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 59274. 1.284 -0.305 -0.968
aji 59275. 1.482 -1.405 -1.403
aji 59276. 1.211 -2.022 -0.799
aji 59277. 1.360 -3.905 -1.003
Ajisai ITT - JAX
Ajisai JAX - SGF
Beacon-C SGF - ITT
bec 59274. -0.138 -2.896 -1.525
bec 59275. -1.610 -8.647 -1.222
bec 59276. -1.865 -20.328 -1.437
bec 59277. -1.451 -37.884 -2.966
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 59274. 4.639 2.281 -2.185
eta 59275. 3.920 2.228 -0.450
eta 59276. 3.077 2.489 0.229
Etalon-1 SGF - DGF
eta 59274. 0.019 0.533 -0.322
eta 59275. -0.040 0.388 -0.554
eta 59276. 0.034 0.444 -0.805
Etalon-1 ITT - DGF
eta 59274. -4.620 -1.748 1.863
eta 59275. -3.960 -1.840 -0.105
eta 59276. -3.068 -1.774 -1.302
eta 59277. -3.262 -2.277 -1.424
Etalon-2 SGF - ITT
etb 59274. 4.836 0.634 -2.051
etb 59275. 5.238 1.338 -2.367
etb 59276. 5.020 2.484 -2.506
Etalon-2 SGF - DGF
etb 59274. 0.066 -0.019 0.032
etb 59275. 0.153 0.003 -0.001
etb 59276. 0.145 0.062 0.034
Etalon-2 ITT - DGF
etb 59274. -4.770 -0.653 2.083
etb 59275. -5.085 -1.335 2.367
etb 59276. -4.875 -2.423 2.540
etb 59277. -4.102 -3.200 2.324
Larets SGF - ITT
lar 59274. 1.516 -2.765 -1.781
lar 59275. 2.192 -3.703 -2.506
lar 59276. 1.369 -4.561 -2.164
lar 59277. 2.575 -5.007 -3.223
LARES SGF - ITT
las 59274. 0.951 -1.297 -0.050
las 59275. 1.279 -2.417 -0.144
las 59276. 0.676 -3.543 0.241
las 59277. 1.322 -5.643 -0.250
LAGEOS-1 SGF - ITT
lga 59274. 2.430 0.249 -0.584
lga 59275. 2.959 0.180 -1.059
lga 59276. 2.855 0.597 -0.988
lga 59277. 2.606 0.243 -0.590
LAGEOS-1 ITT - JAX
LAGEOS-1 JAX - SGF
LAGEOS-1 SGF - DGF
lga 59274. 0.005 -0.054 0.034
lga 59275. -0.012 -0.070 0.053
lga 59276. -0.020 -0.104 0.062
lga 59277. 0.009 -0.114 0.070
LAGEOS-2 SGF - ITT
lgb 59274. 1.615 0.742 -1.105
lgb 59275. 1.952 0.824 -1.433
lgb 59276. 1.506 0.121 -1.415
lgb 59277. 2.068 0.351 -1.525
LAGEOS-2 ITT - JAX
LAGEOS-2 JAX - SGF
LAGEOS-2 SGF - DGF
lgb 59274. -0.001 -0.011 0.095
lgb 59275. 0.096 -0.108 -0.002
lgb 59276. -0.024 -0.550 0.070
lgb 59277. 0.179 -0.636 -0.016
Stella SGF - ITT
ste 59274. 1.672 -0.291 -1.506
ste 59275. 1.367 -1.234 -1.385
ste 59276. 1.127 -3.409 -1.278
ste 59277. 1.604 -5.013 -1.843
Starlette SGF - ITT
str 59274. 1.214 -1.038 -2.279
str 59275. 1.183 -3.291 -2.457
str 59276. 2.022 -5.863 -3.452
str 59277. 0.440 -10.010 -1.828