Map Navigation Back To Welcome Page
A number of tools in the GeoHub NI Map Viewer facilitate map navigation.
Zoom In This tool allows you to zoom in to a narrower view on the map canvas by either dragging a box or clicking a point with the tool.
- Click the Zoom In button on the toolbar to activate Zoom In mode.
- Click to select the point on the map canvas and drag a box over the area you want to zoom in on. The map canvas is updated to display a map area that is zoomed in to the extent of the box drawn.
- Click the point on the map where you want to zoom in. The map canvas is updated to display a map area that is zoomed in and centred on the point you selected
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Zoom Out This tool allows you to zoom out to a wider view on the map canvas by either dragging a box or clicking a point with the tool.
- Click the Zoom Out button on the toolbar to activate Zoom Out mode.
- Click to select the point on the map canvas and drag a box over the area you want to zoom out. The map canvas is updated to display the zoomed out map area. The amount that you have zoomed out is indirectly proportional to the size of your box i.e. the smaller the box the greater the zoom out will be.
- Click to select the point on the map canvas where you want to zoom out. The map canvas is updated to display the zoomed out map area that is centred on the point you selected.
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Pan This tool enables you to move your current view space to a different location on the map i.e. to pan the map. You can pan the map in any direction.
- Click the Pan button on the toolbar to activate the Pan mode.
- Click to select a point on the map and drag the map canvas in the direction you require.
- Release the mouse to update the map to your newly defined extents.
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Navigation Control The Navigation Control tool provides a second method tp pan the map in the compass directions of north, south, east, west, northeast, southeast, southwest and northwest.
- Click the Navigation Control button on the toolbar to open the Navigation Control window, showing the navigation rose
- Click on the rose in the direction you want the map to be panned. Clicking once will pan the map slightly in the desired direction. Clicking and holding down the mouse button will enable a continuous pan, until the button is released.
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Overview Map The Overview Map tool allows you to see your overall location on a map of smaller scale. This also provides a third method of panning and a further means of zooming by moving the red extent rectangle or by changing its size.
- Click the Overview Map button on the toolbar to open the Overview Map window. The red extent rectangle shows your location and the extent of your current map canvas view on a map of smaller scale.
- Holding down the left mouse button click within the red extent rectangle and move the rectangle around. This acts to pan the map canvas.
- Position the mouse at one of the corners of the red extent rectangle until the cursor changes to a double-ended arrow. When this occurs you can resize the red extent rectangle rectangle by pulling the box outwards to enlarge (zoom out) or by dragging the box inwards to reduce (zoom in).
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Full Extent The Full Extent tool is used to refresh the map canvas so that it reverts to the extent of all of Northern Ireland.
- Click the Full Extent button on the toolbar. The map canvas is updated and reverts to the extent of all of Northern Ireland.
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Back The Back or Previous Extent tool is used to refresh the map canvas so that it reverts to the extent of the previous view.
- Click the Back button on the toolbar. The map canvas is updated and reverts to the extent of the previous view.
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Next The Next or Forward Extent tool is used to refresh the map canvas so that it goes forward to the next extent that you have viewed.
- Click the Next button on the toolbar. The map canvas is updated and goes forward to the extent of the next view.
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Magnifier The Magnifier tool is used to have look at your map in closer detail without having to change your current map settings. There are nine different magnifications available, from magnification of two up to magnification of ten.
- Click on the Magnifier button on the toolbar to open the Magnifier tool.
- Move the magnifier window over the area on the map canvas that you want to see in more detail.
- Set the magnification to an appropriate level for what you want to see by choosing from the drop-down magnification field.
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Status Bar The StatusBbar is located at the bottom of the map canvas. The Status Bar gives you the coordinates of the current location of the mouse pointer on the map canvas and is updated as the pointer is moved. It also gives your current map scale, which updates as different zoom functions are carried out.
The Status Bar also provides another method of navigation by manually entering coordinates and/or scale values.
- Click once on the Status Bar to activate it.
- Type the Easting and Northing coordinates you want to centre the map on directly into the Easting and Northing fields.
- Click on Refresh to recentre the map or else type a suitable scale into the scale box and then click Refresh. In this case the map canvas will be recentred and zoomed to the scale specified.
- Double-click on the Status Bar to deactivate it again.
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Zoom to Make Visible and Zoom to Layer The Zoom to Make Visible tool is useful for layers that have scale references associated with them (i.e. they are only visible at certain scales). This is a quick way of getting the map canvas to zoom to a scale at which the layer is visible. The Zoom to Layer tool is a quick method of zooming to the full extent of the particular layer in question (which in some cases may not be the whole of Northern Ireland).
- To access these tools, you must right-click on the layer of interest in the table of contents (TOC). A contect menu appears from which you can choose either Zoom to Make Visible or Zoom to Layer tools.
Context Menu
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