drgclip

Identification Information

[smtype]

Citation Information

Originator	U.S. Geological Survey (USGS), Maine Office of Geographic Information Systems (MEGIS) (comp.)(ed.)
Publication Date	19991231
Title	drgclip
Geospatial Data Presentation Form	raster digital data
Series Name	Maine GIS
Issue Identification	SDE server; Internet Data Catalog
Publication Place	Augusta ME
Publisher	Maine Office of Geographic Information Systems
Other Citation Details	Maine Office of Geographic Information Systems (MEGIS) has developed a set of collarless DRGs. The process applied by MEGIS is described in FGDC metadata for DRGCLIP. Publication date is unique to each quadrangle in the map series, additional information on the source dates of USGS DRGs used to develop DRGCLIPs for Maine can be found in .dbf and comma delimited text format at http://megis.maine.gov/catalog/ "Tables" link.
Online Linkage	http://megis.maine.gov/catalog/
[smcilnkh]	true
[smcisrcs]	24000
[smcisrcm]	online
Beginning Date	19480101
Beginning Time	Unknown
Ending Date	19951231
Ending Time	Unknown
[smcisrcc]	source dates

Abstract

DRGCLIPs are collarless digital raster graphics (DRGs), produced from 1:24,000 USGS DRGs covering all of Maine. These are .TIFF format images of US Geological Survey (USGS) 7.5 minute series topographic maps, clipped from USGS Digital Raster Graphics (DRGs) for Maine. DRGCLIPs do not include map collar information. Each image represents the area, of a USGS DRG, inside the map neatline and is georeferenced to the surface of the Earth. DRGCLIPs retain, from the USGS DRG source, the associated .tfw files and the GeoTIFF 0.2 specifications that define a set of TIFF tags. The tags describe all cartographic information associated with the source file. This GeoTIFF information now contains the UTM projection and the NAD83 datum. DRGCLIPs retain the 8-bit color image of the USGS DRGs. USGS DRGs employ a standardized color palette to ensure uniform colors throughout.

Purpose

DRGs can be used to collect, review, and revise other digital data. When the DRG is combined with other digital products, such as digital orthophoto quadrangles (DOQ) or digital elevation models (DEM), the resulting image provides additional visual information for the extraction and revision of base cartographic information. It can also be used to produce "hybrid" products. These include combined DRGs and DOQs for revising and collecting digital data, DRGs and DEMs for creating shaded-relief DRGs, and combinations of DRG, DOQ, and DLG data. Although a standard DRG is an effective mapping tool, its full potential for digital production is realized in combination with other digital data.

Time Period of Content

Beginning Date	19480101
Beginning Time	unknown
Ending Date	19951231
Ending Time	unknown
Currentness Reference	source dates

Status

Progress	Complete
Maintenance and Update Frequency	As needed

Bounding Coordinates

West Bounding Coordinate	-71.3
East Bounding Coordinate	-66.8
North Bounding Coordinate	47.6
South Bounding Coordinate	42.9

Keywords

Theme	digital raster graphics, topographic map images (Maine GIS Thesaurus-Theme)
Theme	imageryBaseMapsEarthCover (ISO Keyword Thesaurus)
Place	Maine, Gulf of Maine, United States (Maine GIS Thesaurus-Place)
Stratum	human dimensions (GCMD Parameter Keyword)

Access Constraints

none

Contact Organization

(MEGIS) Maine Office of Geographic Information Systems

Contact Person

GIS Coordinator

Contact Position

GIS Coordinator

Address Type

mailing address

Address

State House Station 174

City

Augusta

State or Province

Postal Code

04333-0174

Country

USA

Contact Voice Telephone

207 624-7700

Contact Facsimile Telephone

207 287-3842

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

Maine Office of Information Technology (OIT) Oracle 9i, Maine Office of Geographic Information Systems (MEGIS)

Citation Information

Originator	U.S. Geological Survey (USGS)
Publication Date	20000901
Title	DRGMETA
Geospatial Data Presentation Form	tabular digital data
Series Name	Maine GIS
Issue Identification	SDE server; Internet Data Catalog; Tables
Publication Place	Augusta ME
Publisher	Maine Office of Geographic Information Systems (MEGIS)
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\\oit-teaqfsemc01\oit-mgis\crypt83\state

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DUMMYSTATE

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[smllbla]

24k

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INI=\\oit-teaqfsemc01\oit-mgis\crypt83\state\state.ini

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Attribute Accuracy Report

The source of this DRGCLIP, the USGS DRG. USGS DRGs are examined to ensure color consistency within a series. Inspections are performed on selected DRGs to ensure that both the order of digital numbers and digital number values are correct. Colors will be checked for color compliance to map series and for major color differences between features on the DRG and similar features on the source map. Color consistency throughout each series is checked by comparing a DRG to its neighboring quadrangles whenever possible.

