To use the applets you will need a web browser which supports Java, as most modern web browsers do. The applets have been tested with different browsers on a number of platforms. You will, of course, need to check that your browser has been configured with Java enabled.
Figure 1 A browser displaying an applet.
All of the applets have the same general layout (figure 1): at the top there are three buttons, on the left there is a map and on the right there is a legend. Not all of the buttons may be enabled. This is normal: features of the applets are only enabled when it makes sense to do so.
Let us examine a simple intervisibility applet. As the mouse is moved over the map a number of things happen when it approaches a monument:
Figure 2 Control panel.
Clicking on the button marked 'Control Panel' at the top of the applet brings up a separate window (figure 2) which allows us to control many aspects of the display. Among the controls available are:
Note that some point data, such as the radio masts and electricity pylons in the basic intervisibility applet, don't have intervisibility information. Also, some monuments can have multiple subtypes. For example, in the applet showing barrow contents it is possible for a barrow to contain more than one type of artefact. In this case the artefact subtype displayed for a monument is the one furthest down the list in the legend. Turning off a subtype may not turn off the display of a monument if it also contains a different subtype of artefact.
The animation applet demonstrates the changing visibility of monuments as a point moves along a path. In addition, the viewshed of each point on the path can be displayed. The control panel is again similar to the one for the basic intervisibility applet (figure 3) but has features which control the animation:
Figure 3 Animation control panel.
Panoramas are implemented as pictures showing a large part of the landscape (often covering 360 degrees). The points from which panoramas are available are marked with a special symbol in the applets. Clicking on this symbol invokes a separate window in which the panorama can be viewed.
The direction of view can be changed by holding down the mouse button anywhere in the panorama window and moving the mouse in the direction you want to move. The further you move the mouse from its original position the faster the view rotates. Releasing the mouse button stops the rotation.
At the bottom of the panorama window there is an 'Annotation' button to turn on or off any textual annotations on the display. Browsers which can support it also have a scrollbar at the bottom of the display to change the level of zoom.
The panorama view can also be controlled using keyboard commands (table 1). It may be necessary to click in the display window before keyboard commands can be used.
Table 1 Controlling the panorama display.
|Direction||Left arrow||Rotate 10 degrees anti-clockwise|
|Right arrow||Rotate 10 degrees clockwise|
|Shift left arrow||Rotate 1 degree anti-clockwise|
|Shift right arrow||Rotate 1 degree clockwise|
|n, e, s, w||Set direction to compass point|
|Zoom||i||Zoom in (reduce field of view by 5 degrees)|
|o||Zoom out (increase field of view by 5 degrees)|
|I||Zoom in (reduce field of view by 1 degree)|
|O||Zoom out (increase field of view by 1 degree)|
The applets on this website have been specially optimised for use on the web. They therefore have fewer facilities than the versions on the CD-ROM which comes with the book Stonehenge Landscapes. A separate page describes the additional features of the enhanced versions of the applets.