Archive for February, 2008

Where in the world are people looking? part 1

Friday, February 29th, 2008

As some may know this site serves a number of Network Links for Google Earth, for a long time I have thought it would be fun to map the data from that, but finally got round to trying it. This is still work in progress, so the current images are very much easly tests, but shows promise, hopefully can make some better visualizations – maybe even as KMZ :)

‘Lookat’ point v1: (click for 145k version)

View In Google Earth (don’t forget to try adjusting the tranparency slider!)

Shows some interesting patterns, there are a number of lines on the map, and definitily appears to be flight lines, I suspect this is from people leaving tours on loop, and a fudging a networklink to refresh periodically. Not sure how else to explain such repeatable loops – can a large number of visitors really be all following the same route? I’ll investigate this more in follow up map(s).

But WHAT is that point in the middle of the Atlantic?

Update: this is from about 900k hits from aug-nov ’07 – still processing the rest of the data!

Update 2: More maps here, all maps seem to to show the same overall pattern which is slightly puzzling, eg the IPs graph suggests that many users are following these flight lines.

When service users go bad?

Friday, February 29th, 2008

This is probably a purely a rhetorical question, and a means to vent. As background, I have just noticed a single user use a very disportionate number of requests against one of the Google Earth Grid Layers (MGRS), it look’s like they set it to refresh every 10 seconds, and for a while did browse around the globe, after that it stuck on one view and just happily refreshed away for 20 hours.

So what is the response to this type of thing (and I have no idea of the identity of users)?

  1. Blacklist at firewall level – effectively cutting them off from using nearby ever again.
  2. Blacklist them from that feature permanently
  3. Impose a temporally ban
  4. Add a throttling to the service for everyone, such as a quota or rate limiting – difficult to get the sweat spot
  5. Google Earth offers <maxSessionLength> which could be used to curtail the long term effect, but this would have a minor effect on legitimate users
  6. similar to last but only start adding it once they trigger some limit

So far (and only in a handful of cases) have done either 1 or 2. In the example that has triggered this post have done 1. but might change it to 3.

(the api and coordinate converter have their own dynamic limit, essentially 4. )

Geohash converter; API limit upped

Thursday, February 28th, 2008

Recently was released; the premise: short easy links that encode a location. The website offers instant conversion, but as the algorithm is Public Domain, Lordelph was quick to implement a php class, and I could quickly add the conversion to my existing conversion API. Convert a postcode to geohash anyone?

Updating the documentation noticed the API was last updated in 2005 – gulp, how time flies! Anyway as a celebration have upped the throttling on the API, now three times the previous limit. Running on much improved hardware than when it was launched so maybe the limit can be tweaked even more, will run some analysis of its impact – it already seems the API is a minor part of the overall load on the server – particularly against the Google Earth layers. : short (network) links for KML

Wednesday, February 27th, 2008

For a project wanted to create a small script to make generation of network link wrappers to KML content easy, but then I thought could have it create ‘short’ urls, ala, to make reuse easy. But then thought if going to that trouble might as well make it a full blown mini application, so I give you :: Short Links to KML content

I think it turned out pretty well (esp for just an evenings hacking) – it even has an element of ‘design’ – which is saying something! : short (network) links for KML

So if you want to create a network link wrapper with the minimum of fuss, and might enjoy having it as a short url, then give it a go.

Of course there are still a few things that could be done, but will leave these for another day…

  • Auto discover the ‘title’
  • Intelligence for ‘My Map’s – eg support multiple pages, and maybe some other KML types.
  • Actually make the admin page useful – display stats (they are stored already) , and edit the link
  • A public gallery of popular/new etc links – maybe even some sort of search – esp if we can do rudimentary indexing of the content (when fetch the title)
  • Support for named links eg could choose
  • Complete the support for the various network link options – particulaly making it easier to select the appropriate settings.
  • Maybe even support for forwarding the link by email (and/or sending the admin link to yourself)
  • Any thing you can think of :) – let me know!

(static) Google Maps in Google Earth…

Thursday, February 21st, 2008

Now that Google have just announced a brand spanking new NON JS Maps API, to be able to display maps with a simple img tag, similar to the Chart API. Well I thought it would be fun to re-purpose the
FlashEarth code to create a network link to display Google Maps in a popup balloon on Google Earth. Not totally sure the utility, but sure is fun (until the novelty wears off!)

Open in Google Earth

Hopefully needless to say the map inside the balloon is static and non draggable.

Update to clarify: You get to draw 1,000 maps daily, which is probably plenty, but go over that and the maps will stop working for you.

Update: as alluded to in the official post, you can use the static API to load a quick map, while the rest of the page loads, then at the last minute change it into a dynamic map. A series of demos showing various ways of lazy loading!

Another Whole Myriad :: TG

Sunday, February 10th, 2008

Preview of TG Myriad Mosaic The pace new photos on Geograph is not relenting, so much so we how have another whole Myriad! This time its TG and covers East Anglia and Norwich area, covering 1991 land squares. There is more on the overall progress here, which shows the coverage by Myriad (which by the way is a Geographism for a 100x100km square on the National Grid)

To try to showcase these have been creating some Zoomable viewers to really see the coverage:

Geograph Mosaic Collection

Unfortunatly they require too much manual work to be part of the real site (creating a ‘printable page’ at the appriate scale, stitching all the images, and then running it though zoomifies utility) – but it would be really good to get a Flash programmer to be able to create a viewer like this that runs directly off Geograph tiles!