Black and White orthos

Identification Information

Citation Information

Originator	U.S. Geological Survey (USGS), Maine Office of Geographic Information Systems (MEGIS) (comp., ed.)
Publication Date	20010131
Publication Time	Unknown
Title	Black and White orthos
Geospatial Data Presentation Form	remote sensing image
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	MEDOQ flight dates are available in comma delimited text, and .dbf format, on the MEGIS Data Catalog at http://megis.maine.gov/catalog/ "Tables" link medoqmeta.zip and in the WMS dataset medoq_1m_bw_98_dates.
Online Linkage	http://www.maine.gov/geolib/wms.htm
Beginning Date	1991
Beginning Time	Unknown
Ending Date	2003
Ending Time	Unknown
[smcisrcc]	source dates

Abstract

MEDOQ are digital orthorectified aerial imagery in gray-scale with 1-meter ground resolution. They are derived from the original US Geological Survey Digital Orthophoto Quarter Quads but cover one full 7.5 minute quadrangle. MEDOQs are compressed using the Lizardtech MrSid software (http://www.lizardtech.com) and are referred to as MrSid format ( .sid ) imagery. The MEDOQs are suitable for applications at a scale of 1" = 1,000 ( 1:12,000 ).

Purpose

MEDOQs are are suitable for applications at a scale of 1" = 1,000 ( 1:12,000 ) or larger. According to National Map Accuracy Standards for maps at that scale 90% of well defined points tested must be within 1/30 of an inch or 33.33 feet of their true position on the ground. DOQs serve a variety of purposes, from interim maps to field references for earth science investigations and analysis. The DOQ is useful as a layer of a geographic information system and as a tool for revision of digital line graphs and topographic maps.Users must assume responsibility in determining the usability of this data for their purpose. Data at this scale may be useful for parcel level studies and detailed planning.

Supplemental Information

Information in this document was drawn, compiled and modified to fit this data presentation from: USGS. 1998. Metadata for Digital Orthophoto Quadrangles. September 28, 1998, Reston VA. For more information see: http://mac.usgs.gov/. Dataset searching and ordering capabilities are available through EarthExplorer at URL http://earthexplorer.usgs.gov

Time Period of Content

Beginning Date	1996
Beginning Time	Unknown
Ending Date	1998
Ending Time	Unknown
Currentness Reference	source dates

Status

Progress	Complete
Maintenance and Update Frequency	none planned

Bounding Coordinates

West Bounding Coordinate	-71.24604
East Bounding Coordinate	-66.8
North Bounding Coordinate	47.6
South Bounding Coordinate	42.90479

Keywords

Theme	imageryBaseMapsEarthCover (ISO Keyword Thesaurus)
Theme	digital orthophotoquad, doq, aerial photograph (Maine GIS Thesaurus-Theme)
Place	United States, Gulf of Maine, Maine (Maine GIS Thesaurus-Place)
Stratum	land surface, radiance or imagery (GCMD Parameter Keyword)

Access Constraints

none

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 correct copy of both data and metadata from the Maine GIS Data Catalog. 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

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

Attribute Accuracy Report

During photographic reproduction of the source photography, limited analog dodging is performed to improve image quality. Analog dodging consists of holding back light from certain areas of the sensitized photographic material to avoid overexposure. The diapositive is inspected to insure clarity and radiometric uniformity. Diapositive image brightness values are collected with a minimum of image quality manipulation. Image brightness values may deviate from brightness values of the original imagery due to image value interpolation during the scanning and rectification processes. Radiometry is verified by visual inspection of the digital orthophoto quadrangle with the original unrectified image to determine if the digital orthophoto has the same or better image quality as the original unrectified input image. Slight systematic radiometric differences can be detected between adjacent DOQ files due primarily to differences in source photography capture dates and sun angles of aerial photography along flight lines. These differences can be observed in an image's general lightness or darkness when compared to adjacent DOQ file coverages.

Logical Consistency Report

All DOQ header data and image file sizes are validated by the Tape Validation System (TVS) software prior to archiving in the National Digital Cartographic Data Base (NDCDB). This validation procedure assures correct physical format and field values for header record elements. Logical relationships between header record elements are tested.

