National Atlas VMAP0 Data for Canada (V2)– Release Notes

GeoAccess Division, Canada Centre for Remote Sensing

November 2000

Please address comments and questions to the following email address
info@atlas.gc.ca. .Please report any problems or errors here as well. If
reporting errors, please try to include the unique feature id in your
description of the errors.

The National Atlas of Canada is a program of the GeoAccess Division of the
Canada Centre for Remote Sensing.

Manifest

The metadata associated with this data includes:

  1. Release Notes (HTML (This document)




References

Many of the attribute definitions in this dataset are derived from the
feature coding section (Part 4 and appendix) of the DIGEST standard. This
standard is available online at http://www.digest.org.

The US National Imagery and Mapping Agency (NIMA) is responsible for the
VMAP0 Revision 4 data. Information about it is available from their web
site http://www.nima.mil.



Introduction

The GeoAccess Division of the Canada Centre for Remote Sensing undertook a
project to restructure, improve and generalise the VMAP level 0 data for
use as national base map compatible with a global vector mapping base. To
date only the boundary and hydrology layers have been edited. As these 2
layers have evolved from their original state they can no longer be
referred to as part of the vmap level 0 revision 4 collection. Updated
boundary and hydrology layers are available through the GeoBase Data link
from the geogratis home page.

The GeoAccess division is actively trying to improve the accuracy and
utility of this data, and is interested in your comments. However, we do
not have the resources to actively support this dataset, and therefore
cannot guarantee a reply to any comments submitted.

This document accompanies the data, released through the Geogratis program
in Fall 2000.

General usage information

The data is divided in a number of Arc Info export format coverages. Each
of these coverages may contain a number of thematic feature classes. Each
feature class may contain one or more different types of features which may
have different attributes. Where applicable the coding scheme and attribute
items conform to the FACC digest standard. In some cases it was necessary
for us to derive new f_codes and attributes in order to code all the
features in our covers. Those f_codes and attributes that have been added
will be documented in appendix II. For all other attributes we would like
to direct our users to the digest standard website online at
http://www.digest.org.



Lineage

This data is primarily derived from the VMAP0 Revision 4 data for North
America, as distributed by NIMA in DIGEST format. That data is described in
the VMAP0 Revision 4 Metadata and MIL-V-89039 documents.

This document describes the primary modifications to this data, which are:

  1. Conversion into Arc/Info format

     The data was converted to Arc/Info format using ESRI’s VPFimporter in
     Arc/Info 7.2.1, together with custom routines. If you are viewing the
     data in another format, then it has been translated.

  2. Denormalisation of Attributes

     In its original VPF format, the attributes for the data are spread out
     over a number of tables using database normalisation rules. It proved
     more convienient for our users to have all the data placed into the
     feature attribute tables. This has increased the size of the database
     somewhat, but all the attribute information is more readily available.

  3. Clipping to the Canadian area

          These datasets cover all the land and water area of Canada. Some
          data outside Canada has been included for visual reference.

The boundary and hydrology layers have undergone significant enhancements
and quality control . As these 2 layers have evolved from their original
state they can no longer be referred to as part of the Vmap level 0
revision 4 collection. Updated boundary and hydrology layers are available
through the GeoBase Data link from the geogratis home page.



The data has been organised into different Arc/Info coverages. These relate
to, but do not exactly correspond to the original VMAP0 coverages. Within
each coverage there may be a number of thematic feature classes. For
instance roads and railroads are both within the transportation coverage.