Analysis of Theory and Model of Background Magnetic Field of High-spinning Projectile

At present, methods of the navigation and the attitude measurements of projectile utilizing the magnetic fields are facing the interference from the BMF (background magnetic field). The principle and mathematical model of the BMF for the spinning projectile are been researched to realize the high accuracy measurement of the geomagnetic field on projectile. The composition and jamming mechanism of the projectile's BMF are derived with the Faraday electromagnetic induction theory. High precision compensation model of the geomagnetic measurement is established by synthesizing the magnetic sensor error model. Based on the idea of the error transfer, the attitude measuring errors caused by the BMF are analyzed and the error calculation formulas are given. On this basis, numerical simulation is conducted combining with projectile's flight rules. The results show that the influence of attitude angle measuring precisions caused by the background interference magnetic field are much bigger than the errors caused by the sensor noise and the established compensation model has obvious effect. Besides, the effective BMF compensation of geomagnetic measurements on the projectile must be conducted if the attitude angle measurement error is in requirements within +/- 1 degrees.