DEM 10 Meter Index

7.5 Digital Elevation Models - DEM - 10 meter - Index for the State of Nebraska

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Nebraska Department of Natural Resources in work-share agreement with the U.S. Geological Survey
Publication_Date: 19980701
Title:
7.5 Digital Elevation Models - DEM - 10 meter - Index for the State of Nebraska
Geospatial_Data_Presentation_Form: raster digital data
Publication_Information:
Publication_Place: Menlo Park, CA
Publisher: U. S. Geological Survey
Online_Linkage: digital-elevation-models
Description:
Abstract:
Digitntains a series of elevations ordered from south to north with the order of the columns from west to east. The DEM is formatted as one ASCII header record (A- record), followed by a series of profile records (B- records) each of which include a short B-record header followed by a series of ASCII integer elevations per each profile. The last physical record of the DEM is an accuracy record (C-record). 7.5-minute DEM (10- by 10-m data spacing, cast on Universal Transverse Mercator (UTM) projection). Provides coverage in 7.5- by 7.5-minute blocks. Each product provides the same coverage as a standard USGS 7.5-minute quadrangle without over edge.
Purpose:
DEM's can be used as source data for digital orthophotos, and, as layers in geographic information systems, for earth science analysis. DEM's can also serve as tools for volumetric analysis, for site location of towers, or for drainage basin delineation. These data were collected as part of the National Mapping Program.
Supplemental_Information:
7.5-minute DEMs have rows and columns which vary in length and are staggered. The UTM bounding coordinates form a quadrilateral (no two sides are parallel to each other), rather than a rectangle. The user will need to pad out the uneven rows and columns with blanks or flagged data values, if a rectangle is required for the user's application. Some software vendors have incorporated this function into their software for input of standard formatted USGS DEMs.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 197907
Ending_Date: unknown
Currentness_Reference:
ground condition
Status:
Progress: In work
Maintenance_and_Update_Frequency: Irregular
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -101.129005
East_Bounding_Coordinate: -100.996312
North_Bounding_Coordinate: 40.627193
South_Bounding_Coordinate: 40.497767
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: DEM
Theme_Keyword: digital elevation model
Theme_Keyword: digital terrain model
Theme_Keyword: hypsography
Theme_Keyword: altitude
Theme_Keyword: height
Theme_Keyword: contour line
Theme_Keyword: digital contours
Theme_Keyword: elevation
Theme_Keyword: imageryBaseMapsEarthCover
Theme_Keyword: geoscientificInformation
Place:
Place_Keyword_Thesaurus: U.S. Department of Commerce, 1977, Countries, dependencies, areas of special sovereignty, and their principal administrative divisions (Federal Information Processing Standard 10-3):Washington, D.C., National Institute of Standards and Technology.
Place_Keyword: Nebraska
Place_Keyword: County
Place_Keyword: Quadrangle
Place_Keyword: USA
Place:
Place_Keyword_Thesaurus: U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of The United States, and associated areas (Federal Information Processing Standard 5-2): Washington, D. C., National Institute of Standards and Technology.
Place_Keyword: FIPS code of State or Province
Place:
Place_Keyword_Thesaurus: U.S. Department of Commerce,1990, Counties and equivalent entities of The United States, its possessions, and associated areas (Federal Information Processing Standard 6-4): Washington, D.C. National Institute of Standards and Technology.
Place_Keyword: FIPS code for county or counties.
Access_Constraints: None
Use_Constraints:
None. Acknowledgement of the Nebraska Department of Natural Resources and the U.S. Geological Survey would be appreciated in products derived from these data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Organization: Nebraska Department of Natural Resources
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address:
301 Centennial Mall South, P.O. Box 94676
City: Lincoln
State_or_Province: Nebraska
Postal_Code: 68509-4676
Country: USA
Contact_Voice_Telephone: 402-471-2363
Contact_Facsimile_Telephone: 402-471-2900
Contact_Electronic_Mail_Address: dnr.gis@nebraska.gov
Hours_of_Service: 8:00-5:00 - CST
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000
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Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The accuracy of a DEM is dependent upon the level of detail of the source and the grid spacing used to sample that source. The primary limiting factor for the level of detail of the source is the scale of the source materials. The proper selection of grid spacing determines the level of content that may be extracted from a given source during digitization.
Logical_Consistency_Report:
The fidelity of the relationships encoded in the data structure of the DEM are automatically verified using a USGS software program upon completion of the data production cycle. The test verifies full compliance to the DEM specification.