Logical Consistency Report

The USGS DRG is produced with the intention of replicating as close as possible the original source map. Users will note, however, that a certain amount of "noise" can be discerned when small areas are blown up or viewed under zoomed-in conditions. This noise is in the form of random specks or pixels of color and halos due to any number of factors, such as, the quality of the source, the use of screens and patterns on the litho, and the unevenness of ink due to saturation and absorption. Discontinuities or breaks in linear features may also be present and are due to improper calibration or usage of the scanner, the condition of the source, and resampling. Descreening, quantizing, and noise filtering are methods used to reduce noise, which, besides creating a more aesthetically pleasing image, have the added benefit of reducing the size of the image file. Removal of lithographic screen patterns is preferred but not required.

Completeness Report

The USGS has checked for image completeness by visually inspecting a sampling of DRGs. Each was examined for gaps (missing data) in the main body of the map, the map collar, the overedge areas, and any insets. The map collar and all its contents have been removed from DRGCLIPs for Maine.

Horizontal Positional Accuracy Report

USGS DRGs have been accuracy tested. The accuracy test was performed by comparing the positions of UTM grid intersections on the source graphic against the corresponding location on the digital image. A visual inspection will determine whether those coordinates fall within the pixels that define a grid tick. USGS DRGs duplicate the horizontal accuracy of the source maps.

Horizontal Positional Accuracy Value

Horizontal Positional Accuracy Explanation

USGS DRGs retain the horizontal accuracy of the source maps. Most USGS printed maps contain the National Map Accuracy Standards (NMAS) note in the collar area. The NMAS states that for maps on publication scales of 1:20,000 or smaller, not more than 10 percent of the points tested shall be in error by more than 1/50 inch measured on the publication scale. Test points must be "well-defined", that is, easily visible or recoverable on the ground. For DRGs this accuracy statement applies only to that area of the DRG that falls within the neatline of the source map (excluding inset areas). Overedge areas falling outside the transformation boundary area (the map neatline), can exhibit anomalies or discrepancies. These anomalies also appear in the map inset areas and in the map collar. For maps without the NMAS note, the horizontal accuracy is unknown. The DRGCLIPs retain the accuracy of the source map. The map collar and all its contents have been removed from DRGCLIPs for Maine.

Vertical Positional Accuracy Report

National Geodetic Vertical Datum of 1929. USGS topographic maps utilize the vertical positional accuracy of the source. This accuracy is retained in USGS DRGs; however, the DRGCLIPs for Maine have been projected to NAD83 and vertical positional accuracy of elevation data may be affected by this conversion. The National Map Accuracy Standard applies to USGS topographic maps. At all map scales, the maximum allowable vertical tolerance is one half the published contour interval.

Citation Information

Originator	U.S. Geological Survey (USGS)
Publication Date	199804
Publication Time	Unknown
Title	(DRG) Digital Raster Graphics
Edition	1.0
Geospatial Data Presentation Form	raster digital data
Series Name	USGS Digital Raster Graphics
Issue Identification	Digital Raster Graphics (DRGs) are scanned color images of USGS topographic maps
Publication Place	Sioux Falls
Publisher	U.S. Geological Survey
Other Citation Details	Earth Science Information Centers (ESIC) offer nationwide information and sales service for USGS map products and earth science publications. Additional metadata on USGS DRGs for Maine can be found in .dbf and comma delimited text format at http://megis.maine.gov/catalog/ tables link. For additional information, contact any USGS Earth Science Information Center (ESIC), or call 1-800-USA-MAPS.
Online Linkage	http://edcwww.cr.usgs.gov
[smcilnkh]	false
[smcisrcs]	24000
[smcisrcm]	CD-ROM
Beginning Date	19480101
Beginning Time	Unknown
Ending Date	19951231
Ending Time	Unknown
[smcisrcc]	ground condition

Source Scale Denominator

24000

Type of Source Media

CD-ROM

Beginning Date

19480101

Beginning Time

unknown

Ending Date

19951231

Ending Time

unknown

Source Currentness Reference

ground condition

Source Citation Abbreviation

drg

Source Contribution

The collar information was removed from USGS Digital Raster Graphic (DRGs) to create DRGCLIP images for Maine GIS.

