抗震救灾中航空摄影测量的应急响应

在抗震救灾行动中,航空摄影测量可提供高分辨的正射影像图、精确的DEM和三维景观图等测绘产品,并能提供各种直观、精确的可视化量测工具,帮助救援队伍及时制定出有效的救援计划并进行合理的人员调度.但在应急响应中,航空摄影必须沿着主要道路、河流、桥梁等重要交通干线进行,甚至在城市上空还需进行盘旋飞行,以获取居民区更多的地面信息.因此,如何能快速、高效地对这种"非常规"海量航空摄影数据进行处理,及时生成各类测绘产品,成为抗震救灾中航空摄影测量应急响应的关键.结合中国自主研发的数字摄影测量网格(DPGrid)系统对震区海量"非常规"航空影像快速处理的流程,介绍了航空摄影测量在应急响应中的应用.

The Use of Aerial Photogrammetry in the Fast Response for China Earthquake Rescue

The aerialphotogrammetry can provide notonly high resolution ortho mi ages, accurateDigitalElevationMod- els and 3D LandscapeMaps, butalso allkindsofaccurate and visualizedmeasuring tools for the fastresponse to the disas- ter rescue.These applications ofaerialphotogrammetry can help the breakdown gang design effective rescue plans and dis- patch salvagers rationally shortly after the disaster. However, in the emergency response, the aerial mi ages can notbe taken according to the conventionalaerialphotography in the lmi ited tmi e.Thatmeans the airplane should fly along themain traffic lines, e. g. roads, rivers and bridges, and when the airplane fly above a county itshould circle around in the air to acquire the detailed information ofthe county.Atthe same tmi e, although there are POS(GPS/IMU)data, the precision ofPOS is very low, because there are neither reference stations forGPS norground controlpoints for calibrating the POS system at emergency tmi e.So for the disaster rescue, it is very mi- portant to process themass unconventional aerial mi ages accurately and quickly in a highly efficientway. DPGrid is a haerialphotogrammetry software developed byWuhanUniversity. Itutilizes the blade severs as the com- puting nodes and applies the robustdigitalphotogrammetry arithmetic and parallel computing to realize quick processing of mass aerial data. In the ChinaEarthquakeRescueDPGrid processed 4393 unconventional aerialphotographyDMC mi ages in 111 hours and providedmany tmi ely and accurate surveying andmapping products for the rescue organization. This paper introduces the applications of aerial photogrammetry in the emergency response through discussing the method ofhowDPGrid processed themass aerial mi ages in ChinaEarthquakeRescue.Themain content includes: the ar- chitecture ofDPGrid; the robust stereo mi agematching for the mi ageswith large rotation angle; the bundle adjustment with POS butwithoutground controlpoints for removing the POS relative error; theDPGrid parallel computing forgenera- ting ortho mi ages and itsproduction efficiency. The paperalso shows readers some aerialphotogrammetry products and ap- plications in the EmergencyResponse.For example, the operator canmeasure the length of broken bridges on ortho mi a- ges, evaluate the area and earth volume of landslidemass on ortho mi age superposedwithDEM, and roam andmeasure 3D coordinates in the 3D virtual environment, etc. The aerial photogrammetry has provided many visualized, accurate and valuable surveying data for the China Earth- quakeRescue, and showed its mi portantrole in the emergency response.Buthow to perfect the emergency responsemecha- nism of aerial photogrammetry andmake it an mi portantpartof theNationalEmergencyResponseMechanism is the duty and incumbency of all surveyingworkers.