GPS for Dummies.pdf - Engineering Surveyor

306Part IV: Using Web-hosted Mapping ServicesMapServer displays all map coordinates using the NAD 27 map datum. If youdon’t know (or remember) what datums are, head to Chapter 4 to read whythey are important when you’re using a GPS receiver.Changing a MapServer map sizeYou can change the size and appearance of a MapServer map three ways: Click To Zoom: Underneath the map are a series of bars between iconsof two magnifying glasses: one with a plus sign and the other with aminus sign. Click one of the bars to zoom in or out on the map. The barsclosest to the plus magnifying glass zoom in, and the bars closest to theminus magnifying glass zoom out. Scale: The Scale drop-down list box allows you to change the scale of themap. For example, a topographic map can be viewed at 1:24,000, 1:50,000,1:100,000, or 1:250,000 scale. The larger the number to the right of thecolon, the less detail there is and the more area shown. A 1:100,000 scalemap is shown in Figure 19-3. Zoom: Use the Zoom drop-down list box to change the size of the map,either showing it at 100% or reducing its size to 50% of normal. Selectthe size from the drop-down list box and click the Go! button. Figure 19-3shows the same map at 50% as in Figure 19-2 at 100%.Figure 19-3:Map of BarHarborshown at1:100,000scale with50% zoom.