Robin's Blog

Archive for the ‘GIS’ Category

Finally…a nice way to download satellite images!

Quite through chance I just happened to stumble upon the USGS New EarthExplorer, and I’m really quite impressed. Remote sensing is a field that is almost entirely based around new technology: satellite sensors, computer processing techniques and so on, but for ages actually acquiring the data has been an exercise in frustration. Much as the […]

How to: Find closest objects in ArcGIS with Python

As part of my DunesGIS project I had a need to calculate ‘closeness statistics’ for objects in ArcGIS. By ‘closeness statistics’ I mean statistics giving information about how close the objects are to each other. I needed to do this to calculate how dune patterns change over time. The code below takes a shapefile as […]

Aeolian Philosophy or “What is a sand dune?”

No, this isn’t about thinking deeply while the wind is blowing, or philosophising about how the wind is there but we can’t see it – it’s about sand dunes. Now, you might think that sand dunes are quite boring things, just hills made out of sand that sit there and do nothing. That couldn’t be […]

How to: Snap points to lines in ArcGIS with Python

I’ve recently starting scripting ArcGIS using Python as part of one of my academic projects (about which I’ll post more later) and needed to be able to snap points to polylines – that is, move points so that they lie on the nearest polyline. An example would help to explain this: In the image above, […]