USGS Historic Topos circa 1910

Identification Information

Contact Person

Michael Smith

Contact Organization

Maine Office of GIS

Contact Position

State GIS Manager

Contact Electronic Mail Address

michael.smith _at_ maine.gov

Citation Information

Title	USGS Historic Topos circa 1910

Abstract

This layer includes the 15', 1:62500 USGS topographic maps for Maine from the late 1800s and early 1900s, ranging from 1891-1935. There are 83 quads in this layer, covering 43% of the state, mostly southern and central Maine and Down East Maine. The maps were scanned from paper copies, georeferenced, and then had the collars clippled and the edges mosaicked. Most maps were scanned originally at 600dpi, either by MEGIS or USGS. All georeferencing of these was done by USGS. A few quads were not either in the collection of Maine or USGS, and in those cases quarter-quads were downloaded from the UNH library web site, those quarters were then georeferenced separately and if needed, rubber-sheeted along seamlines to make the quad. Most of these quads do not indicate land cover (green areas). Note that the source paper maps vary considerably in their paper color, ink contrast, fading, and so forth. The user will see great variation between quads which cannot be made more consistent at this time.

Purpose

For historical reference.

Time Period of Content

Beginning Date	1891
Ending Date	1935
Currentness Reference	publication date

Status

Progress	Complete
Maintenance and Update Frequency	None planned

Bounding Coordinates

West Bounding Coordinate	-66.875
East Bounding Coordinate	-71.25
North Bounding Coordinate	45.75
South Bounding Coordinate	43

Keywords

Theme	topography, history

Access Constraints

None

Use Constraints

None

Data Set Credit

Maine Office of GIS (MEGIS), US Geological Survey (USGS), University of New Hampshire Library (UNHLIB)

Native Data Set Environment

GeoPDFs and TIFFs

Process Description

Paper maps were scanned using a sheet scanner, images were saved as 600dpi 24-bit TIFFs with no compression.

Process Date

2010

Process Description

Digital images were sent to USGS, who compiled the images with their own collection of 600dpi scanned TIFFs. USGS georeferenced the TIFFs and created GeoPDFs from the TIFFs.

Process Date

2011

Source Scale Denominator

62500

Type of Source Media

paper

Beginning Date

1891

Ending Date

1935

Source Currentness Reference

publication date

Source Citation Abbreviation

USGS

Process Description

GeoPDFs were converted to GeoTIFFs, the collars were clipped, and the edges were mosaicked to adjacent quads by MEGIS.

Process Date

2011

Attribute Accuracy Report

Raster data - no attributes

Completeness Report

All known maps from this early era are included.

Horizontal Positional Accuracy Report

These maps pre-date the National Map Accuracy Standard (NMAS), but if one goes by the NMAS, the data are likely to be +/- 40m or so.

Metadata Reference Information

Metadata Contact

Contact Person	Michael Smith
Contact Organization	Maine Office of GIS
Contact Position	State GIS Manager
Contact Electronic Mail Address	michael.smith _at_ maine.gov

Metadata Date

Jan 12 2012

Metadata Review Date

Jan 12 2012

Metadata Standard Name

FGDC Content Standards for Digital Geospatial Metadata

Metadata Time Convention

local time

Metadata Access Constraints

None

Metadata Use Constraints

None

Direct Spatial Reference Method

Raster

Raster Object Type

Pixel

Row Count

Column Count

Horizontal Datum Name

North American Datum of 1983

Ellipsoid Name

Geodetic Reference System 80

Resource Description

GeoPDFs can be downloaded from store.usgs.gov.