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 58654. 2.852 -1.696 -4.576
aji 58655. 2.624 -2.070 -4.696
aji 58656. 2.800 -3.476 -5.314
aji 58657. 2.818 -4.165 -5.256
Ajisai ITT - JAX
aji 58654. -2.841 1.162 4.479
aji 58655. -2.654 1.319 4.585
aji 58656. -2.753 2.522 5.091
Ajisai JAX - SGF
aji 58654. -0.011 0.535 0.097
aji 58655. 0.030 0.752 0.111
aji 58656. -0.047 0.954 0.222
Beacon-C SGF - ITT
bec 58654. 2.139 -1.709 -0.929
bec 58655. 2.166 -4.619 -0.520
bec 58656. 1.928 -7.858 0.084
bec 58657. 2.265 -12.811 1.001
Cyrosat-2 ESA - ITT
Etalon-1 SGF - ITT
eta 58654. 9.284 1.969 2.349
eta 58655. 9.907 3.559 3.514
eta 58656. 8.576 4.731 5.491
eta 58657. 7.728 4.337 7.919
Etalon-2 SGF - ITT
etb 58654. 8.210 3.473 -1.952
etb 58655. 7.764 4.268 -1.946
etb 58656. 7.555 4.335 -1.201
etb 58657. 7.751 5.727 -1.722
Jason-2 SGF - ITT
Jason-2 ITT - CNES
Jason-2 CNES - SGF
Larets SGF - ITT
lar 58654. 4.093 -3.874 -3.460
lar 58655. 3.708 -4.449 -3.621
lar 58656. 4.223 -5.630 -3.975
lar 58657. 4.501 -7.425 -4.551
LARES SGF - ITT
las 58654. 4.563 0.425 -1.638
las 58655. 5.043 1.890 -1.781
las 58656. 4.882 3.932 -1.382
las 58657. 5.580 5.249 -1.677
LAGEOS-1 SGF - ITT
lga 58654. 6.618 -1.273 -1.313
lga 58655. 7.038 -2.951 -0.001
lga 58656. 7.333 -3.010 -2.616
lga 58657. 6.418 -2.249 0.038
LAGEOS-1 ITT - JAX
lga 58654. -6.625 1.336 1.286
lga 58655. -7.024 2.964 -0.016
lga 58656. -7.312 3.026 2.524
LAGEOS-1 JAX - SGF
lga 58654. 0.008 -0.063 0.027
lga 58655. -0.013 -0.013 0.016
lga 58656. -0.021 -0.016 0.093
LAGEOS-2 SGF - ITT
lgb 58654. 4.571 -0.793 -5.718
lgb 58655. 4.416 -1.087 -6.210
lgb 58656. 4.695 -0.765 -6.220
lgb 58657. 4.321 -1.226 -7.070
LAGEOS-2 ITT - JAX
lgb 58654. -4.518 0.919 5.625
lgb 58655. -4.404 1.340 6.122
lgb 58656. -4.690 1.370 6.167
LAGEOS-2 JAX - SGF
lgb 58654. -0.053 -0.126 0.093
lgb 58655. -0.012 -0.253 0.088
lgb 58656. -0.060 -0.307 0.091
Stella SGF - ITT
ste 58654. 5.160 1.617 -4.175
ste 58655. 5.471 3.353 -4.851
ste 58656. 5.824 5.721 -5.353
ste 58657. 6.483 8.280 -6.481
Starlette SGF - ITT
str 58654. 2.019 -3.797 -3.906
str 58655. 1.819 -5.068 -3.798
str 58656. 2.427 -6.632 -4.657
str 58657. 2.066 -7.247 -4.297