News An artist’s surreal view of Australia — created from satellite data

Of course satellites are expensive to launch and maintain. The main players are either powerful corporate providers, enormous public sector agencies like NASA and the European Space Agency (ESA), or private sector startups with links to these groups.

Luckily, many of these agencies make their data freely available to the public.

The NASA/United States Geological Survey Landsat program makes 40 years of Earth imaging data available through Earth Explorer. The ESA provides data from their Sentinel satellites to users of the Copernicus Open Access Hub.

In Australia, Geoscience Australia’s DEA platform provides researchers and the public with access to Australian satellite data from a range of agencies.

Understanding and processing the data

Making satellite imaging data accessible, though, is not the same thing as making it usable. There is considerable technical know-how required to process satellite data.

The Landsat and Sentinel satellites are used by scientists and the private sector to monitor environmental change over time, using what is known as 'remote sensing'. They travel in the low Earth orbit range, around 700 km above the Earth, and circle the Earth in around 90 minutes. After numerous orbits, they return to the exact same spot every 16 days.

Landsat and Sentinel satellites are equipped with sensors that record reflected electromagnetic radiation in a range of wavelengths. Some of these wavelengths fall within the visible light part of the spectrum (between 390–700 nanometers). In that sense, satellites image the Earth in a way comparable to a digital camera.

But the satellites also record other wavelengths, particularly in the near and shortwave infrared range. Vegetation, water and geological formations reflect and absorb infrared light differently to visible light. Recording these wavelengths allows scientists to track, for instance, changes in vegetation density or surface water location that indicate drought, flood or fire.

A single satellite image is made up of numerous bands recording data in very specific wavelengths. Getting a full-colour image requires processing in a Geographic Information System (GIS) to combine them, and assign the bands to either red, green, or blue in an output image.

Bringing creativity to the data

This is where creativity can enter the picture. Being able to create false colour images that combine infrared and visible light in different ways allows me to produce beautifully surreal images of Australian landforms.

The image below shows the variance in environmental conditions over 12 months in 2016 at the Stirling Range National Park in WA.

Because geoscientists need clear images of the Earth’s surface to analyse, they filter clouds from the data. I chose to take the opposite approach, highlighting the incredible array of meteorological conditions experienced by the country.

There are many other artists working with satellite data. Clement Valla’s ‘Postcards from Google Earth’ focuses on glitches in Google’s mapping algorithm, and bio-artist Suzanne Anker uses satellite imaging to produce extruded 3D environments in petri dishes. Working with the Nevada Museum of Art, photographer Trevor Paglen will launch the Orbital Reflector satellite as an inflatable, visible sculpture, a prompt for wonder and reflection.

Artists place satellite data and usage in new contexts. They question surveillance practices and expose scientific tools and representations to new audiences outside science and the private sector.

The thousands of satellites winging their way around the Earth represent power and possibility, a chance to look again at the intersection between humankind and a changing planet.

Grayson Cooke is Associate Professor and Chair of Creative Arts at Southern Cross University. His Open Air project has continued to receive accolades and awards, including the prestigious Waterhouse Natural Science Art Prize at the South Australian Museum in December 2020. This article originally appeared on The Conversation and is republished with permission. Learn more about Grayson and his work here.