Horizontal Datum Conversions

26 February 1998
This paper outlines the steps required to convert ARC/INFO coverages from the North American Datum of 1927 (NAD27) to the more accurate North American Datum of 1983 (NAD83).

Managing Data Layer Updates

26 August 1993
Data maintenance is often an expensive yet neglected aspect of managing GIS data. Each data layer is unique and will have its own system for making and tracking updates. By consequence, tools for data maintenance are generally not built into GIS software. This guideline contains a collection of techniques and procedures for managing GIS data layer updates. Appropriate techniques can be adopted (with modification as need be) for a given data layer. Some data layers change very little over time, and may only require simple procedures for reporting errors and making rare revisions. Other layers change often and require procedures for recording updates in a manner that supports quality control and tracking of changes over time. A full range of techniques is discussed here, including methods which enable an audit trail of modifications over time for a given feature. The text is primarily intended for those familiar with the Arc/Info GIS software.

Contracting with GIS Consultants

26 June 2004
This guideline provides local communities with guidance in developing a project and project goals, preparing a request for proposals (RFP), and executing a contract for GIS mapping or analytical services. Included are technical and administrative specifications that are important to ensure the creation of a quality community product useful for many years to come.

GIS Data Directories and File Names

26 January 1991
This document is primarily for ARC/Info system managers and technicians. The directory and file naming conventions recommended here are used by VCGI. Communications with VGIS sites and user support will be simplified if these conventions are followed. Also, any applications, software or SMLs/AMLs developed by VCGI will use these conventions. Most importantly, if these conventions are followed, this document can serve as part of your system documentation for future users at your site.

Attribute Definitions and Codes

26 January 1991
GIS attributes contain information associated with geographic features on a map. GIS users, present and future, will most likely need to develop attribute tables for new layers of map information. Existing attribute tables will need to be expanded as well. The Vermont Center for Geographic Information, Inc. (VCGI) encourages Vermont users of geographic information to use the same base attributes and codes so that data can be more easily exchanged and understood by all users.

Vermont Future Land Use GIS Data Standard

12 December 2018
The Vermont Future Land Use GIS Data Standard seeks to: 1. define a data framework for using GIS to map regional future land use plans. 2. Define a data framework that supports easy identification of: a) RPC to which a data set pertains. b) adoption date of plan that the data set models. 3. Provide the data framework as a resource that can be extended to meet local-regional business needs.

Guidelines for the Use of the Vermont Coordinate System

26 November 1992
The objective is to provide a source document for any organization or political body wishing to regulate the use of the Vermont Coordinate System, and as such, the impact of these standards is dependent on the actions of those outside institutions. The reasons for utilizing the Vermont (state plane) Coordinate System are: 1. To describe on a common datum, the position of points on, above, or under the surface of the earth. 2. To perpetuate said positions in a convenient format. 3. To standardize the location of objects, points, and other entities, as recorded in geographic/ land information systems, (G/LIS) and other spatially related databases, for use in analytic and mapping applications. 4. To facilitate future survey retracement of land boundaries.

Vermont GIS Parcel Mapping Guideline

13 April 2017
This guideline will identify aspects of the parcel mapping process, issues to consider, and provide template documents that will assist listers, assessors, and other town officials with their duties as they relate to the development of parcel maps and data. An overview of the process is provided before the template documents. Please refer to the current VT GIS Parcel Data Standard at the VCGI web site ( for technical specifications relevant to the creation or update of the parcel data used to create maps.

VT 3-Phase Geodata Exchange Standard

08 August 2018
This standard provides a common data-schema for exchanging and conflating generalized 3-phase-power GIS data; the intended result of using this standard is production of data sets that are used for cursory analysis and broad-stroke planning (e.g., energy planning). The data schema’s simplicity supports simple data-load processes and efficient exchange/conflation of data amid heterogeneous sources. Ideally, this standard yields a statewide 3-phase-power GIS data set that is updated at least annually.


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