ISG-98

Radar Set ISG-98 will be a V Beam height finding equipment employing components built to specification for AN/FPS-5 Radar. It will, however, utilize "Vee Beam" height finding technique (as in CFP-6B) and, in association with search radar FPS-3, will provide complete range, azimuth and elevation information necessary for CGI usage.

1. "Vee" beam height finding technique incorporated - the antenna of the FPS-3 search radar being utilized to provide the vertical beam.
2. The ISG-98 is mounted on a tower separately from the associated FPS-3 but azimuth rotation is synchronized with rotation of FPS-3 at 6.6 or 10 rpm; when MTI is used with FPS-3, a fixed speed of 6.6 rpm only will be available.
3. Using two ISG-98 height finders with one FPS-3, height readings on individual targets will be obtainable at intervals not exceeding 20 seconds. This meets the presently stated Controller requirements.

It was the original intention to utilize FPS-5 height finders but this equipment employs the "beaver tail" aerial nodding system and would have inadequate traffic handling capacity to meet RCAF operational requirements. A specification has therefore been prepared based on US AN/FPS-5 but changed to "Vee Beam" technique to increase the traffic handling capacity. Contract has been let to Canadian Marconi Company for re-engineering and production of eight equipments the first of which is expected to be delivered April 1951. Cost $398,000 each inclusive of installation costs.

1. Range - see coverage diagram for FPS-5.

1. Continuous azimuth rotation through 360 degrees synchronized with FPS-3 search radar at 6.6 or 10 rpm.

(a) Cut paraboloid approximately 15 feet high 3 feet 2 inches wide. Exact dimensions not yet determined.