Completeness_Report:
The DEM is visually inspected for completeness on a DEM view and edit system for the purpose of performing a final quality control and if necessary edit of the DEM. The physical format of each digital elevation model is validated for content completeness and logical consistency during production quality control and prior to archiving in the National Digital Cartographic Data Base. Due to the variable orientation of the quadrilateral in relation to the Universal Transverse Mercator (UTM) projection grid, profiles that pass within the bounds of the DEM quadrilateral, may be void of elevation grid points, and are not presented in the DEM. This condition occurs infrequently and is always the first or last profile of the dataset. Level 2 DEM: Level 2 DEM's may contain void areas due to interruptions to contours in the source graphic or DLG. Void area elevation grid posts are assigned the value of -32,767. In addition, suspect elevation areas may exist in the DEM but are not specifically identified. Suspect areas can be located on the source graphic as a "disturbed surface, " symbolized by contours overprinted with photorevised or other surface patterns.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The horizontal accuracy of the DEM is expressed as an estimated root mean square error (RMSE). The estimate of the RMSE is based upon horizontal accuracy tests of the DEM source materials which are selected as equal to or less than intended horizontal RMSE error of the DEM. The testing of horizontal accuracy of the source materials isaccomplished by comparing the planimetric (X and Y) coordinates of well-defined ground points with the coordinates of the same points as determined from a source of higher accuracy.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 10
Horizontal_Positional_Accuracy_Explanation:
RMSE of the DEM. Digital elevation models meet horizontal National Map Accuracy Standards (NMAS) accuracy requirements.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
The vertical RMSE statistic is used to describe the vertical accuracy of a DEM, encompassing both random and systematic errors introduced during production of the data. The RMSE is encoded in element number 5 of record C of the DEM. Accuracy is computed by a comparison of linear interpolated elevations in the DEM with corresponding known elevations. Test points are well distributed, representative of the terrain, and have true elevations with accuracies well within the DEM accuracy criteria. Acceptable test points include, in order of preference: field control, aerotriangulated test points, spot elevations, or points on contours from existing source maps with appropriate contour interval. A minimum of 28 test points per DEM is required to compute the RMSE, which is composed of a single test using 20 interior points and 8 edge points. Edge points are those which are located along, at, or near the quadrangle neatlines and are deemed by the editor to be useful to evaluating the accuracy of the edge of the DEM. Collection of test point data and comparison of the DEM with the quadrangle hypsography are conducted by the quality control units within the USGS. There are three types of DEM vertical errors; blunder, systematic and random. These errors are reduced in magnitude by editing but cannot be completely eliminated. Blunder errors are those errors of major proportions and are easily identified and removed during interactive editing. Systematic errors are those errors that follow some fixed pattern and are introduced by data collection procedures and systems. These error artifacts include: vertical elevation shifts, misinterpretation of terrain surface due to trees, buildings and shadows, and fictitious ridges, tops, benches or striations. Random errors result from unknown or accidental causes. DEM's are edited to correctly depict elevation surfaces that correspond to water bodies of specified size. Level 2 DEM: A vertical RMSE of one-half of the contour interval, determined by the source map, is the maximum permitted. Systematic errors may not exceed one contour interval, determined by the source map, is the maximum permitted. Systematic errors may not exceed one contour interval specified by the source graphic. Level 2 DEMs have been processed or smoothed for consistency and edited to remove identifiable systematic errors.
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: 10
Vertical_Positional_Accuracy_Explanation:
RMSE of the DEM.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 199807
Title:
digital contour lines
Geospatial_Data_Presentation_Form: map
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Source_Scale_Denominator: 24000
Type_of_Source_Media: magnetic tape
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 197907
Ending_Date: unknown
Source_Currentness_Reference:
ground condition
Source_Citation_Abbreviation:
CONTOUR1
Source_Contribution:
hypsographic vector information which is interpolated to regular grid posts to form DEM grids in 10- by 10- meter UTM data spacing within the 7.5 minute DEM bounds.
