Design Studies for 440-Foot-Diameter Radio and Radar Telescope

Studies conducted by the Cambridge Radio Observatory Committee during the past two years show that a large steerable telescope can be constructed at lower cost and with higher precision if the antenna is protected from the environment by a radome. These studies also indicate that the extremely high pointing precision (10 arc-sec) needed to make effective use of a large aperture at wavelengths as short as 5 cm can be obtained with a radome-protected antenna. The proposed 440-foot antenna employs a deflection-compensated vertical truss reflector support structure to maintain a 0.09-inch rms tolerance in the primary reflector under all operating conditions. The low cost of the antenna results from the ability to use lightweight reflector panels, an efficient computer-optimized reflector support structure, a small-diameter azimuth bearing, and a low-power control system. The estimated cost of this novel antenna design and the radome is substantially lower than the cost of alternative exposed antennas. The equivalent aperture and gain of the proposed antenna-radome system are made equal to that of a 400-foot antenna by increasing the antenna diameter by 10 percent. This report also describes the 520-foot-diameter space-frame radome and the planned electronic instrumentation and control facilities for a proposed radio and radar observatory. Accepted for the Air Force Franklin C. Hudson Chief, Lincoln Laboratory Office