Spatial Adjustment

ESRI, 1990, defines GIS as an organized collection of computer hardware, software, geographic data and personnel designed to efficiently acquire, store, update, manipulate, analyze, and display all forms of geographic referenced information.Spatial Adjustment is one of the facilities in the ArcGIS 9.x softwareAdjustment in ArcGIS Spatial provides three types of transformations are: affine, similarity, and projective.Affine transformation can perform differential scaling, skew, rotation, and translation on the data. Affine transformation requires a minimum of three displacement links.Scale a similarity transformation, rotating, and translating the data while maintaining the aspect ratio of the transformed feature. Similarity transformation requires at least two displacement links.

Projective transformation based on a more complex formula that requires a minimum of four displacement links:x '= (Ax + By + C) / (Gx + Hy + 1)y '= (Dx + Ey + F) / (Gx + Hy + 1)This method is used for the transformation of the data obtained directly from aerial photography.In addition to the above transformation method, there is also another method of adjustment and the rubbersheet edgesnap.Rubber sheetingGeometric distortion in general override the source maps. Can be caused by imperfections in the registration, the lack of geodetic control on the source data, or other causes. Rubber sheeting coordinates with the geometric error correction adjustment.EdgematchingEdgematching process set features along the edge of one layer to layer features of the adjoint. Layer is less accurate in-adjust, and the other layer as a control.There is another facility associated with the attributes of the data to adjust ...Attribute transferAttribute transfer is usually used to copy the attributes of the layer of detail to be less accurate or more accurate. For example, is used to transfer the name of the hydrology of the map feature digitization and generalize the results to a map scale of 1:500,000 scale 1:24,000.In ArcMap, you can specify the attributes you want to transfer between the layers interactively by selecting the feature source and target.