An Experimental 220-MC Radar System for Airships
Abstract
The Naval Research Laboratory has designed and constructed an experimental 220-Mc radar for installation in a modified ZPG-2W airship. Important features of this system include a large internally mounted antenna, a high-power triode oscillator, a lobe-counting height finder, and a clutter-gated noncoherent MTI. The transmitter, tunable from 216 to 225 Mc, is a 3W10,000A3 triode oscillator in a so-called grid-bell circuit. Nominal pulse-power output is 750 kw with a 5-mu sec pulse at a duty cycle of 0.015. Two antennas designed and built for the system are a 17-1/2 x 4 foot antenna which was used in preliminary system tests, and a 33-1/2 x 9 foot antenna which is being mounted in the gas enclosure of the airship. Both antennas are two -dimensional dipole arrays. The computed gain of the smaller antenna is 16 db with a horizontal half-power beamwidth of 18.4 degrees. The larger antenna has a computed gain of 22 db and a horizontal beamwidth of 8.9 degrees. The height-finding equipment consists of a range-gated tracker and a Brush two channel recorder which measure the number of lobes per mile traversed by the target, and a special slide rule which facilitates the computation of target height. The MTI is of a noncoherent. type, employing a clutter gate which enables the system to switch automatically from MTI to normal operation in the absence of clutter. Subclutter visibility is expected to be about 24 db for the complete MTI radar.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 11, 1957
- Accession Number
- AD1223307
Entities
People
- A. G. Ferris
- A. M. Knopp
- G. W. Hermann
- P. A. Lantz
- R. L. Eilbert
- T. S. Golden
Organizations
- United States Naval Research Laboratory