Engineering and QC Analysis Session
R. Noomen and V. Glotov
|Title of Paper
|Numerical Noise in Satellite Laser Ranging Data Processing
|Is Your Performance being Ruined by Interpolation Errors?
|Engineering Data File Processing and Distribution
|Herstmonceux Time Bias System as A Possible Real-Time QC Tool
|Determination of the Station Coordinates for Quality Control
of the Satellite Laser Ranging Data
|Results of the SLR Tracking Data Quality Control During the
|MCC Analysis Procedure of the SLR Data Quality and Stations
|18 Years of Q/C Analysis at Delft University Of Technology
This session addresses two general topics: (1) a variety of engineering
aspects of the SLR observations, and (2) data quality control by
means of orbital techniques.
Prochazka addressed the issue of numerical noise, in particular
introduced by the processing of the laser data. A comparison of SLR
data fitting procedures was done, either using an integrator plus
range/time bias functions, or by using a polynomial representation.
He concluded that artificial effects of about 3 ps (round trip travel
time) might be introduced; single-shot effects are smaller. It is
smaller than 1 ps for normal points, and is negligible compared to
the satellite signature effect.
Luck presented an evaluation of interpolation effects. In particular,
he studied different interpolation techniques, on various targets.
Depending on the exact application, large errors may be introduced
here. In conclusion, predictions need to be integrated at step sizes
much smaller than the normal point bin size, and interpolation should
be done in x/y/z rather than azimuth/elevation/range. Cubic splines
are not to be used.
Salminsh reported on an Engineering Data File system, in which a
large variety of aspects of the laser station (configuration) are
stored. Applications are comparison studies, to explain data anomalies,
to record the system history and such. Implementation of this configuration
management system is complete or in progress in Potsdam, Graz and
Wettzell. Results and examples are available at www.astr.lu.lv/edf.
Gibbs reported on the time bias detection and monitoring system
that is operational at Herstmonceux. It provides a rapid-turnaround
option to QC passes of a variety of satellites, taken by arbitrary
stations. A possible time bias is the particular parameter that can
be detected by this technique.
Glotov addressed the MCC experience on weekly, operational QC analysis.
He noted the differences between various QC reports, and suggested
several explanations: station coordinates, rejection procedures,
orbit solutions and incorrect estimations of range and time biases.
Schillak also addressed the QC analysis of the global network of
stations. In particular, he solves for (a time-series of) station
coordinates, which are used to monitor station performance (possible
range biases), or which may be used to expand ITRF2000 with epoch
coordinates and velocities of new stations.
Müller gave a presentation on the weekly network/EOP solutions,
that are generated for the AWG pilot project, and the QC aspects
embedded in this activity. This may focus on the latter (biases)
or on products (Helmert transformations, orbit overlaps). In addition
to these operational solutions, multi-year solutions are used for
Noomen gave an overview of the Delft QC analyses. He showed the
developments in data quality, computation models and analysis strategies,
and highlighted the progress in quality of the orbital solutions.
The inherent uncertainty of range and time bias estimates was discussed.
The system is expected to switch to a daily mode of operation shortly.