Abstract: A frequency-modulated continuous-wave (FM-CW) ranging system produces a first signal of frequency corresponding to the measured range of a target which signal is sometimes below a given quality and produces a second signal of frequency corresponding to the measured range of a simulated target of known range. A threshold detector determines when the target signal is above the given quality at which time the period of the first signal is determined from a given cycle thereof while concurrently the period of the second signal is determined from which the range to the target can be computed.

Abstract: A technique using sector antennas on a plurality of decoy transmitters such hat each antenna only has to cover a portion of the required azimuth coverage but the total azimuth is covered at all times by all the decoy transmitters. Switching between sectors of the various decoy transmitters is done to provide pseudo-blinking decoy field.

Abstract: Threshold circuit for selecting video signals derived from small stationary and moving objects amidst an abundance of clutter in a harbor area. The threshold voltage generator (1) of this circuit is suitable for detecting the temporal average .DELTA.P of the positive peak value and the temporal average .DELTA.N of the negative peak value from the AC component of the applied video voltage (V.sub.DC +V.sub.AC) and for generating modified voltages (l+k)(V.sub.AC -.DELTA.P) and k(-V.sub.AC -.DELTA.N). The modified voltages together with the inverted video voltage are combined to form the threshold voltage V=V.sub.DC +.DELTA.P+k(.DELTA.P+.DELTA.N) being k times the average peak-peak value above the average peak value of the video voltage, where k is a constant.

Abstract: A method and apparatus for automatic suppression of weather echoes or clutter which can disturbingly appear, apart from the flying target-Doppler signal as further Doppler signals in a pulse Doppler-tracking radar device containing quadrature channels, wherein there is regulated the frequency of the Doppler signals or the phase relationship between the Doppler signals and a reference signal derived from the transmitted signal.

Abstract: In a tube/coil assembly of the type wherein the tube includes a gun for directing a beam of electrons to a target electrode and both focus and alignment coils are included within the assembly, the alignment coil is electrically energized with some portion of the current flowing through the focus coil to eliminate the need for an independent alignment coil current source.

Abstract: An independent landing monitoring system (ILM) for guiding airborne vehicles on final approach to a landing using a ground-based beacon which transmits a sequence of pulse signals including an omnidirectional signal coded to identify its location and used for initial approach, followed by time spaced directionally radiated right/left and up/down signals used for precision guidance along the final approach path. The time spacing of the various beacon signals and their order of succession in the sequence identify the signals, and the relative intensities of paired precision guidance signals as received by the aircraft is used to provide precision indications of the location of the aircraft on the path. The beacon can be either triggered by the weather radar in the aircraft which then receives the beacon signals on its beacon mode receiver, and/or it can be triggered randomly by a noise jittered oscillator in the beacon for use by approaching aircraft equipped only with a beacon receiver but no weather radar.

Abstract: A filter for tracking the ground signal return in an FM/CW radio altimeter. The filter has a variable band pass frequency response which is adjusted as a function of the altitude measured by the altimeter. The control means of the filter respond to altitude measurements in digital format.

Abstract: A monolithic waveguide radar front end subsystem utilizing dielectric coments. The use of dielectric waveguide transmission elements permits conformal mounting while exhibiting operating characteristics comparable to those of conventional metal waveguide subsystems.

Abstract: A technique for simulating various signals, such as from radar emitters, in a broad frequency spectrum by generating at any given instant only those of the signals that affect a receiver which is tuned to a particular bandwidth. As the receiver is tuned to a new bandwidth, the simulating system responds by quickly generating any signal or signals that exist in the new bandwidth.