AMICA

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• AMICA
• STAR TRACKER for AMS02
• CARSO
• Center For Advanced Research in Space Optics
• Trieste, Italy
• Paolo Trampus
• CERN, 22 Jan 2004

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INTRODUCTION

• AMICA is a star tracker designed for the AMS02
  instrument
• It compares the position of the stars acquired by
  the cameras with the stars stored in the on-board
  catalogue

• It will give the pointing direction of the
  Silicon Tracker with arc-second precision
• It uses two cameras looking in different
  directions to increase the recognition probability

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ASTC OPTICS BAFFLE

Separated components baffle, lens cover with
filters and lens.
Note the baffle in the drawing has no connection
parts to the AMS structure they will be added
when the attachment point will be defined (to the
M-structure or to the vacuum case) .
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ASTC OPTICS BAFFLE SECTION
Section of the lens, lens cover with filters and
baffle. A MLI (or equivalent material) will
optically isolate the rear part of the baffle.
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LENS COVER

  Section of the lens cover with filters the
blue filter is 3 mm thick , the red is 2 mm both
have a diameter of 70 mm   masses blue filter
21 gr red filter 32 gr   Al cover 35.7
gr    Cover material Al 6061
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CCD BOARD
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SOFTWARE STRUCTURE-1
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SOFTWARE STRUCTURE-2
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AMICAGPS CONNECTION TO AMS
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INTERFACING DATA FLOW

• ASTE will be connected to a USCM (Universal Slow
  Control Motion) through RS-232 lines.
• There will be two RS232 lines, one for each of
  the two redundant USCM
• Both lines can be used for sending all the
  commands and for receiving all the data.
• The two lines are 19.2Kbaud and 9.6Kbaud
  respectively, the signals levels are TTL.
• Only one USCM should be active at a given time.

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INTERFACING SYNCHRONIZATION

• The AMS Sync signal (coming from the GPS) resets
  the 32-bit Relative counter. This counter has an
  input clock of 1Khz, the maximum count is
  4,294,967,296, corresponding to 49.7 days.
• After the digital Sync reset is given, AMS
  provides through the serial line the absolute
  time command.

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INTERFACING COMMANDS (1)

• UPLOAD COMMAND
• Upload Command contains part of a new program
  version that is sent to Amica ASTE
• Attitude RPY command
• contains the three float values corresponding to
  the Roll, Pitch and Yaw of the ISS and the
  starting time of the new attitude.
• Orbit TLE command
• The Two Lines Elements of the orbit are sent to
  Amica with this command.

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INTERFACING COMMANDS (2)

• Time command
• Sends to Amica an absolute time corresponding to
  the last Sync signal
• Pointing data request command
• The request of the pointing data, at the relative
  time in ms with the format of pointing data, is
  sent with this command.
• Image data request command
• Request for a portion of image data

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INTERFACING DATA

• Pointing direction data (long)
• Pointing direction data (short)
• give pointing measurements and related
  information
• Housekeeping data
• Transmits to ground measurements (temperature,
  voltages, currents) and status of Amica
  subsystems
• Image data
• Transmits data to a selected portion of image

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STATUS (1)

• COMPLETED ACTIVITIES
• Amica-AMS02 electrical, mechanical and data
  interfaces
• Instrument HW/SW architecture
• Preliminary ASTC/ASTE/ASTS design
• ASTC electronics, baffle and support breadboards
• CCD radiation test

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STATUS (2)

• FUTURE ACTIVITIES
• ASTC/ASTE/ASTS detailed design
• Electronics and mechanical manufacturing
• TV, vibrations, EMI, functionals tests
• Integration