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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   60370.         0.372         1.095        -2.883
 aji   60371.         0.144        -0.758        -3.268
 aji   60372.        -0.019        -3.330        -3.958
 aji   60373.        -0.251        -6.994        -4.577
Ajisai SGF - DGF    
 aji   60370.         0.012         1.957        -0.519
 aji   60371.         0.025         3.582        -0.952
 aji   60372.        -0.070         5.536        -1.326
 aji   60373.        -0.281         8.257        -1.714
Ajisai ITT - DGF    
 aji   60370.        -0.360         0.862         2.364
 aji   60371.        -0.119         4.339         2.316
 aji   60372.        -0.051         8.866         2.633
 aji   60373.        -0.030        15.250         2.862
Beacon-C SGF - ITT  
 bec   60370.         2.098       -38.830         6.231
 bec   60371.         0.134       -66.411         7.598
 bec   60372.         1.869      -101.789        13.989
 bec   60373.        -1.880      -140.602        14.808
Etalon-1 SGF - ITT  
 eta   60370.      -244.731       419.818      -140.146
 eta   60371.      -237.036       249.588      -119.304
 eta   60372.      -109.713       193.427       -66.447
 eta   60373.        -0.422       204.376      -167.544
Etalon-1 SGF - DGF  
 eta   60370.         0.725        -0.972         0.317
 eta   60371.         0.619        -0.416         0.090
 eta   60372.         0.193        -0.143        -0.233
 eta   60373.        -0.240        -0.155        -0.131
Etalon-1 ITT - DGF  
 eta   60370.       245.456      -420.790       140.463
 eta   60371.       237.655      -250.004       119.394
 eta   60372.       109.905      -193.569        66.214
 eta   60373.         0.183      -204.531       167.413
Etalon-2 SGF - ITT  
 etb   60370.        -0.796         7.352        -0.428
 etb   60371.         0.856         5.927         0.344
 etb   60372.         1.842         5.356        -2.613
 etb   60373.         1.754         5.231        -4.466
Etalon-2 SGF - DGF  
 etb   60370.         0.227         0.678        -0.516
 etb   60371.         0.005         1.055        -0.421
 etb   60372.        -0.238         1.019        -0.206
 etb   60373.        -0.299         0.969         0.016
Etalon-2 ITT - DGF  
 etb   60370.         1.023        -6.675        -0.088
 etb   60371.        -0.850        -4.872        -0.765
 etb   60372.        -2.080        -4.337         2.408
 etb   60373.        -2.054        -4.263         4.482
Larets SGF - ITT    
 lar   60370.        -0.511        15.679         2.736
 lar   60371.        -7.326        26.497         7.734
 lar   60372.        -1.830        42.031         4.193
 lar   60373.       -10.834        56.859        10.564
Larets SGF - DGF    
 lar   60370.        -4.454        23.288         7.155
 lar   60371.       -20.626        53.319        20.194
 lar   60372.       -12.603       100.789        14.730
 lar   60373.        -9.218       166.441         7.317
 lar   60374.       -59.426       238.383        55.419
Larets ITT - DGF    
 lar   60370.        -3.942         7.609         4.419
 lar   60371.       -13.300        26.822        12.460
 lar   60372.       -10.773        58.758        10.538
 lar   60373.       -26.295        93.341        23.123
LARES SGF - ITT     
 las   60370.         1.741         3.100        -1.579
 las   60371.         2.112         2.896        -1.060
 las   60372.         2.250         2.292         0.036
 las   60373.         2.303         0.815         1.773
LARES SGF - DGF     
 las   60370.         0.007         0.637        -0.122
 las   60371.        -0.003         0.778        -0.115
 las   60372.        -0.036         0.899        -0.148
 las   60373.        -0.037         0.931        -0.143
 las   60374.        -0.113         0.894        -0.144
LARES ITT - DGF     
 las   60370.        -1.734        -2.463         1.457
 las   60371.        -2.114        -2.118         0.945
 las   60372.        -2.286        -1.392        -0.184
 las   60373.        -2.340         0.116        -1.916
LARES-2 SGF - DGF   
 la2   60370.        -0.045         0.078         0.021
 la2   60371.        -0.037         0.084         0.045
 la2   60372.        -0.055         0.111         0.053
 la2   60373.        -0.059         0.163         0.029
 la2   60374.        -0.056         0.169         0.058
LAGEOS-1 SGF - ITT  
 lga   60370.         1.140         3.404        -0.509
 lga   60371.         1.071         3.739        -0.494
 lga   60372.         0.839         3.647        -0.435
 lga   60373.         1.069         3.279        -0.169
LAGEOS-1 SGF - DGF  
 lga   60370.        -0.036        -0.084         0.032
 lga   60371.        -0.059        -0.138         0.047
 lga   60372.        -0.029        -0.162         0.034
 lga   60373.        -0.072        -0.190         0.043
 lga   60374.        -0.051        -0.254         0.031
LAGEOS-2 SGF - ITT  
 lgb   60370.         0.933         3.457        -1.007
 lgb   60371.         0.519         4.992        -1.774
 lgb   60372.         0.967         6.027        -0.871
 lgb   60373.         0.477         8.268        -1.115
LAGEOS-2 SGF - DGF  
 lgb   60370.         0.022         0.044        -0.016
 lgb   60371.         0.013        -0.105         0.031
 lgb   60372.         0.008        -0.198        -0.015
 lgb   60373.         0.068        -0.570         0.032
 lgb   60374.         0.030        -0.761         0.069
Stella SGF - ITT    
 ste   60370.         2.441         7.188        -2.414
 ste   60371.         3.035        12.720        -3.317
 ste   60372.         3.424        20.361        -4.134
 ste   60373.         2.254        28.803        -2.718
Stella SGF - DGF    
 ste   60370.         0.580         0.672         0.076
 ste   60371.         1.252         2.870        -0.541
 ste   60372.         2.186         7.424        -1.415
 ste   60373.         3.202        12.809        -2.013
 ste   60374.         3.904        20.447        -3.069
Stella ITT - DGF    
 ste   60370.        -1.861        -6.516         2.490
 ste   60371.        -1.783        -9.850         2.776
 ste   60372.        -1.237       -12.938         2.719
 ste   60373.        -0.093       -14.265         1.605
Starlette SGF - ITT 
 str   60370.         1.462         3.175        -1.856
 str   60371.         1.445         2.819        -1.701
 str   60372.         1.578         3.988        -1.811
 str   60373.         1.841         2.828        -1.137
Starlette SGF - DGF 
 str   60370.        -0.071         1.285        -0.037
 str   60371.        -0.021        -0.249        -0.116
 str   60372.         0.428        -3.110        -0.565
 str   60373.         0.510        -7.211        -0.729
Starlette ITT - DGF 
 str   60370.        -1.533        -1.890         1.819
 str   60371.        -1.466        -3.068         1.585
 str   60372.        -1.150        -7.099         1.246
 str   60373.        -2.484       -10.261         1.299