Friday, April 16, 2010

Thai MGRS grid

Ever since I was first infected with the idea of a Thai Geograph website - the blog One Tambon One Photo is the training ground for it - I had been slowly been implementing code for geographic coordinate transformation, mostly to be able to parse the coordinates in the boundary definition announcements. Now I had the necessary algorithms, understood the MGRS coordinate system used by geograph and how they define their squares, hecards and myriads, I now created some code to create these squares for Thailand as well.

View Larger Map

As you can see in the map, there are exactly 100 MGRS squares each covering 10,000 km² spread over Thailand, except those squares at the UTM zone boundary at 102° East. Someone better at graphic art can now use that KML file and the country boundaries to create a nice appealing emblem for Thai Geograph.

Actually, I did this coding not for this purpose, but to easier parse the coordinates in the Royal Gazette announcements - those few I tried sometimes had a wrong letter code, sometimes the letters were omitted as being clear from the rough location, or even had obvious wrong codes. With this and smaller scale grids I can easier notice where the subdistrict or village boundary marker is supposed to be, when the direct coordinate conversion fails.

By the way, my readers in Germany might be interested in the Geograph Germany, which just now reached 1% coverage - but still more than 300,000 square kilometer without a photo.

2 comments:

[OTOPH] said...

Interesting Andy. Obviously a step in the right direction, and one that I would never have managed. You have the right technical background. If you decide to make a go of it, please do let me know, as you may need moderators etc.

[OTOPH]is offline at the moment. The main reason being that I have recently lost all interest in living in this country. And yes, it is to do with the deadend politics!(Been here close to 2 decades.)However, I daresay the interest may return.

Please contact tynllidiart@gmail.com
if you wish to discuss future developments.

[OTOPH] said...

I did once create a rather crude Geograph Thailand logo based on the same grid-square design as 'Geograph Britain & Ireland.(They changed the name to be more politically correct after a recent conference they held at the Ordnance Survey Office in Southampton. It was felt that 'Geograph British Isles' was a bit too indicative of a colonial past.)

It would not be difficult for some one with slightly better graphic skills than myself to create such a site logo. Even my version looked quite good after I had reduced it in size to fit a page header. (No better and no worse than the Britain & Ireland original.) However, I decided not to proceed with that project - since my more immediate aim was to gather and post representative photos for some very ungridlike tambons. (I was also thinking that a grid-like logo could wait until someone figured out what grid to use.)

I note that the Geograph Britain & Ireland logo is still pretty crude - and doesn't really capture the very familar UK shape that well.

While involved in my own logo creation, I realised that Thailand does have a shape that many people worldwide would instantly recognise in a small logo - but it is hard to capture the log thin isthmus with fairly large grid squares. So I would suggest the logo contains both grid squares and a more accurately drawn borderline.

Meanwhile, Geograph Germany has created a logo that looks nothing like the Britain & Ireland site.