13th International Laser Ranging
Workshop
"Toward Millimeter Accuracy"
Submitted
Abstracts
Station Performance Evaluation (C. Luceri and R. Wood)
Title |
Primary Author |
The stability of the SLR stations coordinates determined
from monthly arcs of LAGEOS-1 and LAGEOS-2 laser ranging in 1999-2001 |
Stanislaw Schillak |
Stanislaw Schillak
Space Research Centre of PAS
Borowiec, ul Drapalka 4
62-035 Kornik
POLAND
Voice: +48-61-8170-187
Fax: +48-61-8170-219
Email: sch@cbk.poznan.pl
Wnuk Edwin
A. Mickiewicz University, Astronomical Observatory, Poznan, Poland
Voice: +48-61-8292-771
Fax: +48-61-8292-772
Email: wnuk@amu.edu.pl
The determination of coordinates stability of the satellite laser
ranging stations is one of the methods for control the quality
of the laser ranging data. This work is continuation of the similar
paper about coordinates stability of the all SLR stations in 1999
and 2000. The paper presents results of the coordinates stability
determination for all SLR stations in the period 1999-2001 calculated
in the ITRF2000 system on the basis of data provided by the LAGEOS-1
and LAGEOS-2 laser ranging. The calculations were performed with
the usage of the GEODYN II program. Coordinates of the stations
were determined from monthly arcs. Typical RMS of (O-C) values
for the monthly orbital arcs was on a level of 1.7 cm. The final
stability of the coordinates of SLR stations for all components
varies from several millimeters to several centimeters. It was
found real movement for two stations Tateyama in 2000 and Arequipa
in 2001.
Oral presentation; received July 31, 2002
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MyStationPerformance.COM |
Van Husson |
HTSI
7515 Mission Drive
Lanham, Md 20706
USA
Voice: 301-805-3981
Fax: 301-805-3974
Email: van.husson@honeywell-tsi.com
P. Stevens, O. Brogdon, H. Vo
HTSI
7515 Mission Drive
Lanham, Md 20706
USA
There is a need for standardized, more comprehensive, easily
accessible and current ILRS network performance feedback as the
ILRS strives toward mm level reliability and accuracy.
Currently, many ILRS sites have limited on-site data assessment
capabilities. At some locations, system problems (e.g. equipment
problems, data instability, large biases, insufficient data) linger
for prolonged periods of time. Conflicting bias information from
different analysis centers can also complicate and delay problem
resolution.
Our recommended solution to these challenges is the development
of a new service, MyStationPerformance.COM .
The key features of MyStationPerformance.COM will be:
- Web-based
- Dynamic - near real time analysis (short and long term)
- Comprehensive (i.e. data quantity, RMS stability, bias stability)
- Graphical
- User Friendly
- Interactive
The primary customer of this service will be the ILRS sites (i.e.
operators and engineering support). Utilizing this service, sites
can expedite the diagnosis of their performance problems, thereby
facilitating a rapid resolution and return to acceptable performance.
The ILRS analyst community can also use these site assessment
tools to aid in the quick identification of station performance
problems.
If effectively used, MyStationPerformance.COM will enable the
transition of data quality control from the analysts to the individual
stations.
Oral presentation; received August 20, 2002
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Results of the triple laser ranging collocation
experiment at the Grasse observatory, France (September - November
2001) |
Joëlle Nicolas |
Observatoire de la Côte d'Azur/CERGA
Avenue Nicolas Copernic
F- 06130 GRASSE
FRANCE
Voice: 33-493405381
Fax: 33-493405333
Email: Joelle.Nicolas@obs-azur.fr
P. Bonnefond, O. Laurain, P. Exertier, and F. Barlier
Observatoire de la Côte d'Azur/CERGA
Avenue Nicolas Copernic
F- 06130 GRASSE
FRANCE
At the Grasse observatory, France, we have the opportunity to
have three independent laser ranging stations very close one to
each other (about 20 m): a Satellite Laser Ranging (SLR) station,
a Lunar Laser Ranging (LLR) station, and the French Transportable
Laser Ranging Station (FTLRS). We used this unique configuration
to perform a collocation experiment between these three stations
from September to November 2001. This experiment was first performed
to qualify the new performances of the FTLRS after a long phase
of great improvements and before its departure to Corsica for
the oceanographic satellite JASON-1 (2001) calibration and validation
campaign during the first six-month of 2002. But furthermore,
we used this unique configuration to estimate and compare instrumental
bias for each station. Herein, we present the main results on
the SLR, the LLR and the FTLRS stations obtained with the analysis
of this collocation experiment. One of the main results is the
validation at the millimetric level for the performances of the
FTLRS in its new configuration. Moreover, our analysis shows the
consistency at the level of few millimeters between the three
laser stations of the OCA, result which demonstrates the strength
of the SLR technique. Another important result is the confirmation
of a systematical error of 2 cm on TOPEX/POSEIDON laser mean residuals
for some European stations such as Grasse and Herstmonceux stations.
