真实方位保持
maintenance of true bearing
测方位角精度
azimuth measuring accuracy
船磁方位测量
heading survey of ship magnetism
单点井斜方位测量仪
single shot directional surveying instrument
地－井方位测量
surface-borehole azimuth survey
方位测角计
azimuth indicating goniometer
方位测量系统
orientation measuring system