GOM - the Global Overlay Mapping System
A Guided Tour of the Overlay Mapping System
This tour provides a quick guide of the facilities. For full instructions on how to use the Global Mapper, click HERE. This tour is designed to be read whilst looking at the Global Mapper Screen. Open both windows on your monitor, or print out this topic before opening the Global Mapper.
Start the Global Mapper by clicking on its icon. The screen that opens in front of you shows the Software and Overlay versions, and gives the current licensing information. (If the program has not been licensed, it will show my own postional information.) Above the main window is a standard Windows menu bar, that we are all familiar with. The first 7 of the labels: North America,South America, Europe, Africa, Asia, Oceania, and Polar, will take you straight to the maps. Lets try viewing one of the maps right now. Click on one of these 7 labels, and from the box that drops down, select one of the maps.
What you are looking at now in the main area of the screen is the background layer of the map that you just selected. You will notice the sea, and some sea or ocean names. Over this, the Country overlay has been turned on by default. You can tell this by noticing that the 'Country' button is turned on in the new blue toolbar, along the top of the map. You can see each country, which has been colored to make it obvious where one starts and another ends. In a lighter color you can also see the region boundaries, which represent counties or provinces of that country. Each map has 12 overlays that you can add, and so far, just the Country overlay is on. Try turning it off and on again by clicking on the 'Country' button. Any of the other overlays can be tuned on or off by clicking on the other buttons in the toolbar at the top of the map. Click on the 'Names' button, and you will see the country names and region names, where available. The country names are in darker text, and use capital letters.
Click on the 'Cities' button, and the city names appear. Note the capital cities, which are bolder than the others, and use a red dot to indicate their exact position. Try moving your cursor on to one of those dots, and look down at the status bar, on the bottom of your screen. There is a lot of information presented. You can find out more about the status bar by clicking HERE, but for now, note how easy it is to get the exact bearing and distance from your QTH.
An extra feature with every map, is the dragable Scale-Bar, which can be turned on and off by clicking on the 'Scale' button, located to the right of the upper tool bar. For more information about this, visit the Scale-Bar help-page, by clicking HERE. Note that the Scale-Bar is only dragable when it is the current top layer. In other words, if you turn it on, then turn on another overlay, you will not be able to drag the Scale-Bar about, as the new overlay takes precendence in the stacking order. To regain control of the Scale-Bar, simply turn it off then on again.
Now lets try finding a feature, and displaying it on a map. On the main toolbar, click the word 'Locate', then choose 'Find' from the box that drops down. When the 'Find' page loads, click on the 'Select Map by Name' dropdown-box, and choose the first entry, 'Amateur Radio Prefixes'. You will notice that the dropdown-box below it fills up, showing the first prefix, '1S - Spratly Islands'. Choose a prefix from the list, then click the 'Go' button to the right of it. The correct map will be loaded, and a flashing box will show the centre-point of that prefix area. Click on the flashing box to hide it.
OK, you've reached the end of the introductory tour. For more information, explore the rest of the pages in this Help & Information Guide. If you have any questions, don't hesitate to email me - the address is on the Contact Page.
 
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