Map Browser Help
The Map browser is based on OpenLayers
Some actions will cause a pop-up window to appear. To obtain full functionality, pop-up blockers must be disabled for this page
Map Panel
The map panel displays a map of the selected area, and accepts mouse-clicks to change the area displayed. The Map panel contains various tools that can be used to change the display
The content of the map is controlled by two factors:
- Scale of display
- The ADD contains data optimized for use at different scales. Data are provided at the scale of data acquisition (Scale 0), generalized to 1:1,000,000 (Scale 1, equivalent to a horizontal resolution of approximately 300 m) and generalized to a scale of 1:10,000,000 (Scale 10, equivalent to a horizontal resolution of approximately 3,000 m). The map browser automatically switches between data at different levels of generalization according to the scale of the current map display. Some layers will be unavailable (grayed out) in the layer switcher tool when the scale is inappropriate for their display.
- Layers selected
- The ADD contains many data layers. On entry, all the layers appropriate to the scale of display are switched on. Layers may be switched off or on using the Layer Switcher button at the top right of the map panel.
Controls and tools
The Map panel contains several groups of tools
Pan and Zoom control group- This group of controls provides fixed zoom and pan functions. Clicking on one of the four arrows pans the map in the direction of the arrow. Clicking the "+" will zoom in by a fixed amount and clicking the "-" sign will zoom out by a fixed amount.
Navigation Toolbar- This toolbar contains five buttons, providing a variety of navigation options.
Pan control- Clicking on this icon so the background turns pale blue (as shown) changes the action of the mouse so that draging on the map will move the map within the window. This is the default action.
Zoom to box control- Clicking on this icon so the background turns pale blue changes the action of the mouse so that dragging on the map create a box on the map. When the left mouse buton is released, the map will zoom to the extent of the box.
History controls- Clicking on this icon will go to the last or next item in the map display history. If no history is available, the icon will be greyed out (as shown).
Zoom to name- Clicking this button opens a popup window with an input box. Entering the first few characters of a placename in the input box and pressing carriage return will populate the drop-down selection box with names starting with the characters entered. Select one of the names than click on the icon at the bottom, and the main map will zoom so it is centred on the location in the Composite Gazetteer of Antarctica for the name selected, with a "best guess" of the extent of the name.
Layer selector- The layer selector tool controls the display of different layers of information. Clicking this control opens a menu.
On clicking the icon, the panel to the left is displayed. This panel shows two sets of data. At the top are two options for the basemap data to be used; this is either a display of the land and sea distribution, or the Landsat Image Mosaic of Antarctica (LIMA). These two options are mutually exclusive; selecting one will deselect the other.
Below this is a list of layers that can be selected. The names are self-explanatory. Some layers are not available at all scales of display; they are disabled at inappropriate zoom levels.
The data displayed is automatically changed so that the level of detail is appropriate to the scale of display.
- Information displays
- These are all located in the bottom right corner of the map display.
- Scale display
- A rough indication of the scale of display is displayed as a scale ratio. This is not precise, as the software has no way of knowing the display resolution of the user's monitor.
- Permalink
- Clicking on this link goes to a link that preserves the status of the current display. This can be bookmarked to provide ready access to a particular view, or sent by email to present a particular map to a correspondent.
- Position indicator
- Displays the longitude and latitude of the cursor position. The position is given in degrees and decimal degrees.
The Antarctic Digital Database is copyright © the Scientific Committtee on Antarctic Research 1993 - 2006.