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 59110. 3.530 -3.961 -4.678
aji 59111. 3.364 -6.643 -4.482
aji 59112. 3.372 -10.462 -4.515
aji 59113. 2.943 -16.101 -4.370
Ajisai ITT - JAX
aji 59110. -3.559 3.388 4.760
aji 59111. -3.435 5.497 4.620
aji 59112. -3.464 8.629 4.684
Ajisai JAX - SGF
aji 59110. 0.030 0.573 -0.083
aji 59111. 0.071 1.146 -0.138
aji 59112. 0.093 1.832 -0.169
Beacon-C SGF - ITT
bec 59110. 2.900 8.136 -5.522
bec 59111. 2.713 29.514 -5.893
bec 59112. 4.048 69.896 -0.446
bec 59113. -1.663 138.206 13.918
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 59110. 11.638 11.806 -6.252
eta 59111. 12.005 13.243 -0.392
eta 59112. 11.162 15.102 1.494
eta 59113. 9.566 16.958 2.887
Etalon-1 SGF - DGF
eta 59110. 0.049 0.245 -0.074
eta 59111. 0.036 0.188 0.141
eta 59112. 0.082 0.213 0.348
eta 59113. 0.085 0.285 0.542
Etalon-1 ITT - DGF
eta 59110. -11.589 -11.561 6.178
eta 59111. -11.969 -13.055 0.534
eta 59112. -11.080 -14.889 -1.146
eta 59113. -9.481 -16.673 -2.345
Etalon-2 SGF - ITT
etb 59110. 11.986 2.696 -1.830
etb 59111. 12.443 2.233 0.724
etb 59112. 13.142 0.837 2.334
etb 59113. 16.244 12.169 -0.640
Etalon-2 SGF - DGF
etb 59110. -0.008 0.126 0.030
etb 59111. -0.033 0.066 -0.067
etb 59112. -0.013 0.005 -0.168
etb 59113. 0.037 0.100 -0.291
Etalon-2 ITT - DGF
etb 59110. -11.994 -2.570 1.860
etb 59111. -12.476 -2.167 -0.791
etb 59112. -13.155 -0.832 -2.501
etb 59113. -16.219 -11.986 0.338
Larets SGF - ITT
lar 59110. 6.341 -3.051 -4.951
lar 59111. 5.944 -3.640 -5.789
lar 59112. 6.327 -3.863 -6.821
lar 59113. 6.973 -3.522 -8.151
LARES SGF - ITT
las 59110. 6.546 -3.806 -4.770
las 59111. 7.213 -9.102 -6.487
las 59112. 7.499 -14.271 -7.866
las 59113. 8.276 -21.799 -11.298
LAGEOS-1 SGF - ITT
lga 59110. 8.244 1.409 0.077
lga 59111. 8.679 1.066 0.069
lga 59112. 7.823 1.440 -1.630
lga 59113. 7.486 0.984 0.238
LAGEOS-1 ITT - JAX
lga 59110. -8.272 -1.392 -0.052
lga 59111. -8.658 -1.090 -0.043
lga 59112. -7.834 -1.494 1.603
LAGEOS-1 JAX - SGF
lga 59110. 0.028 -0.017 -0.024
lga 59111. -0.021 0.024 -0.027
lga 59112. 0.011 0.053 0.027
LAGEOS-1 SGF - DGF
lga 59110. 0.015 -0.036 -0.060
lga 59111. -0.028 -0.022 -0.079
lga 59112. 0.008 -0.040 -0.048
lga 59113. 0.032 -0.001 -0.154
lga 59114. -0.049 -0.025 -0.151
LAGEOS-2 SGF - ITT
lgb 59110. 5.609 -1.941 -4.573
lgb 59111. 6.678 -5.164 -5.693
lgb 59112. 4.751 -5.393 -3.827
lgb 59113. 6.855 -12.567 -6.911
LAGEOS-2 ITT - JAX
lgb 59110. -5.541 2.400 4.570
lgb 59111. -6.682 5.900 5.774
lgb 59112. -4.583 6.164 3.779
LAGEOS-2 JAX - SGF
lgb 59110. -0.068 -0.459 0.003
lgb 59111. 0.003 -0.736 -0.081
lgb 59112. -0.168 -0.771 0.049
LAGEOS-2 SGF - DGF
lgb 59110. 0.017 -0.039 0.028
lgb 59111. 0.018 0.076 0.018
lgb 59112. 0.055 0.163 0.016
lgb 59113. 0.009 0.366 0.033
lgb 59114. 0.092 0.406 0.016
Stella SGF - ITT
ste 59110. 6.869 3.415 -4.315
ste 59111. 7.574 7.060 -5.720
ste 59112. 7.600 12.088 -6.023
ste 59113. 7.836 15.608 -6.673
Starlette SGF - ITT
str 59110. 2.979 -0.703 -3.827
str 59111. 2.809 -1.388 -3.682
str 59112. 2.707 -1.579 -3.667
str 59113. 2.716 -2.124 -3.649