Investigation of principles of simulation of space-time processing of wideband signals

The paper states the principles of simulation of wideband signals applied in a surveillance radar. The resource of the radar model is analyzed with respect to sample rate of processed signals and required memory size as generated signals, noises, active and passive interferences demand a lot of memory. It is proposed to simulate only active intervals of operation of a pulse radar at zero frequency in the frequency domain.

Optical Theodolite Based Rationality Check of Measurement Data From Pulse Radar

Theodolite and radar are important measurement and control devices in aviation, aerospace and other fields. In order to make sure the tracking measurement and navigation control of aircraft and spacecraft safely, this paper creatively proposes a novel method to check the rationality of the three-dimensional measurement data (distance, azimuth and pitch angle) of the pulse radar by using the two-dimensional measurement data (azimuth and pitch angle) of the optical theodolite. Specifically, three different rationality checking functions are constructed for the three different cases of unreliable ranging channel, unreliable angle measuring channel and unreliable ranging and angle measuring channels, and are used for the rationality checking of radar data in the above three cases respectively. Simulation results show that the correct rate is more than 95% as long as the data measured by optical theodolite are reliable.

Arteriovenous Fistula Flow Dysfunction Surveillance: Early Detection Using Pulse Radar Sensor and Machine Learning Classification

Vascular Access (VA) is often referred to as the “Achilles heel” for a Hemodialysis (HD)-dependent patient. Both the patent and sufficient VA provide adequacy for performing dialysis and reducing dialysis-related complications, while on the contrary, insufficient VA is the main reason for recurrent hospitalizations, high morbidity, and high mortality in HD patients. A non-invasive Vascular Wall Motion (VWM) monitoring system, made up of a pulse radar sensor and Support Vector Machine (SVM) classification algorithm, has been developed to detect access flow dysfunction in Arteriovenous Fistula (AVF). The harmonic ratios derived from the Fast Fourier Transform (FFT) spectrum-based signal processing technique were employed as the input features for the SVM classifier. The result of a pilot clinical trial showed that a more accurate prediction of AVF flow dysfunction could be achieved by the VWM monitor as compared with the Ultrasound Dilution (UD) flow monitor. Receiver Operating Characteristic (ROC) curve analysis showed that the SVM classification algorithm achieved a detection specificity of 100% at detection thresholds in the range from 500 to 750 mL/min and a maximum sensitivity of 95.2% at a detection threshold of 750 mL/min.

Independent PRF Generation and Control for Frequency Phase Calibration on Mono-pulse Radar at a Remote Location

This paper presents a method of independent pulse repetition frequency(PRF) generation and control for frequency phase calibration on mono-pulse radar at a remote location. In order to generate an independent PRF signal of 320[Hz], pulse width modulation(PWM) of 16-bit timer/counter was applied. For a precision control of PRF signal, 16-bit timer/counter interrupt was changed for each period. Therefore, average frequency of PRF could be controlled by 0.0001[Hz]. To calibrate a frequency phase of mono-pulse radar at a remote location, the proposed PRF generator with a precision control of frequency was used regardless of receiving PRF signal from a radar. For the verification of the proposed PRF generator, theoretical analysis and experimental results are included.