Analysis Of Electromagnetic Environment Effects Of Radar Reconnaissance

With the improvement of information level,the electromagnetic signals radiated by various electronic equipment in modern battlefield interact and crisscross.And the battlefield electromagnetic environment is becoming more and more complex.Radar reconnaissance receivers,as one of the important reconnaissance equipment on the battlefield,are bound to face the test of a complex electromagnetic environment.Local wars in recent years have shown that the main threat they face in the process of combat is the threat of the electromagnetic environment under the condition of electronic countermeasures.And the influence mechanism of the electromagnetic environment effect of the radar reconnaissance receiver is related to all kinds of interference in the electromagnetic environment.In order to understand the influence mechanism of radar active interference signal on the working performance of radar reconnaissance receiver and improve its adaptability to complex electromagnetic environment,this thesis conducts research on the problems related to the effect of electromagnetic environment of radar reconnaissance receiver,which is divided into the following four parts.Firstly,the electromagnetic environment of radar reconnaissance receiver is classified and modeled.In order to make the performance analysis of radar reconnaissance receivers in subsequent chapters general,the complex and diverse radar signals on the battlefield are classified according to both signal form and signal power after an in-depth analysis of the electromagnetic environment faced by radar reconnaissance systems and its characteristics.In addition,mathematical modeling and jamming effect simulation are carried out for radar active jamming,which is the most common jamming method in modern war.Secondly,a method for assessing the complexity of the electromagnetic environment of radar reconnaissance receivers is investigated.In view of the shortcomings of existing evaluation methods and the special complexity of electromagnetic environment,according to the working mechanism of radar reconnaissance receiver,a radar reconnaissance receiver operational effectiveness assessment index system is constructed.And a radar reconnaissance receiver electromagnetic environment complexity assessment method based on operational effectiveness is proposed.Then,the influence of radar active jamming on the interception performance of radar reconnaissance receiver is analyzed from three aspects:detection performance,reconnaissance range and front-end interception probability.In terms of detection performance,mathematical models of false alarm probability and discovery probability of radar reconnaissance receiver under jamming conditions are constructed,and the influence of jamming signal power on them is modeled and simulated.In terms of reconnaissance range,the relationship between the maximum reconnaissance ranges under two conditions is obtained by analyzing the sensitivity conditions required by radar reconnaissance receiver to complete signal detection and recognition with and without interference.In terms of front-end interception probability,a more comprehensive front-end interception probability mathematical model is developed,considering the five domain conditions of time,space,frequency,energy,polarization and pulse loss probability required for radar signal interception.Furthermore,the effect of interception time and JSR on the interception probability of the radar reconnaissance receiver is simulated and analyzed using this model.Finally,the influence of radar active jamming on traditional pulse description word measurement is analyzed.To address the shortcomings of the IFM receiver in its ability to handle simultaneously arriving signals,mathematical modelling of the simultaneous phase identification of interfering signals and radar signals is carried out,and the effects of the frequency and power of the interfering signals on the measurement results are simulated and analyzed.The effect of JSR on pulse time of arrival and pulse width measurement is analyzed by using the method of equivalent noise power.According to the principle of direction finding of single baseline phase interferometer,the mathematical modeling and simulation of azimuth measurement of radar signal by interferometer under jamming condition are carried out,and the influence of incident direction,frequency and power of jamming signal on azimuth measurement of radar signal is discussed.