Abstract: A reply decoder (30) for declaring mode 4 replies when used with a KIR cryptograph computer (25) is described including timing logic (114), memory (112) for storing mode 4 replies and logic circuitry for analyzing replies stored in the memory (112). The invention further provides logic circuitry for detecting railing (117) i.e., successive replies, for detecting garbled or overlapping replies (123), for providing a floating density value window (114, 120) for summing the replies in nonselected reply positions and for target start/stop determination (215) based on selected criteria. The invention overcomes the problem of declaring excessive mode 4 replies which over burden the subsequent reply processing in a reply processor (50).

Abstract: A decoder for separating pulse code modulated messages of the type used in ATCRBS where the messages are identified by two framing pulses separated by 20.3 us. and contain information pulses between the framing pulses separated from the framing pulses and from one another by 1.45 us. The decoder receives an input stream of pulses of uniform width from a Leading Edge Detector which has created the stream from video pulses received from the transmitter of another station. The decoder input pulse stream may contain interleaved pulses from more than one message. The decoder includes an input shift register, an analysis shift register, a plurality of buffer storage devices and additional registers to which selected pulses are fed from the input register for use in determining whether a received message is clear of interfering pulses or whether the message is potentially or actually garbled.

Abstract: An improved Leading Edge Detector/Pulse Quantizer (LED) for use in a pulse code communications system. A prior LED included three shift registers for storing in relative time order, according to the time of reception of video pulse signals by an associated receiver, (a) pulse leading edges, (b) pulse trailing edges and (c) Quantized video (quantized video comprises a pulse having a width equal to the time the received video exceeds a threshold amplitude). The prior LED further included a plurality of logic means for examining the contents of the three registers to determine whether pulse leading or trailing edges of the received video signal were possibly missing because of interference between received video pulses and for inserting extra leading edges in the leading edge register if such extra leading edges could be logically inferred to be present.

Abstract: A signal conditioning circuit (30) using an oscillator (32) which feeds a counter (34) whose output addresses a programmable memory (42). The output of the programmable memory (42) provides a selected processed signal which is used for excitation of a transducer (12). The processed signals can have various phase shifts, frequencies, or amplitudes. The transducer (12) has a mechanical input (14) and provides a modulated signal output which is a function of the mechanical input. The output of the transducer (12) is fed to a phase sensitive demodulator (36). Demodulator (36) provides an output signal in response to the signal from transducer (12) and an appropriate demodulator drive signal. The output signal from demodulator (36) is indicative of the mechanical input to transducer (12). Averaging means (40) is connected to the output of the demodulator (36) to provide a DC signal which is proportional to the mechanical input to transducer (12).

Abstract: A novel system is provided for detecting the presence of a characteristic feature on an illuminated surface of an object when used in conjunction with known electro-optical systems for determining the position of the centroid of the outline of the object with relation to the supporting surface and the rotation of the object relative to the rotational orientation of a test part. The surface is illuminated at an angle that enhances the contrast of the characteristic feature while using a vidicon-type image converter tube which scans the field which includes the object. The location, with respect to the centroid, of a circular window area encompassing the characteristic feature and the radius of the circular window are determined utilizing a television monitor connected to the vidicon.