Project News


  • Apache Point Lunar Laser Ranging StationFirst year of Apache Point Lunar Laser Ranging data released under NASA stewardship
    02/11/2022

    In 2021, the Apache Point Lunar Laser Ranging station became part of the NASA Space Geodesy Network with New Mexico State University responsible for the on-site day-to-day operations and maintenance of the system. Over the past year, the NASA team worked with the former APOLLO team to establish best practices regarding observation and reduction of raw data into normal points, including the development of a new quality control process to identify centimeter-level biases in lunar laser ranging data. The new process helps to eliminate erroneous normal points and systematic biases prior to data publication. NASA Postdoctoral Fellow Nicholas Colmenares (one of the primary members of the former APOLLO group) led the development of the data procedures and archival of the data in the new version 2 of the Consolidated Range Data (CRD) format. The full set of 2021 data is now available from the Crustal Dynamics Data Information System (CDDIS) at https://cddis.nasa.gov/Data_and_Derived_Products/SLR/Lunar_laser_ranging_data.html.

  • George VeisThe passing of Professor George Veis
    01/31/2022

    It is with great sadness that we convey the passing of George Veis, scientist, teacher, and a good friend to all of us; truly one of the fathers of Space Geodesy.

    George was born in Athens in 1929. In 1951 he graduated in Surveying Engineering from the National Technical University of Athens (NTUA). In 1955 he was the recipient of a Greek state fellowship for advanced studies in Paris at the Sorbonne and the Ecole Nationale des Sciences Geographiques. He then spent some time at the Observatoire de Paris and the Bureau Gravimetrique International. Starting in 1957 he continued his postgraduate studies at the Ohio State University, where he was awarded with his PhD in 1958, after defending his famous dissertation on the "Geodetic Applications of Observations of the Moon, Artificial Satellites and Rockets".

    George was one of the framers of the early Satellite Geodesy Program at the Smithsonian Astrophysical Observatory, which itself was a fundamental element of the early NASA Space Geodesy Activity.

    George joined the Smithsonian Astrophysical Observatory (SAO), (later the Harvard Smithsonian Center for Astrophysics) in 1959 at the beginning of satellite geodesy era and the deployment of the Baker Nunn Satellite Tracking Cameras for geodetic and other scientific research. Over two decades as principal scientific consultant at SAO, he helped guide activities as the satellite geodesy program evolved with the Baker Nunn Camera and the emergence of Satellite Laser Ranging (SLR). He worked with the engineers on the design of the SAO SLR systems and the retroreflectors on satellites.

    While at SAO, George contributed the early concept and evolution of the Differential Orbit Improvement (DOI) Program, which became the main analysis tool for satellite tracking, geopotential estimation, station coordinate determination, and satellite drag research. He defined the fundamental reference system used for many years, which now forms the basis of modern models of earth rotation, precession, and nutation. He also initiated the SAO Star Catalogue project, which provided a uniform all-sky catalogue for precision camera observations, and was used for many years all over the world.

    Keeping his connection with SAO, George returned to NTUA, where he was elected Professor of Surveying (renamed later Higher Geodesy and Cartography) to develop satellite geodesy in Greece.

    In 1969 he established the tracking station at Dionysos, installed a Baker-Nunn camera there, and began developing a laser ranging system. He had the vision of a complete geophysical observatory with, of course, satellite tracking, a meteorological observatory, earth tide monitoring, strain gauges, etc. He also developed surveys based on Transit Doppler measurements and GPS when the equipment became available. As an early mobile SLR deployment, George transported the Dionysos laser system to the remote island of Othoni, north of Corfu, Greece, and used it in October of 1973 to measure the distance to an Italian target at Specchia, Cristi at the tip of the boot. This measurement enabled for the first time the accurate connection of the Greek geodetic network with main Europe (Balodimos D., Geodetic Connection between Greece and Italy, Anno xxxvi, Bollettino di Geodesia e scienze Affini, 1977).

    Dionysos laser system deployed on the island of Othoni northeast of Corfu, Greece, in October of 1973 (D. Balodimos personal archive).

    Dionysos laser system deployed on the island of Othoni northeast of Corfu, Greece, in October of 1973 (D. Balodimos personal archive).

    George's department at NTUA was a major source of young geodesists for the global community.

    The Dionysos station contributed to the MERIT, MEDLAS, WEGENER and other programs. Between 1965 and 1984 George also organised the famous series of international symposia, in Lagonissi and Athens, on the "Use of Artificial Satellites for Geodesy and Geodynamics". The five volumes of the proceedings of these symposia document a great part of 20 years of geodetic history.

    George's career as a science-administrator was also rich. As a member of the NTUA's senate and the Dean of the Faculty of Surveying Engineering, he suffered a short, but painful imprisonment by the military dictatorship in Greece, because of his proper academic comportment during students protest which caused the furious reaction of the regime. He was the Secretary General of the Hellenic Committee for Geodesy and Geophysics, its President from 1982 to 1990. He was President of the Board of the Athens National Observatory and the President of the Observatory's Scientific Council. He was the President of the Cadastre and Mapping Organization of Greece and the President of the National Consultative Council for Research. He also presided over several IAG/IUGG and COSPAR organizations. George retired from the NTUA in 1997. The ETH of Zurich honored him with an Honorary Doctor's degree.

