全数字摄影测量技术在航道工程测量中的应用

在长距离的航道带状地形测量中，利用全数字摄影测量技术，具有速度快、周期短、效率高、精度好、现势性强、自动化程度高、使用方便等优点。在全数字摄影测量实施过程中，首先建立了基本控制网，首级控制采用E级GPS控制网，在它的控制下，沿航道布设平均边长为500m的一级光电测距导线。航摄像片是全数字摄影测量的重要依据，直接影响成图质量，必须认真进行航摄资料的检查验收工作。像控点平面及高程以航道沿线的E级GPS点、一级导线点为起算点，采用GPS快速定位法施测。数字化测图作业中内业测图是用全野外的像控点进行定向，根据工作站上模型参照野外调绘进行测图，然后在计算机中进行编辑成图。实践证明，全数字摄影测量技术与传统的摄影测量相比，具有明显的经济效益和社会效益。

Application of full digital photogrammetry technology in navigation project

In the topographic survey of long-distance narrow navigation channels,the application of full digital photogrammetry technology has many advantages of quick-speed survey,short survey period,high efficiency and accuracy,highly automatic operation,being convenient for use,etc.During the implementation of full digital photogrammetry,a basic control network should be firstly established,and a grade-E GPS control network is used for superlative control network,and under the control of this control network,grade-1 photoelectric distance-measuring tranverses with an average length of 500 m are arranged along the navigation channel to be surveyed.Aerial photos are the basis of the full digital photogrammetry and directly affect the quality of mapping,therefore,aerial data should be carefully checked and accepted.The plane position and elevation of image-controlling points are calculated by using a GPS quick-positioning method,taking grade-E GPS points along the navigation channel and grade-1 tranverse points as datum points.In the digitized mapping work,the indoor mapping is oriented by all the field image-controlling points and conducted on the basis of the model at the working station and with reference to the field investigation and mapping,and a computer is used to compile the digital data into a final map.The practice has proved that the full digital photogrammetry technology has remarkable economic and social benefits,compared with a traditional photogrammetry.