Abstract: In recent years,the use of UAV aerial photography for three-dimensional mapping technology has become a hot research.In view of the fact that there are some problems of poor robustness and stability due to the lack of observational redundancy,the small base height ratio,the intersection angle badness,the traditional method of stereo mapping is proposed.The method is not susceptible to the size of the intersection angle.With the use of two-dimensional forward intersection,while the introduction of the least squares principle,you can get a higher accuracy of the coordinates of the object,and thus improve the UAV aerial scale accuracy.Using the UAV aerial image data,the proposed method is experimentally demonstrated.At the scale of 1:500,the experimental results show that the error in the plane is 0.054 9 m.The accuracy of the proposed method is better.

Key words: photogrammetry, front intersection, unmanned aerial vehicle, stereogram, least squares principle, precision detection