GENERIC METADATA FOR 10 METER DEMS Metadata for a specific file can be acquired from the Internet at the URLs listed below in "Online_Linkage". NOTE: 10 meters dems offered by RGIS are in native format, i.e. *.dem. Metadata: Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey (USGS) Publication_Date: 20011010 Title: DEM 7.5 Quadrangle: Quadrangle name Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Online_Linkage: http://earthexplorer.usgs.gov Online_Linkage: http://edcwww.cr.usgs.gov/products/elevation/dem.html Description: Abstract: The 7.5-minute digital elevation model (DEM) data are digital repre- sentations of cartographic information in a raster form. The DEMs consist of an array of elevations for ground positions at regularly spaced intervals. The data are produced in 7.5- by 7.5-minute blocks from either digitized cartographic map contour overlays of a scanned National Aerial Photography Program (NAPP) photographs. The DEM data are stored as profiles with a 10-meter square grid spacing along and between each profile. Approximate file sizes are 9.9 mega bytes for a 10-meter resolution horizontal resolution. Data profiles for this product do not always have the same number of elevations because of the variable angle between true north and grid north in the Universal Transverse Mercator (UTM) projection coordinate system. The DEM data for 7.5-minute units correspond to the USGS 7.5-minute topographic quadrangle map series for all of the United States and its territo ries except Alaska. Purpose: DEMs can be used as source data for digital orthophotos, and for earth science analysis as layers in geographic information systems. DEMs 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: The 7.5-minute DEM data have rows and columns that vary in length and are staggered. The UTM bounding coordinates form a quadrilateral in which no two sides are parallel to each other, rather than a rec tangle. If a rectangle is required for the user's application, the user will need to pad out the uneven rows and columns with blanks or flagged data values. Some software vendors have incorporated this function into their software for input of standard formatted USGS DEMs. USGS dlgv32--Windows 95/NT based freeware viewer that supports a va riety of digital cartographic data. For more information visit: http://mcmcweb.er.usgs.gov/viewers/dlg_view.html The USGS has entered into an agreement with the GeoCommunity to serve updated, SDTS format, DEMs through the GIS Data Depot at http://www.gisdatadepot.com for no charge. The 7.5' SDTS DEM data are also available for purchase via premium (fast) download and on CD-ROM from GeoCommunity. The decision to provide SDTS DEMs through the GIS Data Depot is con sistent with the USGS goal of making more public domain data avail able at no charge while enabling the private sector to have a greater role in the distribution of USGS data. SDTS DEMs placed on media in response to customer orders will be sold by the GeoCommunity at a price less than the USGS currently charges. The GeoCommunity will continue to receive SDTS versions of the DEMs as they are made available by the USGS. Native format DEMs are still available for sale from USGS on various media and via ftp. If you have additional questions or comments, please contact sdts@usgs.gov. Please monitor the SDTS Home Page for further news and updates on this issue. http://mcmcweb.er.usgs.gov/sdts Time_Period_of_Content: Time_Period_Information: : Single_Date_Time: Calendar_Date: 20010101 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: East_Bounding_Coordinate: North_Bounding_Coordinate: South_Bounding_Coordinate: Keywords: Theme: : Theme_Keyword_Thesaurus: None Theme_Keyword: EARTH SCIENCE > LAND SURFACE > Topography > Landforms Theme_Keyword: contours Theme_Keyword: Digital Terrain Model Theme_Keyword: height Theme_Keyword: altitude Theme_Keyword: DEM Theme_Keyword: Digital Elevation Model Theme_Keyword: Hypsography Theme_Keyword: EARTH SCIENCE > LAND SURFACE > Topography > Terrain Elevation Theme_Keyword: 7.5-minute DEM Place: : Place_Keyword_Thesaurus: GCMD Location Keywords Place_Keyword: North America > Puerto Rico Place_Keyword: United States of America Place_Keyword: Pacific Ocean > Hawaii : Place_Keyword_Thesaurus: U.S. Department of Commerce, 1995, Countries, dependencies, areas of special sovereignty, and their principal administrative divisions (Federal Information Processing Standard 10-4):Washington, D.C., National Institute of Standards and Technology. Place_Keyword: US Place_Keyword: MX Place_Keyword: CA : 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_Keyword: NM Access_Constraints: none Use_Constraints: None. