大地线切线角
angle of geodesic coutingence
切线方向变化率
change rate of tangent orientation
切线方向进给机构
tangential feed mechanism
角平分线方向向量
direction vector of angle bisector lines
对向方向角法
method by reciprocal bearings
测地切线角
angle of geodesic contingence
六角切向燃烧
tangential firing with burners located at six corners