Identification_Information: SMMS_Type: 1 Citation: Citation_Information: Originator: U.S. Geological Survey Publication_Date: 200307 Title: medem10 Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: Maine GIS Data Catalog; Maine GIS SDE Server Publication_Information: Publication_Place: Augusta ME Publisher: Maine Office of Geographic Information Systems (MEGIS) Other_Citation_Details: 10 meter digital elevation models, MEDEM10s, are downloadable in zipped GRID format at http://megis.maine.gov/catalog. MEDEM10.DEM Ascii text files from which the grids were generated will download with the grids. The digital elevation models are developed as part of the orthorectification process. Availability will roughly precede the anticipated delivery dates for the high resolution orthophotography project. A status map of showing the expected order of MEDEM10 development will be made available at http://www.maine.gov/geolib/ortho%20committee/highresolorthoproject.htm. Online_Linkage: http://megis.maine.gov/catalog SMMS_Citation_Linkages_Hyperlinked: false SMMS_Citation_Source_Scale: 24000 SMMS_Citation_Source_Media: CD-ROM SMMS_Citation_Source_Time_Period: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2003 Ending_Date: Present SMMS_Citation_Source_Currentness: publication date Description: Abstract: MEDEM10s are digital terrain elevation models of Maine, in grid format, based on USGS 7.5 minute DEMs (10 by 10 m square grid or data spacing). Digital Elevation Model (DEM) is the terminology adopted by USGS to describe terrain elevation data sets in a digital raster form.The standard DEM consists of an array of elevations from ground positions at regularly spaced intervals, cast on a designated coordinate projection system, produced in 7.5 by 7.5 minute blocks from cartographic map contour overlays or scanned National Aerial Photography (NAPP_ photographs. USGS DEM data are stored as profiles with a 10 or 30 meter square grid spacing inwhich the spacing of elevations along and between each profile is in regular whole number intervals. USGS has used four methods to collect DEM data. Of these, only one, interpolation from vectors or digital line graph (DLG) hypsographic and hydrographic data is currently used for 7.5 minute DEMs and other series. MEDEM10s, produced using 1:24000 cartographic map contour overlays, represent the 10 meter profile of USGS 7.5 minute DEM series. Purpose: MEDEM10'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. Not intended for uses at scales greater than 1:24,000. Users must assume responsibility in determining the useability of this data for their purpose. Data at this scale may be useful for detailed studies and local planning. Supplemental_Information: MEDEM10 development is in progress as part of the Maine Library of Geographic Information (GeoLibrary) high resolution orthophotography development and acquisition. More information on completion status of the project represented by this coverage is available at http://www.maine.gov/geolib/projects.htm . Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2003 Ending_Date: Present Currentness_Reference: publication date Status: Progress: In Work Maintenance_and_Update_Frequency: continually Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -71.3 East_Bounding_Coordinate: -66.8 North_Bounding_Coordinate: 47.6 South_Bounding_Coordinate: 42.9 Keywords: Theme: Theme_Keyword_Thesaurus: Maine GIS Thesaurus-Theme Theme_Keyword: imageryBaseMapsEarthCover Theme_Keyword: 24000 Theme_Keyword: IMAGERY AND REMOTE SENSING Theme_Keyword: elevation Theme_Keyword: altitude Theme_Keyword: digital elevation model Theme_Keyword: digital terrain model Theme_Keyword: hypsography Theme_Keyword: contours Theme_Keyword: raster Theme_Keyword: relief Place: Place_Keyword_Thesaurus: Maine GIS Thesaurus-Place Place_Keyword: Maine Place_Keyword: United States of America Stratum: Stratum_Keyword_Thesaurus: Maine GIS Thesaurus-Stratum Stratum_Keyword: land surface Access_Constraints: Secondary distribution by permission only. Please see Maine Office of Geographic Information Systems (MEGIS) License Agreement at http://megis.maine.gov/ . Any secondary distribution must have this documentation appended. Use_Constraints: Users must assume responsibility in determining the usability of this data for their purposes. Digital maps retain the accuracy of their source materials. The best use of data mapped at scales of 1:500,000 