The Research Of Aircraft Real-Time Emulation System In Remote Sensing Yield Estimation Based On Digital Agriculture

The crop yield estimation using remote sensing data based on digital agriculture has characteristics such as fleetness, macroscopic, economy, impersonality. It may carry out dynamic monitoring on crops growth process, and remove the limitation of active jamming. So it has a very good development prospect. It may carry out grain overall policy decision on the grain producing and planning, and provide scientific basis on the policy of distribution , supplying, storing, transportation and the trade of home and abroad for the country and all of the various levels government. In the crop yield evaluation information system, if taken aircraft as remote sensing platform, simulation display system must be developed urgently in order to create a suppositional world, then we can make aircraft state clear more well.Firstly, the thesis set forth the theory of the crop yield estimation using remote sensing data. It affirmed the structure and the function of the crop yield evaluation system, and integrated the relation of the geographical information system.The thesis recommended VR technology, computer graphics theory and OpenGL technology, which established a rationale for the system design.Secondly, according to the principle of the crops evaluation information system principle and the application circumstances of the aircraft flying, the thesis ascertained the systematic exploitation platform and procedure and design idea, then it designed out the general structure and system function of the aircraft flying real-time simulation.The aircraft simulation system adopted Windows XP as system operation environment, it used Visual C + + 6.0 as development tools, made use of VC + + MFC and large amount of API function, programmed based on 3D graphic industry standard OpenGL up to the minute, and adopted 3D Studio MAX to build model in complicated three-dimensional entity.Then, according to general system design, the thesis carried out detailed design on aircraft simulation display system. It built the model location and direction which is beneficial to be observed OpenGL view system, and used the basic alternation for the view system. For increasing the real sense of the 3D models, the procedure was adopted realistic technologies such as blanking, colorized model, illumination and vein mapping. Be based on the 3D model diversity in procedure, the models had been built by different ways: to some comparatively simple, well-regulated 3D models, fundamental graphic units were chosen. To some complicated curved surface models, quadratic equations rendering surface were adopted. To the most complicated 3D models, they were built by 3D MAX, and used certain conversion mode leading-in OpenGL to control and transform in progress of OpenGL.Besides, the data of aircraft flying originated from the database in system. We used Visual C + +6.0 as software platform, and ODBC of MFC to establish and manage the database. Aircraft fetched the interrelated data from the data base, real time updated flying state, thereby, realized the aircraft simulation display.Finally, the animation displayed is the final outcome of the aircraft flying simulation procedure, which is the most important section. The aircraft simulation system used double-buffers technology to raise the function of animation, postpone refreshing and improving the written time, which made animation effect to be continuous, smooth, which strengthened sight feeling.