ANALYSIS ON THE NECESSITY OF CALIBRATION OF FHD UNCLEAR PRECESSION MAGNETOMETER

In this paper, the relative night average value of the Z component of FHD-2B unclear precession was analyzed using the slope method and the differential technique.It is showed that all the relative night average value of Z component, that haven't been revised according to observation bases, wandered to some extent.The influences include temperature, steps caused by all kind of factors and the pier skew of instrument.So it is necessary to calibrate the instrument to eliminate the measurement error.