Table Of Contents
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__________________________________________________________________ |
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| Identification Information |
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| Citation Information |
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Title: |
Enhanced Digital Elevation Model, Nova Scotia, Canada
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Originator: |
Service Nova Scotia and Municipal Relations, Registry and Information Management Services, Nova Scotia Geomatics Centre |
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Publication Date: |
Unpublished Material |
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Edition: |
1 |
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Data Type: |
raster digital data |
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Series: |
none |
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Issue Identification: |
none |
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Publisher: |
Service Nova Scotia and Municipal Relations, Registry and Information Management Services, Nova Scotia Geomatics Centre |
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Publication Place: |
Amherst, Nova Scotia, Canada |
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Online linkage: |
https://novascotia.ca/natr/meb/download/dp055ns20.asp |
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| Data Description |
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Abstract: |
Service Nova Scotia and Municipal Relations, Registry and Information Management Services, Nova Scotia Geomatics Centre produced the Enhanced Digital Elevation Model in conjunction with the Department of Natural Resources, the Department of Environment, and the Department of Agriculture and Fisheries. This product was generated at a resolution of 20 meters and geographically covers the province of Nova Scotia. The Enhanced Digital Elevation Model was developed in the Grid environment of ArcInfo version 7.1 using the topogrid command. This interpolation method generated a hydrologically correct grid of elevation for Nova Scotia.
Input coverages were selected from the 1:10 000 Digital Resource Mapping Series.
The input coverages include:
elevation points, irregularly spaced approximately 80 meters;
elevation points, representing hydrologic features (streams);
open water outlines with elevation values (lakes, coastline);
breakline features (cliffs);
contour lines - 5 meter where applicable;
spot heights - where applicable; |
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Purpose: |
To produce a hydrologically correct Digital Elevation Model for the province of Nova Scotia. This product may be useful in a number of applications, including terrain analysis and watershed mapping. |
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Supplemental Information: |
Data Set ID = e056ns25;
Data Class = dem10;
NovaScan ID = none;
Project ID = dem10; |
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Language |
English |
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Data Credit: |
Service Nova Scotia and Municipal Relations, Registry and Information Management Services, Nova Scotia Geomatics Centre |
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Data Environment |
ArcInfo 8.3 on a SUN Sparc 20 workstation running Solaris 7 |
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Native Data Set Format |
ArcInfo Grid |
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| Contact Information |
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Kevin Legere |
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Service Nova Scotia and Municipal Relations, Registry and Information Management Services, Nova Scotia Geomatics Centre |
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Distrbution Officer |
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1701 Hollis Street, P.O. Box 698 |
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Halifax, Nova Scotia, Canada |
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B3J 2T9 |
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(phone)
902-667-6286 |
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klegere@linux.nsgc |
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Available:
9:00 a.m. to 5:00 p.m. |
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| Time Period Information |
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Beginning Date: |
1999-06-01 |
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Ending Date: |
2000-03-15 |
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Currentness Reference: |
publication date |
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| Data Status |
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Progress: |
Complete |
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Update Frequency: |
None planned |
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| Spatial Domain |
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West Coordinate: |
-67.0 |
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East Coordinate: |
-59.0 |
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North Coordinate: |
47.25 |
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South Coordinate: |
43.00 |
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G-Poly coordinates |
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G-Poly Pair(1 of 1) |
90, 90 |
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| Keywords |
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Theme Keywords: |
Geologic & Geophysical; geoscientificInformation; digital elevation model; shaded relief |
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Place Keywords: |
Nova Scotia |
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| Access and Usage Information |
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Access Constraints: |
Required to enter into a license agreement for access to the data. |
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Use Constraints: |
As per license agreement. |
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| Browse Graphic Information |
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Filename: |
none |
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Description: |
none at this time |
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| Security Information |
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Classification System: |
none |
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Classification: |
Unclassified |
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Handling Description: |
none |
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| Cross Reference Information |
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| Cross Reference (1 of 2) |
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Title: |
DP ME 56, Version 1, 2003, Shaded Relief Images derived from a 25 metre Digital Elevation Model of the Province of Nova Scotia |
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Originator: |
Nova Scotia Department of Natural Resources, Mineral Resource Branch |
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Publication Date: |
November 2003 |
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Data Form: |
raster digital data |
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Online linkage: |
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Series: |
Digital Product |
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Issue: |
DP ME 55 |
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Publication Place: |
Halifax, Nova Scotia |
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Publisher: |
Nova Scotia Department of Natural Resources, Mineral Resource Branch |
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| Cross Reference (2 of 2) |
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Title: |
DP ME 57, Version 1, 2003, Shaded Relief Images derived from a 100 metre Digital Elevation Model of the Province of Nova Scotia |
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Originator: |
Nova Scotia Department of Natural Resources, Mineral Resource Branch |
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Publication Date: |
November 2003 |
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Data Form: |
raster digital data |
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Online linkage: |
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Series: |
Digital Product |
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Issue: |
DP ME 57 |
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Publication Place: |
Halifax, Nova Scotia |
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Publisher: |
Nova Scotia Department of Natural Resources, Mineral Resource Branch |
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__________________________________________________________________ |
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| Data Quality Information |
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| Positional Accuracy |
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Accuracy Report: |
The 20 metre DEM was produced from vector data contained in the 1:10 000 Digital Resource Mapping Series (see source contribution).
