Metadata: Identification_Information: Citation: Citation_Information: Originator: Defense Mapping Agency Publication_Date: unknown Title: 1-degree Digital Elevation Models Geospatial_Data_Presentation_Form: map Publication_Information: Publication_Place: Reston, VA Publisher: U. S. Geological Survey Description: Abstract: Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of a regular array of elevations cast on a designated coordinate projection system. The DEM data are stored as a series of profiles in which the spacing of the elevations along and between each profile is in regular whole number intervals. The normal orientation of data is by columns and rows. Each column contains 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). 1-degree DEM (3- by 3-arc second data spacing). Provides coverage in 1- by 1-degree blocks. Two products (three in some regions of Alaska) provide the same coverage as a standard USGS 1- by 2-degree quadrangle. The basic elevation model is produced by or for the Defense Mapping Agency (DMA), but is distributed by the USGS in the DEM data record format. Coverage is for the United States. 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. Supplemental_Information: 1-degree DEM's have rows and columns which are based on the geographic coordinate system. The use of this system results in a rectangular DEM which shares a common edge and therefore duplicate points with other adjacent 1-degree DEM's. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19791000 Ending_Date: 19900331 Currentness_Reference: ground condition Status: Progress: complete Maintenance_and_Update_Frequency: Irregular Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -104.0 East_Bounding_Coordinate: -94.0 North_Bounding_Coordinate: 41.0 South_Bounding_Coordinate: 36.0 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 Access_Constraints: None Use_Constraints: None. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data. Browse_Graphic: Browse_Graphic_File_Name: dem250k Browse_Graphic_File_Description: 3-Dimensional DEM of the Wichita West Quadrangle Browse_Graphic_File_Type: GIF Native_Data_Set_Environment: DEM 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. 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" which are symbolized by contours overprinted with photorevised or other surface patterns. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Digital elevation models meet horizontal National Map Accuracy Standards (NMAS) accuracy requirements. NMAS horizontal accuracy requires that at least 90 percent of points tested are within 0.02 inches of the true position. The primary reference from which 1-degree DEM accuracy is derived is source-based, as a minimum, meeting NMAS for 100,000-scale USGS topographic series maps. Quantitative_Horizontal_Positional_Accuracy_Assessment: Horizontal_Positional_Accuracy_Value: RMSE of the DEM. The 1-degree DEM accuracy is source-dependent and is based on the 1:100,000-scale USGS topographic series map. Horizontal_Positional_Accuracy_Explanation: Digital elevation models meet horizontal National Map Accuracy Standards (NMAS) accuracy requirements. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The vertical root-mean-square error (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 error; blunder, systematic and random. These errors are reduced in magnitude by editing but cannot be completely eliminated and may be encountered. 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. DEMs 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 (of 100,000-scale source), 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 DEM's have been processed or smoothed for consistency and edited to remove identifiable systematic errors. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: RMSE Vertical_Positional_Accuracy_Explanation: Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: Title: digital contour lines Geospatial_Data_Presentation_Form: map Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Type_of_Source_Media: magnetic tape Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: various Ending_Date: various 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 3- by 3-arc second data spacing within the 1-degree DEM bounds. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: Title: digital elevation model Geospatial_Data_Presentation_Form: map Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Type_of_Source_Media: magnetic tape Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: various Ending_Date: various Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: DEM1 Source_Contribution: Elevation data in the form of a digital elevation model regridded to 3- by 3-arc second data spacing within the 1-degree DEM bounds. Process_Step: Process_Description: DEM's are created by gridding digital line graph (DLG) contours or the equivalent from USGS 1:24,000-scale or 1:100,000-scale maps. DEM's may also be created from regridding 7.5-minute DEMs to the coarser 3-arc second grid spacing of the 1-degree DEM. The accuracy and data spacing are intended to support computer applications that analyze hypsographic features to a level of detail similar to manual interpolation of information from printed source maps. 