Process_Step:
Process_Description:
Level 2 DEM: Level 2 DEM's are produced by converting 1:24,000-scale and 1:100,000-scale hypsography digital line graph (DLG) data to DEM format or the DEM's are generated from vector data derived from scanned raster files of USGS 1:24.000-scale or 1:100,000-scale map series contour separates. Level 3 DEM: Level 3 DEM's are created from DLG data that has been vertically integrated with all categories of hypsography, hydrography, ridge line, break line, drain files and all vertical and horizontal control networks. The production of level 3 DEMs requires a system of logic incorporated into the software interpolation algorithms that clearly differentiates and correctly interpolates between the various types of terrain, data densities and data distribution. Water body editing: DEM surface areas corresponding to water bodies are flattened and assigned map specified or estimated surface elevations. Water body areas are defined as ponds, lakes, and reservoirs that exceed 0.5 inches at map scale and double line drainage that exceeds 0.25 inches at map scale. Water body shorelines are derived either from a hypsographic DLG or by interactive delineation from 1:24,000-scale or 1:100,000-scale USGS map series. Edge matching and edge joining: DEM datasets within a project area (consisting of a number of adjacent files) are edge match and edge join edited to assure terrain surface continuity between files. Edge matching is the process of averaging adjacent elevation values along common edges within a zone of approximately 5 row or column grid posts on both edges. When edge values exceed 3 elevation units difference, edge joining is performed. Edge joining is an extensive level of editing and requires editing elevation values internal to the DEM in order to create more accurate terrain representations by correcting the alignment of ridges and drains, and overall topographic shaping within an approximately 25-30 row or column grid post zone on both edges. Quality control: DEM's are viewed on interactive editing systems to identify and correct blunder and systematic errors. DEM's are verified for physical format and logical consistency at the production centers and before archiving in the National Digital Cartographic Data Base (NDCDB) utilizing the Digital Elevation Model Verification System (DVS) software.
Source_Used_Citation_Abbreviation:
CONTOUR1, PHOTO1, CONTROL1
Process_Date: 199807
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Organization: Nebraska Department of Natural Resources
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address:
301 Centennial Mall South, P.O. Box 94676
City: Lincoln
State_or_Province: NE
Postal_Code: 68509-4676
Country: USA
Contact_Voice_Telephone: 402-471-2363
Contact_Facsimile_Telephone: 402-471-2900
Contact_Electronic_Mail_Address: gis@dnr.ne.gov
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Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 1412
Column_Count: 1091
Vertical_Count: 1
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Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 14
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -99.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: row and column
Coordinate_Representation:
Abscissa_Resolution: 10.000000
Ordinate_Resolution: 10.000000
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Semi-major_Axis: 6378206.400000
Denominator_of_Flattening_Ratio: 294.978698
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: National Geodetic Vertical Datum of 1929
Altitude_Resolution: 1
Altitude_Distance_Units: meters
Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates
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Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
The digital elevation model is composed of a 6-character integer raster representing a gridded form of a topographic map hypsography overlay. Each rasterentity contains a 6-character integer value between -32,767 to 32,768.
Entity_and_Attribute_Detail_Citation:
U.S.Department of the Interior, U.S. Geological Survey, 1992, Standards for digital elevation models: Reston, VA,
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Nebraska Department of Natural Resources
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address:
301 Centennial Mall South, P.O. Box 94676
City: Lincoln
State_or_Province: Nebraska
Postal_Code: 68509-4676
Contact_Voice_Telephone: 402-471-2363
Contact_Facsimile_Telephone: 402-471-2900
Contact_Electronic_Mail_Address: dnr.gis@nebraska.gov
Hours_of_Service: 0800-1600
Resource_Description: Downloadable Data
Distribution_Liability:
Although these data have been processed successfully on a computer system at the Nebraska Department of Natural Resources and the U.S. Geological Survey, no warranty expressed or implied is made by the Geological Survey or Nebraska Department of Natural Resources regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: DEM
Format_Information_Content:
USGS standard DEM: The standard USGS DEM can be described as an ASCII formatted elevation file preceded by a metadata header file which consists of one 1024 byte ACSII record.
Transfer_Size: 1.575
Digital_Transfer_Option:
Offline_Option:
Offline_Media: CD-ROM
Recording_Capacity:
Recording_Density: 700
Recording_Density_Units: megabytes
Recording_Format: maybe compressed
Compatibility_Information:
none
Fees: The online copy of the data set (when available electronically) may be accessed without charge.
Ordering_Instructions:
For delivery of the data there may be additional charges for processing the information plus the cost of the media. Currently, the 8mm tapes are $20 and CD-ROM are $2 each, if no additional processing is involved.
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Metadata_Reference_Information:
Metadata_Date: 20090921
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Nebraska Department of Natural Resources
Contact_Position: GIS Coordinator
Contact_Address:
Address_Type: mailing and physical address
Address:
301 Centennial Mall South, P.O. Box 94676
City: Lincoln
State_or_Province: Nebraaska
Postal_Code: 68509-4676
Country: USA
Contact_Voice_Telephone: 402-471-2363
Contact_Facsimile_Telephone: 402-471-2900
Contact_Electronic_Mail_Address: dnr.gis@nebraska.gov
Hours_of_Service: 8:00-5:00 - CST
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: http://www.esri.com/metadata/esriprof80.html
Profile_Name: ESRI Metadata Profile
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