Distortion Magnetic Field Compensation of Geomagnetic Vector Measurement System Using a 3-D Helmholtz Coil. - Zhongyan Liu; Qi Zhang 068; Mengchun Pan; Qingxiao Shan; Yunling Geng; Feng Guan; Dixiang Chen; Wugang Tian (IEEE Geosci. Remote. Sens. Lett., 2017)