There may be positional accuracy errors in the digital data that come from the original data collection, plus there are errors added by the process of gridding the data.
The entire risk as to the quality and accuracy of the data is with the user and the user shall use his/her own judgment in making use of the data or drawing conclusions from it. |
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| Source Information |
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| Source (1 of 1) |
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Title: |
1:10 000 Digital Resource Mapping Series |
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Originator: |
Service Nova Scotia and Municipal Relations, Registry and Information Management Services, Nova Scotia Geomatics Centre |
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Publication Date: |
Unknown |
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Publication Time: |
Unknown |
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Data Form: |
vector digital data |
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Series Name: |
1:10 000 Digital Resources Mapping Series |
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Issue Identification: |
none |
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Publication Place: |
Amherst, Nova Scotia, Canada |
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Publisher: |
Service Nova Scotia and Municipal Relations, Registry and Information Management Services, Nova Scotia Geomatics Centre |
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Scale Denominator: |
1:10 000 |
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Source Media: |
disc |
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Citation Abbreviation: |
1:10 000 Digital Resources Mapping Series |
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Source Contribution: |
Input coverages were selected from the 1:10 000 Digital Resource Mapping Series.
The input coverages include:
elevation points, irregularly spaced approximately 80 meters;
elevation points, representing hydrologic features (streams);
open water outlines with elevation values (lakes, coastline);
breakline features (cliffs);
contour lines - 5 meter where applicable;
spot heights - where applicable |
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Currentness Reference: |
publication date |
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| Processing Step Information |
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| Processing Step (1 of 1) |
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Description: |
The DEM was created as part of a joint project with NSGC and a number of other government departments.
Phase 1 of the project was worked on by casual employee Krista Fraser under the direction of Brian Fisher at the Nova Scotia Department of Natural Resources, Mineal Resources Branch. Phase 2 was completed at the Nova Scotia Geomatics Center by Krista Fraser and Brad Potter. The processing report, written by NSGC, outlining the creation of the DEM is included as follows:
The primary objective of this phase was met with the successful completion of the Digital Elevation Model (DEM) of Nova Scotia at a 20 meter resolution. This product was developed in the Grid environment of ArcInfo version 7.1 using the topogrid command. Topogrid was chosen to create the DEM due to its ability to generate hydrologically correct grids of elevation. This interpolation method required the input of well selected elevation coverages. After reviewing all digital data available at the 1:10,000 scale the following coverages were selected.
- elevation points, irregularly spaced approximately 80m;
- elevation points, representing hydrologic features (streams);
- open water outlines with elevation values (lakes, coastline);
- breakline features (cliffs);
-contour lines -5m where applicable;
-spot heights -where applicable;
In reviewing the data for the province, it was noted that the information had been collected by two separate methods. The majority of south west Nova Scotia was collected in the older PDP format while the rest of the province was collected in the newer VAX format.
