Electro-Optical Observations

Gated Intensified Camera

 

For extremely short (microsecond) instantenous meteor exposures a specialized gated image intensified large format CCD camera is in use. This system is a commercially available digital Qimaging Extended Blue Intensified Retiga camera, details of the basic system can be found here. Its unique capabilities allow very high temporal and spatial measurements of meteors and has been used in deceleration, wake and fragmentation studies.

gated
gating box

The system supports C-mount objective lens and a variety of exposure times. The CCD is 1360x1036 square pixels of 6.45 microns size. The camera is a 12 bitdepth system and is able to produce 5 frames per second at maximum resolution and bitdepth. Gating is externally controlled by a custom signal box which triggers both CCD exposure times and gating of the intensifer. A meteor captured with the gated system is shown below. In this example, the pixel scale is 0.7 arcmins, the field of view is 16x12 and the lens being used is a 50 mm f/0.95. The system is recording at 5 frames per second and the gating is set to 200 Hz; hence each dot in the image along the meteor trail corresponds to an equivalent exposure of 5 ms. The limiting stellar magnitude in this image is near +9.

gated meteor