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 60878. 3.322 -7.388 -4.190
aji 60879. 3.174 -11.219 -3.827
aji 60880. 3.350 -16.278 -4.106
aji 60881. 3.157 -23.126 -4.167
Ajisai SGF - DGF
aji 60878. 0.338 0.555 0.325
aji 60879. 0.442 2.014 0.489
aji 60880. 0.465 4.052 0.710
aji 60881. 0.596 7.023 0.852
aji 60882. 0.861 10.079 0.777
Ajisai ITT - DGF
aji 60878. -2.984 7.943 4.515
aji 60879. -2.732 13.233 4.316
aji 60880. -2.885 20.330 4.815
aji 60881. -2.561 30.150 5.020
Beacon-C SGF - ITT
bec 60878. 3.425 8.736 -6.298
bec 60879. 3.313 11.277 -7.948
bec 60880. 3.381 14.199 -10.384
bec 60881. 2.832 16.633 -12.564
Etalon-1 SGF - ITT
eta 60878. 52.687 4.913 -107.312
eta 60879. -4.996 70.447 -124.153
eta 60880. -34.900 42.138 -105.191
eta 60881. 77.145 -75.595 -419.378
Etalon-1 SGF - DGF
eta 60878. 0.002 0.164 0.266
eta 60879. 0.202 0.069 0.361
eta 60880. 0.312 0.217 0.278
eta 60881. -0.056 0.164 0.492
eta 60882. 0.080 -0.195 0.821
Etalon-1 ITT - DGF
eta 60878. -52.684 -4.749 107.577
eta 60879. 5.198 -70.378 124.515
eta 60880. 35.211 -41.921 105.469
eta 60881. -77.448 75.716 420.137
Etalon-2 SGF - ITT
etb 60878. 15.300 1.145 3.898
etb 60879. 16.103 3.516 3.726
etb 60880. 16.506 6.136 3.938
etb 60881. 17.097 8.979 4.405
Etalon-2 SGF - DGF
etb 60878. 0.211 0.348 0.107
etb 60879. 0.369 0.578 0.012
etb 60880. 0.511 0.837 -0.118
etb 60881. 0.779 1.261 -0.197
etb 60882. 0.947 1.987 -0.175
Etalon-2 ITT - DGF
etb 60878. -15.090 -0.797 -3.791
etb 60879. -15.734 -2.939 -3.713
etb 60880. -15.996 -5.298 -4.056
etb 60881. -16.350 -7.762 -4.664
Larets SGF - ITT
lar 60878. -0.731 8.336 -1.020
lar 60879. -2.051 15.814 0.831
lar 60880. -3.336 27.255 1.155
lar 60881. -8.610 31.224 4.855
Larets SGF - DGF
lar 60878. 3.908 -11.709 -3.358
lar 60879. 5.632 -23.349 -6.134
lar 60880. 6.654 -41.572 -7.331
lar 60881. 14.441 -53.778 -13.497
lar 60882. 6.850 -88.593 -7.760
Larets ITT - DGF
lar 60878. 4.639 -20.044 -2.339
lar 60879. 7.683 -39.163 -6.965
lar 60880. 9.990 -68.826 -8.486
lar 60881. 23.052 -85.002 -18.353
LARES SGF - ITT
las 60878. 1.942 -2.119 -5.518
las 60879. 1.608 -3.552 -6.552
las 60880. 0.636 -1.854 -7.166
las 60881. 0.171 -3.646 -8.297
LARES SGF - DGF
las 60878. 0.165 0.649 -0.252
las 60879. 0.162 1.116 -0.276
las 60880. 0.249 1.513 -0.424
las 60881. 0.166 2.333 -0.380
las 60882. 0.393 3.116 -0.597
LARES ITT - DGF
las 60878. -1.777 2.768 5.266
las 60879. -1.447 4.668 6.275
las 60880. -0.387 3.367 6.742
las 60881. -0.006 5.979 7.917
LARES-2 SGF - DGF
la2 60878. 0.059 0.141 -0.012
la2 60879. 0.070 0.149 0.020
la2 60880. 0.133 0.225 -0.022
la2 60881. 0.077 0.341 0.025
la2 60882. 0.123 0.265 0.052
LAGEOS-1 SGF - ITT
lga 60878. 7.348 -0.857 -1.234
lga 60879. 7.832 -0.199 -1.094
lga 60880. 7.153 0.919 -1.132
lga 60881. 7.433 1.925 -0.855
LAGEOS-1 SGF - DGF
lga 60878. 0.032 -0.189 -0.038
lga 60879. 0.046 -0.232 -0.049
lga 60880. 0.072 -0.250 -0.071
lga 60881. 0.030 -0.300 -0.074
lga 60882. 0.072 -0.331 -0.103
LAGEOS-2 SGF - ITT
lgb 60878. 6.555 -15.919 -4.424
lgb 60879. 2.424 -22.260 -2.887
lgb 60880. 7.895 -36.565 -4.583
lgb 60881. 12.092 -44.933 -10.475
LAGEOS-2 SGF - DGF
lgb 60878. 0.044 0.157 -0.113
lgb 60879. 0.072 0.210 -0.103
lgb 60880. 0.061 0.302 -0.113
lgb 60881. 0.100 0.352 -0.108
lgb 60882. 0.071 0.560 -0.098
Stella SGF - ITT
ste 60878. 6.161 9.452 -4.686
ste 60879. 6.444 13.228 -5.367
ste 60880. 6.725 20.248 -5.469
Stella SGF - DGF
ste 60878. -0.026 -0.905 -0.149
ste 60879. 0.019 -1.051 -0.211
ste 60880. -0.413 -1.499 0.072
ste 60881. -0.472 -2.973 -0.112
ste 60882. -0.279 -4.962 -0.399
Stella ITT - DGF
ste 60878. -6.187 -10.357 4.537
ste 60879. -6.426 -14.279 5.155
ste 60880. -6.898 -21.999 5.290
Starlette SGF - ITT
str 60878. 3.104 6.973 -5.903
str 60879. 2.711 13.004 -6.331
str 60880. 3.090 20.385 -7.323
str 60881. 3.192 29.264 -8.316
Starlette SGF - DGF
str 60878. 0.315 2.895 -0.269
str 60879. 0.326 5.280 -0.332
str 60880. 0.503 8.030 -0.604
str 60881. 0.041 11.427 -0.402
str 60882. 1.116 16.039 -1.240
Starlette ITT - DGF
str 60878. -2.789 -4.079 5.634
str 60879. -2.384 -7.724 5.999
str 60880. -2.587 -12.355 6.719
str 60881. -2.492 -17.638 7.461