and 1:250,000 is in statewide planning and studies; at 1:100,000 in regional planning and studies; at 1:62,500 and 1:24,000 in detailed studies and local planning; and at 1:12,000 and 1:5,000 or larger scales in parcel level studies and detailed local planning. In the use of Maine GIS data, please check sources, scale, accuracy, currentness and other available information. Please confirm that you are using the most recent copy of both data and metadata from the Maine GIS Data Catalog. The Maine Office of Geographic Information Systems (MEGIS) provides notice of updates and corrections directly to the Maine GIS Technical Group and Maine GIS Users, through the MEGISTECH and MEGISUSER list servers. To subscribe please contact the MEGIS technical support line at (207) 287-6144. To request data correction in, or provide updates to, Maine GIS data a feedback form is available at http://megis.maine.gov/, or you may contact MEGIS directly. MEGIS is not responsible for local edits to data or metadata. Updates, corrections, and feedback, incorporated in the Maine GIS database are made in accordance with "Data Standards for Maine Geographic Information Systems", 2002, and coordinated by MEGIS in consultation with the Maine GIS Executive Council. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: (MEGIS) Maine Office of Geographic Information Systems Contact_Address: Address_Type: mailing address Address: State House Station 145 City: Augusta State_or_Province: ME Postal_Code: 04333-0145 Country: USA Contact_Voice_Telephone: (207) 287-6144 Contact_Facsimile_Telephone: (207) 287-4563 SMMS_Contact_Email_Hyperlinked: false Hours_of_Service: Monday through Friday 0800 - 1700 EST Data_Set_Credit: Credit should always be given to the data source and/or originator when the data is transferred or printed. Native_Data_Set_Environment: ArcInfo version 9, Solaris 9, pathname = /home24/dems/24k/tiles//medem10, file size ~1.25 MB; Maine GIS SDE, sdeusers, sde, Bureau of Information Services (BIS) Oracle 9i Cross_Reference: Citation_Information: Originator: U.S. Geological Survey (USGS), Maine Office of Geographic Information Systems (MEGIS) (ed.) Publication_Date: 20010131 Publication_Time: Unknown Title: medem30 Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: Maine GIS Data Catalog; Maine GIS SDE Server Publication_Information: Publication_Place: Augusta ME Publisher: Maine Office of Geographic Information Systems Other_Citation_Details: 24000 Online_Linkage: http://megis.maine.gov/catalog/ SMMS_Citation_Linkages_Hyperlinked: true SMMS_Citation_Source_Scale: 24000 SMMS_Citation_Source_Media: online SMMS_Citation_Source_Time_Period: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19790701 Ending_Date: 20010131 SMMS_Citation_Source_Currentness: source dates SMMS_Dataset_Capture_Browse: false SMMS_Dataset: SMMS_DatasetLayer: SMMS_DatasetLayer_Order: 1 SMMS_DatasetLayer_Type: 0 SMMS_DatasetLayer_LabelVisible: 0 SMMS_DatasetLayer_Style1: 0 SMMS_DatasetLayer: SMMS_DatasetLayer_Order: 0 SMMS_DatasetLayer_Type: 1 SMMS_DatasetLayer_Location: \\bis-isa1AS2GIS\HOME24\dems\24k\tiles\bowdoinham SMMS_DatasetLayer_Name: medem10 SMMS_DatasetLayer_LabelVisible: 0 SMMS_DatasetLayer_Style1: 0 SMMS_DatasetLayer_Color: 0 SMMS_DatasetLayer_Weight: 0 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: Data profiles for this product do not always have the same number of elevations because of the variable angle between true north and north in the Universal Transverse Mercator (UTM) projection coordinate system. 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 rectangle. 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 the standard formatted USGS DEMs. 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 http://rmmcweb.cr.usgs.gov/nmpstds/demstds.html . Completeness_Report: Coverage for the State of Maine is complete. 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 represented in the DEM. This condition occurs infrequently and is always the first or last profile of the dataset. MEDEM10s, generated from vector data derived from scanned raster files of USGS 1:24,000 scale map series contour separates, 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 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. 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 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_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. 