[Therion] Cave Overlays on Google Maps Web Sites

[Bill Chadwick]

Hi,

It is quite easy to create a web page that shows a cave survey overlay on
top of Google / Virtual Earth maps.

For an example go to

http://www.bdcc.co.uk/mendip.html?Latitude=51.2988&Longitude=-2.7104&Zoom=18
&MapType=Aerial

and then select Caves in the overlays drop down (best in Firefox). You will
find overlays for Upper Flood (exciting new extensions), Swildons Hole,
Manor Farm and Longwood August.

I use the Microsoft MapCruncher to generate the tile sets (256x256 pixel
PNGs) for Google Maps from a single PDF or .png image.

As this is quite a nice way of presenting cave surveys, perhaps a Google
tile generator would be a good add on for Therion. The advantage of building
the renderer into Therion would be that the overlay could be drawn
separately for each Google Zoom level to achieve a good line width and text
size.

I am well informed in the areas of coordinate systems and map projections
and able to program in C++. With some guidance I might be able to help with
the coding of such an extension.

Regards,

Bill Chadwick