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DCW Drainage Features, Polygons
- Identification Information
- Data Quality Information
- Spatial Data Organization Information
- Spatial Reference Information
- Entity and Attribute Information
- Distribution Information
- Metadata Reference Information
- Identification Information
- Citation
- Originator
- National Imagery and Mapping Agency (now National Geospatial-Intelligence Agency)
- Publication Date
- 19920701
- Title
- DCW Drainage Features, Polygons
- Edition
- First
- Geospatial Data Presentation Form
- vector digital data
- Publication Information
- Publication Place
- Fairfax, VA
- Publisher
- National Imagery and Mapping Agency
- Online Linkage
- https://hgl.harvard.edu/catalog/harvard-dcw-dn-poly
- Abstract
- This datalayer is a polygon coverage representing drainage features located throughout DCW (Digital Chart of the World) geographic coverage as of 1992. Features found in this layer include: Perennial inland water features (streams, lagoon, estuaries, reservoirs); Non-perennial features such as seaonally fluctuating rivers, lakes and streams; Areas of wet sand; Snowfields and glaciers; and areas which are classed as "none of the above." This coverage contains a generalized small-scale depiction of the world's drainage features. It is designed to provide geographic orientation and serve as a visual backdrop for dataq uality-type browse coverages. These data were derived from a custom drawn small-scale (1:31 million) map of the world. This layer was derived from the VMAP0 series produced by the National Geospatial-Intelligence Agency (NGA), formerly known as NIMA (National Imagery and Mapping Agency), an agency of the United States government. VMAP data set products use the "vector product format" (vpf). The term "VMap" is derived from "Vector Smart Map." Digital Chart of the World is a comprehensive 1:1,000,000 scale vector basemap of the world. It consists of cartographic, attribute, and textual data. The primary source for the database is the National Imagery and Mapping Agency's (NIMA) Operational Navigation Chart (ONC) series. This is the largest scale unclassified map series in existence that provides consistent, continuous global coverage of essential basemap features. The coverage is is organized into 10 thematic layers which feature a vast number of files organized into libraries. These libraries, or coverages, are geographicially bounded areas, rather than feature-linked coverages. DCW Layers in the Harvard Geospatial Library are feature-based as we have processed the multiple tiles from the VMAP0 libraries into a series of seamless coverages (e.g. aeronautical features appear in a single layer, "Aeronautical Facilities, Points") which depict a particular feature as it occurs throughout the available geographic coverage areas. Since different geographic areas were mapped by NIMA at different times using various types of feature capture and scanning and digitizing methods and software, multiple map sources of varying dates and multiple processing approaches are represented in each of these HGL layers. We have necessarily generalized the discussion of data source material and process steps in the Data Quality section of this metadata document.
- Purpose
- The Digital Chart of the World is a general purpose global database designed to support Geographic Information Systems applications. This layer is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production. This layer will provide a basemap for layers related to socio-economic and political anaylsis, statistical enumeration and analysis, or to support graphical overlays and analysis with other spatial data. More advanced user applications may focus on demographics, urban and rural land use planning and related areas including defining boundaries, managing assets and facilities, integrating attribute databases with geographic features, spatial analysis, and presentation output.
- Supplemental Information
- Entities (features) and Attributes for DCW are fully described in: Department of Defense, 1992, Military Specification Digital Chart of the World (MIL-D-89009): Philadelphia, Department of Defense, Defense Printing Service Detachment Office. The DCW used a product-specific attribute coding system that is composed of TYPE and STATUS designators for area, line, and point features; and LEVEL and SYMBOL designators for text features. The TYPE attribute specifies what the feature is, while the STATUS attribute specifies the current condition of the feature. Some features require both a TYPE and STATUS code to uniquely identify their characteristics. In order to uniquely identify each geographic attribute in the DCW, the TYPE and STATUS attribute code names are preceded by the two letter coverage abbreviation and a two letter abbreviation for the type of graphic primitive present. The DCW Type/Status codes were mapped into the Feature Attribute Coding Catalogue (FACC) coding scheme. A full description of FACC may be found in The DIgital Geographic Information Exchange STandard (DIGEST) Edition 1.2, January 1994. Please consult the DIGEST FACC website for complete coding data. (http://www.digest.org/html/DIGEST_2-1_Part4_AnnexB.pdf)
- Temporal Extent
- Currentness Reference
- publication date
- Time Instant
- 19920701
- Bounding Box
- West
- -180.000000
- East
- 180.000000
- North
- 83.575951
- South
- -90.000000
- ISO Topic Category
- inlandWater
- Theme Keyword
- Glaciers
- Rivers
- Reservoirs
- Theme Keyword Thesaurus
- LCSH
- Theme Keyword
- Snow regions
- Hydrographic features
- Theme Keyword Thesaurus
- Alexandria Digital Library Feature Type Thesaurus
- Place Keyword
- Northern Hemisphere
- Southern Hemisphere
- Eastern Hemisphere
- Western Hemisphere
- Africa
- Asia
- Australia
- Europe
- North America
- South America
- Polar regions
- Place Keyword Thesaurus
- LCSH
- Temporal Keyword
- Access Restrictions
- None
- Use Restrictions
- For educational, non-commercial use only. Although this data set has been developed by the NGA no warranty expressed or implied is made by them as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the NGA in the use of this data, or related materials.
