CAROL Help Overview

Welcome to CAROL, the Centralized Air emissions Repository OnLine!

The CAROL site provides quick and easy access to a massive database housing a multi-year repository of air toxics emissions for the Great Lakes states (IL, IN, MI, MN, NY, OH, PA, WI) and the province of Ontario. At the present time, data is available in the repository for the years of 1996, 1997, 1998, 1999 and 2001.


There are four different CAROL interfaces that you may use to search and explore the Great Lakes emissions repository:


The Mapping Explorer can be accessed by using either the orange "maps" tab present at the top of every CAROL page or via the CAROL home page by selecting either of the two "Mapping Explorer" links. The Standard Query and Facility Query links are available in the left column of every CAROL page, in the box titled "Query Database".


To receive help about any of these individual components, please click on one of the component names at the top of this Help window.






















































CAROL Mapping Explorer Help

Using the drop down selection tools present above the map in the "Emissions Selector", you may select one emittant at a time to map within the Mapping Explorer. As shown on the right of the map, there are a number of different background data layers present in the Mapping Explorer to provide contextual information. You may turn these layers on or off using the checkboxes to the left of each layer. To see the current map legend, simply select the "Legend" tab. Several map navigation tools are also accessible in the Mapping Explorer:


Click once anywhere on the map to cause the map to recenter and zoom in on the spot you selected, or click and drag the mouse to define a box and the map will zoom in the extent you described.

Click once anywhere on the map to cause the map to recenter on the spot you selected and zoom out, showing a larger portion of the Great Lakes region.

Click to zoom to the full extent of the mapped area for this project.

Click to enter a set of bounding box coordinates (in decimal degrees) to zoom the map.

Click to recenter the map to the spot you selected.

Click once on the map to retrieve information about the currently mapped emittants (both point sources and county aggregate values).

Click and drag the mouse to move the map area visible in your browser window without changing the current map scale.

Click to print the map to a printer connected to your computer or to convert the map to Adobe PDF.

Click to measure the distance between two or more points in the map. Left-click to select the locations along the line being measured, and double-click to stop measuring.






















































CAROL Standard Query Help

The Standard Query interface provides a mechanism to submit either a simple or complex query to the repository database. The results are returned as a combination of tabular and graphical data, summarized by the different components of the query in three separate categories:

There are a number of different components of the Standard Query builder, each of which are described briefly below.

First, select an inventory year. In the window immediately below, all emittants in the inventory for that year will appear.
Second, select at least one and as many as five emittants for the query, using the CTRL key to select multiple emittants from the scrolling list.
OPTIONAL You may optionally restrict your search to certain industries by using the SIC Selector. A list will appear containing grouped SIC codes found in the inventory, and you may use the checkboxes to the left of each SIC or group to select them. Once this is complete, results are shown in the scrolling box as seen on the left. To remove SIC codes from the list, simply click on one and press the Remove button (or CTRL-click to select many)
OPTIONAL You may also optionally restrict your search to specific geographies using the Geography Selector. You may either select a rectangular geographic region from a map using the "Select From Map" link, or select one or more counties/states from a folder hierarchy using the "Select From List" link. Once this is complete, results are shown in the scrolling box as seen on the left. To remove SIC codes from the list, simply click on one and press the Remove button (or CTRL-click to select many)

Once a query has been built using these tools, simply press the "Submit" button to issue the query. A new window will appear showing the query results. From this window, you may download the data resulting from the query, and create PDF reports from the query data.






















































CAROL Facility Query Help

CAROL presents users with a very simple interface through which all emittant data pertinent to any one facility can be accessed through a series of drill-down menus. After selecting the:

In the series of menus as shown on the left, select a Year, State and County, and then press the Submit button to view a report showing all of the facilities for that County in the inventory year (as shown below).


Clicking on the name of any facility will create a new page displaying a local map of the facility location (where coordinate data is available) along with a table containing data for all emittants in that particular inventory year.






















































CAROL OGC WMS/WFS Help

CAROL fully supports the Open Geospatial Consortium (OGC) OpenGIS Web Mapping Services (WMS) and Web Feature Services (WFS) This means that all of the data from the CAROL repository can be easily integrated with desktop and server applications by a wide range of GIS users.

The key to utilizing any WMS or WFS data source lies in the XML document returned from a properly formatted "GetCapabilities" request to the server. There are two GetCapabilities requests relevant for CAROL data:


  • For WMS:
http://mds.glc.org/cgi-bin/carolwms?VERSION=1.1.1&REQUEST=GetCapabilities
  • For WFS:
http://mds.glc.org/cgi-bin/carolwms?SERVICE=WFS&VERSION=1.0.0&REQUEST=GetCapabilities

Many different software applications can be used to access WMS and WFS data layers. For specific support related to the client product you are utilizing, please search that product's documentation. For more general information about the OpenGIS WMS and WFS standards, including documentation on all the different types of information and map data that can be obtained via these services, please refer to http://www.opengeospatial.org/specs