Completeness Report

All DOQ imagery is visually inspected for completeness to ensure that no gaps, or image misplacement exist in the 3.75' image area or in overedge coverage. DOQ images may be derived by mosaicking multiple images, in order to insure complete coverage. All DOQs are cloud free within the 3.75' image area. Some clouds may, very infrequently, be encountered only in the overedge coverage. Source photography is leaf-off in deciduous vegetation regions. Void areas having a radiometric value of zero and appearing black may exist. These are areas for which no photographic source is available or result from image transformation from other planimetric systems to the Universal Transverse Mercator (UTM). In the latter case, the void sliver areas are on the outside edges of the overedge area. The data set field content of each DOQ header record element is validated to assure completeness prior to archiving in the NDCDB.

Horizontal Positional Accuracy Report

The DOQ horizontal positional accuracy and the assurance of that accuracy depend, in part, on the accuracy of the data inputs to the rectification process. These inputs consist of the digital elevation model (DEM),aerotriangulation control and methods, the photo source camera calibration, scanner calibration, and aerial photographs that meet National Aerial Photography Program (NAPP) standards. The vertical accuracy of the verified USGS format DEM is equivalent to or better than a USGS level 1 or 2 DEM, with a root mean square error (RMSE) of no greater than 7.0 meters. Field control is acquired by third order class 1 or better survey methods sufficiently spaced to meet National Map Accuracy Standards (NMAS) for 1:12,000-scale products. Aerial cameras have current certification from the USGS, National Mapping Division, Optical Science Laboratory. Test calibration scans are performed on all source photography scanners.

Horizontal Positional Accuracy Value

Horizontal Positional Accuracy Explanation

Field control is acquired by third order class 1 or better survey methods sufficiently spaced to meet National Map Accuracy Standards (NMAS) for 1:12,000-scale products. Aerial cameras have current certification from the USGS, National Mapping Division, Optical Science Laboratory. Test calibration scans are performed on all source photography scanners.

Vertical Positional Accuracy Report

The DOQ accuracy depend, in part, on the accuracy of the data inputs to the rectification process. These inputs include digital elevation models (DEM).

Vertical Positional Accuracy Value

Vertical Positional Accuracy Explanation

DEM aerotriangulation control and methods, the photo source camera calibration, scanner calibration, and aerial photographs that meet National Aerial Photography Program (NAPP) standards. The vertical accuracy of the verified USGS format DEM is equivalent to or better than a USGS level 1 or 2 DEM, with a root mean square error (RMSE) of no greater than 7.0 meters.

Citation Information

Originator	U.S. Geological Survey (USGS)
Publication Date	1995
Publication Time	Unknown
Title	(250kdem) USGS 1:250,000 scale digital elevation models
Geospatial Data Presentation Form	raster digital data
Series Name	USGS Digital Elevation Models
Issue Identification	1:250000 DEM
Publication Place	Reston VA
Publisher	U.S. Geological Survey
Other Citation Details	3- x 3-arc second DEMS provides coverage in 1 x 1 degree blocks for all the contiguous United States, Hawaii and limited parts of Alaska. The basic elevation model is produced by or for the U.S. Department of Defense, Defense Mapping Agency (DMA), but is distributed by the USGS, EROS Data Center, in the DEM data record format. 1:250000 Digital Elevation Model data
Online Linkage	http://mapping.usgs.gov/mac/isb/pubs/factsheets/fs04000.html
[smcilnkh]	false
[smcisrcs]	250000
[smcisrcm]	digital tape media
Calendar Date	1995
Time of Day	Unknown
[smcisrcc]	publication date

Source Scale Denominator

250000

Type of Source Media

digital tape media

Calendar Date

1995

Time of Day

Unknown

Source Currentness Reference

publication date

Source Citation Abbreviation

250kdem

Source Contribution

Elevation data in the form of an ortho-DEM regridded to user-specified intervals and bounds.

