GPS for AMS : Status Report Agnieszka Jacholkowska LPTA Laboratoire de Physique Thorique et Astropar

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GPS for AMS Status ReportAgnieszka
Jacholkowska LPTA - Laboratoire de Physique
Théorique et Astroparticules - Montpellier

• NEWS about TOPSTAR3000
• LOL (Limits of Liability) signed with
  ALCATEL-SPACE (March 2005) , order to be sent in
  June 2005
• Go-ahead from CNES program directorate for the
  collaboration with CNES-Toulouse on tests and
  implementation
• Confirmation from GALILEO/GJU for collaboration
  with AMS contract in preparation

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Collaboration with CNES

• We started the planning with CNES collaborators
  following activities (meetings at CNES on Dec
  2004, Feb 2005)
• Training on data acquisition with a GPS receiver
  placed in a test bench (in the CNES Toulouse
  centre) with orbit simulator and a RF entry (talk
  of C. Zurbach)
• Engineering support for the TOPSTAR3000
  implementation
• Tuning of the flight TOPSTAR3000 parameters
  related to the ISS orbit
• Activities started at CNES Toulouse in February
• Next working sessions in May
• Working convention in preparation

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GPS clock parameters (free mode)stability
measurements with CNES module
UTC corrections for - satellite
distances - satellite velocities
- gravitation
Start-up
0.01 ?sec
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Implementaion

• Work on implementation scheme of GPS in AMS
  detector with A. Lebedev C.H. Lin (meetings at
  CERN, December 10, March 26)
• Main points discussed (talk of A. Lebedev)
• Use of GPS to synchronize AMS internal clocks
  (trigger) with GPS time via a p.p.s. signal. A
  proposal for the implementation exists and was
  elaborated by MIT group.
• Getting the UTC time as a time stamp for each
  trigger at the event builder stage of DAQ

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GPS - antennas

• Robert Becker April 04

GPS
antennas
60? apart 35? from horizontal
support 5cm
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Urgent Tasks

• Positions and pointing of the 2 antennas in ISS
  reference system (underway)
• ? orbital parameters to be inserted into
  TOPSTAR3000 flight module
• Interface with M-crate clarify responsibilities
  contributions
• Investigation of the magnetic field effects
  (hundred Gauss?) on the precision of time
  measurement
• ? Implementation of TOPSTAR3000
• in AMS02 2006 Q2