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.
![](../images/cpf_comparison.png)
Difference between CPF Providers JD X Y Z Ajisai SGF - ITT aji 60518. 3.536 -10.362 -4.444 aji 60519. 3.680 -15.455 -4.622 aji 60520. 3.043 -21.290 -3.775 aji 60521. 3.859 -30.271 -4.051 Ajisai SGF - DGF aji 60518. 0.461 3.708 0.226 aji 60519. 0.496 6.929 0.529 aji 60520. 0.854 10.635 0.406 aji 60521. 0.631 16.184 0.676 aji 60522. 1.368 21.738 0.545 Ajisai ITT - DGF aji 60518. -3.075 14.069 4.670 aji 60519. -3.184 22.384 5.151 aji 60520. -2.189 31.926 4.180 aji 60521. -3.228 46.455 4.727 Beacon-C SGF - ITT bec 60518. -10.663 -211.984 1.123 bec 60519. -24.744 -343.996 8.781 bec 60520. -18.557 -499.496 6.504 Etalon-1 SGF - ITT eta 60518. 35.130 -133.330 -88.356 eta 60519. 59.997 -157.354 -107.803 eta 60520. 92.543 -161.897 -131.322 eta 60521. 110.641 -133.995 -156.228 Etalon-1 SGF - DGF eta 60518. -0.891 4.804 0.861 eta 60519. -1.852 5.809 1.810 eta 60520. -3.160 6.241 2.958 eta 60521. -3.618 5.198 4.541 Etalon-1 ITT - DGF eta 60518. -36.021 138.134 89.217 eta 60519. -61.849 163.163 109.613 eta 60520. -95.703 168.139 134.279 eta 60521. -114.718 139.508 160.469 Etalon-2 SGF - ITT etb 60518. 19.486 5.575 -12.385 etb 60519. 12.420 23.466 -8.782 etb 60520. 1.850 25.358 -0.686 etb 60521. 10.916 3.729 6.690 Etalon-2 SGF - DGF etb 60518. 4.741 2.693 0.291 etb 60519. -0.841 5.862 5.961 etb 60520. -10.255 2.662 1.600 etb 60521. 0.144 6.567 -6.887 Etalon-2 ITT - DGF etb 60518. -14.744 -2.882 12.677 etb 60519. -13.261 -17.604 14.743 etb 60520. -12.105 -22.697 2.286 etb 60521. 4.689 20.540 -22.969 Larets SGF - ITT lar 60518. 0.487 9.541 -0.475 lar 60519. 1.364 22.393 -0.382 lar 60520. 3.134 38.687 -2.157 lar 60521. -7.727 54.118 5.715 Larets SGF - DGF lar 60518. 10.553 -28.306 -9.533 lar 60519. 12.031 -63.645 -12.288 lar 60520. 9.574 -113.342 -9.577 lar 60521. 41.841 -162.200 -35.518 lar 60522. 18.659 -254.067 -20.840 Larets ITT - DGF lar 60518. 10.066 -37.847 -9.057 lar 60519. 10.668 -86.038 -11.906 lar 60520. 6.440 -152.029 -7.420 lar 60521. 49.567 -216.318 -41.233 LARES SGF - ITT las 60518. 4.605 -3.518 0.903 las 60519. 4.565 -4.738 3.165 las 60520. 4.835 -6.717 5.696 las 60521. 4.654 -8.937 8.772 LARES SGF - DGF las 60518. 0.086 0.783 -0.069 las 60519. 0.053 1.078 -0.078 las 60520. 0.162 1.649 -0.126 las 60521. 0.096 2.238 -0.102 las 60522. 0.242 3.136 -0.193 LARES ITT - DGF las 60518. -4.520 4.301 -0.972 las 60519. -4.513 5.816 -3.244 las 60520. -4.673 8.366 -5.822 las 60521. -4.558 11.174 -8.875 LARES-2 SGF - DGF la2 60518. 0.017 0.128 0.001 la2 60519. 0.018 0.142 0.018 la2 60520. -0.022 0.167 0.049 la2 60521. 0.025 0.185 0.047 la2 60522. 0.001 0.182 0.067 LAGEOS-1 SGF - ITT lga 60518. 5.918 -4.974 1.296 lga 60519. 7.167 -6.760 1.600 lga 60520. 4.140 -8.127 5.646 lga 60521. 7.431 -12.536 2.649 LAGEOS-1 SGF - DGF lga 60518. -0.002 -0.064 0.049 lga 60519. -0.004 -0.124 0.078 lga 60520. -0.039 -0.218 0.138 lga 60521. -0.002 -0.296 0.137 lga 60522. 0.033 -0.384 0.153 LAGEOS-2 SGF - ITT lgb 60518. 3.316 4.994 -2.033 lgb 60519. 9.484 14.916 -6.837 lgb 60520. 1.476 18.635 -0.405 lgb 60521. 9.270 35.930 -6.160 LAGEOS-2 SGF - DGF lgb 60518. 0.016 -0.017 -0.050 lgb 60519. -0.053 -0.178 0.088 lgb 60520. 0.050 -0.129 -0.102 lgb 60521. -0.043 -0.317 0.036 lgb 60522. -0.010 -0.265 -0.096 Stella SGF - ITT ste 60518. 5.446 2.110 -3.749 ste 60519. 5.096 5.321 -3.197 ste 60520. 6.324 6.235 -3.944 ste 60521. 6.814 12.029 -4.433 Stella SGF - DGF ste 60518. -1.297 -3.180 1.867 ste 60519. -1.184 -6.464 1.494 ste 60520. -2.233 -8.315 2.176 ste 60521. -3.133 -15.047 2.737 ste 60522. -2.504 -21.982 2.072 Stella ITT - DGF ste 60518. -6.742 -5.289 5.617 ste 60519. -6.280 -11.785 4.691 ste 60520. -8.556 -14.550 6.120 ste 60521. -9.946 -27.076 7.170 Starlette SGF - ITT str 60518. 3.749 3.940 -4.178 str 60519. 3.299 6.055 -3.573 str 60520. 2.684 9.585 -3.014 str 60521. 3.308 11.724 -3.127 Starlette SGF - DGF str 60518. 0.346 1.471 -0.145 str 60519. 0.182 3.845 -0.172 str 60520. -0.296 7.561 0.127 str 60521. 0.009 12.129 -0.064 str 60522. -0.561 17.334 0.421 Starlette ITT - DGF str 60518. -3.403 -2.469 4.033 str 60519. -3.117 -2.210 3.401 str 60520. -2.980 -2.024 3.141 str 60521. -3.298 0.405 3.063