子午线航向 meaning in Chinese

grid heading

The method to correct the declination error of uav geomagnetic heading with gps and igrf is proposed , by means of which the true heading of the craft can be obtained with magnetic sensor in global scope
提出了基于gps ( globalpositionsystem )和igrf ( internationalgeomagneticreferencefield )的无人机磁航向地磁偏角修正方案，使无人机能够在全球范围内利用磁传感器获得子午线航向。