Oral presentation; received August 21, 2002
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Status of the KACST SLR Program Past, Present
and Future |
Turki Al-Saud |
Space Research Institute
King Abdulaziz City for Science and Technology
P. O. Box 6086
Riyadh 11442
SAUDI ARABIA
Email: talsaud@kacst.edu.sa
Overview of King Abdulaziz City for Science and Technology (KACST)
and Space Research Institute (SRI), and how laser ranging fits
the charter, in addition to the important role of Saudi Arabia
in the global network.
SALRO has realized its re-commission process, is now gearing
up to run two operations shifts on a permanent basis. Increasing
emphasis is being placed on regular data productivity.
Planning is underway to install a purpose-built active aircraft
detection system.
Graphics are presented to show performance over the last few
years.
Central to its science charter, KACST will further expand applications
through cooperation with the scientific communities within the
Kingdom, to include such studies as:
- The landmass subsidence, gravity etc.
- Orbital mechanics.
- Relativity.
- Earth rotation.
- etc.
Oral presentation; received August 22, 2002
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Range Bias vs Applied System Delay |
Toshimichi Otsubo |
Takako Genba
Communications Research Laboratory
893-1 Hirai, Kashima
314-0012
JAPAN
Voice: +81-423-27-6923
Fax: +81-299-84-7160
Email: otsubo@crl.go.jp
Having attained the millimetre-level precision (1-2 mm for normal
point, 4-6 mm for single shot), we now have to pay more attentions
to the accuracy of laser ranging data. At CRL, weekly reports
of 7-satellite residual analysis, producing pass-by-pass range
bias and time bias, have been distributed to the ILRS community
for 3 years. The post-fit residuals are also useful to check the
data accuracy when they are sorted by associated data such as
the number of returns per bin [Otsubo, Matera workshop, 2000].
We newly found it useful to choose the applied system delay as
a sorting parameter. That is, it is possible to detect potential
problems in ranging to terrestrial targets or in subtracting system
delay from raw range data. The actual analysis results using recent
one year's data of LAGEOS, AJISAI and STARLETTE will be presented.
Oral presentation; received August 22, 2002
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Absolute and Relative Range Bias Detection Capabilities |
Van Husson |
HTSI
7515 Mission Drive
Lanham, MD 20706
USA
Voice: 301-805-3981
Fax: 301-805-3974
Email: van.husson@honeywell-tsi.com
The computed orbit is the final yardstick in accessing ILRS
data quality. The absolute accuracy of orbit determination depends
ultimately on the quality and quantity of data, but is a trailing
(not leading) indicator of 'true' network performance. In order
to keep pace and to monitor improvements is laser ranging technology,
analysis techniques continually need to be enhanced. This is mandatory
for the ILRS is to achieve its vision of mm level accuracy.
Orbital analysis techniques (i.e. collocation, short arc, long
arc) have their own inherent strength and weaknesses and will
be characterized in terms of absolute and relative range bias
detection capabilities. Some new bias detection techniques will
be explored and evaluated.
Oral paper; received August 23, 2002
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The precise data processing in
MCC Analysis Center |
Vladimir Glotov |
Mission Control Center
4, Pionerskaya st., Korolyov
Moscow region, 141070
RUSSIA
Voice: 007-095-586 83 80
Fax: 007-095-586 83 80
Email: cnss@mcc.rsa.ru
V. Mitrikas, S. Revnivykh, M. Zinkovsky
Mission Control Center
4, Pionerskaya st., Korolyov
Moscow region, 141070
RUSSIA
SLR data Analysis Center is a part of the MCC Navigation and
Coordinate-time Service. MCC has certain technical capabilities
and its own software for the precise navigation and SLR data processing,
the monitoring of the GLONASS and GPS signals performance. The
MCC Navigation and Coordinate-time Service works continuously
in real-time mode.
The products are available from MCC:
- regular daily values of PM and LOD
- bulletins of LAGEOS-1&2 SLR data performance
- GLONASS orbits in SP3 format
- the transformation from PZ90 reference frame to WGS-84
- SLR stations coordinates
- low satellites precise orbits (Reflector, Meteor-3M)
- GLONASS/GPS performance characteristics in real-time and a
posteriori modes
- Precise GLONASS/GPS orbits on the base of navigation receivers
data
- Etc.
The report contain the analysis of the technical and software
capabilities and available precise products of the MCC Navigation
and Coordinate-time Service.
Oral presentation; received August 22, 2002
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