Abstract: A doppler determination system uses an amplitude comparison of odd and even MTI functions derived from the same signal returns in an MTI radar system to determine the doppler frequency of a target return. The system determines the ratio of the amplitudes of the return of a single canceller circuit with a delay of 2/PRF and the amplitude of the return of a double canceller with two delays of 1/PRF. The ratio is then employed to estimate the doppler frequency of the return. The respective amplitudes of the two MTI circuits are also processed in a 3-dimensional radar application to provide estimates of the target radar cross-section and elevation angle, and with PRF switching to determine the target unambiguous range rate.

Abstract: A multiple range interval clutter cancellation circuit for MTI radars is disclosed, for assuring cancellation of narrow band clutter in the second or further range interval, while preserving wideband cancellation in the nearer range intervals and economizing on the number of fill pulses. The circuit includes two clutter cancellers. One canceller has a relatively narrow band clutter rejection bandwidth, and effectively a higher number of fill pulses in relation to the clutter rejection bandwidth and effective number of fill pulses for the second canceller. The outputs of the two cancellers are subjected to an AND gate function, such that only targets which pass through the clutter rejection bandwidth of both cancellers are reported as a target. The circuit obtains the elimination of returns from ambiguous range interval clutter with less transmitted energy and time than conventional canceller circuits.

Abstract: An articulated linkage is disclosed for supporting waveguide and electrical cabling through a predetermined range of movement. The linkage comprises a plurality of elongated rigid sections, joined by articulated joint sections. The joints comprise at least two short links which are pivotably connected to each other and the adjacent rigid sections. Travel limit pins are provided to limit the pivoting motion of the joint links relative to each other and the rigid sections. The lines of waveguide comprise respective sections of flexible waveguide passing through the flexible joints of the linkage and are connected to elongated sections of rigid waveguide which are supported by the rigid sections of the linkage. The travel limits on joint movement are selected to limit the angular excursions to protect the flexible waveguide from undue stresses during movement of the linkage.

Abstract: A system utilizing a tapped or recirculating delay line to effectively slow down a time duration limited signal such that it may be sampled at a slower rate yet preserve all the inherent information in the signal which may have a bandwidth higher than the inverse of the sampling rate. In the systems of the invention a selected number of delayed signal replicas are formed and sampled at selected intervals consistent with the A/D (analog to digital) converter capability. The delay per tap or the delay of the recirculating delay section is made larger than the time duration limited period and the output sampling interval is made equal to the delay per tap (or of the recirculating delay section) .+-. the input sampling interval all divided by the number of samples per signal replica.