Three-dimensional position by two-point intersection involves two vertical angles

Position technology has been playing an important role in forestry,and the new challenges have presented to us because of the expanse,obstruction and amplitude of forestry fields.In view of the economy and practicability,an effective method of three-dimensional position by two-point resection involveing two vertical angles has been discussed in this paper.The characteristic is that we set up the instruments on unknown point for once,observe three parameters including two vertical angles and one horizontal angle.It has less measure data than common methods,and it can solve the position difficulties of sight line in forestry fields.The mathematic modes have been proved in this paper and the precision has been analysed base on the example.