NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Analysis of One-Way Laser Ranging Data to LRO, Time Transfer and Clock CharacterizationWe processed and analyzed one-way laser ranging data from International Laser Ranging Service ground stations to NASA's Lunar Reconnaissance Orbiter (LRO), obtained from June 13, 2009 until September 30, 2014. We pair and analyze the one-way range observables from station laser fire and spacecraft laser arrival times by using nominal LRO orbit models based on the GRAIL gravity field. We apply corrections for instrument range walk, as well as for atmospheric and relativistic effects. In total we derived a tracking data volume of approximately 3000 hours featuring 64 million Full Rate and 1.5 million Normal Point observations. From a statistical analysis of the dataset we evaluate the experiment and the ground station performance. We observe a laser ranging measurement precision of 12.3 centimeters in case of the Full Rate data which surpasses the LOLA (Lunar Orbiting Laser Altimeter) timestamp precision of 15 centimeters. The averaging to Normal Point data further reduces the measurement precision to 5.6 centimeters. We characterized the LRO clock with fits throughout the mission time and estimated the rate to 6.9 times10 (sup -8), the aging to 1.6 times 10 (sup -12) per day and the change of aging to 2.3 times 10 (sup -14) per day squared over all mission phases. The fits also provide referencing of onboard time to the TDB (Barycentric Dynamical Time) time scale at a precision of 166 nanoseconds over two and 256 nanoseconds over all mission phases, representing ground to space time transfer. Furthermore we measure ground station clock differences from the fits as well as from simultaneous passes which we use for ground to ground time transfer from common view observations. We observed relative offsets ranging from 33 to 560 nanoseconds and relative rates ranging from 2 times 10 (sup -13) to 6 times 10 (sup -12) between the ground station clocks during selected mission phases. We study the results from the different methods and discuss their applicability for time transfer.
Document ID
20170002328
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Bauer, S.
(Deutsches Zentrum fuer Luft- und Raumfahrt e.V. Berlin, Germany)
Hussmann, H.
(Deutsches Zentrum fuer Luft- und Raumfahrt e.V. Berlin, Germany)
Oberst, J.
(Deutsches Zentrum fuer Luft- und Raumfahrt e.V. Berlin, Germany)
Dirkx, D.
(Technische Univ. Delft, Netherlands)
Mao, D.
(Joint Inst. for VLBI in Europe Dwingeloo, Netherlands)
Neumann, G. A.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mazarico, E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Torrence, M. H.
(Stinger Ghaffarian Technologies, Inc. Greenbelt, MD, United States)
McGarry, J. F.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Smith, D. E.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Zuber, M. T.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Date Acquired
March 17, 2017
Publication Date
September 21, 2016
Publication Information
Publication: Icarus
Publisher: Science Direct
Volume: 283
ISSN: 0019-1035
e-ISSN: 1090-2643
Subject Category
Lunar And Planetary Science And Exploration
Report/Patent Number
GSFC-E-DAA-TN40011
Funding Number(s)
CONTRACT_GRANT: NNG15HZ37C
CONTRACT_GRANT: NNA14AB01A
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available