    George continued to be active in a key position as the President of the important Supreme Council for Personnel Selection, a state authority responsible for the selection of personnel for the public administration in Greece. George was awarded the Levallois Medal in 2003 in recognition of his distinguished service to the science of geodesy.

    George Veis continued to be endlessly creative, engaging, seducing, elegant, modern and forever young scientist, who shared his ideas with enthusiasm, and helped everyone with whom he had contact. He witnessed the birth of space geodesy, its evolution from many meters to mm's, and continued to think about its future until his death. He had celebrated his 92nd birthday last September 8th, 2021.

    George is survived by his wife Katerina, and children Konstandinos, Alexandros, Ino, Nico and Maria, and his grandchildren. His funeral is set for January 31, at noon.

    May his memory be an abiding blessing.

    George Veis during his last visit to the USA in 2014, while attending the ILRS Annapolis Workshop.

    George Veis during his last visit to the USA in 2014, while attending the ILRS Annapolis Workshop.

  • Tom ClarkThe passing of Thomas Clark
    10/05/2021

    Space Geodesy lost a longtime colleague and friend with the passing of Thomas Arvid Clark on September 28, 2021. Tom was a pioneer in Space Geodesy and Very Long Baseline Interferometry (VLBI), and a founding member of the NASA Crustal Dynamics Project.

    Tom received his B.S. in Engineering Physics and his Ph.D. in Astro-Geophysics from the University of Colorado in 1961 and 1967 respectively. From 1966 to 1968, he served as Chief of the Astronomy Branch at NASA Marshall Space Flight Center and as Project Scientist on the Spacelab Coronagraph. At GSFC, where he moved in 1968, Tom received numerous NASA awards for his pioneering work on Radio Astronomy Explorer 1 and 2 and several generations of Very Long Baseline Interferometry systems. Tom developed the Totally Accurate Clock (TAC), an inexpensive GPS timing receiver that found widespread use in a number of global networks. Tom was named a Fellow of the American Geophysical Union (AGU) in 1991 and a Fellow of the International Association of Geodesy (IAG) in 1999. Tom was also a pioneer in amateur and digital radio; he designed and flew several low cost satellites for relaying amateur radio messages around the globe and is a past president of AMSAT. He was one of only 50 initial inductees into the CQ Amateur Radio Hall of Fame, a list which included such engineering luminaries and inventors as Guglielmo Marconi (radio), Samuel Morse (telegraph), Nikola Tesla (HF generators and radio), and John Bardeen and William Schockley (transistor). Tom retired from GSFC in 2001 but remained active in Amateur Radio activities.

    Those of us who worked with Tom during the Crustal Dynamics period remember him as a brilliant mind, a very interesting and sometimes caustic character, but someone who was kind, supportive, and very helpful to those of us around him. We will miss him.

  • ILRS logoILRS Virtual World Tour 2021 third circular released
    08/31/2021

    Dear Colleagues:

    We look forward to seeing you at "ILRS Virtual World Tour 2021". Progress has been made at the five tour hosts and by the session chairs. Now we have just opened the registration form. Please visit the event website below and find the link.
    https://ilrs.gsfc.nasa.gov/ILRS_Virtual_World_Tour_2021/index.html
    Registration period: October 1 to 15, 2021

    Participants are encouraged to register as a group if possible, due to the limit of Microsoft Teams individual participants allowed. The URL links will be sent only to the registered people.

    See you in a month!

    ILRS Virtual World Tour 2021 Organizers:
    Claudia Carabajal/SSAI, Inc, NASA Goddard Space Flight Center, USA
    Evan Hoffman/NASA Goddard Space Flight Center, USA
    Igor Ignatenko/VNIIFTRI, Russia
    Jason Laing/Peraton NSGN Operations Lead, USA
    Toshimichi Otsubo/Hitotsubashi University, Japan (Chair)
    Michael Pearlman/ Harvard-Smithsonian Center for Astrophysics, USA
    Ulrich Schreiber/Geodetic Observatory Wettzell, Germany
    Zhang Zhongping/Shanghai Astronomical Observatory, China

  • ILRS logoILRS Virtual World Tour 2021 second circular released
    08/31/2021

    Dear Colleagues:

    We are happy to report the updates on this year's "ILRS Virtual World Tour". In addition to the virtual visits to the stations (∼120 min), short special add-on sessions (30-60 min) are planned with the help of the Standing Committee Chairs. We look forward to seeing you in the last week of October.