- Status
- Complete
- Maintenance and Update Frequency
- Biennial
- Point of Contact
- Contact Organization
- National Geospatial-Intelligence Agency
- Delivery Point
- Office of Corporate Relations
- Delivery Point
- Public Affairs Division, MS D-54
- Delivery Point
- 4600 Sangamore Road
- City
- Bethesda
- State
- MD
- Postal Code
- 20816-5003
- Country
- USA
- Contact Telephone
- 800-455-0899
- Hours of Service
- Monday through Friday 9:00 A.M. to 4:00 P.M. EST-USA
- Credit
- National Imagery and Mapping Agency (now known as National Geospatial-Intelligence Agency).
- Native Data Set Environment
- Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 9.0.0.535
- Data Quality Information
- Attribute Accuracy Report
- 100 percent of attribute codes were reviewed against the source manuscripts. No formal effort was undertaken to develop a quantitative attribute accuracy statement.
- Logical Consistency Report
- All data were found to be topologically correct. No duplicate features are present. All areas are completely described as depicted on the source manuscripts. No undershoots or overshoots are present. All data were consistently captured using the rules described in the narrative associated with the Data Quality Table and in the various feature table narrative files present at the coverage level within the library. A few, very dense Drainage line and polygon coverage features were modified so as not to exceed the 10,000 arcs per polygon limit. In order to rectify these situations, the tile boundaries and bisecting straight line segments were added to these DNNET coverages as null coded arcs (DNLNTYPE = 9). These very dense drainage tiles are generally restricted to the former glacial areas of North America and Eurasia. Special automation techniques All drainage polygon features were automated in conjunction with drainage line features from positive source manuscripts containing both feature types. In many cases, nonperennial inland water features were depicted on source manuscripts with dashed line boundaries. These lines were made continuous by manually connecting the dashed lines into solid line features prior to automation. Water bodies were coded using a semiautomated process of scanning water body mask separates, automatically outlining the solid features with vectorization software, building polygon topology, and copying precoded labels to the composite drainage coverage. This process was followed by extensive quality control checks to verify that polygon features were labeled correctly. Text information was removed from the vector data through a combination of symbol trapping and manual editing. All drainage line and area features, and coastlines, were processed in a single coverage through cartographic and attribute code quality control steps. Feature coincidence All drainage polygon features intersect drainage lines at single, coordinate coincident points. All shared boundaries between drainage polygon features, city outlines, and land cover polygon features have coordinate coincident representations. Drainage polygon features were treated as the primary source for common boundaries between the various polygon data types listed above. That is, in cases where drainage polygon were in contact with the other area features on the source, the shared boundary between them was always contributed by the drainage polygon features. Database design issues The minimum feature size for all polygon feature layers within the Digital Chart of the World is 0.12 inch (circumference measure). DNNET coverage features smaller than this size are retained as point locations in the DSPOINT coverage. There are two exceptions to this rule: (1) lake features comprised of more than one line primitive (as when two different streams intersect a lake) are retained in the DNNET coverage as polygon features, and (2) glaciers smaller than the minimum size criteria have been eliminated from the database (without representation in the DSPOINT coverage). The boundaries of some nonperennial water bodies are coded as being made up of both shorelines and streams. This occurs when streams were depicted on the source manuscripts as superseding a shoreline. Boundaries between ocean area features in the PONET coverage and water bodies in the DNNET coverage were captured based on differences in tints on the source manuscripts. Under-construction reservoirs are captured as perennial lake features with indefinite shorelines. Centerline streams are retained in these cases. Due to DIAM65-18 coding conventions where some large inland seas are included as part of PONET coverage ocean aggregations, visually anomalous cases of DNNET polygons within ocean areas do occur occasionally. These are most prevalent in regions where shorelines exhibit large seasonal fluctuations (e.g., the Caspian Sea).
