Resource Links:

1. Ordering CDs
2. Product Description
3. Topo Index Map
4. Technical Documentation
5. Product Size
6. Update Record
7. Disclaimer

Ordering CDs: To order the Vermont Topographic Maps (2003 Revision) 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.  To figure out which CDs you need for a given geographic area, please review the Topo Index Map (pdf) . 

What is new in this release (2003 revision)?  The Topo Index Map (pdf) highlights revised and new (quads that weren't distributed in the previous release).  Check it out to see what has changed.
 
Pricing Schedule

• $30 for a single CD
• $85 for the entire set (3 CD set)

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 (3 CD set) 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 (1:24,000/1:25,000 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

Topo Index Map: Each Topographic image file (TIFF) on this CD represents an area equivalent to a 7.5 minute quadrangle (QUAD). To figure out which QUADs you need for a given geographic area, and which CD they are on, please review the Topo Index Map (PDF) and make note of which QUADs cover your area of interest. The naming convention for each file is documented in the PDF file. It is consistent with QUAD tiling scheme (and naming convention using IDTIC) adopted by the VCGI.  A CDINDEX shapefile has also been included with this product.  This shapefile includes fields such as quad name, lat/long, IDTIC, and topo publication date*.  The shapefile is stored under the ./INDEX directory.  Use Arc/Info, ArcView/ArcGIS (3.x/8.x), 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

* Refer to the CREATEDATE and SOURCEDATE fields.
 

Technical Documentation: The Topographic Image files (TIFFs) included on this CD product were developed from USGS Digital Raster Graphic (DRG) files. DRGs are compressed TIFF image files. These files were converted into Arc/Info GRID format by VCGI 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 compressed TIFF format
5. The original DRG "color pallete" scheme has been retained.  For information on how the USGS DRG standard has changed (ex: non-standard color palette) since 1996 refer to http://topomaps.usgs.gov/drg/drg_standard_change.html