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 60817. 1.763 0.312 -1.999
aji 60818. 1.869 1.821 -2.130
aji 60819. 2.044 3.461 -2.107
aji 60820. 1.721 5.345 -1.895
Ajisai SGF - DGF
aji 60817. 0.071 3.081 -0.555
aji 60818. 0.418 7.239 -1.266
aji 60819. 0.526 11.776 -1.760
aji 60820. -0.741 16.995 -1.507
aji 60821. 1.313 26.162 -3.471
Ajisai ITT - DGF
aji 60817. -1.692 2.769 1.445
aji 60818. -1.450 5.418 0.864
aji 60819. -1.518 8.315 0.347
aji 60820. -2.335 11.729 0.329
Beacon-C SGF - ITT
bec 60817. -2.663 -67.586 1.908
bec 60818. 5.359 -134.017 -2.678
bec 60819. -12.949 -226.894 15.290
bec 60820. -17.648 -335.126 15.258
Etalon-1 SGF - ITT
eta 60817. 9.992 4.828 -40.775
eta 60818. 6.865 13.451 -53.081
eta 60819. 0.775 23.666 -74.859
eta 60820. -0.296 3.033 -84.839
Etalon-1 SGF - DGF
eta 60817. -0.039 -0.061 0.170
eta 60818. -0.087 -0.090 0.231
eta 60819. -0.084 -0.207 0.305
eta 60820. 0.025 -0.264 0.379
eta 60821. -0.003 -0.170 0.397
Etalon-1 ITT - DGF
eta 60817. -10.032 -4.890 40.945
eta 60818. -6.952 -13.542 53.311
eta 60819. -0.859 -23.873 75.165
eta 60820. 0.246 -3.233 85.122
Etalon-2 SGF - ITT
etb 60817. 8.824 19.086 53.702
etb 60818. 6.123 -15.343 36.430
etb 60819. 2.715 -18.100 34.654
etb 60820. -9.137 -28.767 32.334
Etalon-2 SGF - DGF
etb 60817. -0.042 0.046 -0.010
etb 60818. -0.096 -0.037 -0.029
etb 60819. -0.148 -0.164 -0.012
etb 60820. -0.079 -0.320 -0.012
etb 60821. 0.088 -0.373 -0.036
Etalon-2 ITT - DGF
etb 60817. -8.866 -19.041 -53.712
etb 60818. -6.219 15.306 -36.459
etb 60819. -2.863 17.936 -34.666
etb 60820. 9.058 28.447 -32.347
Larets SGF - ITT
lar 60817. 2.581 -0.393 0.356
lar 60818. 2.628 2.487 1.146
lar 60819. 1.248 4.850 2.749
lar 60820. 3.108 10.372 2.167
Larets SGF - DGF
lar 60817. 0.935 -4.241 -1.272
lar 60818. 1.721 -9.086 -1.749
lar 60819. 3.954 -14.108 -3.910
lar 60820. 2.721 -26.859 -2.565
lar 60821. 7.866 -35.730 -6.061
Larets ITT - DGF
lar 60817. -1.646 -3.848 -1.628
lar 60818. -0.907 -11.573 -2.895
lar 60819. 2.706 -18.958 -6.660
lar 60820. -0.386 -37.230 -4.733
LARES SGF - ITT
las 60817. 3.292 0.474 -2.396
las 60818. 3.390 0.932 -2.397
las 60819. 3.840 2.070 -2.823
las 60820. 4.252 2.821 -3.205
LARES SGF - DGF
las 60817. 0.016 0.260 0.085
las 60818. 0.059 0.275 0.120
las 60819. 0.085 0.268 0.088
las 60820. 0.054 0.261 0.227
las 60821. 0.080 0.314 0.170
LARES ITT - DGF
las 60817. -3.276 -0.214 2.481
las 60818. -3.331 -0.658 2.517
las 60819. -3.755 -1.802 2.911
las 60820. -4.197 -2.560 3.432
LARES-2 SGF - DGF
la2 60817. -0.010 0.046 -0.008
la2 60818. -0.012 0.036 0.015
la2 60819. -0.014 0.041 0.013
la2 60820. -0.034 0.017 0.002
la2 60821. -0.021 0.038 0.079
LAGEOS-1 SGF - ITT
lga 60817. 4.675 -0.287 -0.835
lga 60818. 3.634 1.277 -1.598
lga 60819. 4.226 4.452 0.556
lga 60820. 6.308 4.590 -1.931
LAGEOS-1 SGF - DGF
lga 60817. 0.002 -0.187 -0.003
lga 60818. -0.019 -0.232 -0.004
lga 60819. -0.031 -0.351 -0.033
lga 60820. -0.043 -0.327 -0.031
lga 60821. -0.011 -0.426 -0.041
LAGEOS-2 SGF - ITT
lgb 60817. 3.626 -5.060 -2.868
lgb 60818. 4.700 -10.231 -2.038
lgb 60819. 4.045 -13.436 -2.378
lgb 60820. 3.495 -20.290 -5.160
LAGEOS-2 SGF - DGF
lgb 60817. 0.021 -0.015 -0.041
lgb 60818. 0.024 -0.172 -0.006
lgb 60819. 0.011 -0.240 0.018
lgb 60820. 0.026 -0.540 -0.003
lgb 60821. 0.087 -0.769 -0.049
Stella SGF - ITT
ste 60817. 3.866 1.327 -2.146
ste 60818. 3.514 3.189 -1.864
ste 60819. 3.693 5.098 -1.816
ste 60820. 3.726 8.220 -1.898
Stella SGF - DGF
ste 60817. 0.235 0.002 -0.302
ste 60818. 0.429 1.173 -0.633
ste 60819. 0.487 2.832 -0.701
ste 60820. 1.043 3.683 -1.353
ste 60821. 0.553 5.934 -1.022
Stella ITT - DGF
ste 60817. -3.631 -1.324 1.843
ste 60818. -3.085 -2.015 1.231
ste 60819. -3.205 -2.267 1.115
ste 60820. -3.485 -3.638 1.220
Starlette SGF - ITT
str 60817. 1.449 1.099 -2.047
str 60818. 1.222 1.204 -2.012
str 60819. 1.335 3.203 -1.921
str 60820. 1.220 5.180 -1.702
Starlette SGF - DGF
str 60817. -0.125 0.963 0.028
str 60818. -0.251 2.124 0.144
str 60819. -0.405 3.879 0.264
str 60820. -0.899 6.578 0.608
str 60821. -0.537 9.975 0.861
Starlette ITT - DGF
str 60817. -1.574 -0.136 2.075
str 60818. -1.473 0.919 2.156
str 60819. -1.740 0.676 2.186
str 60820. -1.689 1.297 2.307