Basic Map Navigation

It's time to learn how to navigate around the map. It is surprisingly easy, and best of all, involves absolutely no map folding whatsoever. We can't re-fold paper maps properly either. That’s how we ended up in this line of work.

Getting Started

When you open the web-based map in your Internet browser, you should see something that looks a lot like the image you see below (Figure 1).

The map information is displayed in the Map Window (1) . Beside it is the Information Panel (2), which displays information about the map and lets you do interesting things with the map. Specifically, the Information Panel displays the Overview Map and Layer List, as well as Selection Results and interfaces for various tools and processes.

At the top of the viewer you can see the Toolbar, where you’ll find tools that will help you use your map. These tools will allow you to navigate around the map, ask questions of it, and otherwise interact with the information. Scale Information and map coordinates are found at the bottom of the Map Window.

If you are feeling lost already... don't worry. Everything will be described in detail soon.

Figure 1. The Web-based Map Application

Navigating Around Maps

Pan

PanTools
With the map you can look at a specific area of interest. You can move around the map using the Pan tool. The Pan tool lets you slide around to different parts of the map. Suppose you want to go north (up the map). Take the Pan tool and grab (press and hold down the mouse button) onto the map, pulling it down. Whatever part of the map you grab with the little hand will end up where you let go of the mouse button. Just like in real life. This works for moving any direction on the map.

Alternatively, you can click on the Navigation Control (located at the top-left edge of the map window) to pan without switching to the Pan tool. Single-click on a directional arrow to incrementally shift the map in that direction. You can also press and hold the mouse button on the navigation control and move the mouse over different directional arrows to navigate around the map. To stop scrolling, just release the mouse button.

Pan

Zoom Tools
The Zoom tools are unique to digital maps. They are very much like using an actual magnifying glass, as the icons imply. The main difference is you can't burn ants with them (yes, this is a cruelty-free technology). The magnifying glass with the little plus sign lets you 'zoom in,’ while the one with the little minus sign lets you 'zoom out.’ There are a couple of ways to use these tools.

First, click on one of the magnifying tools to select it, then go somewhere on the map and press the left mouse button. With the Zoom In tool, the map zooms in. The center of the new map is wherever on the map you clicked the mouse button. The Zoom Out tool zooms out the same way.

Second, you can use the Zoom tools more precisely by pressing the mouse button somewhere on the map, holding it down, and dragging a box. When you let go of the mouse button, the new map extent will be the area defined by the box. Whether you are zooming in or out, the area defined by the box will become the new map extent.

Click here for a relevant, but not essential, discussion of scale.

Here are a couple other functions that make navigating around maps easier:

Pan

Zoom to Full Extent
The Zoom to Full Extent tool is a quick and easy way to zoom out as far as possible. Just click on the tool and the map will zoom out to its maximum extent.

You can also zoom in and out by dragging the handle on the Scale Slider located in the upper left corner of your Map Window. Move the handle towards the plus or minus sign to zoom in or out on the map, or simply click the plus or minus signs to zoom in or out with set increments.

Scale Bars

Another possible method of zooming uses the Scale Box (Figure 2) displayed at the bottom of the Map Window. The current map scale is always displayed as a ratio in this box. To change the scale, enter the desired ratio and press ‘Go.’ This is a quick way to automatically zoom directly to the scale you need.

Figure 2. The Scale Input Box

Along with the Scale Input Box, there is also a Scale Bar for estimating distances at the bottom of the Map Window.

Figure 3. The Scale Bar

Please note that the Scale Box and Scale Bar are for map navigation only, and are not necessarily accurate. Without information about the size of your monitor or display device, it is impossible for us to accurately provide a ratio scale. An error will be most pronounced if you are operating a large monitor (or a projection device) running at a very low resolution, or if you are running a small monitor at a very high resolution. A 17" monitor running at a resolution of 800x600 or 1024x768 is much better represented by the denoted ratio scale.

It’s also worth mentioning that some maps have limits on the scales at which you can view the data, and some layers and/or map labels may only appear at certain scales. If the layer you need is unavailable (Figure 3) at your current map scale, change the ratio in the Scale Box the until the layer becomes available (Figure 3).

Figure 4. Unavailable Layer (grey) and Available Layer icons (white)

Wondering what those little icons mean? Well, they are part of the Layer List. Just read on, and you will find out how the Layer List allows you to work with layers and interact with map information.

Next > Exploring the Information