How satellites are boosting the NZ economy

Our approach to age-old New Zealand primary industries like farming and forestry is moving into the space age. In the first of a three-part series, Baz MacDonald looks at how advanced satellite data is developing our economy. 

It is difficult to imagine how images of crops taken from space might benefit farmers, but agri-technology company LIC is discovering immense potential for gains from their satellite pasture measurement service, aptly named SPACE (Satellite Pasture and Cover Evaluation).

This service offers farmers reports on the levels of grass on their pasture, by collecting satellite data and analysing it using an algorithm co-developed by LIC and American company FarmShots.

This is a major advance for farmers, who currently need to check their grass every seven to 10 days - spending half a day manually inspecting each paddock on their farm. SPACE saves farmers time and effort by making this information readily available on their computer.

LIC business advisor Simon Parry said the service has been rolled out to several regions over the past three months and the response from farmers has been positive, with feedback indicating SPACE readings are as accurate as manual inspection.

However, although LIC is capable of providing farmers with reports every day, the frequency of reports can be sporadic depending on the weather. This is because when the satellites pass by New Zealand to capture images capable of analysis, it needs to be cloudless - and that is a considerable challenge in this, the land of the long white cloud.

“In a perfect world, it would be a clear day every seven days, and we would provide a report the day after,” Parry said. “But, the reality is that farms can have two or three reports in a row, and then a break of seven days, or 10 days.”

Parry said weather trends typically mean reports are available within the 7-10 days farmers need an update on their dry-matter conditions.

LIC is currently working on rolling this service out to other regions, but Parry sees many more applications for farmers using this Earth Observation Sattelite (EOS) data – including, measuring moisture levels, analysing a pasture’s metabolisable energy, and assessing pasture health.

Earth Observation Satellites

Earth Observation Satellites (EOS) have been an important aspect of scientific research since the launch of the first earth observation satellite Landsat 1 in 1972. These satellites represent the non-military applications of satellite technology and have an increasing presence in our global orbit. As of last August, there were 1738 satellites in orbit and 620 of those had the main purpose of earth observation – about a third of all satellite activity.

NZ has a close-tie to these observation satellites, tracking more than 200 of them as they pass over from satellite ground stations at Awarua and Lochiel in Southland.

The number of EOS satellites has grown exponentially in the past two years, with a 66 percent rise since 2016.

This growth is due in part to the increasing commercial applications of EOS data, like the work happening at LIC.

Industries across the globe are starting to realise the potential this data offers for managing and developing their businesses.

NZ’s recent growth in this space has been partly a result of the increasing availability of satellite resources. In 2005, there were only 50 EOS satellites in orbit, compared to 620 last year. As a result, NZ has much more frequent coverage, making it more viable for business use.

At the forefront of this work are some of NZ’s biggest players, including Indufor and GNS Science – each of which has begun to develop and experiment with practical applications for EOS data within their fields.

Efficient felling

To many companies the rise in EOS data has gone hand in hand with the development of technological advancements, such as drones and LiDAR.

Forestry consultancy group Indufor has been combining these technologies for the management and assessment of forestry stocks around NZ.

Indufor use a combination of EOS data, drones and LiDAR in order to keep an active record of the quantity and quality of forestry companies’ stocks - essentially acting as auditors for the industry. This includes evaluating how plantations are growing, monitoring any damage to them, and reconciling harvests with the tree stocks.

Indufor head of resource management Pete Watt said in the past this required much leg work, with staff on the ground manually checking forestry stock. However, earth observation satellites have offered a more efficient solution.

“Rather than drive the roads, we are able to process satellite data and provide an indication of how well the forest is actually performing.”

One of the advantages satellite data has offered Indufor is the ability to immediately recognise and locate anomalies.

“An example of that might be if you’ve established a crop and it hasn’t performed. You want to know exactly where it hasn’t performed so that you can send the foresters out to change the management strategy or replant it.”

Watt said this trend towards satellite imagery has been supported by the corresponding rise in cloud-based processing, which allows users to access the satellite data and analyse it much more quickly.

“In the bad-old days, we would take down maybe three satellite images, which would be about a gigabyte each, and process it on a desktop computer – that would take maybe three or four hours. But now you’ve got all of the same datasets just sitting in the cloud. We’ve moved away from downloading and prepping the data, to just doing the analysis.”

An evolving practice

The developments made by Indufor and LIC are at the forefront of this EOS movement, but the truth is that we are only just beginning to discover the depth of practical applications EOS data could offer.

As satellites become equipped with more sensors, this increases the amount of data available in each image, making more applications possible.

Researchers worldwide are working to find new ways of using EOS data for practical applications. NZ’s own GNS Science is at the forefront - using EOS data to identify possible mineral and geothermal deposits.

In its latest study, it has worked to improve the precision by using new satellites with more accurate data. Previously, GNS had been using an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), an instrument aboard NASA’s flagship EOS, Terra. In this latest study, however, GNS has moved to the more accurate WorldView3 (WV-3) satellite.

GNS Science remote sensing scientist Dr Salman Ashraf said due to NZ’s thick vegetation you need the highest possible resolution image for the identification of possible deposits.

ASTER takes images where each pixel represents 30m x 30m of land mass. Ashraf said in Australia, where the land being analysed is mostly bare, it is possible to properly map with this resolution. However, the vegetation density here makes this resolution less optimal, with the majority of each pixel dominated by flora and fauna, and with perhaps no, or a small amount, of data regarding the ground composition.

The move to WV-3 has allowed Ashraf and his team to access images which are 7.5m x 7.5m a pixel – allowing them to see the surface of NZ’s landscape in much higher detail.

This additional information makes it more likely GNS scientists will be able to identify the specific readings associated with mineral and geothermal deposits. This is achieved by taking readings at a site where they know there are currently deposits, and then using MV-3 readings to try and find similar patterns in the surrounding area.

“For instance, gold presents a certain way. So, if we know that it exists in a spot, and a similar situation is somewhere else, then we can check that area for the presence of gold,” Ashraf said.

By mapping with this MV-3 technique, Ashraf and his team have produced 12 mineral maps related to orogenic gold deposit formation at Macraes Flat in the Otago schist area. These maps do not necessarily mean there is a certainty of gold deposits in highlighted sites – but, do immediately narrow the search parameters, and give a solid starting point for ground teams and aerial photography to investigate.

Ashraf said these identification techniques are particularly useful in mapping geothermal deposits, as it is often not possible to walk around these areas to take samples due to the volatile nature of geothermal hot-spots.

These mapping techniques also offer a more socially acceptable approach, Ashraf said, especially in areas where there are cultural restrictions which stop scientists from taking samples – for instance, iwi have jurisdictio on some of NZ’s geothermal hot-spots. Using satellite imaging, scientists can now map and analyse these areas through un-invasive means.

“We can look at it from a distance without disturbing the sacredness of these places.”

In a similar vein, this is a more environmentally sound approach to mapping our geological deposits, Ashraf said, as it doesn’t require scientists to dig up as many samples or to create explorative pits or mines.

Next: In part two of Baz MacDonald's series he looks at how big data is helping map our buildings, roads and waterways

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