A few months ago I explained how you could get your blog into Multimap’s local information facility by linking to an appropriate map. Well now there’s a new method. For the past month Multimap has been populating the database with geotagged blogs and now has nearly 4,000 mapped. You can geotag your blog by adding meta data like this:
<meta name="geo.position" content="latitude;longitude" />Where latitude is followed by longitude and separated by a semi-colon. Make sure you specify the correct format for your coordinates. The values of lat and lon should both be decimal with latitude and in the range -90 to 90 and longitude in the range -180 to 180. Positive latitudes are north of the equator, positive longitudes are east of the Greenwich meridian. For example:
<meta name="geo.position" content="50.8183;-0.1106" /><meta name="geo.position" content="50.8183N;0.1106W" /><meta name="geo.position" content="50:49:06;-00.06:38" /><meta name="geo.position" content="5049'06N";0006'38"W" />Update: Multimap also looks for ICBM tags which are constructed in exactly the same way, but with the coordinates separated by a comma instead of a semi-colon, eg.
<meta name="ICBM" content="50.8183,-0.1106" />You can find the coordinates of your chosen location (perhaps your house, office or just the centre of your city) using Multimap – the latitude and longitude of any location is displayed in the Map Info box below every map.
Multimap uses weblogs.com as its source of blogs. Every now and then a script grabs the weblogs.com XML feed and visits each blog looking for geo tags and extracts the coordinates where it can. If you want to get into Multimap’s index this way, add your geo tags and then make sure the weblogs.com XML feed is up, as it is down quite a lot, either missing, requiring authentication or not well-formed (alternatives anyone?). Then ping the weblogs feed – I recommend you use Pingomatic.
I’ve created a couple of handy bookmarklets to show maps and nearby blogs. If you click them on a geotagged page they will show a map of the page location. Drag these links to your bookmarks/favourites bar:
By way of explanation, here’s the show map bookmarklet written in long hand:
// grab all the meta tags on the page
var metatags=document.getElementsByTagName('meta');
var geoloc=null;
// loop through all the meta tags
for (var i=0; i<metatags.length; i++) {
// extract geo.position value if present
var name=metatags.item(i).getAttribute('name');
if((name=='geo.position' || name=='ICBM') && metatags.item(i).getAttribute('content')) {
geoloc=metatags.item(i).getAttribute('content');
break;
}
}
// use regex to extract the latitude and longitude
var re=/^([d-.]+)s*[,;]s*([d-.]+)/;
if(geoloc) {
if(re.test(geoloc)) {
var lat=RegExp.$1;
var lon=RegExp.$2;
var mqURL='http://www.multimap.com/map/browse.cgi?';
mqURL=mqURL + 'scale=25000&icon=X&lat='+lat+'&lon='+lon;
document.location=mqURL;
} else {
alert('Couldn't parse location: '+geoloc);
}
} else {
alert('No location meta-tag found.');
}The bookmarklets were created via the wonderful Bookmarklet Crunchinator.
Blogging · Mapping & Geospatial
Andrew Hume wrote:
This is very cool Richard. I missed your last post about this (I think) so hadn’t added a link to the map.
I’m all geotagged up though, so should be in soon. Just have to make do with the feast of weblogs in sunny Brighton till then. ;)
Bryan Price wrote:
Excellent! I’ve verified that my blog is properly tagged. And I’ve found that the closest blog to me is 6 miles away. As the crow flies. I’m almost afraid to see how many miles it would actually take on the road, being separated by a river and all that.
Phil Wilson wrote:
That’s interesting. Why not use (or at least also accept) the <meta name=”ICBM” etc.> which geourl used before it went off air? Loads of blogs already use this, not being able to use it seems like a waste, and means duplication of data for those interested in such things.
Phil Wilson wrote:
Sorry, just to be clear, I understand that the bookmarklets can be rewritten if((name==’geo.position’||name==’ICBM’) or somesuch, but couldn’t the multimap bot also be using the wealth of pre-existing ICBM data?
Rich wrote:
Actually Phil, Multimap does also accept coordinates tagged as ICBM. I didn’t mention it because I didn’t want to cloud the issue. In hindsight, perhaps I should have.
Phil Wilson wrote:
Ah, good stuff. Thanks for the clarification. Gosh, we’re a little sparse here in South Yorkshire.
Rich wrote:
Note I’ve updated the bookmarklets to also accept ICBM tags.
Ian wrote:
Very cool indeed. Any thoughts as to why I can get neither bookmark to work in Safari and only the ‘nearby blogs’ one to work in Firefox?
Small Paul wrote:
I think Safari can be a bit bookmarklet unfriendly. Firefox thing is weird, though.
Rich wrote:
For me, both bookmarklets work in Firefox. Neither one works in Safari – I don’t know why because the links themselves work fine in Safari.
Ian wrote:
I re-dragged them in Firefox and they both work now, sure what happened last time.
Des Walsh wrote:
Used the process on my blog – www.thinkinghomebusiness.com – and got an accurate map. Academic geospatial expert of mine in Sydney emailed me : ‘Detail might be good but according to MultiMap, I live in a hospital!! (the hospital closed several years ago and is now an appartment complex), so they’ve obviously used some pretty old data (WhereIs shows the roads in the development, although the street names have changed since). ’
Don’t know if you have a comment on this or if the Multimap Sydney rep might be able to clarify?
Des Walsh
Gold Coast, Australia
Rich wrote:
Des – thanks for the feedback on Multimap’s Australia maps. I will pass the details on to the mapping suppliers and see if they can’t give us some updated data ASAP.
Scott wrote:
how long does it take for multimap to index your site? i’ve set mine up about 16 hours ago and still haven’t noticed my blog being indexed in my geo location. any thoughts?
Tom wrote:
I’ve added my data but I dont seem to be showing up where I should be. The find nearest bookmarklet works, so the tags must be in my page correctly.
:(
Rich wrote:
Scott, it takes 24 hours for Multimap to index a site, and that’s assuming your site has appeared in a well-formed Weblogs.com changes feed, so no guarantees. Anyhow in your case, it look likes you’re in.
alex wrote:
I’m bothering you with the same issue here – I began using your bookmark a few days ago – but no luck :(
I’ve also tried weblogs.com but somehow I can’t get listed…
Can’t find any problem in my tags though…
Rich wrote:
Alex – Weblogs.com has mechansims in place to filter out sites that are not blogs. It doesn’t look to me like your site is a blog so that is probably why you’re not getting in the system.
alex wrote:
well it’s just a matter of layout I think – it would be interesting which are the guidelines they look up to.
Anyway, do the same standards apply to what gets listed on Multimap? I mean there is a wide variety of usefull sites which do not render their content in 1–2 columns :)
alex wrote:
In fact, the new question would be: how does someone get listed in the ‘Local websites’ category
Rich wrote:
Just ask me nicely and I’ll add you in manually :-)
Actually, I’ve just done it – you’ll be on the map this time tomorrow. The other way is to add an appropriate link to Multimap as explained here.
Jessica Lopez wrote:
Damn that stuff looks cool. Keep it up!
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