
jsb 58468. -1.069 -7.931 6.086
Larets SGF - ITT
lar 58465. 2.874 1.143 0.468
lar 58466. 2.770 1.245 0.908
lar 58467. 2.881 0.785 1.142
lar 58468. 2.849 0.036 1.136
LARES SGF - ITT
las 58465. 4.898 3.113 -4.055
las 58466. 5.021 3.712 -5.523
las 58467. 5.313 4.249 -6.232
LAGEOS-1 SGF - ITT
lga 58465. 5.830 4.340 -2.450
lga 58466. 5.812 5.094 -3.260
lga 58467. 5.334 6.256 -3.864
lga 58468. 6.853 8.546 -5.268
LAGEOS-1 ITT - JAX
lga 58465. -5.919 -4.496 2.560
lga 58466. -5.840 -5.269 3.372
lga 58467. -5.366 -6.523 3.872
LAGEOS-1 JAX - SGF
lga 58465. 0.090 0.156 -0.111
lga 58466. 0.028 0.175 -0.112
lga 58467. 0.031 0.266 -0.008
LAGEOS-2 SGF - ITT
lgb 58465. 5.821 19.619 -0.431
lgb 58466. 4.036 24.955 1.204
lgb 58467. 8.779 36.091 -0.999
LAGEOS-2 ITT - JAX
lgb 58465. -5.893 -20.989 0.661
lgb 58466. -3.951 -26.611 -1.042
lgb 58467. -9.027 -38.429 1.411
LAGEOS-2 JAX - SGF
lgb 58465. 0.072 1.370 -0.230
lgb 58466. -0.084 1.656 -0.162
lgb 58467. 0.248 2.338 -0.411
Stella SGF - ITT
ste 58465. 2.215 -3.405 -0.095
ste 58466. 2.000 -5.856 0.706
ste 58467. 1.037 -9.888 1.539
Starlette SGF - ITT
str 58465. 3.304 0.907 -2.095
str 58466. 3.513 3.367 -1.783
str 58467. 3.806 7.986 -1.830