- Completeness Report
- 100 percent of features depicted on the ONC source materials have been captured. 100 percent of the features have valid attribute codes assigned to them. Airport features were derived from the DMA Digital Aeronautical Flight Information File (DAFIF). Where DAFIF was incomplete, locations were added from the ONC.
- Horizontal Positional Accuracy Report
- The Horizontal Positional Accuracy Value represents overall accuracy. Source chart-specific accuracies are available as area feature attributes in the VMap-0 data quality coverage. The primary accuracy analysis was performed on one chart only in the prototyping phase of the DCW project. Horizontal Positional Accuracy is expressed in meters. Detailed horizontal accuracy figures were developed by comparing the positions of well-defined points in the roads, railroads, utility lines, and drainage coverages against sources of higher accuracy, measuring the offsets, and expressing differences as a Circular Map Accuracy figure at a 90% confidence interval. This figure was independently verified by adding known production errors to source chart accuracies in a root sum square calculation.
- Quantitative Horizontal Positional Accuracy Assessment
- Lineage
- Source
- Originator
- National Imagery and Mapping Agency
- Publication Date
- 1974-1992
- Title
- Operational Navigational Chart (ONC)
- Geospatial Data Presentation Form
- map
- Publication Information
- Source Scale Denominator
- 1000000
- Type of Source Media
- stable-base material
- Source Temporal Extent
- Time Period Information
- Range of Dates/Times
- Beginning Date
- 1974
- Ending Date
- 1992
- Source Currentness Reference
- ground condition
- Contribution
- All information found on the source with the exception of aeronautical data. The U.S. Defense Mapping Agency Operational Navigation Chart (ONC) series and the Jet Navigation Charts (JNCs) for the region of Antarctica were the primary sources for the Digital Chart of the World database. The ONCs have a scale of 1:1,000,000, and they are the largest scale, unclassified map series produced by the DMA that provides consistent, continuous global coverage of essential basemap features. Some collateral sources have been used to enhance road and railroad connectivity through selected urbanized areas. The DMA's Digital Aeronautical Flight Information File (DAFIF) was the primary source for the airport data in the aeronautical layer. An Advanced Very High Resolution Radiometer (AVHRR) image for the coterminous United States is the source for the data in the Vegetation layer. The Defense Intelligence Agency Manual (DIAM) 65-18 is the source for the Geopolitical codes and the ocean boundaries information contained in the Political and Oceans layer. The product specifications for the ONCs and JNCs have been used extensively in the design of the database.
