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 60848. 3.208 -2.061 -4.497
aji 60849. 2.948 -4.110 -4.276
aji 60850. 3.419 -6.148 -4.857
aji 60851. 3.509 -8.330 -5.176
Ajisai SGF - DGF
aji 60848. -0.775 10.314 0.786
aji 60849. -0.647 15.092 0.553
Ajisai ITT - DGF
aji 60848. -3.982 12.374 5.283
aji 60849. -3.594 19.202 4.829
Beacon-C SGF - ITT
bec 60848. 0.852 17.250 0.620
bec 60849. -1.361 36.252 2.852
bec 60850. -0.232 59.076 4.661
bec 60851. -1.928 89.154 4.749
Etalon-1 SGF - ITT
eta 60848. 14.791 -0.569 4.109
eta 60849. 15.696 4.936 0.036
eta 60850. 10.945 10.027 -2.906
eta 60851. 11.028 4.863 10.379
Etalon-1 SGF - DGF
eta 60848. -0.106 0.135 0.443
eta 60849. -0.238 -0.016 0.756
eta 60850. -0.085 -0.308 1.074
eta 60851. 0.246 -0.392 1.114
eta 60852. 0.303 -0.260 1.057
Etalon-1 ITT - DGF
eta 60848. -14.897 0.704 -3.665
eta 60849. -15.934 -4.952 0.719
eta 60850. -11.029 -10.335 3.980
eta 60851. -10.908 -5.179 -9.818
Etalon-2 SGF - ITT
etb 60848. 7.644 67.834 27.224
etb 60849. 10.766 67.894 27.894
etb 60850. 19.205 72.823 26.643
etb 60851. 19.331 87.610 24.595
Etalon-2 SGF - DGF
etb 60848. 0.116 0.534 0.466
etb 60849. -0.040 0.491 0.455
etb 60850. -0.141 0.308 0.415
etb 60851. -0.182 0.048 0.265
etb 60852. -0.085 -0.176 0.347
Etalon-2 ITT - DGF
etb 60848. -7.528 -67.301 -26.757
etb 60849. -10.806 -67.403 -27.438
etb 60850. -19.346 -72.515 -26.228
etb 60851. -19.477 -87.535 -24.243
Larets SGF - ITT
lar 60848. 1.700 2.508 4.873
lar 60849. 0.606 4.961 7.194
lar 60850. 0.764 8.685 8.230
lar 60851. -1.133 10.416 11.679
Larets SGF - DGF
lar 60848. -9.610 129.848 11.534
Larets ITT - DGF
lar 60848. -11.310 127.339 6.661
LARES SGF - ITT
las 60848. 3.365 -0.442 0.160
las 60849. 3.139 -0.276 0.080
las 60850. 3.478 -0.403 -0.848
las 60851. 3.306 -0.646 -1.479
LARES SGF - DGF
las 60848. -0.052 1.181 0.127
las 60849. -0.169 1.375 0.190
LARES ITT - DGF
las 60848. -3.416 1.622 -0.033
las 60849. -3.308 1.651 0.109
LARES-2 SGF - DGF
la2 60848. -0.012 0.224 0.061
la2 60849. 0.035 0.285 0.050
LAGEOS-1 SGF - ITT
lga 60848. 5.768 -0.472 0.698
lga 60849. 5.248 -0.149 1.412
lga 60850. 5.944 1.934 1.842
lga 60851. 5.981 2.275 2.089
LAGEOS-1 SGF - DGF
lga 60848. -0.028 -0.267 -0.112
lga 60849. 0.101 -0.379 -0.103
LAGEOS-2 SGF - ITT
lgb 60848. 3.829 -2.665 -1.769
lgb 60849. 4.480 -4.535 -1.264
lgb 60850. 5.044 -8.339 -0.142
lgb 60851. 6.018 -10.420 -0.749
LAGEOS-2 SGF - DGF
lgb 60848. 0.082 -0.156 -0.029
lgb 60849. 0.060 -0.316 -0.145
lgb 60850. 0.163 -0.673 -0.007
lgb 60851. 0.074 -0.930 -0.217
lgb 60852. 0.182 -1.537 0.102
Stella SGF - ITT
ste 60848. 4.827 4.837 -3.225
ste 60849. 4.761 7.807 -3.184
ste 60850. 7.846 10.805 -5.946
ste 60851. 5.629 19.003 -4.928
Stella SGF - DGF
ste 60848. 0.903 6.058 -0.708
ste 60849. 0.768 9.387 -0.572
Stella ITT - DGF
ste 60848. -3.923 1.221 2.517
ste 60849. -3.993 1.581 2.613
Starlette SGF - ITT
str 60848. 3.009 1.930 -2.068
str 60849. 3.431 6.332 -2.078
str 60850. 4.331 13.545 -2.359
str 60851. 3.890 23.250 -1.969
Starlette SGF - DGF
str 60848. -0.301 -7.700 0.475
Starlette ITT - DGF
str 60848. -3.310 -9.630 2.543