Study Of Methods For Using Ionospheric Disturbances To Detece Space Targets

With the continuous development of space science,adjacent space around the earth occupies an important position in military and human activities,especially for the unknown space target detection and warning is paramount.This thesis is on the background of earth's ionosphere in near space,with the interaction of space target and the ionosphere and the transmission of radar electromagnetic wave in the ionosphere plasma as the theoretical basis,using the ionosphereobservation data and radar electromagnetic echo signal to analyze the ionospheric disturbance caused by space target so as to achieve the aim of space target detection.The main work of this thesis is divided into four parts:1.The ionospheric disturbances generated by the movement of space targets in the ionosphere were studied.The principle of the ionospheric electron loss caused by the exhaust gas emitted during the launch of the rocket and the process and characteristics of the plasma sheath during the reentry of the space target are described,and numerical simulation analysis is performed.2.The principle of Total Electron Content(TEC)and the TEC inversion method for real-time observation of ionospheric total electron content using ground-based GPS are studied.Ground-based GPS monitoring of ionospheric TEC is a very convenient and practical method.The ionospheric TEC is widely used to analyze ionospheric disturbances through GPS raw observation data.The MATLAB program is designed.The original observation data released by IGS can be used to invert ionization.Layer TEC and satellite hardware delay(DCB)are relatively consistent with the CODE.3.The principle of monitoring ionosphere by incoherent scattering radar and case analysis is studied.incoherent scatter radar is the most powerful method in ionospheric monitoring.The ionospheric electron density is obtained by analyzing the echo power of its scattering signal.The Qujing incoherent scattering radar data was selected,and the echo power profile and electron density profile of the scattering signal were further plotted.It was found that there was a high degree of consistency between the echo power of the scattered signal and the electron density of the ionosphere.At last,the detection of ionospheric inhomogeneity was analyzed by using the Very High Frequency(VHF)incoherent scattering radar and Hainan digital altimeter.4.In combination with the actual rocket launch process,using GPS observation data to invert the ionospheric TEC and comparing it with the previous day's data,it was found that the ionospheric TEC began to decay after 6 to 7 minutes of rocket launch and the decay duration was one hour or more.