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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   59473.         5.738         5.902        -6.715
 aji   59474.         5.965        10.405        -6.768
 aji   59475.         5.874        15.996        -6.828
 aji   59476.         5.658        23.330        -6.899
Ajisai ITT - JAX    
Ajisai JAX - SGF    
Ajisai SGF - DGF    
 aji   59473.         0.152         0.573        -0.098
 aji   59474.         0.228         2.122        -0.227
 aji   59475.         0.224         4.370        -0.390
 aji   59476.         0.121         7.684        -0.560
Ajisai ITT - DGF    
 aji   59473.        -5.586        -5.329         6.617
 aji   59474.        -5.738        -8.283         6.541
 aji   59475.        -5.650       -11.626         6.438
 aji   59476.        -5.537       -15.646         6.339
Beacon-C SGF - ITT  
 bec   59473.         1.952        -6.937        -4.746
 bec   59474.         1.862       -16.701        -7.342
 bec   59475.        -1.740       -34.909        -9.089
 bec   59476.         1.068       -65.521       -13.223
Cyrosat-2 ESA - ITT 
Etalon-1 SGF - ITT  
 eta   59473.         3.355        17.423         7.078
 eta   59474.         1.720         1.730        25.434
 eta   59475.         8.365       -14.768         5.739
Etalon-1 SGF - DGF  
 eta   59473.         0.564         0.208         0.340
 eta   59474.         0.590         0.805         0.028
 eta   59475.         0.219         1.306         0.706
Etalon-1 ITT - DGF  
 eta   59473.        -2.790       -17.215        -6.738
 eta   59474.        -1.131        -0.924       -25.406
 eta   59475.       -11.842        20.528       -21.796
 eta   59476.       -10.432        20.859        18.843
Etalon-2 SGF - ITT  
 etb   59473.        10.413        -5.817       -11.148
 etb   59474.        18.390        -5.172       -13.445
 etb   59475.        17.046        -4.275        -3.973
Etalon-2 SGF - DGF  
 etb   59473.         0.076         0.068        -0.221
 etb   59474.         0.178         0.033        -0.400
 etb   59475.         0.191         0.058        -0.464
Etalon-2 ITT - DGF  
 etb   59473.       -10.337         5.885        10.927
 etb   59474.       -18.213         5.205        13.044
 etb   59475.       -25.821         0.129         5.429
 etb   59476.        -3.216        12.471        -3.767
Larets SGF - ITT    
 lar   59473.         6.474        -1.066        -6.027
 lar   59474.         6.263        -0.061        -6.387
 lar   59475.         6.148         2.795        -7.155
 lar   59476.         5.185         4.939        -6.738
Larets SGF - DGF    
 lar   59473.         0.762        -6.381        -0.963
 lar   59474.         2.827       -11.864        -2.816
 lar   59475.         0.345       -21.275        -0.105
 lar   59476.         7.043       -29.028        -6.922
Larets ITT - DGF    
 lar   59473.        -5.711        -5.314         5.064
 lar   59474.        -3.436       -11.803         3.570
 lar   59475.        -5.803       -24.070         7.050
 lar   59476.         1.858       -33.967        -0.184
LARES SGF - ITT     
 las   59473.         6.641         3.444        -4.127
 las   59474.         7.347         4.119        -4.616
 las   59475.         7.282         3.920        -5.159
 las   59476.         7.992         2.978        -5.555
LARES SGF - DGF     
 las   59473.         0.146         0.685        -0.517
 las   59474.         0.228         1.114        -0.684
 las   59475.         0.152         1.594        -0.767
 las   59476.         0.416         2.190        -1.044
LARES ITT - DGF     
 las   59473.        -6.495        -2.759         3.610
 las   59474.        -7.118        -3.005         3.932
 las   59475.        -7.130        -2.326         4.392
 las   59476.        -7.576        -0.788         4.512
LAGEOS-1 SGF - ITT  
 lga   59473.         9.185         2.483        -1.151
 lga   59474.        10.257         3.662        -1.067
 lga   59475.         9.243         5.032        -1.158
 lga   59476.         8.757         6.653        -1.639
LAGEOS-1 ITT - JAX  
LAGEOS-1 JAX - SGF  
LAGEOS-1 SGF - DGF  
 lga   59473.         0.031        -0.047        -0.032
 lga   59474.         0.058        -0.087         0.000
 lga   59475.         0.041        -0.103         0.044
 lga   59476.         0.017        -0.166         0.038
LAGEOS-2 SGF - ITT  
 lgb   59473.         7.002         0.637        -4.623
 lgb   59474.         7.129        -0.510        -5.338
 lgb   59475.         7.225        -1.706        -4.620
 lgb   59476.         6.919        -1.998        -4.326
LAGEOS-2 ITT - JAX  
LAGEOS-2 JAX - SGF  
LAGEOS-2 SGF - DGF  
 lgb   59473.         0.101        -0.167        -0.007
 lgb   59474.         0.124        -0.474        -0.122
 lgb   59475.         0.187        -0.777         0.027
 lgb   59476.         0.059        -1.005        -0.217
Stella SGF - ITT    
 ste   59473.         6.764         3.078        -3.029
 ste   59474.         7.085         4.443        -3.440
 ste   59475.         7.284         6.771        -3.534
 ste   59476.         7.499         8.595        -3.628
Stella SGF - DGF    
 ste   59473.         0.688         1.768        -0.539
 ste   59474.         0.689         3.511        -0.645
 ste   59475.         0.441         4.893        -0.483
 ste   59476.         0.650         5.482        -0.746
Stella ITT - DGF    
 ste   59473.        -6.076        -1.310         2.491
 ste   59474.        -6.396        -0.932         2.795
 ste   59475.        -6.843        -1.878         3.051
 ste   59476.        -6.849        -3.113         2.882
Starlette SGF - ITT 
 str   59473.         4.244        -1.351        -6.309
 str   59474.         4.313        -1.286        -6.378
 str   59475.         4.306        -0.401        -6.340
 str   59476.         4.270         1.954        -6.409
Starlette SGF - DGF 
 str   59473.        -0.001        -0.519        -0.003
 str   59474.         0.020        -0.289        -0.034
 str   59475.        -0.003         0.224        -0.011
 str   59476.        -0.074         1.088         0.026
Starlette ITT - DGF 
 str   59473.        -4.245         0.832         6.306
 str   59474.        -4.292         0.997         6.344
 str   59475.        -4.309         0.625         6.330
 str   59476.        -4.344        -0.866         6.435