Questions and Answers

Questions can be posted by students on the Ask-an-Expert Web Board. The answers were provided Geospatial Experts and by Shelley the LEARNZ Field Trip Teacher.

All field trips have an Ask-an-Expert web discussion board for this purpose. When the web board closed one month after the field trip, a selection of questions and answers were moved to this page.

Tim, what is the most interesting thing you have learned in your job?

I spend a lot of time with interesting and awesome people both inside and outside government who are working on how to make data more openly available so people can do cool things like:

  • Build new software
  • Start businesses
  • Make better decisions

I am most excited about how the government is embracing open data and the potential that it holds.
From Tim.

Tim, what was your school life like and how did you learn how to survey?

I grew up in Dubai, United Arab Emirates - I went to an English speaking school with people from over 90 different countries. Dubai was an awesome place to grow up and I had the opportunity to do lots of travelling and I learnt to speak Arabic.

I am not actually a surveyor. I am interested in technology and data, and how it can be used to improve our world.
From Tim.

Tim, were you in Christchurch at the time of the earthquake?

I was out in Kaiapoi - standing in a small office. The ground really shook, however it wasn't until I saw some of the information online that I realised how big the earthquake really was!
From Tim.

Jeremy, what is the most interesting thing you have learned in your job?

I have learned so many interesting things in my job - LINZ has such a broad range of things that it does - from surveying and land titles, to geospatial information and development, right through to managing Crown land all over the country. I guess the most interesting thing I have learned is that geography and location can apply to everything and everything we do. Everything is spatial, it has a location, and a lot of what we do in our daily lives is related to where we are, or where we want to go, or what we interact with on the way from A to B.

So that's what I found most interesting in my job is just how much spatial information applies to everything, from working something out using a GIS, to navigating the mountains with a tatty map on horseback - that's what's so special about spatial information - it's in everything we do.
From Jeremy

Jeremy, what was your school life like and did you then learn how to survey?

When I went to school I was always more focussed on the social sciences - History, Geography, and English, and at that time I never thought I would end up in a job that was pretty heavy on Maths and Science. Even so, I did a broad range of subjects right through to 7th Form (Year 13), including always one Maths subject and one Science subject. This was really good as it meant I was able to keep my options open, and as I went through university and my career, I worked out that GIS was a pretty powerful tool for helping to solve real world problems. Since I kept up a good range of subjects, I was able to study at university in GIS because I already had that background.

Interestingly, I am not actually a trained surveyor. I learnt a decent amount about surveying through my work at LINZ and through my GIS degree, but I didn't study at Otago Uni to be a surveyor (which is the only place in NZ that you can do it). I studied GIS at the University of Canterbury, which has led to some pretty cool research and projects.
Feel free to check out and participate in my current project - "Building Our Footprints" - it's a web mapping competition for school students.
From Jeremy

How often do the Google Maps get updated?

I'm not totally sure how often Google Maps get updated - I think it depends on the area. If more people live in an area then more people rely on the maps and can suggest changes when they are needed so these maps would be updated more often.
From Shelley the LEARNZ field trip teacher.

Shelley you are quite right. Aerial photos on the maps can only be updated when Google gets a new image that fits with those around it - the map works with image "tiles", so these would have to blend well with the ones around them. Usually imagery is updated in summertime - there are fewer clouds to get in the way.

Google maps also have a whole bunch of other layers that get updated more frequently than the base imagery. The Google "traffic" layer for example, gets its information for the number of cell phones present on a particular stretch of road, and this is translated onto the map to show how busy a road is. A road will show red for busy, green for good traffic flow, and yellow for somewhere in between. Try it sometime, turn on the traffic option on the map. There is about a half hour delay to process the data and get it onto the map, but half an hour between sensing the data and displaying it (for most of the world too), is pretty quick when you think about it! It definitely helps during rush hour too!
From Jeremy.

Jeremy, were you in Christchurch at the time of the earthquake?

I was in Christchurch for the first earthquake (Sept 2010), but was in Kaikoura on a GIS field trip for the big February 2011 quake. We still felt it up there though. My wife was working in town at the LINZ building, which is usually a twenty minute drive from home. What was crazy is that I jumped in my car straight away to head back to town from Kaikoura (stopping to get water and petrol on the way home), and I still made it home before my wife who was only travelling from the central city!

In the days after the quakes I was in town, and did my best to help out where I could. This included the cliff-edge surveying I talked about on Tuesday in the audioconference, and also signing up to do some voluntary crisis mapping - usually of where people were telling us that help was needed, so that the right services could be directed there. So even though I was out of town for the main event, it was still one of those experiences that I will never forget.
From Jeremy.

Do you think technology will have a big place in the future?
Yes, technology will have a big place in the future in relation to geospatial matters. For instance, satellite imagery and online maps can provide people with more up-to-date information to help inform decisions about natural disasters. People with cartographic skills will still have important roles to play in determining the best way to symbolise and display some geospatial data so map users understand easily what is shown on maps.
From Geoff.

Do you have to use really heavy equipment to survey?

No, you don't have to use really heavy equipment to survey these days. In the 1970s Electronic Distance Measuring (EDM) equipment was quite heavy and sometimes needed heavy car batteries to operate. These days survey total stations or GPS receivers on tripods are not too heavy and surveyors can use them quite easily in remote locations if necessary.
From Geoff.

Can you estimate whether there will be another earthquake?

In New Zealand, GNS Science estimate the possibility of future earthquakes based on models of earth behaviour developed at GNS Science and informed by research done in other seismically-active countries.
In late 2013, GNS science said that their most recent models suggest that the probability that a magnitude 7 or greater earthquake will occur in central New Zealand is about 2% in the coming year. These are estimates only, scientists cannot accurately predict earthquakes.
From Geoff.

When you create a map, do you have to create it again because there is an extra street or a road on the map? And are you releasing new maps at the moment because of the rebuild?

In the past this would be very true - when all maps were made to be printed on paper and sold in shops, it would be very difficult to keep them up to date - especially when the real world is changing so fast like it is in Christchurch.

That's why we are so lucky to live at a time when we have electronic data and GIS, which makes updating maps really very easy. If we have a dataset of streets in Christchurch, it is as simple as adding a new street into this dataset every time one is created. And what's even better is that most people these days view their maps online, using Google Maps or a phone app, or an online map made by the local council. This means that it is now really quick and easy to update maps (it can be done in the time it takes to send an email), and there is no problem with them being out of date.

A good one to check out would be Canterbury Maps, at - this online map is run by Environment Canterbury (the regional council) and brings in data from a whole lot of places across the region.
From Jeremy.

Does it matter (to satellites) if it’s a windy day? Does that make satellites move and harder to get information?

The satellites that are used for getting your location, like GPS, are orbiting the earth in space. Because they are above our atmosphere, there isn't any wind up there that can affect them, or blow them off course.

The way that people on the ground can use the GPS satellites can be affected by the weather though. To connect to a GPS satellite from a device (like a phone), there needs to be a "clear line of sight" between the device and the satellite. This means that on a cloudy day, you can sometimes have a problem getting a good connection. So the weather does matter when you are finding out where you are by GPS, but it's because of the clouds, not the wind.
From Jeremy.