- Source
- Originator
- National Imagery and Mapping Agency
- Publication Date
- 199006
- Title
- Digital Aeronautical Flight Information File
- Publication Information
- Type of Source Media
- magnetic tape
- Source Temporal Extent
- Time Period Information
- Single Date/Time
- Calendar Date
- 1990
- Source Currentness Reference
- publication date
- Contribution
- Airport records (name, International Civil Aviation Organization, position, elevation, and type)
- Source
- Originator
- Defense Mapping Agency
- Publication Date
- 1990
- Title
- Jet Navigational Chart
- Geospatial Data Presentation Form
- map
- Publication Information
- Source Scale Denominator
- 2000000
- Type of Source Media
- stable-base material
- Source Temporal Extent
- Time Period Information
- Range of Dates/Times
- Beginning Date
- 1974
- Ending Date
- 1991
- Source Currentness Reference
- publication date
- Source
- Originator
- USGS EROS Data Center
- Title
- Advance Very High Resolution Radiometer
- Geospatial Data Presentation Form
- remote-sensing image
- Publication Information
- Source Scale Denominator
- 1000000
- Type of Source Media
- magnetic tape
- Source Temporal Extent
- Time Period Information
- Range of Dates/Times
- Beginning Date
- 199003
- Ending Date
- 199011
- Source Currentness Reference
- publication date
- Spatial Data Organization Information
- Direct Spatial Reference Method
- Vector
- Point and Vector Object Information
- SDTS Terms Description
- SDTS Point and Vector Object Type
- G-polygon
- Point and Vector Object Count
- 390690
- Spatial Reference Information
- Horizontal Coordinate System Definition
- Geographic
- Latitude Resolution
- 0.000001
- Longitude Resolution
- 0.000001
- Geographic Coordinate Units
- Decimal degrees
- Geodetic Model
- Horizontal Datum Name
- D_WGS_1984
- Ellipsoid Name
- WGS_1984
- Semi-major Axis
- 6378137.000000
- Denominator of Flattening Ratio
- 298.257224
- Vertical Coordinate System Definition
- Altitude System Definition
- Altitude Datum Name
- Mean Sea Level
- Altitude Resolution
- 1.000000
- Altitude Distance Units
- 1.0
- Altitude Encoding Method
- Explicit elevation coordinate included with horizontal coordinates
- Entity and Attribute Information
- Entity Type
- Entity Type Label
- DCW Drainage Polygon Features
- Entity Type Definition
- Polygons represent hydrographic drainage features
- Entity Type Definition Source
- HGL
- Attributes
- TIM.DCW_DN_POLY.AREA
- DCW Drainage Polygon Areas
- Definition Source
- ESRI
- PERIMETER
- Feature Perimeter length measured in coverage units
- Definition Source
- Computed
- DN_
- Unique Feature Identifier
- Definition Source
- ESRI
- DN_ID
- Unique Feature Identifier
- Definition Source
- ESRI
- AFT_ID
- Feature Identifier
- Definition Source
- Assigned
- DNPYTYPE
- Drainage feature type.
- 1
- Perennial inland water. Includes perennial lakes and streams, estuaries, lagoons, unsurveyed perennial streams, reservoirs, and navigable canals.
- 2
- Nonperennial inland water. Includes nonperennial and seasonally fluctuating lakes and streams, wadis, sabkhas, and abandoned navigable canals.
- 3
- Wet sand. Includes wet sand and sand deposits in and along riverbeds.
- 4
- Snowfield, glacier, ice field, or ice caps.
- 9
- None. This code is used for any area that is not water, wet sand, snowfield, glacier, ice field, or ice cap. Polygons with this code would include the background polygon, islands within inland water or ice areas, land areas enclosed by stream or river courses, or ocean areas.
- Definition Source
- ESRI
- TILE_ID
- VPF Format Tile Identifier Code
- Definition Source
- NIMA
- FAC_ID
- Primitive Record Identifier for the Feature
- Definition Source
- NIMA
- SHAPE
- Feature geometry. (Coordinates defining the features.)
- Definition Source
- ESRI
- SHAPE.AREA
- Feature area measured in coverage units
- Definition Source
- Computed
- SHAPE.LEN
- Feature polyline length measured in coverage units
- Definition Source
- Computed
- SHAPE.FID
- Internal feature number. (Sequential unique whole numbers that are automatically generated.)
- Definition Source
- ESRI
- Distribution Information
- Format Name
- Shape
- Distributor
- Harvard Geospatial Library
- Name
- Metadata Reference Information
- Metadata Date
- 20041116
- Metadata Contact
- Contact Information
- Contact Organization Primary
- Contact Organization
- Harvard Geospatial Library
- Contact Person
- Geospatial Resources Cataloger
- Contact Address
- Address
- Harvard University Library
- Address
- Office For Information Systems
- Address
- 1280 Massachusetts Avenue
- City
- Cambridge
- State or Province
- MA
- Postal Code
- 02138
- Country
- USA
- Contact Voice Telephone
- 617-495-2417
- Contact Facsimile Telephone
- 617-496-0440
- Contact Electronic Mail Address
- hgl_ref@hulmail.harvard.edu
- Hours of Service
- Monday - Friday, 9:00 am - 4:00 pm EST-USA
- Metadata Standard Name
- FGDC Content Standards for Digital Geospatial Metadata
- Metadata Standard Version
- FGDC-STD-001-1998
- Metadata Extensions
- Online Linkage
- http://www.esri.com/metadata/esriprof80.html
- Profile Name
- ESRI Metadata Profile
