| According to statistics, in the world, the aeroplaneaccidents during landing stage and closing to the airport accounted for 63.3%, the proportion of deaths reached 60%, studying the new security approaching theory is urgently needed. In particular, China’s air traffic has been ranked second in the world, the eastern airportsis busiest and the environment of western airports is complex, during the aircraft approaching, the safety intervalbetween aircraftsand between aircrafts and obstructions reduced sharply, aircraftsare impacted by the complex terrain, electromagnetic, weather and other special circumstances, present a complex motion of temporal-spatial variation and flying posture variation, especially in low visibility conditions, there are significant risks of flight in approach. Therefore, modeling methodson high-precision, high-resolution, high efficiency of complex airport environment become international academic front and hotspot problem.This thesisanalyzesthe limitation of the existing GIS for spatial and temporal data model, aims at aircraft’s visual navigation, and proposes a series of theoretical approaches about terrain, weather and electromagnetic modeling, achieves a multidimensional expression of theairport environment, real-time environmental awareness and efficient safety navigation decisions. A precise airport environment model of space-ground integration, comprehensiveelements and performance visualization is built. The technical bottleneck of multidimensional space-ground environmental information seamless integration and integrated management is broken throuth. Integrated application ofterrain,3D objects, targets model, the weather forecast information and the electromagnetic environment of the airport terminal area is achieved, the airport environment and situation are expressed true, comprehensive, timely, accurately.A voxel model of uniform semanticis established. This model unifies complex warning information, reduces the confusion, to avoid unnecessary interference, achieve rapidnavigation decision. This model is expected to significantly improve the effectiveness oftheairport’sinformation, provide basic support for visual navigation.The main work and innovations of thisthesis are detailed as follows:(1) Aunified semanticmodel of airport environment threat situation information is established, airport environment information of multi-source, multi-scale, multi-type distribution modeling is proposed. The "change" is emphasized to be driving force and center in this model. The relationship between events, processes, featues and changeis expressed. The voxel model is the highest level of abstraction; itonly cares about the status and the effect before and after the change, the theory and the experiment shows that the model is suitable forair navigationapplication.(2) The data organizationandmanagement methods of the threat situation information field model are proposed, includingdata field organization method, multi-resolution field modelsimplification method, fieldmodel updating methoddriven by change. The data organizational structure and the spatial index are established, the structure supportsthe multi-resolution field model and the3DOR tree is constrainted bythreat situation semantic.The3DOR tree combined the characteristics of R tree’ snode balanceandthe hierarchical octree’s supporting multi-resolution, and it is suitable for dataorganization, field updating and dynamic data scheduling.(3) The threat situation information field voxel model visualization and spatial analysis algorithm for visual navigation are studied, including real-time volume rendering algorithm driven by change, cuttinganalysis algorithm and 3D buffer analysisalgorithm, theefficient visualanalysis of the data field datais achieved.(4) Puts forward a target detection method based on video sequence, detect the locus of airport runway invaderseffectively. Puts forward a real-time access method based on coordinate transformation and the conflict detection ofrunway protection zone. The feasibility of the methods is validated by simulation experiments.(5) Concernedwith the projects and the research content of this thesis, theTibet Linzhi Airport is selected as a typical airport; an experimental prototype system is developed. The prototype system architecture and data structure are proposed, a series of methods and algorithms in this thesisare verified and analyzed.The results of the experiment and analysis show the validity and practicability of the model, methods andalgorithms proposed in this thesis. |
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