News Geoscience Australia part of international effort to compare next generation of satellite data

Geoscience Australia has taken part in a global campaign to compare data from the Landsat 8 and 9 satellites during a rare underfly.

The Landsat 9 satellite was launched by NASA on 28 September 2021, to provide the next generation of Earth Observations from Space (EOS) data.

But a unique event in the lifetime of the satellite occurred between 13 and 17 November.

As Landsat 9 was being maneuvered to reach operational altitude, its orbital path overlapped with that of the older Landsat 8 satellite.

Geoscience Australia’s National Earth and Marine Observations Branch Head Maree Wilson said this “underfly” provided a rare opportunity for scientists to compare the performance of sensors on the sister satellites as they passed over the same area near-simultaneously.

“This was our only opportunity to confirm both the Landsat 8 and 9 satellites are seeing the world in the same way,” Ms Wilson said.

“When Landsat 9 reaches its operational orbit, the orbits of the two satellites will be offset by 8 days, meaning this was the only chance we had to image the same swath of Australia with both satellites at the same time.

“It is important that we know the Landsat satellites are taking like-for-like measurements, as our ability to monitor the entire country and how it is changing depends on having a long, growing and consistent record of data from Landsat satellites.

“We use Landsat data to track changes in the landscape, identify waterbodies and monitor coastal erosion. Ensuring this data is accurate is vital for the health and wellbeing of all Australians.”

coordinated field measurements at multiple sites around Australia, in collaboration with the Queensland Department of Environment and Science, University of Queensland, the New South Wales Department of Planning, Industry and Environment, CSIRO, University of Western Australia, and FrontierSI.