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 58534. 1.066 0.927 -0.899
aji 58535. 1.190 0.059 -0.875
aji 58536. 1.163 -0.630 -1.008
aji 58537. 1.099 -1.643 -1.065
Ajisai ITT - JAX
aji 58534. -1.128 -1.383 0.926
aji 58535. -1.241 -0.646 0.869
aji 58536. -1.229 -0.110 0.999
Ajisai JAX - SGF
aji 58534. 0.063 0.457 -0.027
aji 58535. 0.051 0.587 0.007
aji 58536. 0.066 0.740 0.009
Beacon-C SGF - ITT
bec 58534. -0.477 21.123 -8.107
bec 58535. -1.753 50.573 -17.264
bec 58536. -7.223 96.413 -28.115
bec 58537. -17.175 162.031 -39.835
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 58534. 3.639 3.477 -0.751
eta 58535. 3.188 4.902 -1.985
eta 58536. 3.869 5.962 -1.624
Etalon-2 SGF - ITT
etb 58534. 2.738 4.494 -1.771
etb 58535. 6.643 5.483 -0.979
etb 58536. 5.675 8.638 -2.235
Jason-2 SGF - ITT
Jason-2 ITT - CNES
jsb 58534. 0.697 7.084 -2.473
jsb 58535. 2.411 24.652 -3.472
jsb 58536. 0.684 53.067 -1.761
jsb 58537. 3.039 89.150 -1.868
Jason-2 CNES - SGF
Larets SGF - ITT
lar 58534. 0.732 2.423 -0.547
lar 58535. 0.718 3.991 -0.216
lar 58536. -0.324 5.552 0.164
LARES SGF - ITT
las 58534. 1.697 1.329 -1.182
las 58535. 1.591 1.831 -1.507
las 58536. 1.906 2.950 -2.036
las 58537. 1.802 3.726 -2.513
LAGEOS-1 SGF - ITT
lga 58534. 1.740 2.781 -0.230
lga 58535. 2.057 3.333 -0.074
lga 58536. 1.760 3.735 -0.117
lga 58537. 1.953 4.921 -0.194
LAGEOS-1 ITT - JAX
lga 58534. -1.836 -2.644 0.252
lga 58535. -2.049 -3.104 -0.030
lga 58536. -2.031 -3.481 -0.009
LAGEOS-1 JAX - SGF
lga 58534. 0.096 -0.137 -0.022
lga 58535. -0.008 -0.229 0.104
lga 58536. 0.069 -0.229 0.118
LAGEOS-2 SGF - ITT
lgb 58534. 1.459 3.143 -0.544
lgb 58535. 1.258 4.622 -1.121
lgb 58536. 1.377 5.113 -0.641
LAGEOS-2 ITT - JAX
lgb 58534. -1.479 -2.960 0.489
lgb 58535. -1.247 -4.269 1.128
lgb 58536. -1.432 -4.662 0.570
LAGEOS-2 JAX - SGF
lgb 58534. 0.020 -0.183 0.055
lgb 58535. -0.011 -0.353 -0.008
lgb 58536. 0.055 -0.450 0.072
Stella SGF - ITT
ste 58534. 0.536 0.514 0.128
ste 58535. 0.444 -1.155 0.143
ste 58536. 0.727 -2.262 -0.190
Starlette SGF - ITT