Process Description

Originally clipped DRGs were created from standard USGS 1:24000 Digital Raster Graphics (DRGs) for use by the Maine Forest Service, as part of an Arcview application. USGS DRGs contain the white margin and legend areas found on paper USGS quadrangles. This is inconvenient for those operations needing to mosaic several adjacent quads, so the following procedure was established. The Maine Forest Service has statewide jurisdiction, the project area covered the entire state of Maine. MFS has nine ranger districts, and the finished clipped DRG products were grouped onto CDs corresponding to those districts. The work environment was established in the following steps. The base data was 1:24000 scale USGS DRG quads on CD, supplied by USGS EROS data center, dated April 1998. The DRGs were in a UTM NAD27 georeferenced TIFF format. The data was supplied on CDs conforming to 1:250000-scale tile structure. Each tile was identified by alphanumeric format, not by tile name. In order to conform to MEGIS tile structure, and for operator convenience, the finished products would need to have the appropriate quadrangle names. Each USGS-supplied CD had a text file containing the DRG identification code and the corresponding quad name. For each CD, this data was imported to a Microsoft Access file, edited, then exported to an Info file called Quad.dat. The purpose of this Info file was to select the appropriate TIFF file for each tile when processing, and to name the output file by its quadrangle names. DRGs were processed in batches corresponding to MFS districts. An Arc/Info coverage was created which represents the MFS ranger districts. The getdist.aml was used to establish a workspace for a given district. The AML then created a polygon coverage of the district boundaries by reselecting from the MFS district coverage.

Source Used Citation Abbreviation

drg

Process Date

199910

Contact Organization

(MEGIS) Maine Office of Geographic Information Systems

Contact Person

GIS Coordinator

Contact Position

GIS Coordinator

Address Type

mailing address

Address

State House Station 174

City

Augusta

State or Province

Postal Code

04333-0174

Country

USA

Contact Voice Telephone

207 624-7700

Contact Facsimile Telephone

207 287-3842

Hours of Service

Monday through Friday 0800 - 1700 EST

Process Description

In October 2000, The Maine Department of Environmental Protection used the following process to create clipped DRGs projected to NAD83 and these were used to replace and upgrade original DRGCLIPS at MEGIS. All processes were completed using ArcInfo and ArcInfo GRID. The DRG TIFF image was converted into an ArcInfo GRID using the "imagegrid" command. To remove the collars from the DRG, the DRG grid was then clipped to the extent of the quadrangle using the MEGIS 7.5 minute map series index, 24KINDEX. The collarless, DRG grids were then projected from NAD27 to NAD83 using the ArcInfo "project" command with the "grid" option. The DRG grids were buffered by 100 meters and edges of adjacent grids were merged to fill in the "null" values providing data to complete "tiles" , and finally grids were converted back to TIFF images using the ArcInfo "gridimage" command.

Source Used Citation Abbreviation

drg

Process Date

200010

Contact Organization

(MEGIS) Maine Office of Geographic Information Systems

Contact Person

GIS Coordinator

Contact Position

GIS Coordinator

Address Type

mailing address

Address

State House Station 174

City

Augusta

State or Province

Postal Code

04333-0174

Country

USA

Contact Voice Telephone

207 624-7700

Contact Facsimile Telephone

207 287-3842

Hours of Service

Monday through Friday 0800 - 1700 EST

Process Description

Dataset copied.

[Sync]

TRUE

Source Used Citation Abbreviation

U:\projects\metadata\updated\datasets\drgclip

[Sync]

TRUE

[date]

20100330

[Sync]

TRUE

Time of Day

15060400

[Sync]

TRUE

Cloud Cover

Indirect Spatial Reference

751 image mosaic of Maine

Direct Spatial Reference Method

Raster

Raster Object Type

Pixel

Row Count

204495

Column Count

138708

Grid Coordinate System Name

Universal Transverse Mercator

UTM Zone Number

Scale Factor at Central Meridian

0.9996

Longitude of Central Meridian

-69

Latitude of Projection Origin

False Easting

500000

False Northing

Planar Coordinate Encoding Method

Abscissa Resolution

Ordinate Resolution

Horizontal Datum Name

North American Datum of 1983

Ellipsoid Name

Geodetic Reference System 80

Semi-major Axis

6378137

Denominator of Flattening Ratio

298.257

Entity and Attribute Overview

Each DRGCLIP is a raster image. Pixels contain a digital number from 0 through 12.referencing a color palette of RGB values from 0 through 255 in whichthe standard colors used in the DRG are defined.

