ON THE OPTIMIZATION OF MULTICHANNEL CAMERAS FOR IMAGING ATMOSPHERIC CHERENKOV TELESCOPES

The optimization of the pixel size and of the field of view of the multichannel cameras of imaging atmospheric Cherenkov gamma-ray telescopes is discussed using the minimum distortion of the Cherenkov light images as a basic criterion. The parameters defining the shape of the Cherenkov image in the second-moment approach can already be properly determined using a pixel size similar or equal to 0.25 degrees. The orientation of the image is more sensitive to the pixel size; thus, the optimal determination of orientation parameters requires a reduction of the pixel size to similar or equal to: 0.15 degrees. For observations of point gamma-ray sources the field of view of the imaging camera should not be significantly less than 4 degrees. To study moderately extended sources and sources whose positions are only known within similar or equal to: 1 degrees (like many EGRET gamma-ray sources) a camera with field of view greater than or equal to 5 degrees is required.