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. Quantitative_Vertical_Positional_Accuracy_Assessment: Vertical_Positional_Accuracy_Value: 7 Vertical_Positional_Accuracy_Explanation: MEDEM10s, generated from vector data derived from scanned raster files of USGS 1:24,000 scale map series contour separates. have been processed or smoothed for consistency and edited to remove identifiable systematic errors. 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. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: U.S. Geological Survey (USGS) Publication_Date: multiple dates Publication_Time: Unknown Title: (24k) USGS 1:24,000 scale quadrangles Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: National Mapping Program Standard Series Topographic Maps Issue_Identification: USGS 7.5 Minute Map Series Publication_Information: Publication_Place: Reston VA Publisher: U.S. Geological Survey Other_Citation_Details: 24000 Publication date is unique to each quadrangle in the map series. Standard 7.5x7.5 minute quadrangles cover geographic areas of 49 to 71 square miles. 1 inch at map scale represents 2000 feet. Online_Linkage: http://mapping.usgs.gov/mac/maplists/howtoselectmaps.html SMMS_Citation_Linkages_Hyperlinked: false SMMS_Citation_Source_Scale: 24000 SMMS_Citation_Source_Media: stable-base material (mylar) SMMS_Citation_Source_Time_Period: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19480101 Beginning_Time: Unknown Ending_Date: Present Ending_Time: Unknown SMMS_Citation_Source_Currentness: publication date Source_Scale_Denominator: 24000 Type_of_Source_Media: stable-base material (mylar) Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19480101 Beginning_Time: Unknown Ending_Date: Present Ending_Time: Unknown Source_Currentness_Reference: publication date Source_Citation_Abbreviation: 24k 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: The production procedures, instrumentation, hardware and software used in the collection of standard U. S. Geological Survey (USGS) Digital Elevation Models (DEM's) vary depending on systems used at the contractor, cooperator or National Mapping Division (NMD) production sites. This process step describes, in general, the process used in the production of standard USGS DEM datasets. MEDEM10s are generated from vector data derived from scanned raster files of USGS 1:24,000 scale map series contour separates. 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: DEM datasets within a project area (consisting of a number of adjacent files) are edge matched to assure terrain surface continuity between files. Edge matching is the process of correcting adjacent elevation values along common edges. The objective of edge matching is 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. Process_Date: 2003 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: (USGSHIGHRES) U.S. Geological Survey SMMS_Contact_Email_Hyperlinked: false Process_Step: Process_Description: The delivered product 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). These were: Process_Date: 200307 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: (MEGIS) Maine Office of Geographic Information Systems Contact_Address: Address_Type: mailing address Address: State House Station 145 City: Augusta State_or_Province: ME Postal_Code: 04333-0145 Country: USA Contact_Voice_Telephone: (207) 287-6144 Contact_Facsimile_Telephone: (207) 287-4563 SMMS_Contact_Email_Hyperlinked: false Hours_of_Service: Monday through Friday 0800 - 1700 EST Spatial_Data_Organization_Information: Indirect_Spatial_Reference: sample 1:24000 scale tile Direct_Spatial_Reference_Method: Raster Raster_Object_Information: Raster_Object_Type: Grid Cell Row_Count: 1000 Column_Count: 1500 Vertical_Count: 1 SMMS_Captured: false Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator 1983 Universal_Transverse_Mercator: UTM_Zone_Number: 19 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.9996 Longitude_of_Central_Meridian: -69 Latitude_of_Projection_Origin: 0 False_Easting: 500000 False_Northing: 0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: Coordinate Pair Coordinate_Representation: Abscissa_Resolution: 1 Ordinate_Resolution: 1 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: National Geodetic Vertical Datum of 1929 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: MEDEM10.VAT Entity_Type_Definition: value attribute table Entity_Type_Definition_Source: