July 15th, 2005
A side project that I'm currently working on, involving maps, had a bit of data that I was unfamiliar with. I'll start by saying that I'm very familiar with Latitude/Longitude - it's something that everyone learns in school. However, the data that I was provided with was of an entirely different sort and labeled as 'Easting' and 'Northing'. A couple Google searches later brought me to a an article explaining the concept of something called Universal Transverse Mercator (UTM). The article is very math heavy, but the premise is: The earth is broken down into tiny 'zones' around the ecuator and extending northing and south. Within these zones a measurement, in metres, is taken both to the north and to the east of the ecuator. So your final figure is something like Zone: 17, Easting: 300,000, Northing: 4,000,000 (I just made those numbers up). The reasoning for this is that if your measurements are within a tinier 'slice' of the world, your results immediately become more accurate (especially considering the curvature of the earth). Here's a figure showing all the different zones, taken from this page on different coordinate systems:
Now, using that chart above I determined the zone in which I needed to run all my coordinates through - but the problem is: How to convert them into Lat/Long - which every piece of mapping software understands. There are a number of Java Applets which will do this task, but I wanted something that I could automate. This is where Perl, as always, comes to the rescue - there is a module for it! The module is very lightweight, it simply implements the algorithms specified in the article, mentioned before. Useing that module I was able to quickly run through my data and get perfect numbers out - concluding my UTM adventure. As always, more information can be found on Wikipedia.
Tags: maps, geography, data, conversion, utm, geo
5 Comments on 'Universal Transverse Mercator (UTM)'
July 12th, 2005
- In the new release of Google Earth, there's an exciting feature that lets you dynamically load geographical data in from other sources. They even have an markup language for it called KML. People have already started putting Flickr photos ontop of the maps.
- On a similar note, if you have a Geotagged RSS feed that you want to put onto a Google Map, you should consider giving this utility a try.
- The newer versions of Microsoft Word save their documents in an XML format. So it was only a matter of time before someone wrong an XSL template to generate these documents.
- Do you have a lot of text that you want converted into speech? You should check out the say command on OS X.
- Google now has built in currency conversion. I've been waiting for this for a long time, considering that you've been able to convert units of measurement and weight for the longest time, this step only seemed logical.
- Interested to see how the moods of large-scale communites fluctuate over time? The Livejournal Mood Browser does just that, with informative graphs too!
- What's better then a free textbook on Graph Theory? Not much!
Tags: graph, rss, osx, data, geo, theory, free, livejournal, xml, xslt, geotag, google, earth, kml
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July 10th, 2005
I've just finished up an excellent hack which brings the power of address translation (converting a US Postal Address into a Latitude/Longitude) to the Google Maps API - something that wasn't provided in the default distribution. There's a ton of information available, including demos, screenshots, and code on the project page: Google Address Translation.
Tags: google, maps, api, hacks, geo, perl, javascript, programming
2 Comments on 'Google Address Translation'
July 9th, 2005
One 'movement that I've been keenly watching is the growth of Microformats, embedding reusable data nuggets into the XHTML of a web page that both users, and applications, can understand. A new format that seems to making a rise deals with embedding geographical information into a web page. Attaching a Geographical location to a virtual URL is old hat (see GeoURL) but providing a visual, or intuitive format for the end-user is an interesting challenge. Hopefully this will make some more headway then simple, invisible, meta-tags from the day of GeoURL.
Tags: geo, url, microformat, data
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May 4th, 2005
I'll admit that I didn't give the Yahoo Traffic RSS feed data that close of a look the first time around (I had just assumed that it was purely 'boring' textual data), but now that Greg has posted a link to his Google-Yahoo Traffic Maps mashup, I see that each of the traffic incidents include lat/long - making them easily placable on any map. This is too rich! Now, if only a method of getting driving directions and then attempting to figure out if any of the incidents will affect your travel. (hint! hint!)
Tags: geo, traffic, yahoo, google, maps
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