Establishment Of Forest Resources Information Collection System

With the rapid development of computer technology and the widespread popularity of mobile devices,GIS(Geographic Information System)and GPS(Global Positioning System)technology are applied to the traditional spatial data collection business by mobile development technology,provides a new work mode for the forest resource information collection,instead of the traditional method that handwritten or painted field on the drawing,compass and handheld GPS navigation and positioning,indoor secondary data entry.It achieves the goals that optimizing processes of forest resources survey,reducing human error,improving operational efficiency,reducing operating cost,paperless process.This paper analyzed the research status and the current problems of forest resources inventory system.Based on the development of mobile technology,3S technology and database technology,this study analyzed the business requirements,functional requirements and performance requirements of the system,designed the system functional modules,researched key technology and proposed solutions,developed a forest resource information inventory system that we hold completely independent intellectual property rights on the current using widest range of Android mobile devices.The system was pilot in Songyang,Zhejiang.The main achievements of this study are as follows:(1)Development of Forest Resource Information Inventory System V1.0.This system was an autonomous designed GIS platform,using open source GDAL/OGR library to read and write raster and vector spatial data,constructing compressed image tile pyramid model,designing layers to display of vector raster superimposed on the raster image,using the open source JTS library to merge and edit polygon.Different from the traditional mode,using the system on the mobile device does not need to carry remote sensing images papery,topographic maps,survey cards,etc.,just load dealt raster and vector spatial data on mobile devices.You can view the electronic job data,complete the electronic survey card.(2)Loading remote sensing image based on tile pyramid model.Running single memory-constrained applications,Android system is difficult to directly load those image files,such as high resolution,wide geographical range,multi-image data,larger size files.The solution is that building their tile-pyramid model,storing all tiles in a file and creating indexing,setting the thread pool on the basis of the number of processor cores,using the multi-threaded approach to load tiles.This system could ensure the image loading speed on a mobile device,save storage space of the image data and reduce the data transfer speed between devices,even on the hardware configuration of lower mobile equipment.On the Samsung N5100 Tablet PC,the system supports 25GB of remote sensing images,within 1500ms of loading speed.(3)Achievement vector polygon cutting and merging operations.Using Java Topology Suite that is open source library,implements merge polygons and draw a line to cut polygon on a mobile device.All operation time is within 1000ms,results satisfy the ArcGIS topology check default condition:polygon topology tolerance 0.001 meter.(4)Support multi-thematic forest resource information collection.Existing forest resources survey system are specially developed for a particular investigation,it's great limitations.This platform uses the custom field of information collection,supports defining fields and options by investigation procedures,creates these fields in the DBF file,and then generates an electronic survey card.It can accommodate a variety of forest resources information inventory,expand its applications range.