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 60416. 0.073 1.761 -0.273
aji 60417. 0.277 2.848 -0.321
aji 60418. 0.056 4.447 -0.337
aji 60419. 0.028 6.011 -0.330
Ajisai SGF - DGF
aji 60416. -0.013 1.178 0.880
aji 60417. 0.144 2.940 1.444
aji 60418. 0.052 5.518 1.844
aji 60419. -0.272 8.601 2.660
aji 60420. 1.358 12.507 2.207
Ajisai ITT - DGF
aji 60416. -0.086 -0.582 1.153
aji 60417. -0.133 0.093 1.766
aji 60418. -0.004 1.072 2.181
aji 60419. -0.300 2.589 2.990
Beacon-C SGF - ITT
bec 60416. -2.311 29.226 3.912
bec 60417. -1.453 46.896 5.164
bec 60418. -6.272 75.768 13.107
bec 60419. -9.136 109.562 16.697
Etalon-1 SGF - ITT
eta 60416. 12.862 -4.860 13.812
eta 60417. 13.104 17.717 16.380
eta 60418. 12.521 37.872 7.308
eta 60419. -4.327 45.719 14.749
Etalon-1 SGF - DGF
eta 60416. 0.069 0.225 0.102
eta 60417. -0.148 0.259 0.174
eta 60418. -0.289 0.229 0.372
eta 60419. -0.317 0.115 0.384
Etalon-1 ITT - DGF
eta 60416. -12.793 5.085 -13.710
eta 60417. -13.252 -17.457 -16.206
eta 60418. -12.809 -37.643 -6.936
eta 60419. 4.010 -45.603 -14.365
Etalon-2 SGF - ITT
etb 60416. 37.427 69.360 -2.262
etb 60417. 18.678 108.107 -14.423
etb 60418. -9.286 119.637 -6.296
etb 60419. -20.841 131.265 1.239
Etalon-2 SGF - DGF
etb 60416. 0.136 0.170 0.016
etb 60417. 0.103 0.345 0.052
etb 60418. 0.015 0.472 0.157
etb 60419. -0.030 0.622 0.255
Etalon-2 ITT - DGF
etb 60416. -37.291 -69.191 2.278
etb 60417. -18.575 -107.762 14.474
etb 60418. 9.301 -119.165 6.453
etb 60419. 20.810 -130.643 -0.983
Larets SGF - ITT
lar 60416. 4.789 -17.606 4.997
lar 60417. 6.998 -32.215 3.809
lar 60418. 1.986 -49.913 11.920
lar 60419. 16.696 -65.030 3.598
Larets SGF - DGF
lar 60416. 6.476 -22.550 -1.883
lar 60417. 12.270 -52.236 -9.514
lar 60418. 6.587 -93.856 -2.868
lar 60419. 35.798 -137.949 -27.453
lar 60420. 15.774 -212.778 -7.752
Larets ITT - DGF
lar 60416. 1.687 -4.944 -6.880
lar 60417. 5.273 -20.021 -13.323
lar 60418. 4.601 -43.943 -14.787
lar 60419. 19.103 -72.918 -31.051
LARES SGF - ITT
las 60416. -2.588 8.260 4.590
las 60417. -6.060 19.127 7.773
las 60418. -3.983 37.263 5.088
las 60419. -7.099 53.796 11.326
LARES SGF - DGF
las 60416. 0.032 0.472 0.079
las 60417. -0.017 0.723 0.161
las 60418. 0.023 1.126 0.172
las 60419. -0.050 1.432 0.277
las 60420. 0.037 1.830 0.244
LARES ITT - DGF
las 60416. 2.619 -7.788 -4.511
las 60417. 6.043 -18.403 -7.612
las 60418. 4.006 -36.138 -4.915
las 60419. 7.111 -52.340 -11.053
LARES-2 SGF - DGF
la2 60416. -0.010 0.141 0.011
la2 60417. -0.019 0.160 -0.030
la2 60418. 0.034 0.221 -0.053
la2 60419. -0.094 0.338 -0.008
la2 60420. 0.056 0.386 -0.108
LAGEOS-1 SGF - ITT
lga 60416. 0.361 0.620 -0.276
lga 60417. 0.535 0.457 -0.589
lga 60418. 0.698 0.927 -0.656
lga 60419. 0.613 1.239 -0.627
LAGEOS-1 SGF - DGF
lga 60416. -0.016 -0.121 -0.005
lga 60417. -0.031 -0.075 0.035
lga 60418. -0.063 -0.103 0.059
lga 60419. -0.002 -0.013 -0.004
lga 60420. -0.087 0.007 0.145
LAGEOS-2 SGF - ITT
lgb 60416. 0.192 0.553 -0.218
lgb 60417. 0.332 0.687 -0.150
lgb 60418. 0.231 0.867 -0.208
lgb 60419. 0.600 0.846 -0.388
LAGEOS-2 SGF - DGF
lgb 60416. 0.039 -0.165 0.022
lgb 60417. -0.070 -0.291 0.081
lgb 60418. 0.100 -0.429 0.036
lgb 60419. -0.129 -0.650 0.048
lgb 60420. 0.152 -0.840 0.104
Stella SGF - ITT
ste 60416. -0.320 -1.541 0.899
ste 60417. -0.785 -3.579 1.303
ste 60418. -1.374 -6.139 2.014
ste 60419. -0.906 -11.745 1.728
Stella SGF - DGF
ste 60416. -1.464 -4.024 1.237
ste 60417. -1.798 -8.607 1.468
ste 60418. -1.961 -12.187 1.714
ste 60419. -2.349 -17.128 1.696
ste 60420. -3.653 -25.615 3.300
Stella ITT - DGF
ste 60416. -1.143 -2.483 0.339
ste 60417. -1.013 -5.027 0.166
ste 60418. -0.587 -6.048 -0.301
ste 60419. 0.021 -7.275 -0.922
Starlette SGF - ITT
str 60416. 1.077 6.774 -1.110
str 60417. 0.872 12.679 -1.144
str 60418. 1.519 20.196 -1.647
str 60419. 2.337 28.835 -2.570
Starlette SGF - DGF
str 60416. 0.457 3.301 -0.220
str 60417. 0.426 7.035 -0.306
str 60418. 0.964 12.363 -0.810
str 60419. 1.647 20.105 -1.659
str 60420. 1.051 28.835 -1.340
Starlette ITT - DGF
str 60416. -0.620 -3.473 0.890
str 60417. -0.446 -5.644 0.838
str 60418. -0.555 -7.833 0.837
str 60419. -0.690 -8.730 0.911