[Openstreetmap-dev] Fun with AJAX

nick at hogweed.org nick at hogweed.org
Mon Sep 19 13:41:06 BST 2005

Hello everyone,

Have now got a basic but demonstratable AJAX interactive map interface on the 
development version of Freemap at:


You can use the AJAX interface to:

1. Add features interactively to the map. For example, the summit of The 
Wrekin (Shropshire), which I have not surveyed by GPS, was added by using the 
SRTM contours as a guide:


The summits of Fridays Hill and Green Hill on the default map were similarly 
added (those summits are not accessible by rights-of-way).

2. Add polygons such as woods, heaths and urban areas, using Landsat as a 
guide. If you select Landsat from the "view" menu and then "Polygons" for the 
action, you can trace the outline of polygon features with the mouse and they 
will be added to the database.

This is a test database separate from the production one I'm using for 
Freemap, so feel free to randomly play around (as long as you do not copy 
from OS maps!!!) using the login

Email: osm at hogweed.org
Password: osm

You need a Gecko-based browser such as Firefox; it doesn't work on Opera or IE 
at the moment. Also bear in mind the "Search" doesn't work yet, if you want 
to change location you need to use the query string method such as in the 
above URL, using grid references.

A few thoughts on usability:

1. Adding features really easy :-) In particular, I'm intending to use this to 
enable walkers to survey blockages on paths (fences, bogs etc) which other 
people can then see.... precisely the sort of thing the OS maps don't show 
you :-)

2. Polygons a bit more difficult, but works nicely for small features such as 
ponds or woods in generally open areas. More difficult for large wooded areas 
due to:
a)the map edges slicing a wooded area in two;
b)large woods sometimes indistinct in the Landsat data.

What would be really nice would be to implement a Google Maps style scrolling 
map so that the user can centre the map exactly where they want - should be 
possible using the site Tom pointed me to.

However, the intention is to maintain osm-editor as a mechanism to estimate 
polygons, which might be easier.


More information about the dev mailing list