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data. Point_of_Contact: Contact_Information: : Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey EROS Data Center Contact_Position: Customer Services Representative Contact_Address: Address_Type: mailing and physical address Address: Customer Services U.S. Geological Survey EROS Data Center City: Sioux Falls State_or_Province: SD Postal_Code: 57198-0001 Country: USA Contact_Voice_Telephone: +001 605-594-6151 Contact_Voice_Telephone: U.S. toll free: 1-888-ASK-USGS (275-8747) Contact_TDD_TTY_Telephone: +001 605-594-6933 Contact_Facsimile_Telephone: +001 605-594-6589 Contact_Electronic_Mail_Address: custserv@usgs.gov Hours_of_Service: 0800 - 1600 CT, M-F, -6 h GMT Contact_Instructions: http://edc.usgs.gov Security_Information: Security_Classification_System: none Security_Classification: unclassified Security_Handling_Description: none Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The accuracy of a DEM depends upon the source level of detail and the grid spacing used to sample that source. The primary limiting factor for the source level of detail 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. For 7.5-minute DEMs derived from a photogrammetric source, 90 percent have a vertical accuracy of 7-meter RMSE or better and 10 percent are in the 8- to 15-meter range. 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 comple tion 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, both 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) pro jection grid, profiles that pass within the bounds of the DEM quadrilat eral may be void of elevation grid points and are not represented in the DEM. This condition occurs infrequently and is always the first or last profile of the dataset. Level 2 DEM: Level 2 DEMs 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, sus pect elevation areas may exist in the DEM but are not specifically iden tified. Suspect areas can be located on the source graphic as a dis turbed surface and are symbolized by contours overprinted with photore vised 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 that are selected as equal to or less than the intended horizontal RMSE error of the DEM. The testing of source material horizontal accuracy is accomplished 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: 1 Horizontal_Positional_Accuracy_Explanation: meter(s) Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The vertical RMSE statistic is used to describe the vertical accuracy of a DEM and encompasses 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. Random errors result from unknown or accidental causes. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 2 Vertical_Positional_Accuracy_Explanation: meter(s) Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: unknown 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: 19790701 Ending_Date: present 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 30- by 30- meter UTM data spacing within the 7.5 minute DEM bounds. Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: unknown Title: photo ID number, Geospatial_Data_Presentation_Form: remote-sensing image Publication_Information: Publication_Place: Reston, VA Publisher: U.S. Geological Survey Type_of_Source_Media: transparency Source_Time_Period_of_Content: Time_Period_Information: : Range_of_Dates_Times: Beginning_Date: unknown Ending_Date: present Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: photo1 Source_Contribution: elevation values Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: unknown Title: project control 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: unknown Ending_Date: present Source_Currentness_Reference: ground condition Source_Citation_Abbreviation: control1 Source_Contribution: ground control points Process_Step: Process_Description: The production procedures, instrumentation, hardware and software used in the collection of standard U. S. Geological Survey (USGS) Digital Elevation Models (DEMs) vary depending on the systems used at the contractor, cooperator or National Mapping Division (NMD) production sites. This process step de scribes, in general, the process used in the production of standard USGS DEM datasets. Level 1 DEM: Level 1 DEMs are acquired photogrammetrically by manual profiling or image correlation techniques from either the National Aerial Photography Program (NAPP) or equivalent source photographs. Level 1 30- minute DEMs may be derived or resampled from Level 1 7.5- minute DEMs. Level 2 DEM: Level 2 DEMs are produced by converting 1:24,000-scale and 1:100,000-scale hypsography digital line graph (DLG) data into DEM format or the DEMs can be 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 DEMs are created from DLG data that has been vertically inte grated 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 interpo lation 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 as signed either 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 from either a hypsographic DLG or by interactive de lineation from a 1:24,000- or 1:100,000-scale USGS map series. DEMs are verified for physical format and logical consistency. Source_Used_Citation_Abbreviation: control1, photo1, contour1 Process_Date: 20010701 Spatial_Data_Organization_Information: : Direct_Spatial_Reference_Method: raster : Raster_Object_Information: Raster_Object_Type: grid cell Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: : Planar: : Grid_Coordinate_System: : Universal_Transverse_Mercator: UTM_Zone_Number: 10-13 Transverse_Mercator: Scale_Factor_at_Central_Meridian: .9996 Longitude_of_Central_Meridian: -123 00 00 Latitude_of_Projection_Origin: 0.0 False_Easting: 500000 