Citation Information

Originator	U.S. Geological Survey (USGS)
Publication Date	19870101
Publication Time	Unknown
Title	(NAPP) National Aerial Photography Program
Geospatial Data Presentation Form	aerial photograph
Series Name	National Aerial Photography Program
Issue Identification	1987, 1992, 1997
Publication Place	Reston VA
Publisher	U.S. Geological Survey
Other Citation Details	NAPP photography is acquired at 20,000 feet above mean terrain with a 6 inch focal length lens. The flight lines are quarter quad-centered on the 1:24,000-scale USGS maps. NAPP photographs have an approximate scale of 1:40,000, and are flown in black-and-white or color infrared, depending on state or federal requirements. NAPP photography is indexed on 1:100,000-scale USGS maps.
Online Linkage	http://edc.usgs.gov/glis/hyper/guide/napp
[smcilnkh]	false
[smcisrcs]	40000
[smcisrcm]	paper and online
Beginning Date	19870101
Beginning Time	Unknown
Ending Date	Present
Ending Time	Unknown
[smcisrcc]	publication date

Source Scale Denominator

40000

Type of Source Media

paper and online

Beginning Date

19870101

Beginning Time

Unknown

Ending Date

Present

Ending Time

Unknown

Source Currentness Reference

publication date

Source Citation Abbreviation

napp

Source Contribution

Panchromatic black and white (or color infra-red) NAPP or NAPP-like photograph. NAPP photographs are centered on the DOQ coverage area.

Citation Information

Originator	U.S. Geological Survey
Publication Date	multiple dates
Publication Time	Unknown
Title	(DOQQ) Digital Orthophoto Quarter Quadrangles
Geospatial Data Presentation Form	remote-sensing image
Publication Place	Reston VA
Publisher	U.S. Geological Survey
Other Citation Details	Orthophotos combine the image characteristics of a photograph with the geometric qualities of a map. The primary digital orthophotoquad (DOQ) is a 1-meter ground resolution, quarter-quadrangle (3.75-minutes of latitude by 3.75-minutes of longitude) image cast on the Universal Transverse Mercator Projection (UTM) on the North American Datum of 1983 (NAD83).The geographic extent of the DOQ is equivalent to a quarter-quad plus The overedge ranges a minimum of 50 meters to a maximum of 300 meters beyond the extremes of the primary and secondary corner points. The overedge is included to facilitate tonal matching for mosaicking and for the placement of the NAD83 and secondary datum corner ticks. The normal orientation of data is by lines (rows) and samples (columns). Each line contains a series of pixels ordered from west to east with the order of the lines from north to south. The standard, archived digital orthophoto is formatted as four ASCII header records, followed by a series of 8-bit binary image data records. The radiometric image brightness values are stored as 256 gray levels ranging from 0 to 255. The metadata provided in the digital orthophoto contain a wide range of descriptive information including format source information, production instrumentation and dates, and data to assist with displaying and georeferencing the image. The standard distribution format of DOQs will be JPEG compressed images. U.S. Department of the Interior, U.S. Geological Survey, 1992, Standards for digital orthophotos: Reston, VA. A hypertext version is available at: <URL: http://mapping.usgs.gov/www/ti/DOQ/standards_doq.html> Softcopy in WordPerfect format is available at: <URL: ftp://mapping.usgs.gov/pub/ti/DOQ/doqstnds/doq1_12-96.wp6> <URL: ftp://mapping.usgs.gov/pub/ti/DOQ/doqstnds/doq2_12-96.wp6 Softcopy in Portable Document Format (PDF) is available at: <URL: ftp://mapping.usgs.gov/pub/ti/DOQ/doqstnds/usgsdoq.pdf>
[smcilnkh]	false
[smcisrcs]	12000
[smcisrcm]	CD-ROM
Beginning Date	1997
Beginning Time	Unknown
Ending Date	Present
Ending Time	Unknown
[smcisrcc]	publication date

Source Scale Denominator

12000

Type of Source Media

CD-ROM

Beginning Date

1997

Beginning Time

Unknown

Ending Date

Present

Ending Time

Unknown

Source Currentness Reference

publication date

Source Citation Abbreviation

doqq

Source Contribution

DOQQs were appended to assemble MEGIS tiled MEDOQs.

