GIS Blog

Web Feature Services – real data from the web to your desktop

This post looks at web feature services (WFS) where real data from internet sources can be added to your desktop for analysis purposes. In a previous post we looked at web services that could be added to a map.  While these are great for map making purposes, they do have their limitations, especially if you…

Continue Reading

How do I clip raster data?

This post covers how to clip out portions of raster grids (updated on 8 May). A previous post covered how to clip vector data (feature classes and shapefiles).  Another key skill is being able to clip out portions of raster grids, such as a DEM, or perhaps a TIF image.  We’ve got three options really…

Continue Reading

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…

Continue Reading

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…

Continue Reading

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…

Continue Reading

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…

Continue Reading

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…

Continue Reading

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…

Continue Reading

GIS and Precision Agriculture

This post is about how GIS fits in with precision agriculture, something that’s likely to be an important topic here over the next few years. Someone recently asked me if GIS could be used for precision ag. The definitive answer is: Yes! Another answer is: How could you not? Precision ag strikes me as an…

Continue Reading

Mapping the Census

In this post I’ll take about how we can make the most of the recent (and previous) census data and how to add spreadsheet data to a map. So did you fill in your census form on Tuesday night?  In the course of filling in the forms, you no doubt entered a lot of personal…

Continue Reading

1 5 6 7 8