• garycollins24

This Beautiful World Blog 6 | Mapping Terrain with LIDAR Data | Salisbury Cathedral

Hi, and welcome to Blog 6 in my series entitled "This Beautiful World' where I am sharing my journey in learning how to create better map visualisations. Earlier in this series I have covered an overview to my personal project; how to make your maps POP! with subtle details; How to create long shadows in Mapbox; How to visualise roads in Tableau; and How to Blend Maps into Backgrounds on your viz.

In this blog I am going to cover using LIDAR data to create images such as this one of Salisbury Cathedral, famous for being Englands highest spire:


The Thinking Behind the Viz

I had seen a few visualisations of towns and cities that looked different compared to anything I had seen before. They looked incredible, with skylines created totally from what looked like lego bricks. If I am honest, I really didn't have a clue what the technique was called, as evidenced by a tweet to try and find out some more...

Given I couldn't articulate what I was looking for, it is unsurprising that I didn't get a lot of leads from my tweet. I kept on looking, and eventually found on You Tube that these visualisations were created by LIDAR data.

Light Detection and Ranging (LIDAR) is a technology similar to RADAR that can be used to create high-resolution digital elevation models with vertical accuracy as good as 10 cm.

LIDAR equipment, which includes a laser scanner, a Global Positioning System (GPS), and an Inertial Navigation System (INS), is generally mounted on a small aircraft. The laser scanner transmits brief laser pulses to the ground surface, from which they are reflected or scattered back to the laser scanner. Detecting the returning pulses, the equipment records the time that it took for them to go from the laser scanner to the ground and back. The distance between the laser scanner and the ground is then calculated based on the speed of light." Click here for more information.


Building the Viz

I found this website from the Department for Environment Food & Rural Affairs which enables you to select any location in the UK, and it will create you a LIDAR file to download. I haven't seen any websites that have LIDAR data from other counties as of yet, but I am sure they will exist.

I also found a great free application called Aerialod that can use LIDAR files to create some fantastic images. Unfortunately, this software is only available for a Windows PC, so Apple users, sorry, you are going to have to borrow another laptop to do this.

I found a good tutorial on You Tube to help learn how to use Arielod which you can access here.

I had a good look around various places in the UK that I thought might be an interesting subject to focus on. Eventually, I decided to focus on an iconic location - Salisbury Catherdal, famous for having the highest spire in the UK. Here are a few of my early trials, experimenting with sunsets and positioning within Ariedlod. I was keen to give the emphasis to the spire of the Cathedral.

After much experimenting with colours, backgrounds and positioning, I finally landed on the following image of Salisbury Cathedal.

I then saved this as an image down from Arielod, and put this onto a Tableau dashboard using an Image object. There is no way to integrate Arielod into Tableau in the same was as you can with Mapbox. Also a word of caution, whilst I was building the image in Arielod, I couldn't find any way to save my work, and ended up loosing a few attempts. My advice is to build an image you are happy with, and save it down before you go for a few extra 'refinements'...

If you do find a way to save your work as you go on Arielod, please do let me know.

I hope this blog has been useful to you. Join me for the last blog in this series, which focusing on my learnings on using the highlight feature in Mapbox, and how I created a 'Fly By' view over 'The Skyscrapers of Manhattan'. by embedding You Tube videos into a Tableau dashboard. You can play the video below by clicking on the arrow.

Keep on vizzing!!