The two source data collection methods directly affected which base components were used as input data for grid creation. Due to the absence of elevation values on hydrographic (and other features) in the PDP areas, contours and spot heights were used to enhance the collected elevation points. In the PDP area, contours and spot heights were collected directly from the stereo-plotter, where as, in the VAX areas contours were automatically generated from the elevation points. Contours and spot heights were not used as input for grid creation in the VAX areas
Processing of the provincial DEM was divided into multiple units. Each unit area consisted of a NTS 1:50,000 mapsheet window plus an additional 1:10,000 mapsheet border. This was determined in Phase I to facilitate processing and allowed for sufficient overlap in the mosaicing stage.
After each unit was processed, a preliminary visual inspection was conducted and spot checks of accuracy were performed. Some errors were corrected and others have been logged for future consideration.
The Arclnfo mosaic command was the method chosen to create the final grid. This function combines two or more adjacent grids, making a smooth transition over the overlapping areas of the neighboring grids. During this stage it was determined that a single grid of floating point values exceeded the maximum file size permitted by the Arclnfo software. Two options were pursued. First, two separate floating point grids were created for mainland Nova Scotia and Cape Breton Island, respectively. Secondly, to create a provincial DEM it was necessary to convert the floating point grids to integer grids. This resulted in a significant file size reduction and allowed for a complete DEM of Nova Scotia. It was postulated that this integer DEM would not represent a significant reduction in accuracy. Both the integer and floating point grids were archived.
At this point the floating point and integer grids were filled. This ArcInfo process removes small imperfections in the data filling sinks in a continuous grid. Sinks are often errors in data due to resolution of the data or rounding of elevations to the nearest integer value. They should be filled to ensure proper delineation of basins and streams. If the sinks are not filled, a derived drainage network may be discontinuous. The result of this procedure created a truly hydrologically correct DEM.
This produced the four products now available:
floating point grids of mainland Nova Scotia and Cape Breton Island unfilled;
floating point grids of mainland Nova Scotia and Cape Breton Island filled;
integer grid of Nova Scotia unfilled;
integer grid of Nova Scotia filled |
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Software and Version: |
ArcInfo 7.1 |
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Date: |
June 1999 - March 2000 |
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__________________________________________________________________ |
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| Spatial Data Organization Information |
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Spatial Reference Method: |
Raster only. NOT AVAILABLE AS DEM |
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__________________________________________________________________ |
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| Spatial Reference Information |
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Data Projection: |
Universal Transverse Mercator |
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Zone: |
20
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Scale Factor at Central Meridian: |
0.9996
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Longitude at Central Meridian: |
-63.0
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Latitude of Projection Origin: |
0
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False Easting: |
500000
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False Northing: |
0
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Geographic Coordinate System: |
Universal Transverse Mercator
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Projected Coordinate System: |
UTM_Zone_20N
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Datum: |
North American Datum of 1927
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Ellipsoid: |
Clarke 1866
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Semi-Major Axis: |
6378206.400000
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Denominator Of Flattening Axis: |
294.978698
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__________________________________________________________________ |
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| Entity Attribute Information |
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| Overview Description |
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Dataset Overview: |
The data set contains two Digital Elevation Models maitained as ArcGRID grids. |
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| Detailed Description |
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| Data Layer/Table (1 of 2) |
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Table Name: |
e055ns20 - dem020st |
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Description: |
ArcInfo Grid - 'unfilled' DEM for structural interpretation, 20 metre cell size |
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Metadata Link: |
previous name - ns_dem |
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| Data Layer/Table (2 of 2) |
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Table Name: |
e055ns20 - dem020hy |
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Description: |
ArcInfo Grid - 'filled' hydrologically correct DEM, 20 metre cell size |
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Metadata Link: |
previous name - ns_fill_dem |
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__________________________________________________________________ |
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| Distribution Information |
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Description: |
PRODUCT NOT AVAILABLE FOR DISTRIBUTION |
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__________________________________________________________________ |
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| Metadata Reference |
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Creation Date: |
20031010 |
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Metadata Standard: |
FGDC Content Standards for Digital Geospatial Metadata |
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Standard Version: |
FGDC-STD-001-1998 |
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Metadata Language: |
English |
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Time Convention: |
local time |
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Review Date: |
As required |
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Access Constraints: |
none |
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User Constraints: |
none |
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Security Classification System: |
none |
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Security Classification: |
Unclassified |
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Security Handling Description: |
none |
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Metadata Contact: |
(see Contact Information)
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