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ILRS Data and Products
The ILRS collects, archives, and distributes Satellite Laser Ranging (SLR), Lunar Laser Ranging (LLR), and transponder observation datasets of sufficient accuracy to satisfy the objectives of a wide range of scientific, engineering, and operational applications and experimentation. These data sets are used by the ILRS to generate a number of scientific and operational data products.
ILRS Data: Laser ranging normal points (NPTs) constitute the primary ILRS data product; they are generated following the conclusion of the laser pass and typically transmitted to data centers within hours. Laser ranging normal points are compressed data using all identified signals within a specified time interval. The length of this normal point interval is primarily dependent upon the satellite altitude; lower orbiting satellites have a shorter normal point interval than high-orbit satellites. Full-rate data include all valid satellite returns and are thus larger in volume; these data are routinely provided by most stations in the ILRS network. Full-rate data are useful for both engineering evaluation and scientific applications.
ILRS Products: Products derived from these SLR observations include precise satellite ephemerides, station positions and velocities of sites in the ILRS network, and Earth Orientation Parameters (EOPs, i.e., polar motion and rates, length-of-day).
ILRS Predictions: The laser ranging stations require satellite orbit information in order to point their instrument to the correct location and acquire returns from the retroreflectors. Mission operations centers generate these predicted future orbits from calculated ranging data and radiometric orbits; the files are transmitted to the stations through email or by storing them within data center archives. The Consolidated Prediction Format (CPF) is now used operationally for satellite predictions within the ILRS; CPF provides orbit data that accurately predict positions and ranges for a large variety of targets in tables of X, Y, and Z positions, which can be interpolated for accurate predictions.
ILRS data, products, and predictions are available through two data centers:
- Crustal Dynamics Data Information System (CDDIS) at NASA GSFC, Greenbelt, MD USA
- EUROLAS Data Center (EDC) at DGFI, Munich Germany
Recent News
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https://www.youtube.com/watch?v=Jwqz097N2IY&list=PLIIfsJS7iAuxXGqq0YLAUO_m_06za9vqr
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https://itrf.ign.fr/en/solutions/ITRF2020
The new reference frame realization includes the contributions of all the IAG Geodetic Services (IVS, ILRS, IDS, IGS) and their Analysis Centers and Combination Centers. The ILRS contribution was based on a reprocessing of SLR data to the LAGEOS, LAGEOS-2 & the two Etalon satellites from 1993.0 to 2020.0 and to LAGEOS only from 1983.0 to 1993.0.
The ILRS ASC is working on an ILRS extended version, the SLRF2020, which will include the SLR stations that were not part of the ITRF2020 solution and will provide instructions on how to get the highest accuracy results when implementing this extended model in SLR data analysis.
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We thank our station colleagues Andrea Di Mira, Jens Steinborn for their efforts, and congratulate them on this achievement!
During the current campaign (April 17- 30, 2022) ILRS stations in the Eastern Region of the Indian Ocean (Asia, Australia) will track IRNSS 1C plus IRNSS -1D. ILRS stations in the Western Region of the Indian Ocean (Europe, Africa) will track IRNSS 1C plus IRNSS- 1I. The IRNSS tracking data from the campaigns will be used to assess the performance of these IRNSS satellites, in a similar way to that used to validate the performance of other GNSS constellations such as Galileo.
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The following definitions have been agreed to:
- A pass is defined as all tracking that lasts less than a full satellite period. For geosynchronous satellites, the duration is capped at 24 hours; this is the standard product.
- A pass-segment is another term for a session (interval of continuous data) which is a reflection of how the data was taken at the station and submitted to the data centers. A single pass-segment/session is counted from one H1 to H8.
A pass includes all data taken on a satellite during one transit over the station. The pass-segment is just a magnification of how the data was taken and submitted.
Key Dates:
- June 20, 2022 (Abstract deadline)
- July 25, 2022 (Early registration deadline)
For more information, check the URL for the meeting: www.refag2022.org
Meetings
Many meetings have been canceled or postponed due to COVID-19. Please see the Meetings page for futher information.