Design And Application Of Hanging Aeromagnetic Three Dimensional Gradient Measurement System

In recent years,aeromagnetic triaxial gradient measurement has been paid more and more attention in aeromagnetic measurement because of its advantages in Delimit magnetic anomaly boundary and Highlight the shallow anomalies and Suppressed background magnetic field.It has become an important geological exploration method.In china,the main aeronautical geophysical exploration units have also strengthened the research in this area.However,there is little research work on the triaxial gradient measurement system hanging in helicopter which can be used to measure the height of the plateau and the terrain with severe cutting.In this thesis,an aeromagnetic gradient measurement system hanging in helicopter is presented.At the same time it introduces the design scheme and the main test index and measurement effect.The aeromagnetic triaxial gradient suspension platform is designed as a regular tetrahedron structure.Steering rudder and attitude instrument are installed on the platform,which greatly improves the stability of the platform.The inertial attitude measurement instrument installed on the platform can accurately record the platform attitude Angle.The attitude correction method is applied to the system to solve the precision problem caused by the influence of external factors on the platform.The hanging rope length of the hanging platform was determined,and all parts of the system were made of non-magnetic materials,so as to reduce the influence of external environment on the aeromagnetic gradient measurement data.The main technical indexes were tested,the flight data were counted and the quality was evaluated.The total accuracy of the aeromagnetic field and the total accuracy of aeromagnetic gradient measurement were calculated.The static noise level of the magnetometer and the difference noise of the magnetometer and the consistency of the probe all meet the needs of practical work.All the test results meet the requirements of the specification,and in some aspects are better than the fixed wing aeromagnetic triaxial gradient measurement system developed or introduced in China,fully demonstrating the reliability of the system in the aeromagnetic triaxial gradient measurement work.The measurement results are analyzed.The result proved that aeromagnetic triaxial gradient measurement has advantages in suppressing background field and delineate abnormal boundary and detecting weak linear anomalies.Aeromagnetic gradient measurement system hanging in Helicopter can greatly reduce the flight height from the ground,which the measurement effect is difficult to achieve by the aeromagnetic gradient system of fixed wing aircraft.