Process Description

The production procedures, instrumentation, hardware and software used in the collection of standard USGS DOQs vary depending on systems used at the contract, cooperator or USGS production sites. The majority of DOQ datasets are acquired through government contract. The process step describes, in general, the process used in the production of standard USGS DOQ data sets. The rectification process requires, as input, a user parameter file to control the rectification process, a digital elevation model (DEM1) gridded to user specified bounds, projection, zone, datum and X-Y units, a scanned digital image file (PHOTO1) covering the same area as the DEM, ground X-Y-Z point values (CONTROL_INPUT) and their conjugate photo coordinates in the camera coordinate system, and measurements of the fiducial marks (CAMERA_INPUT) in the digitized image. The camera calibration report (CAMERA_INPUT) provides the focal length of the camera and the distances in millimeters from the camera's optical center to the camera's 8 fiducial marks. These marks define the frame of reference for spatial measurements made from the photograph. Ground control points (CONTROL_INPUT) acquired from ground surveys or developed in aerotriangulation, are third order class 1 or better, and meet National Map Accuracy Standard (NMAS) for 1:12,000-scale. Ground control points are in the Universal Transverse Mercator or the State Plane Coordinate System on NAD83. Horizontal and vertical residuals of aerotriangulated tie-points are equal to or less than 2.5 meters. Standard aerotriangulation passpoint configuration consists of 9 ground control points, one near each corner, one at the center near each side and 1 near the center of the photograph, are used. The conjugate positions of the ground control points on the photograph are measured and recorded in camera coordinates. The raster image file (PHOTO_1) is created by scanning an aerial photograph film diapositive with a precision image scanner. An aperture of approximately 25 to 32 microns is used, with an aperture no greater than 32 microns permitted. Using 1:40,000-scale photographs, a 25-micron scan aperture equates to a ground resolution of 1-meter. The scanner converts the photographic image densities to gray scale values ranging from 0 to 255 for black and white photographs. Scan files with ground resolution less than 1 meter or greater than 1 meter but less than 1.28 meters are resampled to 1 meter. The principal elevation data source (DEM1) are standard DEM datasets from the National Digital Cartographic Data Base (NDCDB). DEMs that meet USGS standards are also produced by contractors to fulfill DOQ production requirements and are subsequently archived in the NDCDB. All DEM data is equivalent to or better than USGS DEM standard level 1. The DEM used in the production of DOQs generally has a 30-meter grid post spacing and possesses a vertical RMSE of 7-meters or less. A DEM covering the extent of the photograph is used for the rectification. The DEM is traversed from user-selected minimum to maximum X-Y values and the DEM X-Y-Z values are used to find pixel coordinates in the digitized photograph using transformations mentioned above. For each raster image cell subdivision, a brightness or gray-scale value is obtained using nearest neighbor, bilinear, or cubic convolution resampling of the scanned image. The pixel processing algorithm is indicated in the header file. An inverse transformation relates the image coordinates referenced to the fiducial coordinate space back to scanner coordinate space. For those areas for which a 7.5-minute DEM is unavailable and relief differences are less than 150 feet, a planar-DEM(slope-plane substitute grid) may be used.

Source Used Citation Abbreviation

250kdem

Source Used Citation Abbreviation

napp

Source Produced Citation Abbreviation

doqq

Contact Organization

(USGSGNIS) US Geological Survey

Contact Position

Chief, Geographic Names Information Section

Address Type

mailing and physical address

Address

523 National Center

City

Reston

State or Province

Postal Code

20192

Country

USA

Contact Voice Telephone

(703) 648-4551

Contact Electronic Mail Address

rwrocest@usgs.gov

Process Description

Rectification Process: The photo control points and focal length are iteratively fitted to their conjugate ground control points using a single photo space resection equation. From this mathematical fit is obtained a rotation matrix of constants about the three axes of the camera. This rotation matrix can then be used to find the photograph or camera coordinates of any other ground X-Y-Z point. Next a two dimensional fit is made between the measured fiducial marks on the digitized photograph and their conjugate camera coordinates. Transformation constants are developed from the fit and the camera or photo coordinates are used in reverse to find their conjugate pixel coordinates on the digitized photograph.

