Resource Links:

1. Ordering CDs
2. Product Description
3. Project Overview
4. Project Participants
5. Topo Image Catalog
6. Topo Index Map
7. Technical Documentation
8. Product Size
9. Disclaimer

Ordering CDs: To order the Vermont Topographic Maps(1:100,000 Edition) CD data product, download and print the CD Products Order Form.  Fill out the form by identifying what you want (which CDs), and mail it in with a check made out to VCGI, Inc. 
 
Pricing Schedule

• $30 for a single CD

NOTE: The order form and index map is in PDF format (Adobe Portable Document Format). You will need the Adobe Acrobat Reader to view this document. Please download the reader from the following site if you don't have it http://www.adobe.com/prodindex/acrobat/readstep.html

Product Description: This CD product contains a set of geo-referenced TIFF image files generated from U.S. Geological Survey Digital Raster Graphic image files (DRG). DRGs are scanned TIFF image files created from "standard" series USGS topographic maps (1:100,000 scale). These are available from USGS (and authorized resellers) as a "public record". However, "raw" DRGs include map "collars" (the white area around the map). This makes it difficult to use adjacent maps because the map collars overlap the adjoining image. DRGs are also in Universal Transverse Mercator project (UTM) NAD27. This is incompatible with Vermont's Spatial Data Infrastructure, which is in Vermont State Plane Meters (NAD83).

The TIFF files included with this product have been processed in order to address these limitations, including:

1. Removal of map collars
2. Re-projection into Vermont State Plane Meters NAD83

Project Overview: The product was developed through a collaborative venture between the Vermont Center for Geographic Information, Inc. (VCGI) and the Vermont Association of Planning and Development Agencies (VAPDA). This product would not have been possible without the support of VAPDA.   U.S. Geological Survey (USGS) Digital Raster Graphic (DRG) TIFF image files were used to create this product. Map "collars" were removed and the images re-projected from UTM NAD27 to Vermont's State Plane Coordinate System (NAD83). Collaborative initiatives such as these foster the development of Vermont's Spatial Data Infrastructure in a way that is "...compatible with, useful to..."⁽²⁾ the entire Vermont GIS Community.

Project Participants: The following organizations were partners in this collaborative effort.

ORGANIZATION	URL	PHONE #
Vermont Center for Geographic Information, Inc.	http://www.vcgi.org/	802-656-4277
Vermont Association of Planning and Development Agencies	http://www.vapda.org/	NA
U.S. Geological Survey*	http://www.usgs.gov/	NA

* Original DRGs used to create this product were acquired from USGS.
 

Topo Image Catalog:This CD product includes an Arc/Info Image Catalog. You can use the Image Catalog if you have either ArcView or "Workstation" Arc/Info software. An Image Catalog is an organized collection of geographically referenced images that can be accessed as one logical image. The Image Catalog on this disk is in an INFO⁽³⁾ database with entries for each topographic image file (TIFF) on this disk. This INFO database is the Image Catalog; it's just a pointer to the data. However, once loaded into ArcView or "Workstation" Arc/Info, the Image Catalog provides the user with the means to interface with dozens of images as if they were a single file.

Topo Index Map: Each Topographic image file (TIFF) on this CD represents an area equivalent to a 30- by 60-minute USGS map sheet.  However, the images have been "clipped" to the Vermont border.   To figure out which image(s) you need for a given geographic area, please review the Topo Index Map (PDF) included with this product and make note of which images cover your area of interest.  The naming convention for each file is documented in the PDF file.  A CDINDEX shapefile has also been included with this product.  This shapefile delineates the boundary of each image with a corresponding IDTIC attribute that matches the number of each file (ex: IDTIC = 24 is TOPO24.TIF).  The shapefile is stored under the ./INDEX directory.  Use Arc/Info, ArcView, or ArcExplorer to view this file.

NOTE: The index map is in PDF (Adobe Portable Document Format). You will need the Adobe Acrobat Reader to view this document. Please download the reader from the following site if you don't have it http://www.adobe.com/prodindex/acrobat/readstep.html
 

Technical Documentation:The Topographic Image files (TIFFs) included on this CD product were developed from 1:100,000 USGS Digital Raster Graphic (DRG) files purchased from Micropath Corporation⁽⁴⁾. DRGs are compressed TIFF image files. These files were converted into Arc/Info GRID format for manipulation. The GRIDs were then manipulated as follows:

1. Map collars were removed
2. Files were re-projected into Vermont State Plane Meters NAD83
3. Adjoining files were "merged" to create "seamless⁽⁵⁾" images
4. Arc/Info GRIDs were converted to uncompressed TIFF format
5. Compressed TIFF files were then created using Image Alchemy⁽⁶⁾ v1.10 (PackBits compression type)
6. The original DRG "color pallete" scheme has been retained

* For more detail information regarding DRGs, refer to Standards for Digital Raster Graphics.
** Detail metadata can also be found in the ./METADATA subdirectory.
*** It may be necessary to alter your system "Display Properties" if the TIFF images don't draw in the right color.
        1) Goto Settings --> Control Panel
        2) Double click on Display icon
        3) Pick Settings tab and change Color Palette to High Color (16 bit)
 

Product Size: 1 CD-ROM