Status of Cloud Cameras

1
Status of Cloud Cameras

• Roger Clay, Paul Davidson, Bruce Dawson, Andrew
  Smith and Neville WildUniversity of Adelaide

Malargue, 11 November 2002
2
Specifications

• Raytheon 2000B OEM digital IR camera
• 320 x 240 pixels (0.15o)FOV 46o x 35o
• spectral range 7-14 mm(matches cloud spectrum)
• 12 bit resolution
• maximum frame rate 30 Hz

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Implementation
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Tests at Los Leones

• Non-scanning unit installed at Los Leones July
  2002
• Test of data acquisition, reliability. Operating
  24 hours per day.
• Auto transfer of 24 representative night-time
  images back to Adelaide daily (3.7Mb)
• www.physics.adelaide.edu.au/auger01/clouds/index.
  htm

5
Sample images
6
Sample Images
Co. Diamante
7
Image correction - barrel distortion
8
Image correction - vignetting
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Schedule

• First scanning system in Malargue Feb 2003(Los
  Leones or Coihueco)
• Second scanning system in Malargue June 2003
• need to finalize integration issues with
  Karlsruhe colleagues - e.g. CORBA communications
  between FD and cloud PC, data format and storage,
  and with CDAS
• need to finalize data analysis scheme for cloud
  identification (edge detection)

10
Proposed Scanning Plan

• scanner capable of imaging 2p sr, but important
  region is telescope FOVs
• IR camera FOV 46o (H) x 35o (V)
• default camera position is stationary, viewing
  bay3/bay4 boundary region
• every 5 mins horizontal scan of FD FOV
• every 15 mins full sky scan (for operators)
• at any time shoot shower region (T3 with some
  angular velocity cut to reduce rate to 20 per
  night?)

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Mosaic - for Remote Operator
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Data Rate

• standard image 155kb, but 45kb with loss-less
  compression
• e.g. full sky scan (20 images) 1Mb (though a
  jpeg of this for operators is only 80kb)
• worst case scenario
• on average one image frame every 10 sec during
  night
• no data thinning
• 190Mb per 12 hour night, or 1.3Gb per typical
  month per site

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Minimalist Approach

• analyze 5-minute FD FOV scans and reduce to 2
  numbers per FD pixel - mean and rms of the 100
  IR pixels within the FD pixel
• store 20 kb per 5-minute scan
• store all 15-minute jpg full-sky mosaics (80 kb
  each)
• store all 20 shoot the shower pictures - 900
  kb
• store 20 diagnostic pictures from night - 900
  kb
• Total of 8.4 Mb per 12 hour night, or 60 Mb per
  typical month

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Open Questions

• scanning scheme
• data storage - database?
• access to cloud PC from Adelaide - second network?