Contact Organization

(USGSGNIS) US Geological Survey

Contact Position

Chief, Geographic Names Information Section

Address Type

mailing and physical address

Address

523 National Center

City

Reston

State or Province

Postal Code

20192

Country

USA

Contact Voice Telephone

(703) 648-4551

Contact Electronic Mail Address

rwrocest@usgs.gov

Process Description

Quality Control: All data is inspected according to a quality control plan. DOQ contractors must meet DOQ standards for attribute accuracy, logical consistency, data completeness and horizontal positional accuracy. During the initial production phase, all rectification inputs and DOQ data sets are inspected for conformance to standards. After a production source demonstrates high quality, inspections will be made to 10% of delivery lots (40 DOQs per lot). All DOQs are visually inspected for gross positional errors and tested for physical format standards.

Contact Organization

(USGSGNIS) US Geological Survey

Contact Position

Chief, Geographic Names Information Section

Address Type

mailing and physical address

Address

523 National Center

City

Reston

State or Province

Postal Code

20192

Country

USA

Contact Voice Telephone

(703) 648-4551

Contact Electronic Mail Address

rwrocest@usgs.gov

Process Description

The Maine Office of GIS used the MrSid Workstation Geospatial Encoder 1.3.1 from Lizardtech, Inc. (http://www.lizardtech.com/index.html), to compress and mosaic the USGS DOQs. The USGS DOQs were copied to the Maine Office of GIS server and then the four quarter quads (DOQQs) that make up one quad were added into MrSid to compress and mosaic together. All images were compressed using the same tolerances in MrSid: a target compression ratio of 12:1, 5 zoom levels, a target thumbnail of 500 pixels, and a block size of 512. The typical input of the four quarter quads added up to approximately 165MB and the typical MrSid output was approximately 12.5MB per quad. The majority of the images were viewed before the mosaic process was completed so the best order to overlap the images that would result in the least of amount of data loss in overlapping areas could be determined. Due to the time-consuming nature of this image comparison procedure it was not performed on all images. MrSid images were created so that MEGIS could store all of the available images on the MEGIS server and also to provide a manageable data size for distribution from the MEGIS website.

Source Used Citation Abbreviation

doqq

Process Date

20001116

Contact Organization

(MEGIS) Maine Office of Geographic Information Systems

Contact Person

David Kirouac

Address Type

mailing and physical address

Address

MEGIS174 SHS

City

Augusta

State or Province

Postal Code

04330

Country

USA

Contact Voice Telephone

(207) 215-6936

Contact Electronic Mail Address

david.kirouac@maine.gov

Hours of Service

8:00 AM - 4:00 PM

Process Description

The MrSid DOQ image (MEDOQ) for the Monhegan Quad has been updated. The southern half of the older image was registered incorrectly and we recently received replacement images from USGS.

Process Date

20020902

Contact Organization

(MEGIS) Maine Office of Geographic Information Systems

Contact Person

David Kirouac

Address Type

mailing and physical address

Address

MEGIS174 SHS

City

Augusta

State or Province

Postal Code

04330

Country

USA

Contact Voice Telephone

(207) 215-6936

Contact Electronic Mail Address

david.kirouac@maine.gov

Hours of Service

8:00 AM - 4:00 PM

Cloud Cover

Indirect Spatial Reference

628 image mosaic Maine

Direct Spatial Reference Method

Raster

Raster Object Type

Pixel

Row Count

492758

Column Count

334280

Grid Coordinate System Name

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

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

WMS

Format Version Number

1.1

Format Specification

OpenGIS (OGC) Web Map Service (WMS)

[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.

[smdistty]

Fees

None

Ordering Instructions

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

Metadata Reference Information

Metadata Date

20000701

Metadata Review Date

20100119

Metadata Future Review Date

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