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 59045. 4.073 1.407 -3.140
aji 59046. 4.277 2.892 -3.032
aji 59047. 4.439 4.809 -2.927
aji 59048. 4.367 6.849 -2.583
Ajisai ITT - JAX
aji 59045. -3.958 -0.833 2.868
aji 59046. -4.155 -1.262 2.626
aji 59047. -4.311 -1.837 2.475
Ajisai JAX - SGF
aji 59045. -0.115 -0.573 0.272
aji 59046. -0.122 -1.630 0.406
aji 59047. -0.128 -2.972 0.451
Beacon-C SGF - ITT
bec 59045. 2.357 2.465 -0.772
bec 59046. 1.562 9.423 0.955
bec 59047. 2.052 21.217 1.930
bec 59048. 4.544 40.010 3.754
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 59045. 13.039 -1.778 3.551
eta 59046. 14.733 0.368 6.172
eta 59047. 14.999 3.544 4.811
eta 59048. 13.964 -0.686 5.773
Etalon-2 SGF - ITT
etb 59045. 10.145 -6.459 -1.885
etb 59046. 10.697 -11.210 -6.441
etb 59047. 10.965 -13.470 -7.545
etb 59048. 12.831 -15.583 -7.313
Jason-2 SGF - ITT
Jason-2 ITT - CNES
Jason-2 CNES - SGF
Larets SGF - ITT
lar 59045. 4.677 -2.925 -0.809
lar 59046. 4.798 -4.094 -0.656
lar 59047. 4.775 -4.731 -0.540
lar 59048. 5.518 -5.982 -1.006
LARES SGF - ITT
las 59045. 5.732 1.940 0.137
las 59046. 5.896 4.476 1.922
las 59047. 6.353 8.503 3.778
las 59048. 6.275 11.845 6.695
LAGEOS-1 SGF - ITT
lga 59045. 7.935 -1.102 -0.195
lga 59046. 8.501 -0.376 -0.768
lga 59047. 7.084 0.500 1.118
lga 59048. 9.434 2.557 -0.588
LAGEOS-1 ITT - JAX
lga 59045. -7.935 1.148 0.253
lga 59046. -8.504 0.412 0.836
lga 59047. -7.096 -0.476 -1.034
LAGEOS-1 JAX - SGF
lga 59045. 0.000 -0.047 -0.059
lga 59046. 0.003 -0.036 -0.069
lga 59047. 0.011 -0.024 -0.084
LAGEOS-2 SGF - ITT
lgb 59045. 5.817 -0.176 -4.722
lgb 59046. 5.849 -1.062 -5.071
lgb 59047. 6.013 -1.440 -4.755
lgb 59048. 5.979 -2.366 -5.364
LAGEOS-2 ITT - JAX
lgb 59045. -5.652 -0.538 4.700
lgb 59046. -5.941 -0.191 5.080
lgb 59047. -5.717 -0.053 4.749
LAGEOS-2 JAX - SGF
lgb 59045. -0.164 0.714 0.022
lgb 59046. 0.091 1.254 -0.010
lgb 59047. -0.296 1.493 0.007
Stella SGF - ITT
ste 59045. 5.766 0.950 -2.116
ste 59046. 6.150 3.320 -1.941
ste 59047. 6.413 6.788 -1.741
ste 59048. 6.523 11.032 -1.896
Starlette SGF - ITT
str 59045. 3.054 3.096 -4.113
str 59046. 3.031 6.113 -4.120
str 59047. 3.351 11.072 -4.654
str 59048. 2.723 17.563 -4.451