Environmental Systems Research Institute, Inc. (ESRI) Attribute: Attribute_Label: COUNT Attribute_Definition: number of pixels with a given value SMMS_Captured: false Attribute: Attribute_Label: VALUE Attribute_Definition: grid interpolated elevation in meters SMMS_Captured: false 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 interger value from -32767 to 32,768. Entity_and_Attribute_Detail_Citation: Standards for Digital Elevation Models,1993, U.S. Department of Interior (USDOI), U.S. Geological Survey (USGS), Reston, VA. A .pdf version is available at: http://rmmcweb.cr.usgs.gov/nmpstds/demstds.html . Distribution_Information: SMMS_Distribution_Name: Standard Grid Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: (MEGIS) Maine Office of Geographic Information Systems Contact_Address: Address_Type: mailing address Address: State House Station 145 City: Augusta State_or_Province: ME Postal_Code: 04333-0145 Country: USA Contact_Voice_Telephone: (207) 287-6144 Contact_Facsimile_Telephone: (207) 287-4563 SMMS_Contact_Email_Hyperlinked: false Hours_of_Service: Monday through Friday 0800 - 1700 EST Distribution_Liability: Users must assume responsibility to determine the usability of this data for their purposes. Although these data have been processed successfully on a computer system at the Maine Office of Geographic Information Systems, no warranty expressed or implied is made by MEGIS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. Neither the Maine Office of Geographic Information Systems, nor any of its contributors, are liable for misuse of the data, for damage, for transmission of viruses, or for computer contamination through the distribution of these data sets. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: GRID Format_Version_Number: GRID 9.x Format_Specification: ESRI Grid ASCII_File_Structure: Case_Sensitive: false Digital_Transfer_Option: Online_Option: Access_Instructions: Anyone with an Internet browser can view and download these data from http://megis.maine.gov/catalog/. Please follow instructions on the website for the Internet Data Catalog. SMMS_Distribution_Type: 1 Fees: Data may be downloaded from Maine GIS Internet Data Catalog at no charge. Turnaround: Data is available for immediate download from the Maine GIS Internet Data Catalog. SMMS_Distribution_Type: 1 Standard_Order_Process: Non-digital_Form: map Fees: MEGIS does some custom mapping, with available Maine GIS data, as time allows. If you have a custom mapping question please call the technical support line at (207) 287-6144 and ask about an estimate for your mapping needs. Turnaround: 15 working days SMMS_Distribution_Type: 2 Custom_Order_Process: MEGIS provides technical support for Maine GIS data, estimates on custom mapping, and consultation on data and application development, as time permits. You may call (207) 287-6144 with questions about Maine GIS data, and to inquire about assistance with your GIS environment. Metadata_Reference_Information: Metadata_Date: 20030701 Metadata_Review_Date: Metadata_Future_Review_Date: Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: (MEGIS) Maine Office of Geographic Information Systems Contact_Address: Address_Type: mailing address Address: State House Station 145 City: Augusta State_or_Province: ME Postal_Code: 04333-0145 Country: USA Contact_Voice_Telephone: (207) 287-6144 Contact_Facsimile_Telephone: (207) 287-4563 SMMS_Contact_Email_Hyperlinked: false Hours_of_Service: Monday through Friday 0800 - 1700 EST Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Use_Constraints: Please confirm that you are using the most recent copy of both data and metadata from the Maine GIS Data Catalog. The Maine Office of Geographic Information Systems (MEGIS) provides notice of updates and corrections directly to the Maine GIS Technical Group and Maine GIS Users through the MEGISTECH and MEGISUSER list servers. To subscribe please contact the MEGIS technical support line at (207) 287-6144. To request correction in, or updates to, Maine GIS data a feedback form is available at http://megis.maine.gov/, or you may contact MEGIS directly. MEGIS is not responsible for local edits to data or metadata. Updates, corrections, and feedback incorporated in the Maine GIS database are made in accordance with "Data Standards for Maine Geographic Information Systems", 2002, and coordinated by MEGIS in consultation with the Maine GIS Executive Council.