About us What is analysis ready data?
The careful processing of satellite data is fundamental to its usability, and we’re making world-leading strides in this work
Published:1 February 2021
Collecting, calibrating, and curating decades’ worth of internationally acquired satellite data is no small task.
Digital Earth Australia (DEA) provides almost 1.5 petabytes of free satellite imagery to Australians; and ensuring the data is ready for their use is a significant part of our work.
The hundreds of thousands of satellite images provided to us by the joint NASA/United States Geological Survey (USGS) Landsat program and European Union (EU) Sentinel program must be prepared for use in Australian contexts and quality-assured for application to Australian projects.
The data processing we undertake means we provide ‘analysis ready data’ (ARD) — allowing users to get up and running with their own analysis of the data as quickly as possible. This makes it simpler to develop applications with the data, and for databases to execute queries with minimal preparation.
Preparing analysis ready data means:
- Comparing and correcting imagery acquired at different times, seasons and geographic locations
- The orthorectification of images: removing the effects of image perspective (tilt) and relief (terrain) effects
- Adjusting imagery to correct for inconsistencies caused by a change in conditions each time an image is captured. These include water vapour, cloud cover, sun position, sensor view angle, surface slope and surface aspect
- Automating satellite data processing workflows based on Earth observation science and physical processes for testing and quality assurance
- Ensuring best practice data management, metadata standards, and common terminology. As a program of Geoscience Australia, we maintain the highest levels of international
How drones support analysis ready data
The validation of satellite data in the field is also critical to ensuring it is fit for purpose. Our ARD team are leaders of best practice measurement protocols governing the acquisition of field data, including field instrument calibration, sampling strategy, and approaches for post-collection processing and management of field data.
We maintain and use a range of field instruments for data calibration and validation activities. These are taken into landscapes across Australia manually — carrying backpack-mounted spectrometers to conduct surveys — and remotely, thanks to our Remotely Piloted Aircraft (drone) program. Drones enable us to use spectrometers and other measurement equipment over otherwise inaccessible territory: over forest canopies, across wetlands and over canyons.
DEA Landsat 9 Collection 3 Analysis Ready Data now available
Landsat 9 data has been validated, calibrated, and adjusted for Australian conditions for easy analysis across the entire continent.