All posts by Stephen Lead

Esri’s 100-lines-or-less competition

Esri are running a coding competition, with the challenge being to write a fully-functional JavaScript map using a maximum of 100 lines of code.

I love this idea, as it’s the functional equivalent of a good GeoRabble talk – cut the crap and get straight to the point. Even better, they’re using GitHub to manage the entries, which makes each entry public so other people can learn from it. The full details of the competition are at

I decided to give it a go – my entry is available here.

Climate Explorer

In order to make it Australian-focussed, I wanted to use the BOM’s climate datasets. Unfortunately I don’t think there’s an easy way to obtain this data, so I wrote a Python script to scrape the data from the site. I’m not sure of the legality of this, but my conscience is clear as it’s just an automated way of getting to publicly accessible information. Hopefully they feel the same way…

Once I had downloaded the information, I made a point featureclass from it, and served it out via ArcGIS Server. My entry is basically a wrapper to make it easy to find weather stations and see their historical records. A link underneath the charts takes your directly to that weather station’s data feed. This is arguably easier and more intuitive than having to look up a station number, as at

I’d love to add more functionality, but I’m already dangerously close to the 100 line limit. Please let me know of any feedback.

Steve (@stephenlead)

Map-making with a balloon

Here is a very cool project which combines high-tech (digital cameras and online georeferencing software) with low-tech (a helium balloon) to create grass-roots maps.

Balloon mapping is sending a camera up on a balloon, snapping photos, and stitching them into a map. Over the past 18 months, we’ve build a global community of mappers who use balloons and kites to take aerial photos, and our browser application MapKnitter to stitch them together.