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: row and column : Coordinate_Representation: Abscissa_Resolution: 30 Ordinate_Resolution: 30 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum 1927 Ellipsoid_Name: Clark 1866 Semi_major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 294.9787 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: National Geodetic Vertical Datum of 1929 Altitude_Resolution: 1 Altitude_Distance_Units: feet 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 hypsogra phy overlay. Each raster entity 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, Digital Elevation Models --Data Users Guide; Reston, VA, A softcopy ex tract is available at: URL: ftp://mapping.usgs.gov/pub/ti/DEM/ U.S.Department of the Interior, U.S. Geological Survey, 1992, Standards for digital elevation models: Reston, VA, Softcopies in ASCII and WordPerfect format are available at: URL http://mapping.usgs.gov/pub/ti/DEM/ Distribution_Information: : Distributor: Contact_Information: : Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey EROS Data Center Contact_Person: Customer Services Representative Contact_Position: Customer Services Representative Contact_Address: Address_Type: mailing and physical address Address: Customer Services, U.S. Geological Survey, EROS Data Center City: Sioux Falls State_or_Province: SD Postal_Code: 57198 Country: USA Contact_Voice_Telephone: +001 605-594-6151 or U.S. toll free: 1-888-ASK-USGS (275-8747) Contact_TDD_TTY_Telephone: +001 605-594-6933 Contact_Facsimile_Telephone: +001 605-594-6589 Contact_Electronic_Mail_Address: custserv@usgs.gov Hours_of_Service: 0800 - 1600 CT, M-F -6 h GMT Contact_Instructions: Distribution_Liability: Although these data have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made by the USGS regarding the use of the data on any other system, nor does the act of distribution constitute any such warranty. The USGS will warrant the delivery of this product in computer-readable format and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer input peripherals, or when the physical medium is delivered in damaged condition. Requests for adjustment of credit must be made within 60 days from the date of this shipment from the order site. Standard_Order_Process: : Digital_Form: Digital_Transfer_Information: Format_Name: DEM (native) 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 ASCII record. Transfer_Size: 1 Digital_Transfer_Option: : Online_Option: Computer_Contact_Information: : Network_Address: Network_Resource_Name: Offline_Option: Offline_Media: CD-ROM Recording_Capacity: Recording_Density: 680000 Recording_Density_Units: Mb Recording_Format: ISO 9660 Compatibility_Information: This CD-ROM can be used with all computer op erating systems that support CD-ROM as a logical storage device. All text files on the disc are in ASCII format. Data files are in ASCII or binary format. : Offline_Option: Offline_Media: cassette Recording_Capacity: Recording_Density: 8-mm high (4.5Gb) Recording_Density_Units: gigabytes Recording_Format: ASCII; available unlabelled; block sizes are multiples of 1024 characters. To ensure compatibility, a maximum blocking factor of 31744 is recommended. For efficiency, blocking factors less than 16,000 are discouraged. Fees: Find pricing information at http://earthexplorer.usgs.gov Ordering_Instructions: Online Ordering: Once you have filled out and submitted the online ordering form found at http://earthexplorer.usgs.gov , it is forwarded to Customer Services at the U.S. Geological Survey's EROS Data Center via the Earth Explorer system. The EROS Data Center uses a secure credit card server that will encrypt your sensitive information and pass it from your browser to the Data Center's web server. Mail Ordering: First obtain the ordering information from Earth Explorer. Mail this information, along with your payment (check or purchase/money order), to any Earth Science Information Center. A full list of these offices can be found at: http://mapping.usgs.gov/esic/esic_index.html Turnaround: 1 - 3 weeks Available_Time_Period: Time_Period_Information: : Single_Date_Time: Calendar_Date: 20010101 Metadata_Reference_Information: Metadata_Date: 20010101 : Metadata_Review_Date: 20010101 Metadata_Future_Review_Date: 20010101 Metadata_Contact: Contact_Information: : Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey EROS Data Center Contact_Position: Information Scientist Contact_Address: Address_Type: mailing and physical address Address: Archive and Information Systems, EROS Data Center City: Sioux Falls State_or_Province: SD Postal_Code: 57198-0001 Country: USA Contact_Voice_Telephone: +001 605-594-6594 Contact_TDD_TTY_Telephone: +001 605-594-6933 Contact_Facsimile_Telephone: +001 605-594-6953 Contact_Electronic_Mail_Address: meta@usgs.gov Hours_of_Service: 0800 - 1600 CT, M-F, -6 h GMT Metadata_Standard_Name: Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998, Version 2 Metadata_Time_Convention: local time Metadata_Access_Constraints: None Metadata_Use_Constraints: None Metadata_Security_Information: Metadata_Security_Classification_System: None Metadata_Security_Classification: Unclassified Metadata_Security_Handling_Description: None