Toward a Coordinated Spatial Data Infrastructure for the Nation (1993) / Chapter Skim
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7 Sharing of Spatial Data
7 Sharing of Spatial Data
Pages 89-110
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From page 89... ...
RATIONALE FOR A SPATIAL DATA SHARING PRO GRA1\] Objectives The principal objective of a spatial data sharing program is to increase benefits to society arising from the availability of spatial data.
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From page 90... ...
Examples of Data Sharing Programs The concept of sharing spatial data is not new. Examples can be found at federal, state, and local levels.
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From page 91... ...
The lO-year effort will eventually incorporate about 500,000 USGS bench marks into NAVD SS, thus vastly increasing the usefulness of the NGRS both in traditional leveling applications and through improved geoid modeling of regions that would otherwise be deficient. This data sharing program works because the donors (private, county, state, and other federal organizations)
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From page 92... ...
Mapping on the State Plane Coordinate System was assisted by the fact that the North Carolina had a Geodetic Survey Office in place to establish and maintain a system of horizontal and vertical control monuments across the state. This office often gave priority to local governments in establishing additional control for mapping programs.
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From page 93... ...
Furthermore, the aircraft were in the same airport. This incident caused the legislative study committee to direct the ERMP to set up a meeting with all fecleral agencies that might be acquiring aerial photography in North Carolina to achieve greater cooperation between the state and the federal governments.
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From page 94... ...
The spatial data sharing program for the NSDT should provide access to cligital geographic base data of known quality and currency through a limited number of access nodes linked to a fully decentralized communication system. We envision a system of spatial data servers, owned and operated by institutions authorized by the FGDC, to be the custodians of the data in question.
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From page 95... ...
SHARING OF SPATIAL DATA - | Spatial Data Servers | FGDC Certified Quality Assurance Programs Producers and Co-Producers of Base Data Federal, State, Municipal, Private 1 ~ + ' Agreements for Base Data Development Plans for Base Data Development ~ + State Spatial Data Advisors ~ + | Metadata Servers | , ~ + , | Users of Spatial Data | Figure 7. ~ Components of a spatial data sharing program.
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From page 96... ...
, Yes Federal Agency Data Base and Distribution l l l Determines Federal Agency Desire for , Non-Federal j SpatialData ~ Bases l Figure 7.2 Representative procedures in a spatial data sharing program.
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From page 97... ...
Metadata support data sharing by providing information on many aspects of spatial data each aspect having meaning in particular application contexts. Metadata that describe data base contents include data dictionaries and definitions attribute ranges and data types.
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From page 98... ...
NSD} Spatial Data Sharing Program The proposed spatial data sharing program (Figure 7.~) in many respects represents a combination of elements of both the Geodetic Advisor Program of the National Geodetic Survey System and the North Carolina ERMP (discussed above)
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From page 99... ...
A number of questions remain unanswered, all of which will require further analysis in cieveloping a workable data sharing system. These include (~)
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From page 100... ...
A spatial data sharing program should place special emphasis on the collection and dissemination of primary or base data. What do we mean by base data?
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From page 101... ...
The standards should be publicly accessible and not proprietary. GIS software companies will eventually respond through the normal forces of the market and enable their software to both react and write to the standards required by the spatial data sharing program.
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From page 102... ...
An exception to this might be the availability of data translator software, for example, which converts spatial data in a file format not supported under the spatial data sharing program into an acceptable format. This would enable organizations with very large inventories of spatial data in unacceptable format to allow users to convert this information with their own time and effort.
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From page 103... ...
The federal government could substantially influence participation of state and local governments by making it a requirement of its numerous grant programs that if spatial data are collected, these data are made available through the spatial data sharing program. What Are the Rules for Usage ?
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From page 104... ...
The FGDC is the federal program with the objectives and intent most comparable with this program, albeit without funds. The MSC believes that at this time the FGDC should assume the initial leadership role to embrace the broader scope of this proposed spatial data sharing program.
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From page 105... ...
Guidelines and legal conditions and liability limitations for organizations and agencies volunteering to deposit data under the program could also be documented. The distribution policy for the spatial data sharing program would be defined for both the metadata base as well as the specific geographic data files.
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From page 106... ...
is a mechanism for identifying the full range of spatial data collected, where the data are stored, who controls access to the data, the data content, the metadata, and the areas of data coverage. Spatial data catalogs provide an important component of the NSDI, one that can be established by using distributed computer networks.
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From page 107... ...
In a typical search for textual information, the client software prompts the user to select which information sources to include in the search and to enter a search request. Once the search request is entered, the client software converts the search words to the standard information retrieval protocol (Z39.50)
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From page 108... ...
This feature is very significant for situations in which a user may want to search hundreds of sources on ciozens of servers at a sitting. Information Sources Information servers provide access to the information sources placed on them.
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From page 109... ...
The USGS is also using WAIS to access a clearinghouse of USGS spatial data holdings. The ESDD interfaces with the interagency Global Change Master Directory, a single interagency source for references to key global change data.
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From page 110... ...
FGCC (1980~. Input Formats and Specifications of the National Geodetic Survey Data Base: Volume 11 Vertical Control Data, Federal Geodetic Coordinating Committee, National Geodetic Survey, Rockville, Maryland.
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