Image(ry) is Everything

This post covers obtaining a high-resolution image of post-earthquake Christchurch and creating a mosaic dataset to manage it. It’s that time of year when the students in ERST310/607 are hard at work on their independent GIS analysis projects; this also means a bit of trouble shooting at GIS Central.  One student, who is looking at […]

A Smokin’ Script

This post covers the development of a Python script to help carry out some analysis, saving me hours of time in the process. It’s been a good month for keeping the Alzheimer’s at bay here at GIS Central.  An analysis project I’ve been working on has thrown up some interesting challenges which I’ll cover in […]

Star Trek at 50: So how did they Boldly get there?

The 8th of September, 2016 marks the 50th anniversary of the first screening of the original Star Trek television series.  In this post we cover some of the locational aspects of the Star Trek phenomenon. Growing up, Star Trek was a pretty big part of my life (more than you wanted to know, I’m sure).  […]

…And Standing Up Straight

In this post we cover New Zealand’s new gravity-based vertical datum, NZVD2016.  Along the way we’ll get familiar with the weirdly wonderful geoid and WGS84.  This post follows on from Keeping Our Heads Above Water, hence the title, and has benefited greatly from comments by LINZ’s Geodetic team – thanks! In a previous post we […]

Keeping Our Heads Above Water

In this post we discuss the highs and lows of sea level. So everyone knows where sea level is, right?  When we talk about elevation, we usually put it in the context of how far above (or below) sea level something is.  Simple, yes?  Well….not quite.  Sea level is one of those things that’s easily […]

Getting to the Point(s)

In this post we look at how points can be mapped from their raw coordinates in a text file or table. So the GIS Helpdesk got a call last week – a postgrad was having some trouble mapping some points.  Ah, it reminds me of that time all those years ago, before I knew about […]

A New Window on the World – ArcGIS Pro

In this post we look at a new application in the ArcGIS suite – Pro. Like most behemoth software applications, ArcGIS is ever changing.  There’s a new horse in the ArcGIS stable and it’s probably one that’s worth getting to grips with, especially as the tea leaves seem to point to this as the direction […]

The GIS Detective – Have LiDAR, Will Travel

In this post we’ll see how LiDAR data were used to help understand a tricky problem. So I’ve got a bit of an issue at my house – and here it is: We live out on the Lyttelton Harbour on steep loess soils, which are prone to tunnel gullies – sub-surface channels that develop in […]

Python Scripting with the Field Calculator

This post details how you can use some Python scripting to do if/else statements in the Field Calculator. If the title of this post and the intro haven’t put you to sleep already, read on!  Perhaps they’ve even piqued your interest!  (There are support groups available for this condition.) I was recently contacted by a […]

Fun with Cholera!

This post looks at how data can be symbolised in different ways to make for more effective communication using data from John Snow’s mapping of the cholera outbreak in Soho.  Well there’s nothing fun about cholera, really.  But there are some important lessons we’ve learned about spatial thinking from cholera, particularly with an outbreak in […]