The Positioning And Speed Measurement Method Of Over-the-line Radar Under Evaporative Wave Guide Environment

Evaporative wave guide is one of the most longest and most likely atmospheric wavelengths on the sea surface,so it is of great practical value to study the practical application of evaporative wave guide.When atmospheric wave export now causes the radar's ray trajectory to change significantly,so that the radar electromagnetic wave trap in the evaporative wave guide layer for refraction,reflection and so on repeatedly continue to spread forward,forming wave guide propagation.That phenomenon can make the radar produce over-the-line detection and increase the radar detection range.At present,this radar detection method has become one of the most important ways to accurately measure low-altitude targets.However,due to the different propagation of electromagnetic waves,the use of conventional radar positioning speed measurement method in the evaporative wave guide environment will cause radar positioning and speed measurement errors,so the search for new positioning and speed measurement methods to achieve radar over-the-line measurement of one of the key technologies.In order to improve the positioning accuracy of radar in evaporative wave guide environment,this thesis first introduces the positioning error,height error and elevation error of conventional radar in evaporative wave guide environment,then introduces the two algorithms of integral and micro-ray trace used in radio ray tracing,and then uses ray tracing as the theoretical basis,details the positioning method of radar in evaporative wave guide environment,and compares the simulation and analysis of different elevations and different atmospheric correction refractive index.The accuracy of radar positioning under evaporative wave guide environment proves the effectiveness and practicality of radar positioning method.In order to improve the speed measurement accuracy of radar in evaporative wave guide environment,this thesis is supported by Doppler effect and Doppler frequency shift,using radar radio ray trace,the path n in the wave guide layer is equally divided,the speed measurement formula of radar in evaporative wave guide environment is dedulated in detail,and matlab is used to simulate,comparing and analyzing the radar's running trajectory and its corresponding radial velocity in the evaporative wave guide layer under different elevations.Using the speed measurement data of this algorithm and the real data for speed error comparison analysis,it is concluded that the speed measurement accuracy is between 0.1% and0.3%.The research results of this thesis can not only be applied directly to the ship and shore-based radar system,to achieve radar over-the-line measurement of low-altitude and ultra-low-altitude targets,to expand the scope of radar,but also to similar communication systems,to achieve over-the-line communication.At the same time,related technologies can also be applied to radio detection systems,as well as civil radio monitoring,meteorology and other thesis.