Status of Cloud Cameras Roger Clay, Paul Davidson, Bruce Dawson, Andrew Smith and Neville Wild University of Adelaide Malargue, 11 November 2002

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

Implementation

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)

Sample images

Sample Images Co. Diamante

Image correction - barrel distortion

Image correction - vignetting

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)

Proposed Scanning Plan scanner capable of imaging 2  sr, but important region is telescope FOVs IR camera FOV 46 o (H) x 35 o (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?)

Mosaic - for Remote Operator

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

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 kb store 20 “diagnostic” pictures from night kb Total of 8.4 Mb per 12 hour night, or 60 Mb per typical month

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