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. Additional information on this software may be found in Department of the Interior, U.S. Geological Survey, 1993, Technical Instructions, DVS Users Manual (draft): Reston, VA Source_Used_Citation_Abbreviation: CONTOUR1, DEM1 Process_Date: Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: raster Raster_Object_Information: Raster_Object_Type: grid cell Row_Count: 1201 Column_Count: 1201 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 3 Longitude_Resolution: 3 Geographic_Coordinate_Units: Decimal seconds 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 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 raster entity contains a 6-character integer value between -32,767 and 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 A hypertext version is available at: A hypertext extract is available at: Softcopy in ASCII format is available at: Softcopy in WordPerfect format is available at: Softcopy in PostScript format is available at: Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Data Access and Support Center Contact_Address: Address_Type: mailing and physical address Address: University of Kansas 1930 Constant Avenue, West Campus City: Lawrence State_or_Province: KS Postal_Code: 66047-3726 Contact_Voice_Telephone: 913-864-3965 Contact_Facsimile_Telephone: 913-864-5317 Contact_Electronic_Mail_Address: dasc@mongogis.kgs.ukans.edu Hours_of_Service: 0800-1700 Resource_Description: 1-degree digital elevation models Distribution_Liability: The State of Kansas Geographic Information Systems Core Database's digital data have been tested and their documentation carefully reviewed. However, the State of Kansas Geographic Information Systems Policy Board's Data Access and Support Center and its representatives make no warranty or representation, either expressed or implied, with respect to the digital data and their documentation, their quality, performance, merchantability, or fitness for a particular purpose. The digital data are distributed on "as is" basis, and the user assumes all risk to their quality, the results obtained from their use, and the performance of the data. In no event will the State of Kansas Geographic Information Systems Policy Board or its representatives be liable for any direct, indirect, special, incidental or consequential damages resulting from and defect in the State of Kansas Geographic Information Systems Core Database`s digital data or in their documentation. This disclaimer of warranty is exclusive and in lieu of all others, oral or written, express or implied. No agent or employee is authorized to make any modification, extension, or addition to this warranty. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: DEM Format_Information_Content: 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 MB Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://gisdasc.kgs.ukans.edu Offline_Option: Offline_Media: CD-ROM, 3.5 inch floppy disk, 4 mm cartridge tape, or 8 mm cartridge tape Recording_Format: ISO 9660 or tar Compatibility_Information: None Fees: Under the Kansas Public Records Law, DASC will attempt only to recover the costs related to the processing and distribution of core database requests. The following is a description of our Basic and Supplemental Conversion Services, as well as costs associated with the distribution of digital data: Basic Conversion Services­DASC will provide coversion services to all Federal/State/municipal tax­support agencies/entities for the cost of media and shipping and handling. Basic conversion services shall include the exportation of the Core Database in their native projection and tiling scheme into DASC supported spatial data exchange formats and technical support for the loading and importation of the data. Basic conversion services are provided to other than tax­supported organizations on a fee­for­service basis. Supplemental Conversion Services­DASC will provide supplemental conversion services to all organizations on a fee­for­service basis. Secondary services shall include the alteration of a Core Database's native projection, tiling scheme, or topological structure. Supplemental services also includes custom map production. Where applicable, recoverable cost include: 1. Labor to process the request 2. Computer processing time to extract/convert database 3. Magnetic media to distribute the data 4. Shipping and handling charges 5. Tax Below are the fees associated with each of the recoverable items: 1. Labor: $35.00/Hour 2. Central Processing Unit (CPU) computer time: $.14/Minute 3. Media: 3.5 inch HD floppy $.90 DC 2120 Mini data cartridge tape $22.00 8mm­112m Data cartridge tape $19.00 4mm­120m Data cartridge tape $20.00 Compact Disks $15.00 Network Transfer No Charge 4. Shipping and Handling: Varies 5. Tax (State of Kansas): 6.90% Metadata_Reference_Information: Metadata_Date: 19970211 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: 508 National Center City: Reston State_or_Province: VA Postal_Code: 22092 Contact_Voice_Telephone: 703-648-4543 Metadata_Standard_Name: Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: 19940608