Citation
Abstract
The Kalman Earth Orientation Filter (KEOF) software developed at the Jet Propulsion Laboratory (JPL) is used operationally to generate Earth orientation parameter (EOP) estimates and predictions of polar motion x (PMX), polar motion y (PMY), and Universal Time (UT1) in support of all JPL interplanetary flight projects. The estimates and predictions are made based on Earth orientation measurements obtained with very long baseline interferometry (VLBI) and satellite laser ranging (SLR), supplemented by atmospheric angular momentum (AAM) forecasts. KEOF uses empirically based stochastic models for the short-term behavior of Earth orientation to interpolate the data optimally and extrapolate the Earth orientation time series to generate near-real-time estimates and short-term predictions. Estimates and predictions made using incomplete raw data sets are evaluated for their accuracy by comparing them with Earth orientation series generated when complete data sets have become available for the time periods in question. The Deep Space Network (DSN) has a general requirement that the knowledge of the Earth’s orientation should be accurate to within 30 cm (1-sigma) in each of the three EOP components. The root-mean-square (rms) accuracy of the KEOF EOP calibrations available to the navigation teams typically is better than 13 cm in PMX, 11 cm in PMY, and 17 cm in UT1. EOP estimates prior to a week before the day the calibrations are generated are accurate at the 3-cm-or-better level.
Details
- Volume
- 42-129
- Published
- May 15, 1997
- Pages
- 1–10
- File Size
- 392.9 KB