利用已有像控点的多期航空影像光束法区域网联合平差

Combined Bundle Block Adjustment Based on Existing Ground Control Points and Multi-period Aerial Imagery

为了充分利用已有航空影像与控制成果,节约作业成本,缩短作业周期,提出一种利用已有像控点联合多期航空影像进行整体平差加密的数学模型,并采用我国南方某地区的数据资料进行了试验证明。结果表明,联合平差能将已有像控点的控制作用通过多期影像间的同名点传递到最新航空影像上,联合平差加密点的平面精度与常规光束法区域网平差加密精度基本一致,而高程精度则取决于多期影像间同名点的观测值个数,同名点观测值越多,加密点高程精度越高,因此只要多期影像间存在足够多的同名点观测值,则联合平差的加密精度完全能够满足摄影测量地形图测绘的生产需要。

In order to make the best use of existing aerial imagery and ground control points,save cost and reduce working hours,a new method of combined bundle block adjustment based on existing ground control points and multi-period aerial imagery is put forward in the paper. Firstly, the mathematical model of combined bundle block adjustment is deduced. Then the data sets of a place in South China ore used to validate the proposed method. The experiment results show that the combined bundle block adjustment can deliver the effect of existing ground control points from former aerial imagery to later aerial imagery through the corresponding points among them. The plane accuracy of pass points of the combined bundle block adjustment is similar to that of the conventional bundle block adjustment. The height accuracy of pass points is dependent on the quantity of corresponding point observations a- mong the multi-period aerial imagery. The more the corresponding point observations are, the better the height accuracy of posspoints is. So as long as there are enough corresponding point observations among the multi-period aerial imagery in the same area, the accuracy of pass points derived from combined bundle block adjustment will be meet the topographic maps specifications for aerophotogrammetric operation.