The National Geodetic Survey and the US Geological Survey have developed various standardized computer programs for transforming data that helps to minimize these errors. The internal representation of data in the computer also influences the amount of conversion error. Single precision is accurate enough for many types of data applications or uses, but some databases need to be stored in double precision to retain their original accuracy. The GIS Steering Committee recommends the conversion of GIS data should be done from the original data source with mapping software adhering to the NGS and USGS standards. If the data were originally stored in double precision form then the conversion should also be produced with double precision accuracy.
Data transfer is the exchange of data and is essential to foster sharing of geographic data.
Data transfer standards are operating rules that accomplish the transfer of data between incompatible systems and provide a common format for exchanging data from various software systems. Data transfer standards provide a road map for interpreting various geographic data models. Since each GIS contains its own unique, conceptual, logical, and physical data model, standards can provide a means for exchanging data between two GIS systems. Resolving characteristics of various spatial data models used by the different systems is a fundamental requirement for data transfer standards. In the vector model, the information is provided in the form of topology comprising of points, lines, and polygons.