Research On Motion Noise Simulation And Portable Data Acquisition System Of Airborne Magnetic Tensor Gradiometer

Airborne magnetic gradient tensor detection has many advantages,such as has a high target resolution,has the capability to gather detailed information,and is almost not affected by the magnetic field,which is widely used in resource exploration,geological survey,military anti-submarine and so on.Currently,foreign countries have made some achievements in the development of airborne magnetic gradient tensor system and the processing and interpreting of experimental data,while the domestic research in this field is still in its infancy.There are two main factors restricting its development: on the one hand,the impact of vibration,attitude change and magnetic interference of the aircraft on the data quality of the magnetic gradient tensor system is large and complex;on the other hand,the magnetic gradient tensor systems are mostly in large size and with high power consumption now,which can only be equipped with a large flying platform.Therefore,it will effectively promote the airborne magnetic gradient tensor detection with the reveal of the motion noise inner mechanism of airborne magnetic gradient tensor system and the development of its portable data acquisition system.The core contents and achievements of this study are as follows:(1)Simulating airborne magnetic gradient tensor detection to reveal the motion noise mechanism of airborne magnetic gradient tensor system.Firstly,using the JSBSim model of the open source flight simulator-Flight Gear as the dynamic model of the flying platform,and using Lab VIEW to implement the flight control module,the navigation module,the communication module,the magnetic gradient tensor model of the magnetic dipole,the magnetic interference model of aircraft,the error model of the measuring device and so on to simulate the flight exploration.Then,analyzing the simulation results to reveal the impact of aircraft vibration,attitude change and magnetic interference on the measured data.Finally,carrying out the flight experiments to get the conclusion that the simulation results are in good agreement with the measured results,thus the simulation results can be used as reference for the design,experimental measurement and data processing of the magnetic gradient tensor system.(2)Designing and implementing a portable airborne magnetic gradient tensor data acquisition system with the simulation results,and completing the system performance evaluation and testing.The data acquisition system is composed of the data acquisition module,the router module,the embedded PC control module,the human-computer interaction module and the power module.The embedded PC control module communicates with the data acquisition module via the TCP / IP protocol,acquires the magnetic field information and transmits the instructions of the data acquisition module,and acquires the inertial navigation information through a serial port.The human-computer interaction module is composed of an external display screen and a mouse,and with the created of the virtual instrument panel,the human-computer interaction is improved.Implementing the software part of the system with the modular idea.The software of the system contains three experimental systems,and each subsystem contains specific functional modules.Then completing the system performance evaluation,such as the magnetic interference,acquisition accuracy and so on of data acquisition system,and finishing system stability test repeatedly indoors and outdoors to ensure the data acquisition system meet the requirements of the field survey.