There exist two versions of the map viewer: The standard version requires Java 2 (or higher). A version with reduced functionality runs under Java 1.1 (or if the Java version has not been recognized correctly; it that case reload the HTML page).
Zooming:
The zoom factor is 2 for the zoom-in button (
) and 0.5 for the zoom-out button (
). The range of zooming is limited by map-specific bounds.
The visibility of map features depends on the current map scale.
Diagram:
The diagram button (
) will be enabled if a city or an administrative area is selected in the map. By clicking this button, the diagram viewer will be started or its data will be updated.
Change to Pan or to Zoom Mode:
The map viewer starts in the zoom mode (see below). Then, a switch to the pan mode is possible by clicking on 
. During the pan mode, the same button (with the modified icon 
) allows returning to the zoom mode.
Visualization Modes:
- Standard: The normal map presentation of cities, administrative areas and other geographical features; the population of cities is visualized by symbols (see below).
- Population Density: The Map visualizes the population density of cities and of administrative areas (color schema: see below).
- Population Change: The Map visualizes the population change of cities and of administrative areas (color schema: see below).
Activate Satellite Image / WMS:
- see last section of this page.
- Help: Opens this help page; this requires allowing a popup.
- Info: Shows the version of the map viewer.
Visualized Information:
- Moving the mouse cursor over a city or an administrative area: Further information about the object will be depicted as tooltip. The information depends on the selected mode of the viewer.
- Clicking on the symbol of a city or on an administrative area.
The feature will be highlighted and further information will be depicted
in the text area of the map viewer. The HTML page scrolls to the corresponding city
or administrative area and its info button (
) will be highlighted.
Zoom Mode:
- Dragging a rectangle: The center of the box defines the new center of the map and the map scale will be enlarged according to the dragged box (if possible).
- Mouse click on the map with pressed Shift key: The clicked position defines the new center of the map (if possible).
Pan Mode:
- Dragging the mouse: The map will be moved according to the move of the mouse (if possible).
- Mouse click on the map with pressed Shift key: The clicked position defines the new center of the map (if possible).
In this visualization mode, the colors of land indicate the elevation.
In this visualization mode, the colors indicate the population density. Its exact value (in inhabitants per square kilometer) will be depicted by a tooltip or by selecting the a city or an administrative area. The color schema is the same for administrative areas as for cities.
The color schema is defined for the depicted values as follows (number correspond to the above map):
- 1 = unknown population density
- 2 = 10 inhabitants per km²
- 3 = 40 inhabitants per km²
- 4 = 100 inhabitants per km²
- 5 = 400 inhabitants per km²
- 6 = 1,000 inhabitants per km²
- 7 = 4,000 inhabitants per km²
- 8 = 20,000 inhabitants per km²
- 9 = 50,000 inhabitants per km²
In this visualization mode, the colors indicate the population change. Its exact value (in per cent per year) will be depicted by selecting the city or the administrative area of interest. For cities, the height of the symbol indicates the size of population change.
The color schema for administrative areas is defined for the depicted values as follows (number correspond to the above map)::
- 1 = decrease of 2% per year
- 2 = decrease of 1% per year
- 3 = decrease of 0.5% per year
- 4 = decrease of 0.25% per year
- 5 = increase of 0.25% per year
- 6 = increase of 1% per year
- 7 = increase of 2% per year
- 8 = increase of 2.5% per year
- 9 = increase of 4% per year
NOTICE: The NASA Global Mosaic server has finished its satellite image service. Therefore, only other WMS services can be currently used.
In case of using a Java 5 JRE (or higher), the visualization of WMS services as background is supported. In this case, a menu item "Activate Satellite Image / WMS" is shown in the "Mode" menu. After clicking on this menu item, the following dialog is shown. After confirming the dialog, the HTML page must be reloaded manually.
The map viewer requires a signed certificate for using external WMS services, i.e. after reloading the HTML page you must confirm the following dialog:
Now, the mode "Satellite Image / WMS" and a "Configuration" menu are available:
As default, satellite images were requested from the NASA WMS Global Mosaic. Instead, the Demis Web Map Server or DataFed can be selected as WMS:
- Configuration / Configure WMS ... / [Select]
- select a service from the list
- after selection click on [ Set ]
Or another WMS 1.x service can be specified using the provided "WMS Configuration" dialog. Such a WMS must support as SRS the EPSG code 4326; i.e. requests using WGS 84 coordinates. After the specification click on [ Set ].
Example using DEMIS:
