Ruban V. Adaptable stroboscopic conversion of video-pulse signals in radar systems

Object of the study: a stroboscopic conversion of electrical pulses of nano- and subnanosecond duration. Objective: to identify the physical laws of the process of stroboscopic conversion of electric pulses of nano- and subnanosecond duration ranges and use this knowledge to reduce the total noise level at the input of the receiving system expand the dynamic range of UWB impulse radar systems. Methods: both mathematical simulations with calculations of pulse signal conversion processes and experimental methods of verifying theoretically obtained regularities are used in work. Theoretical and practical results, scientific novelty: the influence of sample width, analog accumulation, synchronization instability (jitter) on the transient response (operating frequency band), noise characteristics, the transmission coefficient of a stroboscopic converter with an incomplete charge of the storage capacitance is studied; it is founded that a controlled change in the sampling width and, thus, control of the working bandwidth of the stroboscopic ground penetrating radar (GPR) receiver allows changing the dynamic range of the radar receiver, increasing its sensitivity and optimizing the set of parameters of the entire GPR related to its resolution; for the first time, the method of stroboscopic conversion with variable sample width has been proposed that allowed expanding the dynamic range of the stroboscopic receiver; the method of analog accumulation for stroboscopic receivers was further developed; the method of determining the instability of synchronization by amplitude errors, based on the analysis of errors of the converted signal, is improved; the method for adapting stroboscopic conversion parameters in a GPR system is proposed and tested that increased the detecting probability of subsurface objects with electrophysical parameters close to the environment and allowed restoring the spatial distribution of permittivity and conductivity of the medium by probing and, also, allowed determining the thickness of pavement layers with high accuracy. Practical significance: the developed methods of adaptable stroboscopic conversion expand the dynamic range of stroboscopic receivers and, thus, increase the accuracy of UWB impulse radar measurements. Scope of application: designing UWB impulse radar for various purposes for researchers and developers of this class radar equipment.