GIS Blog

How do I Clip Data?

This post covers a very useful skill – clipping subsets of vector data from larger datasets (clipping raster data is covered in another post). As seen is some earlier posts, most of the data on the J: drive is at a national scale.  In many cases, though, you’ll be working at a much larger scale (and…

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How do I create a new feature class/shapefile?

This post covers an essential skill – creating new feature classes and shapefiles.  We’ll cover how to create a blank layer and then how to digistise new features into that. Creating you own data layers is an important part of most analysis projects, so in this post I’ll cover some of the essential steps in…

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The data I need aren’t on the J: drive!

This post outlines some of the on-line data portals, including Koordinates.com, and portals from LINZ and Landcare Research. Before getting to the main topic, I’ll put a quick word of appreciation in for Dorje McKinnon, who is heading overseas for a wee while.  As the Applications Group Manager at ITS, Dorje’s been a big supporter…

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Data with a View

This post covers viewsheds – raster grids that indicate which areas are visible from a specific location. (Updated April 2016 with new images.) Some of you may remember that stately Timeball Station in Lyttelton: Coming out of the tunnel and into Lyttelton, it was hard to miss the structure above the port. The castle-like building…

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Data, data everywhere, but what about what I need?

This post outlines the data currently available on our network. Those of you who have done any work with GIS will know how important the right data are.  Spatial analysis is very much a garbage in-garbage out process so making sure you’ve got good data to start out with is crucial.  Last week’s post was…

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Canterburymaps.govt.nz and Web Services

The Canterbury councils recently got together (gasp!) to produce a map portal for the whole region.  This post covers that as well as brings up how web services can be used to access publicly available data. Canterburymaps.govt.nz It may sound hard to believe, but the district, city and regional councils got together recently and decided…

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