conclusions on scale map
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Map projections and coordinate system in mapping are important for position specification on the earth, which is transferred to flat map. The coordinate system enables us to know material’s point and position on the earth through Meridian Line dividing the earth into parts based on angular distance or meridian called Geographic Coordinates.
The Geographic Coordinates are transferred to map through three-dimension and two-dimension vector systems. Several types of map projections present different characteristics: area keeping, shape and directions influencing on selecting consideration in using it to present different types of map data in different areas and content. Map projections are different due to different types of lines: plane, funnel-shaped and cylinder, including characteristics of light source that affects different characteristics of map projections and is used to consider appropriate mapping. The popular map projection is Universal Transverse Mercator (UTM), which is from the use of cylinder as map projection with globe model on the Meridian line. It is used to correctly present long north-south area. This type of projections is used in UTM coordinate system in making geographic map and base map in all around the world.
Answer:
The workshop participants and the committee recognize that the National Map vision of the USGS is ambitious, challenging, and worth-while. Nevertheless, there is also a uniform sense that the project is not well defined and needs a thorough definition. Technically the project may be feasible; organizationally it will require a significant investment in restructuring and rethinking the systems that have changed little over the last two decades.
In this report the Committee on the U.S. Geological Survey Concept of The National Map discussed the similarities of The National Map and the existing National Atlas. The latter is described by USGS as being a
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Suggested Citation:"5 Conclusions and Recommendations." National Research Council. 2003. Weaving a National Map: A Review of the U.S. Geological Survey Concept of 'The National Map'. Washington, DC: The National Academies Press. doi: 10.17226/10606. ×
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component of The National Map (USGS, 2001). In large part the National Atlas has been built using coordination and partnerships, using a national standard to develop nationally consistent small-scale databases from larger-scale data. Data themes are owned and maintained by different federal agencies and updates are provided to the USGS for inclusion in the National Atlas. The same should be true of The National Map, though at larger scales and with more partners.
The USGS concept of The National Map has two principal components, each dependent on the other. We have used a blanket and patchwork quilt metaphor in explaining these two components. The blanket, which we have termed the enhanced National Atlas (to extend the existing program), is a consistent national digital map coverage maintained at one or more scales. This blanket coverage that includes Framework layers would be built from public domain data and broadly disseminated following the philosophy in OMB Circular No. A-16. The second component, the patchwork quilt National Map, would be the result of contributed imagery and maps from local, state, and tribal governments, and from private and nonprofit organizations, contributed as part of a sweeping collaborative effort. This quilt would consist of patches of larger-scale data adhering to national standards but with varied resolutions and filled with smaller-scale data from the enhanced National Atlas when no other source exists. Some of the data will be public, some proprietary with publicly accessible metadata.
The USGS would serve as the integrator for all map contributions, assembling and merging data, and certifying and issuing a “seal of approval” to data included in The National Map or as an update in the nationally consistent enhanced National Atlas. As the Delaware pilot has shown, the USGS goal of seven-day updates could be attainable using the enhanced National Atlas/National Map approach. Such a dynamic National Map will need to support multiple scales, resolutions, classifications, and feature types provided by National Map partners. It will also require extraordinary coordination.
Implementation of the enhanced National Atlas could be attainable in stages. Larger-scale Framework data at the 1:12,000 or 1:24,000 scale such as geodetic control, digital orthoimagery, Public Land Survey System data, and public ownership boundaries could become part of the enhanced National Atlas in the near term. Other data types, such as hydrography and transportation, may not be completed for several years, since they require significant integration with other data types at the 1:12,000 or 1:24,000 scale.
Implementation of the patchwork quilt component, The National Map, is insufficiently specified in the USGS’s vision document to estimate
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