Transponder WG Charter

This charter was created June 2005.

Preamble

Presently, transponders are not used in the field of SLR and LLR. The great advantage of this technology is a considerable improvement in the link budget for lunar or deep space ranging applications. However, this comes at the expense of more technological complexity. Now that science missions requiring precise ranging and/or time transfer on an interplanetary scale are being seriously proposed, it is both appropriate and timely that the ILRS form a Working Group to consider all aspects of the transponder technique to ensure that laser ranging will play an important role in interplanetary science.

Goals

Recognizing the existing diversity of the laser ranging technology, this working group seeks to evaluate the potential of transponder applications and to recommend basic concepts to the ILRS. Items of particular importance are:

• Evaluate the technical and operational implications of echo transponders
• Evaluate the technical and operational  implications of asynchronous transponders
• Investigate the implications of different lasers and their respective wavelength
• Evaluate the operational and cost consequences for participating ILRS stations and analysis centers, which the transponder application implies. This includes hardware and operating software modifications, prediction format issues, data file structures, and formats and data reduction practices
• Evaluate the instrumental requirements of the space segment, including the range reduction to the center of mass of the satellite, space transponder design and telemetry requirements.

The working group organizes transponder sessions at the ILRS workshops.

Responsible Government Official: Carey Noll
NASA's Privacy Policy and Important Notices

Send us your comments

Last modified date: Friday, July 08, 2005
Author: Ulrich Schreiber
Maintained by: Carey Noll