How to use the DOQ Interactive Map

Digital versions of DOQ data files are available by county as MrSID compressed <filename>.sid files, which can be saved to your computer's hard drive.

Instructions for downloading Illinois Digital Orthophoto Quarter Quadrangles in MrSID format, a screen shot of the Interactive Mapping Web Interface, and descriptions of the navigational tools of the Interactive Mapping Web Interface are detailed below.

The 1998/1999 DOQ Interactive Map was the
Third Place winner of the 2001 Geography Network Challenge contest

Geography Network Challenge: 3rd place winner

Instructions for Downloading Illinois DOQ Data

Environmental Settings for Interactive Mapping

Your browser must have Frames and JavaScript enabled.
The Web interface is best viewed using Internet Explorer.
It is not possible to bookmark map views. Instead, bookmark this access page.

Map manipulation tools are offered on the left side of the interface. The currently selected tool will be outlined in red, as the "Zoom In" tool is outlined in the screen shot shown below. Data layer visibility and activation control is located on the right side of the interface. The visitor must set desired "Active" layer combinations and then implement "Refresh Map" in order to create a custom map view.

Step 1: Enlarge an appropriate area.: The "Zoom In" tool is the default tool upon launch of the Interactive Mapping Interface.

Step 2: Use the "Select Within" tool to view the attributes of DOQ files: The "DOQ Boundary" data layer is the default Active Layer. Attribute information for your selected DOQ files are listed in the lower frame of the map interface. View the Map Name, USGS Index Code, Quadrangle quarter, UTM Zone, USGS Source Image reference, and Image aquisition Date for each record. Use the USGS Code hyperlink to download a DOQ file.

Other: The "Refresh Map" button.: The "Refresh Map" button is listed below all data layers and will complete alterations to the selection of "Visible" layers. Data layers "Counties" and "DOQ Boundary" are set to "Visible" in the screen shot shown below.

Representative screen shot of Interactive Mapping Web Interface

Navigational Tools of the DOQ Interactive Mapping Web Interface

	Overview Map	Turn the Overview Map displayed in the upper left corner of the map frame on or off.
	Zoom In to see DOQs	Use this tool by clicking on the map image. Alternatively, zoom into an area by dragging a rectangle around the area of interest. This is the default tool at startup.
	Zoom Out	Use this tool by clicking on the map image; alternatively, zoom out of an area by dragging a rectangle. The map will zoom out to the extent such that the current view fits within the rectangle drawn.
	Pan View	Use this tool by clicking and dragging on the map image so that the area of interest is in the center of the view.
	Zoom to Active Layer	Enlarge or reduce the map image to the fullest extent of the data layer selected to be the "active" layer.
	Back to Last View	Click this icon to return the map view to the previous zoom level.
	Zoom Out to Full View	Click this icon to zoom the map out to the entire state of Illinois.
	Select Within	Use this tool to graphically select DOQs by dragging a rectangle around the DOQs of interest. DOQs contained and intersected by the rectangle will be selected and be highlighted in yellow. A new window will open containing a table of information pertaining to the DOQs, including a link for downloading each selected DOQ.
	Select One DOQ	Use this tool to graphically select a single DOQ for download. After clicking on the desired DOQ, a file download window appears. Only one DOQ can be downloaded at at time.
	Identify DOQs	Use this tool to graphically identify DOQs by clicking on the DOQ of interest. A new window will open containing a table of information pertaining to the identified DOQ, including a link for downloading the identified DOQ.
	Find QUAD	Use this tool to textually search data attributes within the "Active Layer"; "DOQ Boundary" is the default "Active Layer". The search is case sensitive; QUADRANGLE NAMES are in all CAPs. To discover quadrangle names, access a Digital Map Index by County, or order a paper Topographic Map Index The Find tool can be used on any data layer. However, the case of attributes varies. Only Quadrangle Names are listed in all caps.
	Clear Selection	Click this icon to unselect any selected data elements.
	Print DOQ Map	Click this icon to open a new window allowing the user to submit a map title. After typing and submitting the title, a new window opens. This window contains a properly formatted title, map image, and legend suitable for printing. Use the browser "Print" button to print the map.
	Toggle Legend/Layers	Click this icon to toggle the legend from a graphical representation of the map layers to a list of layer names.