This set a germ of an idea, and I had O.S. maps scanned by a step and repeat camera and turned into a series of photographs, no such thing at that time as file standards like JPG. The photos were then stamped onto a video disc, and yes I do mean stamped using a process known as the two P process within Philips. It was known as the two P process as no one could pronounce the chemicals name, but it had two Ps !
The map disc could then be “played” in still frame mode on the new Philips player which also had the capability of serial data control. An index of OS grids versus page number and map corners was built together with a place name gazetteer.
The video from the player was routed via a graphics inserter board which had a family of graphical shapes representing the status modes of mobile resources. The whole system was controlled by the latest in computing technology, the DEC PDP 11.
The new modem performed well at 9600 baud over both A.M. and F.M. radio systems, and reception of a status message from the mobile placed a symbol into the correct “zone” no GPS then, and the colour of the symbol represented the readiness of the resource. The dispatch information, street name etc was manually input to the system and from the gazetteer the pin point location suitably noted in graphics.
The in car display solution was never developed and the dead reckoning navigator suffered from errors due to road slip until differential GPS came along.
The only photograph I have of the new system, which we named Video Overlay Resource Availability System or VORAS is below. It was incidentally an exhibition at the MET police.
21st October 2009
Photo Source: Joe Bell
Many thanks to Joe for his article, which is appropriately linked to the MADE Equipment that can be viewed in the Image Library.