    Schedule (tentative; in UTC):

    Monday, October 25
    12:00 Opening session with reports from ILRS CB and Geodetic Community
    12:45 Virtual Tour of Herstmonceux, UK

    Tuesday, October 26
    13:00 Virtual Tour of Wettzell, Germany
    15:00 Special Session on Network & Engineering, LLR and Space Debris Ranging

    Wednesday, October 27
    13:00 Virtual Tour of Mendeleevo, Russia
    15:00 Special Session on Analysis

    Thursday, October 28
    06:00 Virtual Tour of Shanghai, China
    08:00 Special Session on Missions (1)

    Friday, October 29
    16:00 Virtual Tour of Monument Peak, USA
    18:00 Special Session on Data Format and Missions (2), and Closing

    Workshop website: https://ilrs.gsfc.nasa.gov/ILRS_Virtual_World_Tour_2021/index.html

    Logistics:
    Microsoft Teams will be used for all of these sessions.
    The Third Circular will be issued later with details on registration.

    ILRS Virtual World Tour 2021 Organizers:
    Claudia Carabajal/SSAI, Inc @ NASA Goddard Space Flight Center, USA
    Evan Hoffman/NASA Goddard Space Flight Center, USA
    Igor Ignatenko/VNIIFTRI, Russia
    Jason Laing/Peraton NSGN Operations Lead, USA
    Toshimichi Otsubo/Hitotsubashi University, Japan (Chair)
    Michael Pearlman/Center for Astrophysics, USA
    Ulrich Schreiber/Geodetic Observatory Wettzell, Germany
    Zhang Zhongping/Shanghai Astronomical Observatory, China

  • USNA and NASA logosThe Rector of the University of San Augustin in Arequipa, Peru, Dr. Rohel Sánchez Sánchez, visited the Instituto Astronómico y Aeroespacial Pedro Paulet (IAAPP) and the TLRS-3 Station
    08/26/2021

    The Rector of the University of San Augustin in Arequipa, Peru, Dr. Rohel Sánchez Sánchez, visited the Instituto Astronómico y Aeroespacial Pedro Paulet (IAAPP) and the TLRS-3 Station to commemorate legalizing UNSA ownership of the property that has been used by USNO to support NASA and other research activities for the past 62 years. The Manager of the TLRS-3 Station, Dr. P. Raul Yanyachi, is also featured in the video posted by UNSA TV on social media.

    Watch video on social media

  • group photo with Dan O'Gara in the centerDan O'Gara retired after 37 years of dedicated support to the International Geodetic Community
    05/12/2021

    The International Laser Ranging Service (ILRS) and the NASA Space Geodesy Project (SGP) express our appreciation and congratulations to Dan O'Gara for his 37 years of service to the international geodetic community. Dan retired from the University of Hawaii (UH) on April 30, 2021.

    Much of Dan O'Gara's work at UH was with the Lunar Ranging Experiment (LURE) observatory. The University of Hawaii's LURE was installed on Haleakala in 1973. Dan joined the team in the early 1980s, performing maintenance and developing the software to control the LURE beam director and operating the system. The station became known as HOLLAS by the ILRS community as it gained the capability to track satellites and took on the 4-character code of HALL (for Haleakala Laser), but the locals always referred to it as LURE. Dan eventually became the station manager for LURE while he continued to develop the software and operate the system.

    See https://ilrs.gsfc.nasa.gov/network/stations/inactive/HALL_station_info.html and http://koa.ifa.hawaii.edu/Lure/#:~:text=The%20Lure%20Observatory%20is%20located,Maui%20in%20the%20Hawaiian%20archipelago.&text=The%20Lunar%20Ranging%20Experiment%20(LURE,and%20reflectors%20on%20the%20Moon

    The LURE facility was decommissioned in 1990 to make room for another experiment. In 2006, NASA installed the TLRS-4 Satellite Laser Ranging station at a different location on the top of the mountain. Dan continued his work as station manager, operator, and laser ranging software expert for TLRS-4.

    Dan is well known and liked by everyone in the ILRS and SGP. He continued his interest in the lunar community even after the UH lunar laser ranging program ended. He participated in multiple ILRS Workshops including the Workshop in Annapolis which celebrated the 50th anniversary of SLR. He hosted numerous site visits to Haleakala by many groups and supported the Space Geodesy Project's preliminary work to deploy a next generation SLR station and new GNSS stations on the top of Haleakala, helping the SGP team find a good location for the new SLR system and supporting the team's site visit in 2015.

    The Maui SLR stations have played a critical role in the international SLR network by covering satellite tracking over the Pacific. The station team under the leadership and management of Dan O'Gara has done a great job. His calm demeanor and sense of humor has been much appreciated.

    Dan was the face of Hawaii laser ranging for many decades. He will be greatly missed by his colleagues and friends in the Space Geodesy Project and the International Laser Ranging Service. We wish Dan a healthy and happy retirement, and great success in his future plans!

    group photo with Dan O'Gara in the centerDan O'Gara, featured at the center of the picture, accompanied by SGP folks during a site visit in 2015. From left to right: Jan McGarry, Stephen Merkowitz, Dan O'Gara, Jim Long, Scott Wetzel, and David Stowers. (Photo credit: Scott Wetzel)