The ILRS: approaching 20 years and planning for the future
Loading...
Links to Files
Author/Creator ORCID
Date
2019-03-19
Type of Work
Department
Program
Citation of Original Publication
Pearlman, M.R., Noll, C.E., Pavlis, E.C. et al. J Geod (2019). https://doi.org/10.1007/s00190-019-01241-1
Rights
This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
This is a post-peer-review, pre-copyedit version of an article published in Journal of Geodesy. The final authenticated version is available online at: https://doi.org/10.1007/s00190-019-01241-1
Access to this item will begin on March 19, 2020
This is a post-peer-review, pre-copyedit version of an article published in Journal of Geodesy. The final authenticated version is available online at: https://doi.org/10.1007/s00190-019-01241-1
Access to this item will begin on March 19, 2020
Abstract
The International Laser Ranging Service (ILRS) was established by the International Association of Geodesy (IAG) in 1998
to support programs in geodesy, geophysics, fundamental constants and lunar research, and to provide the International Earth
Rotation Service with data products that are essential to the maintenance and improvement in the International Terrestrial
Reference Frame (ITRF), the basis for metric measurements of changes in the Earth and Earth–Moon system. Other scientific
products derived from laser ranging include precise geocentric positions and motions of ground stations, satellite orbits,
components of Earth’s gravity field and their temporal variations, Earth Orientation Parameters, precise lunar ephemerides
and information about the internal structure of the Moon. Laser ranging systems are already measuring the one-way distance
to remote optical receivers in space and are performing very accurate time transfer between remote sites in the Earth and in
Space. The ILRS works closely with the IAG’s Global Geodetic Observing System. The ILRS develops (1) the standards and
specifications necessary for product consistency, and (2) the priorities and tracking strategies required to maximize network
efficiency. The service collects, merges, analyzes, archives and distributes satellite and lunar laser ranging data to satisfy a
variety of scientific, engineering, and operational needs and encourages the application of new technologies to enhance the
quality, quantity, and cost effectiveness of its data products. The ILRS works with (1) new satellite missions in the design
and building of retroreflector targets to maximize data quality and quantity, and (2) science programs to optimize scientific
data yield. Since its inception, the ILRS has grown to include forty laser ranging stations distributed around the world. The
ILRS stations track more than ninety satellites from low Earth orbit (LEO) to the geosynchronous orbit altitude as well as
retroreflector arrays on the surface of the Moon. Applications have been expanded to include time transfer, asynchronous
ranging for targets at extended ranges, free space quantum telecommunications, and the tracking of space debris. Laser
ranging technology is moving to lower energy, higher repetition rates (kHz), single-photon-sensitive detectors, shorter pulse
widths, shorter normal point intervals for faster data acquisition, and increased pass interleaving, automated to autonomous
operation with remote access, and embedded software for real-time updates and decision making. An example of pass interleaving
is presented for the Yarragadee station (see Fig. 4); tracking of LEO satellites is often accommodated during break
in LEO and GNSS passes. New satellites arrays provide more compact targets and work continues on the development of
lighter less expensive arrays for satellites and the moon. The service now provides operational ITRF products including daily/
weekly station positions and daily resolution Earth orientation products; the flow of weekly combination of satellite orbit
files for LAGEOS/Etalon-1 and -2 has recently been established. New products are under testing through a pilot project on
systematic error monitoring currently underway. The article will give an overview of activities underway within the service,
paths forward presently envisioned, and current issues and challenges.