ILRS Home Page

Overview

Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) use short-pulse lasers and state-of-the-art optical receivers and timing electronics to measure the two-way time of flight (and hence distance) from ground stations to retroreflector arrays on Earth orbiting satellites and the Moon. Scientific products derived using SLR and LLR data include precise geocentric positions and motions of ground stations, satellite orbits, components of Earth’s gravity field and their temporal variations, Earth Orientation Parameters (EOP), 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 can perform very accurate time transfer between sites far apart. Laser ranging activities are organized under the International Laser Ranging Service (ILRS) which provides global satellite and lunar laser ranging data and their derived data products to support research in geodesy, geophysics, Lunar science, and fundamental constants. This includes data products that are fundamental to the International Terrestrial Reference Frame (ITRF), which is established and maintained by the International Earth Rotation and Reference Systems Service (IERS). The ILRS develops the necessary global standards/specifications for laser ranging activities and encourages international adherence to its conventions.

Quick Links

Welcome

NGSLR Greenbelt, MD

Highlights

EOSDIS awarded the 2015 Pecora awardRelease Date: 02/14/2018EOSDIS was awarded the 2015 Pecora award. This prestigious award is given to groups that make outstanding contributions toward understanding the Earth by means of remote sensing. The citation highlights the EOSDIS accomplishments in providing an open archive system for a global user community. CDDIS is one of twelve DAACs supporting EOSDIS efforts through the Earth Science Data and Information System (ESDIS) project. Carey Noll, CDDIS Manager, accepted their award certificate from Andy Mitchell, ESDIS Project Manager, and Jeanne Behnke, Deputy Project Manager/Operations, at the 2018 DAAC Managers Meeting.

LARGE campaign to begin February 15Release Date: 02/06/2018The first LARGE Campaign for 2018 will run from February 15 to May 15. Each GNSS constellation has identified 4 primary and 4 secondary satellites for tracking:

System
GLONASS
Galileo
COMPASS

Primary
GLONASS-131, -134, -136, -137
Galileo-102, -202, -209, -210
Compass-G1, -I3, -M3, -MS1

System
GLONASS
Galileo
COMPASS

Secondary
GLONASS -128, -132, -133, -135
Galileo-103, -203, -211, -213
Compass-I5, -IS2, -I6B, -MS2

Please refer to the ILRS priority list on February 15 for the exact priorities. Also note that in April, the list of secondary satellites for Galileo will change as per request from the mission.

https://ilrs.cddis.eosdis.nasa.gov/missions/mission_operations/priorities/index.html

During the campaign, the ILRS will provide GLONASS, Galileo, and Compass predictions to the stations for ONLY THESE SELECTED SATELLITES in order to encourage stations to focus on only these targets.

Stations are requested to track the primary satellites over at least two, preferably three, widely spaced segments over the arc, with each segment containing at least two normal points. For the secondary satellites, stations are asked to track at least one segment with at least two normal points over the arc. If some of the primary satellites cannot be tracked due to daylight, weather conditions or other reasons, then we are asking the stations to put more emphasis on the secondary satellites.

First Circular for the 21st International Workshop on Laser Ranging ReleasedRelease Date: 02/02/2018The Space Environment Research Centre (SERC) and the International Laser Ranging Service (ILRS) are pleased to announce that the 21st International Workshop on Laser Ranging will be held in Canberra, Australia during the week of November 04-09, 2018 at the John Curtin School of Medical Research (Australian National University) and Mount Stromlo. The first circular has been released.

ILRS Approves New Network Application Form and PolicyRelease Date: 06/14/2017The ILRS has approved a new policy and application form for new stations to join the ILRS network.

More news...

Recent News

First successful SLR returns to S-Net - The SLR system in Riga, Latvia was the first ILRS station to obtain returns from one of the four SNET satellites (SNET-4); Yarragadee, Australia also tracked SNET-4 the following day. Riga obtained returns at 21:57 UTC on April 12; Yarragadee's first successful pass was on April 13 at 16:00 UTC. Congratulations to both stations on their persistent efforts to range to these difficult targets.

Time Transfer by Laser Link (T2L2) mission onboard the Jason-2 satellite is now completed - The Time Transfer by Laser Link (T2L2) mission onboard the Jason-2 satellite is now completed. The T2L2 space instrument, which has been in operation for nearly 10 years, will be turned off on April 09, 2018. Most of the initial objectives for the experiment have been successfully achieved. The Jason-2 satellite remains operational, as does laser ranging to the satellite.

New NASA VLBI Civil Servant position open for applications - A new NASA VLBI Civil Servant position is now posted and open for applications. There are two postings, one senior and one mid-level, and applicants should decide which one best fits his/her experience level:

GS-14: http://www.usajobs.gov/GetJob/ViewDetails/493509700

GS-15: http://www.usajobs.gov/GetJob/ViewDetails/493510000

The postings currently close on Tuesday, March 27, 2018. Please note that the job is only open to U.S. citizens and U.S. nationals.