Design And Implementation Of Geomagnetic Signal Detection System Based On Channelizatio

In recent years,the development and utilization of underground space has become an important issue for medium and large cities in China,and accurate urban underground space detection is a prerequisite for the reasonable development and utilization of underground space.When using geomagnetic signals for underground space detection,the amplitude and phase of geomagnetic signals need to be accurately obtained.Since the geomagnetic signal has a large attenuation in the underground space,it is important to develop a geomagnetic signal detection system with strong weak signal detection capability.The main focus of the thesis is the design and implementation of a geomagnetic signal detection system based on channelization.The thesis firstly introduces the research background of underground space detection,the current status of domestic and international research on signal detection technology;secondly,introduces the theory of signal processing algorithm in signal detection system;again,gives the overall design scheme of signal detection system according to the system index,and introduces the algorithm flow,parameter design and hardware scheme of signal processing system respectively;then,according to the system scheme,the FPGA module in the channelized geomagnetic signal detection system was designed and implemented,including the excitation signal emission module,echo signal sampling module,filter extraction module,first-stage channelization module,second-stage channelization module,FFT module and Ethernet communication module;finally,each module of the signal detection system is debugged and the performance of the system is verified and analyzed.The performance of the channelization-based geomagnetic signal detection system is experimentally verified to meet the specification requirements and works normally in the actual environment.The weak signal detection capability of 1 u V in high accuracy mode and 4 u V in fast detection mode was measured during the commissioning of the system.