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 58941. 1.236 2.295 -0.856
aji 58942. 1.121 4.323 -0.817
aji 58943. 1.038 7.028 -0.829
aji 58944. 1.423 9.644 -1.052
Ajisai ITT - JAX
aji 58941. -1.165 -1.716 0.965
aji 58942. -1.081 -3.061 0.986
aji 58943. -1.024 -5.031 1.051
Ajisai JAX - SGF
aji 58941. -0.070 -0.579 -0.109
aji 58942. -0.041 -1.262 -0.170
aji 58943. -0.015 -1.996 -0.222
Beacon-C SGF - ITT
bec 58941. 1.309 -16.254 -5.533
bec 58942. 0.769 -16.374 -8.530
bec 58943. 0.724 -7.442 -13.847
bec 58944. 0.623 12.347 -22.183
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 58941. 18.438 -16.610 5.246
eta 58942. 19.717 29.673 -23.322
eta 58943. 10.381 46.137 -28.408
eta 58944. -2.905 45.492 -29.118
Etalon-2 SGF - ITT
etb 58941. 19.434 10.859 -75.490
etb 58942. 29.402 9.374 -89.275
etb 58943. 39.976 25.501 -96.946
etb 58944. 32.296 46.415 -85.444
Jason-2 SGF - ITT
Jason-2 ITT - CNES
Jason-2 CNES - SGF
Larets SGF - ITT
lar 58941. -7.395 -0.797 -0.106
lar 58942. -8.079 -4.483 -1.800
lar 58943. -8.651 -12.510 -3.210
lar 58944. -11.896 -13.115 -4.264
LARES SGF - ITT
las 58941. 1.722 -0.022 -0.818
las 58942. 1.866 -0.032 -1.220
las 58943. 1.933 -0.283 -1.457
las 58944. 2.061 -0.626 -1.913
LAGEOS-1 SGF - ITT
lga 58941. 2.711 1.898 0.283
lga 58942. 2.850 2.849 0.407
lga 58943. 4.281 2.956 0.074
lga 58944. 2.442 7.204 0.925
LAGEOS-1 ITT - JAX
lga 58941. -2.727 -1.778 -0.331
lga 58942. -2.854 -2.739 -0.466
lga 58943. -4.277 -2.835 -0.139
LAGEOS-1 JAX - SGF
lga 58941. 0.015 -0.120 0.048
lga 58942. 0.004 -0.110 0.059
lga 58943. -0.004 -0.121 0.064
LAGEOS-2 SGF - ITT
lgb 58941. 2.519 2.969 -1.824
lgb 58942. 1.672 4.985 -1.831
lgb 58943. 2.733 6.152 -2.184
lgb 58944. 1.975 9.906 -2.489
LAGEOS-2 ITT - JAX
lgb 58941. -2.736 -4.344 2.139
lgb 58942. -1.625 -6.913 2.005
lgb 58943. -2.946 -8.270 2.550
LAGEOS-2 JAX - SGF
lgb 58941. 0.216 1.375 -0.315
lgb 58942. -0.048 1.928 -0.174
lgb 58943. 0.213 2.118 -0.365
Stella SGF - ITT
ste 58941. 1.235 -0.072 0.004
ste 58942. 1.008 -1.167 0.343
ste 58943. 0.789 -3.328 0.671
ste 58944. 1.132 -4.930 0.447
Starlette SGF - ITT
str 58941. 0.975 3.529 -2.266
str 58942. 1.115 6.037 -2.013
str 58943. 0.189 10.752 -1.707
str 58944. 1.386 16.447 -2.052