Abstract: A method and apparatus for resolving a radar return by an object or layer below the earth's surface from a radar return of an air-to-earth interface. More specifically, a method and apparatus for generating short pulsewidth, broad bandwidth RF signals and for effecting control and timing of transmitted and received radar signals in order to focus an antenna illumination pattern. The apparatus includes an antenna array including a plurality of antenna elements which transmit and receive the RF pulsed signals and a custom control module which generates the control signals fed to the antenna array to delay the RF pulse signals with respect to each other, upon transmission and receipt, in order to form transmit and receive antenna illumination patterns.

Abstract: A high speed arrangement for detecting the occurrence of a flag character in a stream of serial digital data signals employs a pattern register in which are stored the bits of the referene flag pattern. As each bit of the serial data is received, it is simultaneously compared by a set of comparators with each of the bits in the flag pattern. The first comparator of the set compares the data bit with the first bit of the flag pattern and each successive comparator compares the data bit with the next successive bit in the pattern. The outputs of the comparators are coupled to corresponding stages of a shift register in the same ordered sequence as the comparators. All the stages of the shift register are arranged to be simultaneously clocked by clock signals.

Abstract: A rotary switch includes a contact bar movable between a switch-open and a switch-closed position and a rotatable circular cam member controlling the movement of said contact bar. Spring means urges the contact bar into operative engagement with the surface of said cam member. The cam member is rotatably contained within a cavity in the switch housing, the cavity having a wall surface guiding the cam member during rotation of the latter. Biasing action of the spring means upon said contact bar urges the cam member against the wall surface of said cavity, with said wall surface serving as the only bearing surface for said cam member during rotation of the latter. A pin and slot coupling is also provided as an integral portion of the cam member and housing to limit rotary movement of said cam member between precise switch-open and switch-closed positions.