Proceedings of the IEEE · 1963 · 350 citations · 0 references
EngineeringElectrical EngineeringAnalog ElectronicsOptoelectronicsSensorsDetector TechnologyDigital Signal ProcessingPulse ProcessingPulse Processing ElectronicsSignal Detection TheoryBackground NoiseBackground Noise EffectsDetector DesignDetectorsRange ResolutionReceiver DesignSignal Noise ReductionTransmitter Design
The smallest detectable signal in pulsed‑carrier systems depends on pulse energy, repetition rate, receiver design, and integration/indicating methods; electromechanical integrators can improve visibility on Type‑A scans, but integration before detection, though theoretically optimal, faces practical challenges. The study avoids practical difficulties by performing integration after detection and introduces a transmitter criterion that allows comparison of transmitter effectiveness, demonstrating that longer pulses can improve visibility at the cost of range resolution. The authors formulate optimum predetector selectivity, identify the square‑law detector as optimal, compare alternative detectors, and show that a transmitter criterion can be used to compare transmitter effectiveness, revealing that longer pulses enhance visibility while reducing range resolution.
The smallest signal discernible through background noise is formulated in terms of the pulse energy, its repetition rate, the receiver design, and the choice of integrating and indicating means. The smallest signal visible on a Type-A scan can be improved upon by the use of electromechanical integrators. Integration before detection is, in theory, ultimately the most effective, but runs into serious practical difficulties. These are avoided when the integration is performed after detection. Optimum predetector selectivity is formulated. The optimum detector (square law) is found, and other detectors compared. A transmitter criterion provides a basis for comparing the effectiveness of transmitters, and shows how, at the expense of range resolution, longer pulses can increase visibility.