Video Tracking Camera


Video Tracking Camera

The Video Tracking Camera is designed for very high performance daylight video imaging. The camera delivers monochrome CCIR or RS170 format video with over 1,000 pixels per line and 4:3 aspect ratio.  
  Video Tracking Camera  
  Resolution: 1000 pixels per line
Aspect Ratio: 4:3
Contrast transfer: > 100% @ 6.4 MHz
Sensitivity: > 6 lux @ minimum gain < 0.5 lux @ maximum gain
Signal-to-Nose Ratio: >52db @ minimum gain
Gain: > 24 dB, automatic or manual
Gamma: 1 or 0.45
Integration period: Manual 20, 10, 5, 1 msec
Mirror readout: Option left to right
  Tracking Lens  
  The 400-3000mm Zoom Lens is a 180mm aperture (7 inch) catadioptric lens that yields a zoom ratio of 7.5 to 1. The short focal length of the lens is operating at f/2.2 while at the long focal length the ratio has increased to f/16.9 The primary optical design is a Maksutov Cassegrain type and consists of both refractive and reflective elements that have been ruggedized to withstand a maximum of 10Gs shock load. A common mounting plate is provided to support the optical system and the camera as well as a camera platform to establish proper alignment between camera and the optical axis.  
  General Specifications  
  Lens Design: Maksutov Cassegrain
Clear Aperture: 180mm (7 inches)
Focal Length: Zoom – 400mm (15.76 inches) to 3045mm (120 inches)
Geometrical f ratio: f/2.2 through f/16.9
Resolution: .65 arc second (diffraction limited)
Material: Primary Mirror – Zero-Dur Substrate
Corrector Lens: BK-7, Focusing Lens
Coatings: All reflective surfaces – Enhanced Aluminum
All air-glass surfaces – AR – with MgF2
  The 400-3000mm Zoom Lens is made up of several subassemblies: lens barrel, lens/mirror, beam splitter, neutral density filter wheels, and video camera. The zoom lens consists of both refractive and reflective elements that are located in the lens barrel. The advantage of a catadioptric (mixed lens and mirror) design is that the triple light path through the lens barrel allows relatively "powerful" optics to be packaged into a compact barrel. Both the corrector lens and primary mirror are hard mounted and do not move.

The optical front end is constructed with Invar, and in combination with the DOS temperature-compensated barrel design, bore sight is maintained to within ±5 arc seconds, over a 50ºF temperature variation and focus is also maintained. A pellicle beam splitter is positioned at a 45º angle to the main optical axis to allow the super-positioning of a reference reticule pattern at the intermediate image plane. The 95%-5% split has little effect on the main beam, but does allow a brightly illuminated reticule to serve as a calibration and camera replacement aid if desired.

The system includes a matched set of counter-rotating neutral density filter wheels, which when activated, provide a continuously variable density with even attenuation across the video format. This is accomplished without altering the geometrical f ratio, thus being preferable over the conventional mechanical iris. The neutral density wheels can be operated manually via switch closures, or serve as an auto-iris with any TV camera that provides p-p video level. Serial communications port neutral density level control is available with auto/manual override mode select.

The video camera is also housed in the rear enclosure, and the camera/lens assembly is sealed against dust and moisture. It is pressurized with dry nitrogen with a leak rate not exceeding two pounds per square inch in 168 hours. It comes complete with Shraeder valve for re-pressurizing, safety relief valve, and pressure gage to determine proper pressure. Rechargeable desiccant cartridges are installed, which guard against internal moisture forming. It is a safeguard in the event internal pressure has not been maintained at the proper level. Remotely controlled focus, with actuation by a microprocessor-controlled servomotor, provides a focusing range of 1000 feet to infinity. The servo axis is under redundant software and hardware limit switch control to prevent

Photo-Sonics, Inc.
    818-842-2141     (ph - switchboard paging)
    818-842-2610     (fax)

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