South Portland 2005

Identification Information

Citation Information

Originator	City of Portland
Publication Date	20050506
Publication Time	Unknown
Title	South Portland 2005

Keywords

Theme	ImageryBaseMapsEarthCover (ISO Keyword Thesaurus - Theme)
Theme	Digital orthophotos, Digital image map, Aerial photograph, Rectified image, Rectified photograph, Orthophoto, Ground sample distance .15m (none)
Place	South Portland, Maine (none)

Contact Person

Mark Bradstreet

Contact Organization

Bradstreet Consultants

Contact Position

President

Address Type

mailing and physical address

Address

69 Peters Rd

City

Searsmont

State or Province

Maine

Postal Code

04973

Country

USA

Contact Voice Telephone

207-621-8500

Contact Electronic Mail Address

markb@bradstreet.com

Abstract

This OGC-compliant web mapping service (WMS) provides 6" pixel resolution orthoimagery of South Portland from May 6, 2005. This WMS is provided by the Maine Office of GIS and the Maine GeoLibrary Board. As the prime contractor, Bradstreet Consultants, Inc. used the aerial photography flown in one session on May 6, 2005, by Richard Crouse & Associates, Inc. of Frederick, MD who acquired approximately 1335 photos @ 1"=600' with airborne GPS using a Wild RC-30 (#13261) aerial camera. Bradstreet Consultants, Inc. painted and repainted ground targets for photo survey control points (~200) to support full analytical aerotriangulation. The aerotriangulation solution was used to set up each stereopair of photos for orthorectification and DTM compilation. The ortho imagery was created by scanning (14 microns (um) per pixel or 1815 dpi) the original 1"=600' scale film and employing a digital terrain model (DTM) from updating some town's original DTM and some town's from scratch using the 1"=600' scale negatives or diapositives using both analytical and softcopy (digital) stereoplotter in the Kork KDMS format.

Purpose

Use in GIS for viewing and analysis along with sale to surveying, engineering, GIS and other intersted individuals and companies.

[langdata]

English

Time Period of Content

Calendar Date	20050506
Currentness Reference	ground condition

Status

Progress	Complete
Maintenance and Update Frequency	None planned

Bounding Coordinates

West Bounding Coordinate	-70.38
East Bounding Coordinate	-70.22
North Bounding Coordinate	43.66
South Bounding Coordinate	43.59

Access Constraints

none

Use Constraints

Data should not be used beyond the scale of 1:2400.

Data Set Credit

Data Set Produced by Bradstreet Consultants, Inc., 69 Peters Road, Searsmont, ME04973 www.bradstreet.com

Native Data Set Environment

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.3.1.1850

Completeness Report

Orthoimagery for South Portland, Maine clipped to within about 100 feet beyond the town line.

Horizontal Positional Accuracy Report

The horizontal accuracy of the aerial photos is +/- 1 foot. Ground control used in aerotriangulation solution accurate to within 0.1 ft. Said solution was used to compile 1:1200 vector base mapping, which was subsequently used to control the orthorectification process. Vector data was compiled to meet ASPRS Class 1 accuracy standards. The orthorectification process was applied to the imagery and those features which are at ground level. No attempt was made to correctly rectify elevated structures as part of this project.

Horizontal Positional Accuracy Explanation

Comparison to Source

Vertical Positional Accuracy Report

Gound control used in aerotriangulation solution accurate to within 0.1 ft. Said solution was used to compile terrain data to support generation of 2 foot contour data. This elevation data was subsequently used to control the orthorectification process. The elevation data was compiled to meet ASPRS Class 1 accuracy standards. The orthorectification process was applied to the imagery and those features which are at ground level. No attempt was made to correctly rectify elevated structures as part of this project.

Source Scale Denominator

6000

Type of Source Media

Aerial photography film

Calendar Date

20050506

Time of Day

unknown

Source Currentness Reference

ground condition

Process Description

Bradstreet Consultants, Inc. used the aerial photography flown in one session on May 6, 2005, by Richard Crouse & Associates, Inc. of Frederick, MD who acquired approximately 1335 photos @ 1"=600' with airborne GPS using a Wild RC-30 (#13261) aerial camera. Bradstreet Consultants, Inc. painted and repainted ground targets for photo survey control points (~200) to support full analytical aerotriangulation. The aerotriangulation solution was used to set up each stereopair of photos for orthorectification and DTM compilation. The ortho imagery was created by scanning (14 microns (um) per pixel or 1815 dpi) the original 1"=600' scale film and employing a digital terrain model (DTM) from updating some town's original DTM and some town's from scratch using the 1"=600' scale negatives or diapositives using both analytical and softcopy (digital) stereoplotter in the Kork KDMS format.

[ModDate]

20100330

[ModTime]

10595700

Metadata Reference Information

Metadata Date

20100330

[Sync]

TRUE

Metadata Contact

Contact Person	Mark Bradstreet
Contact Organization	Bradstreet Consultants
Contact Position	President
Contact Voice Telephone	207-621-8500
Contact Electronic Mail Address	markb@bradstreet.com

Metadata Standard Name

FGDC Content Standards for Digital Geospatial Metadata

Metadata Access Constraints

none

Metadata Use Constraints

none

[mdDateSt]

20100330

[Sync]

TRUE

Direct Spatial Reference Method

Raster

Raster Object Type

Pixel

Row Count

Column Count

Grid Coordinate System Name

SPCS Zone Identifier

Maine West NAD83

Network Resource Name

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

[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.