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13th International Laser Ranging Workshop
"Toward Millimeter Accuracy"

Target Design, Signatures, and Biases (G. Appleby and G. Bianco, for V. Vasiliev)
Session Summary

Title Primary Author
Retroreflector Array Transfer Functions David Arnold
Difference of LAGEOS satellite response from raw data analysis of the collocation experiment between the Grasse Satellite and Lunar Laser Ranging stations Joëlle Nicolas
Recovery of target response function for centre-of-mass corrections of spherical satellites Toshimichi Otsubo
International experiment in space for investigation of a novel-type laser retroreflector Vladimir Vasiliev
Development and on-orbit performance of moderate-cost spherical retroreflector arrays for the STARSHINE program Robert Kessel
Reflector arrangement on H2A-LRE satellite Toshimichi Otsubo
The Atmospheric Neutral Density Experiment: a Mission Overview Andrew Nicholas
Velocity Aberration David Arnold
Design of a laser retro-reflector for the first satellite ranging mission in S. Korea on an elliptical orbit Seungbum Kim
Laser Retroreflector Array (LARA) for IRS Mission Kattimuthu Elango
LAGEOS-2 spin rate and orientation Robert Sherwood

This was a full session dealing with current and future laser reflector arrays. There is a need to understand the interactions between the arrays and the interrogating laser pulses in order not to degrade mm-levels of measurement precision when computing centre-of-mass corrections. Knowledge of the array configurations can also be exploited to determine spacecraft attitude through laser ranging and solar-glint analyses. New arrays are being developed which could open up new applications for SLR

Satellite Signatures

  • LAGEOS – there is theoretical, empirical and observational evidence for the need at mm levels of precision to apply system-dependent centre-of-mass (CoM) values to the data;
  • There are also aberration-space effects at the few mm level that have non-zero averages;
  • CoM values were derived for LAGEOS, AJISAI and ETALON that are applicable to the major system types – weak SPAD, strong C-SPAD, MCP.
  • The unique opportunity of co-located systems at Grasse was exploited as a check on system-dependent CoM corrections for LAGEOS and the large T/P ring array.
  • The point source Luneberg lens on METEOR-3 looks to be a good zero-signature target for further work, although there are link-budget issues;
  • The multi-array REFLECTOR satellite continues to be a challenge for interpretation of full-rate data for attitude-dynamics studies.

Spin-vector, velocity aberration

  • The spin rate of LRE has been determined from sparse SLR and optical flash data.
  • An operational system has been set up to record flash data at millisecond resolution during normal SLR work and has been used to determine LAGEOS-2 spin vector evolution for more than two years.
  • A theoretical treatment of the velocity aberration effect shows it to be independent of the refractive index of the CCR medium, which thus cannot be chosen to circumvent the need for CCR-spoiling.

Starshine , ANDE, IRS

  • The ongoing Starshine project has objectives including outreach and a retro-aging element.
  • The Atmospheric Neutral Density Experiment for shuttle launch by NRL includes novel active CCRs for telemetry through modulation of laser beams and two spherical satellites, active and passive.
  • The Indian Space Research Organisation is recommending that its future remote-sensing missions carry laser arrays to support precise orbit determination.


Content Owner and Webmaster: Carey Noll
Responsible NASA Official: Ed Grayzeck
Last Updated: June 17, 2014



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