Archives for posts tagged ‘GIS’

How To Get High Quality Topo Maps For Free

I really like a good map. A GPS + Laptop is great, but nothing works like a piece of paper when the batteries go dead or your laptop falls into the lake. Unfortunately, finding high quality topo maps for free is a chore.<!–more–>
When I first started searching for topo maps all I was able to [...]

Geodesic Distance Function

I was working on some code to process some GPS track logs and I wanted to be able to accurately calculate the distance between 2 points in the log. I did some searches, but there were no obvious solutions written in PHP. However, I did run across Chris Veness’ version in javascript. I worked through [...]