Frequently Asked Questions

GIS (Acronym for Geographic Information System) is an integrated collection of computer software and data used to view and manage information about geographic places, analyze spatial relationships, and model spatial processes. A GIS provides a framework for gathering and organizing spatial data and related information so that it can be displayed and analyzed.

GPS (Acronym for Global Positioning System) is a system of radio-emitting, and receiving, satellites used for determining positions on the earth. The orbiting satellites transmit signals that allow a GPS receiver anywhere on earth to calculate its own location through trilateration. Developed and operated by the U.S. Department of Defense, the system is used in navigation, mapping, surveying, and other applications in which precise positioning is necessary.

GIS (Geographic Information Systems) is tool to display and analyze information geographically. GPS (Global Positioning Systems) is a technology that uses satellites to give one its position on the Earth with the aid of a GPS device or unit. GPS can be incorporated into GIS by using a GPS device to collect points, lines, or polygons, which can be imported into a GIS application for future analysis and interpretation.

This is a common technical term in surveying (and tax collecting), though not widely known outside those specialisms. A cadastral survey is one on a scale sufficiently large to accurately show the extent and measurement of every field or other block of land. The most common reason for such a survey is as a basis for taxation, but in some countries, particularly the US, it is associated with the need to accurately identify land boundaries.

Information that describes the content, quality, condition, origin, and other characteristics of data or other pieces of information. Metadata for spatial data may describe and document its subject matter; how, when, where, and by whom the data was collected; availability and distribution information; its projection, scale, resolution, and accuracy; and its reliability with regard to some standard. Metadata consists of properties and documentation. Properties are derived from the data source (for example, the coordinate system and projection of the data), while documentation is entered by a person (for example, keywords used to describe the data).

An orthophoto or orthophotograph is an aerial photograph geometrically corrected ("orthorectified") such that the scale is uniform: the photo has the same lack of distortion as a map. Unlike an uncorrected aerial photograph, an orthophotograph can be used to measure true distances, because it is an accurate representation of the earth's surface, having been adjusted for topographic relief, lens distortion, and camera tilt.

Earth is an oblate spheroid. In order to represent its surface as a flat map, complex mathematical transformations are required.

Geodetic datum defines reference points on the Earth's surface against which position measurements are made. Central to this concept is an associated model of the shape of the Earth (that is, reference spheroid) to define a coordinate system.

Map coordinates are usually shown in one of two ways, as geographical coordinates (ie latitude and longitude values, in degrees) or grid coordinates, (as easting and northing values, in metres).

Map projection is a method of representing the surface of a sphere on a plane. By definition, all map projections show a distorted representation of the Earth surface therefore different map projections exist in order to preserve some properties of the sphere-like body (ie. either area, shape, direction, bearing, distance and/or scale) at the expense of other properties.

The GIS Consortium has a variety of datasets including administrative, political and taxing district boundaries, parcel data, topographic data, planimetric data, assessment data, prints, orthophotos, and geo-referenced tax maps. For a complete listing of current available products, please refer to our Data Order Form.

If you have any additional questions about our products or services please contact us by phone at 217-328-3313, or by email at ccgis@ccrpc.org.

To purchase Champaign County GIS data, please fill out the Data Order Form and return it with a check for the total amount made out to: CCRPC. Orders can be mailed to:
CCGISC
C/O – Champaign County Regional Planning Commission
1776 E. Washington St.
Urbana, IL 61802

Orders can also be faxed in to 217-328-2426. Faxed in orders will be shipped after receipt of full payment.

If you have any additional questions about our products or services please contact us by phone at 217-328-3313, or by email at ccgis@ccrpc.org.

All GIS layers are continuously updated as changes in the county occur.

Not yet. The GIS Consortium is in the process of creating an interactive web mapping site. This site is expected to launch at the end of the year. More information about this site will be available soon.

The current tax map atlas is the 32th Edition.

The 32nd Edition tax map atlas includes the 2008 assessment year along with the 2009 subdivisions.

A new tax map atlas will be issued once a year. The actual date of release varies from year to year based on the extent of changes over the previous tax year.

No. In accordance with the CCPRC Sustainability Initiative, the 32th Edition of the tax map atlas was the last edition available in printed book form. We have improved the searching capabilites of the tax map cd and hope that users will find this new application to be more user friendly than previous editions released on CD.