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		| Paper: | 
		The D4A  Digitiser | 
	 
	
		| Volume: | 
		347, Astronomical Data Analysis Software and Systems XIV | 
	 
	
		| Page: | 
		651 | 
	 
	
		| Authors: | 
		De Cuyper, J.-P.; Winter, L. | 
	 
	
	
		| Abstract: | 
		The D4A (Digital Access to Aerial- and Astro-photographic Archives) project aims to acquire the necessary know-how, hardware and software to digitise the astro-photographic collections of the Royal Observatory of Belgium and the aerial-photographic collections of the National Geographic Institute and the Royal Museum of Central Africa in collaboration with AGFA-Gevaert. The D4A digitiser under construction consists of a granite based Aerotech ABL 3600 open frame air bearing XY positioning system, with custom build hardware to mount glass plates, film sheets and film rolls. The optical subsystem consists of a C-Cam Technologies CMOS camera mounted to a Schneider telecentric Xenoplan lens and will be illuminated by a computer controlled LED. The maximum scanning area is 350mm × 350mm with a speed of 6 plates (240mm × 240mm) per hour. A first benchmark of a prototype ABL 3600 was done and the proposed illumination system tested as detailed below. | 
	 
	
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