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 59177. 3.260 2.609 -4.253
aji 59178. 3.333 3.043 -4.052
aji 59179. 3.343 3.514 -3.693
aji 59180. 3.396 4.050 -3.913
Ajisai ITT - JAX
aji 59177. -3.295 -1.538 4.025
aji 59178. -3.503 -1.465 3.894
aji 59179. -3.218 -0.969 3.201
Ajisai JAX - SGF
aji 59177. 0.035 -1.070 0.228
aji 59178. 0.170 -1.579 0.158
aji 59179. -0.125 -2.545 0.492
Beacon-C SGF - ITT
bec 59177. 2.087 -2.837 -3.761
bec 59178. 2.869 -4.467 -4.151
bec 59179. 2.899 -5.821 -4.191
bec 59180. 3.129 -6.152 -4.180
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 59177. 9.005 6.068 -1.662
eta 59178. 8.885 4.639 -3.709
eta 59179. 8.762 4.801 -4.053
Etalon-1 SGF - DGF
eta 59177. 0.168 0.406 0.153
eta 59178. 0.040 0.555 0.200
eta 59179. 0.024 0.559 0.243
Etalon-1 ITT - DGF
eta 59177. -8.837 -5.662 1.815
eta 59178. -8.845 -4.084 3.908
eta 59179. -8.738 -4.242 4.295
eta 59180. -8.204 -4.215 5.065
Etalon-2 SGF - ITT
etb 59177. 9.692 10.816 -17.975
etb 59178. 12.432 12.865 -12.565
etb 59179. 11.414 16.016 -20.474
Etalon-2 SGF - DGF
etb 59177. -0.028 0.148 -0.157
etb 59178. 0.057 0.154 -0.119
etb 59179. 0.032 0.176 -0.231
Etalon-2 ITT - DGF
etb 59177. -9.720 -10.668 17.818
etb 59178. -12.375 -12.711 12.446
etb 59179. -9.753 -20.250 16.736
etb 59180. -15.288 -12.918 28.668
Larets SGF - ITT
lar 59177. 2.764 3.540 1.604
lar 59178. 3.139 5.166 1.966
lar 59179. 2.353 6.009 2.727
lar 59180. 3.673 7.927 2.709
LARES SGF - ITT
las 59177. 3.452 5.767 -2.008
las 59178. 3.500 8.498 -1.877
las 59179. 2.883 12.271 -1.377
las 59180. 3.345 15.472 -1.351
LAGEOS-1 SGF - ITT
lga 59177. 4.952 2.680 1.330
lga 59178. 5.188 2.434 2.366
lga 59179. 5.449 2.108 1.933
lga 59180. 4.476 1.922 3.773
LAGEOS-1 ITT - JAX
lga 59177. -4.955 -2.624 -1.306
lga 59178. -5.211 -2.403 -2.332
lga 59179. -5.502 -2.083 -2.013
LAGEOS-1 JAX - SGF
lga 59177. 0.003 -0.055 -0.024
lga 59178. 0.023 -0.031 -0.034
lga 59179. -0.002 -0.025 -0.015
LAGEOS-1 SGF - DGF
lga 59177. 0.000 0.025 -0.015
lga 59178. -0.016 0.052 -0.077
lga 59179. -0.038 0.077 -0.035
lga 59180. 0.019 0.067 -0.138
LAGEOS-2 SGF - ITT
lgb 59177. 4.940 3.777 -5.112
lgb 59178. 5.712 6.071 -4.751
lgb 59179. 3.706 8.387 -3.690
lgb 59180. 7.309 12.730 -4.639
LAGEOS-2 ITT - JAX
lgb 59177. -4.935 -4.488 5.013
lgb 59178. -5.960 -7.152 4.767
lgb 59179. -3.525 -9.628 3.395
LAGEOS-2 JAX - SGF
lgb 59177. -0.005 0.712 0.099
lgb 59178. 0.249 1.081 -0.016
lgb 59179. -0.181 1.242 0.295
LAGEOS-2 SGF - DGF
lgb 59177. -0.028 0.238 -0.019
lgb 59178. -0.016 0.156 0.031
lgb 59179. -0.017 0.056 -0.050
lgb 59180. -0.103 -0.185 0.127
Stella SGF - ITT
ste 59177. 4.602 5.994 -0.893
ste 59178. 4.575 8.991 -0.646
ste 59179. 4.507 12.464 -0.175
ste 59180. 4.564 15.251 0.089
Starlette SGF - ITT
str 59177. 3.200 4.181 -4.176
str 59178. 3.171 6.890 -3.924
str 59179. 2.869 9.098 -3.873
str 59180. 3.113 13.849 -3.814