Entity and Attribute Detail Citation

USGS Digital Raster Graphic Standards

Entity and Attribute Overview

Each DRGCLIP is a raster image. Pixels contain a digital number from 0 through 12.referencing a color palette of RGB values from 0 through 255 in whichthe standard colors used in the DRG are defined.

Entity and Attribute Detail Citation

USGS Digital Raster Graphic Standards

Contact Organization

Maine Office of Geographic Information Systems

Contact Position

GIS Coordinator

Address Type

mailing address

Address

State House Station 174

City

Augusta

State or Province

Postal Code

04333-0174

Country

USA

Contact Voice Telephone

(207) 624-7700

Contact Facsimile Telephone

(207) 287-3842

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.

Format Name

GeoTIFF

Format Specification

Tagged Image File Format

Format Information Content

TIFF image format is in widespread use in the desktop publishing world. It serves as an interface to several scanners and graphic arts packages. TIFF supports black-and-white, grayscale, pseudo color, and true color images, all of which can be stored in a compressed or decompressed format. TIFF images may contain georeferencing information in header tags, or a .tfw file, defined by the GeoTIFF standard. ArcGIS currently supports GeoTIFF tags.

File Decompression Technique

Data available from this website is in .zip compressed format. WinZip is a Windows based, PKZip-compatible compression utility. You will need a program like this to extract the data. A link to a trial copy WinZip software is available at http://megis.maine.gov/links/

Network Resource Name

http://megis.maine.gov/catalog/

[accinstr]

These data are available to Internet browsers for download from the Maine GIS Internet Data Catalog. Data available from this website is in .zip compressed format. WinZip is a Windows based, PKZip-compatible compression utility. You will need a program like this to extract the data. A link to a trial copy WinZip software is available at http://megis.maine.gov/software.asp.

Beginning Date

19991231

Beginning Time

unknown

Ending Date

Present

Ending Time

unknown

Contact Organization

Maine Office of Geographic Information Systems

Contact Position

GIS Coordinator

Address Type

mailing address

Address

State House Station 174

City

Augusta

State or Province

Postal Code

04333-0174

Country

USA

Contact Voice Telephone

(207) 624-7700

Contact Facsimile Telephone

(207) 287-3842

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.

Format Name

ARCSDE

Format Version Number

ArcSDE 9.x

Format Information Content

Oracle 9i

[accinstr]

Please contact the Maine Office of GIS (MEGIS) for access instructions.

[smdistty]

Fees

Access is available through Maine's wide area network; WAN users may contact the Maine Office of Information Technology, Maine Office of Geographic Information Systems (MEGIS) for a login.

Metadata Reference Information

Metadata Date

20000701

Metadata Review Date

20100114

Metadata Contact

Contact Organization	(MEGIS) Maine Office of Geographic Information Systems
Contact Person	GIS Coordinator
Contact Position	GIS Coordinator
Address Type	mailing address
Address	State House Station 174
City	Augusta
State or Province	ME
Postal Code	04333-0174
Country	USA
Contact Voice Telephone	207 624-7700
Contact Facsimile Telephone	207 287-3842
Hours of Service	Monday through Friday 0800 - 1700 EST

Metadata Standard Name

FGDC Content Standards for Digital Geospatial MetadataMetadata

Metadata Standard Version

FGDC-STD-001-1998

Metadata Access Constraints

None

Metadata Use Constraints

None

[ModDate]

20100330

[ModTime]

15112400

[MetaID]

{A8DFEB2E-323D-4891-BBB4-A5C49126FF4E}

[CreaDate]

20100330

[CreaTime]

15060400

[SyncOnce]

TRUE

[mdDateSt]

20100330

[Sync]

TRUE

[linkage]

file://\\oit-teaqfsemc01\oit-mgis\projects\metadata\WMS\USGS topo NOAA Charts\drgclip

[Sync]

TRUE

[protocol]

Local Area Network

[Sync]

TRUE

Contact Organization

Maine Office of GIS and Maine GeoLibrary

Format Name

Web Mapping Service (WMS)

Format Version Number

1.1

[accinstr]

The Maine Office of GIS and the GeoLibrary Board provide web mapping services to distribute aerial photos and other digital data. A WMS is not a web application which you can see in a web browser; rather, it requires you to add the service to a GIS software application.

Network Resource Name

http://www.maine.gov/geolib/wms.htm