Overlay,Clipping And Stitching For 4D Geospatial Data Products

4D geospatial data products are national foundation geographic information products, which include DLG, DRG, DOM and DEM. They are the basal geospatial information that obtained by 3S technology. The frame of NSDI is composed of 3S technology , the network technology and 4D products, these geographic information that compose the basal frame have already become the indispensable support condition of macro-decision, programming and management.Limited by the production and management of data, the whole real world only can be described by every kind of scale map subdivision data'1'. However, in actual application we usually need to require data of arbitrary longitude and latitude degree, not that subdivision is for the unit. If we retrieve the data with subdivision, that conduce necessarily the situation of retrieval set much than require set, and it make the data of the user operating increase, though it's unnecessary. So we should clip and stitch them according to required longitude and latitude, and finally provide the support of the data for kinds of aided decision systems.Additionally, overlay maps of 4D geospatial data products are becoming a kind of new rquire of geographical information. So research of Overlay, Clipping and Stitching for 4D Geospatial Data Products can enrich geographical information products' format; provide abroad and convenient service for user; set up the system of based geographical information products.In this paper, its main works are detailed as follow: expatiate detailedly theory and methods for overlay, clipping and stitching the different data of 4D geospatial data products according to arbitrary longitude and latitude, and present realization process; discuss how to set up the system of basic geographical information products, and basic geographical information products'applications and development; at last, analyse, design and program an experimental system of overlay, clipping and stitching the different data of 4D geospatial data products, and introduce the function of system.