a State Spatial Data Infrastructure (SSDI) and a Local Spatial Data Infrastructure (LSDI), the data for these layers need to be collected at the lowest level and generalized to the other levels. This ensures logical consistency among the parts of the extended NSDI Framework. Again, it must be noted that the data content standards being developed by the FGDC working groups are facilitating this process. The 16 accepted standards and the additional ones under development represent a major effort to develop consistent definitions and descriptions of geographic features and attributes.
There are at least nine major steps necessary to realize this extended Framework:
Definition of the contents of the city, county, or local extended Framework.
Definition of the contents of the state or tribal nation extended Framework.
Definition of the extended Framework hardware architecture.
Definition of coordination mechanisms.
Assignments for layer responsibilities.
Definition of quality standards (collection and maintenance) and procedures for the development of the extended Framework at all levels.
Data generation in agreement with the corresponding Framework.
Data maintenance program.
This chapter primarily addresses the first and second items above. For further details and discussions, the interested reader is directed to the recent National Academy of Public Administration’s volume entitled Geographic Information for the 21st Century (NAPA, 1988). With respect to the last item above, the lack of financial resources will be an impediment to development of an extended Framework for smaller counties, cities, and possibly states. In such cases, substantial subsidies will be needed from higher levels of government, unless development can be financed through partnerships with other organizations.