Glossary

The angle between a ray reflected from a surface and the line perpendicular to the surface at the point of emergence.

A product that was not generated by Geoscience Australia. These products have fewer information field requirements.

A measurement that splits the landscape into three parts, or fractions; green vegetation (leaves, grass, and growing crops), brown vegetation (branches, dry grass or hay, and dead leaf litter), and bare ground (soil or rock). Fractional Cover (FC) provides a representation of the proportions of living vegetation, dry and dying vegetation (including deciduous trees during autumn, dying grass, etc.), and bare soils across the Australian continent for any point in time in the Landsat archive since 1987.

A general term used to denote an increase in signal power in transmission from one point to another, usually expressed in decibels. It can also be used to represent the multiplier used to transform satellite image digital numbers to measures of at-sensor radiance.

An Australian Government agency that carries out geoscientific research. It is the government’s technical advisor on all aspects of geoscience and is the custodian of geographic and geological data.  

For more information, see Geoscience Australia. 

A distributed geospatial data server, which allows you to interact with datasets using standard community protocols. GSKY (pronounced ji-skee) accesses and analyses the geospatial data on NCI’s cloud and high-performance computing systems, and delivers it to a user device or website. Behind the scenes, GSKY manipulates the datasets so they seamlessly work together.

To use GSKY, choose from the list of datasets, specify a region and timeframe, and GSKY will analyse the information as harmonised data.  

For more information, see GSKY Introduction, NCI: Data Services.

The angle between a ray incident on a surface and the line perpendicular to the surface at the point of incidence. 

Landsat Collection 1 includes more than 9 million satellite images, representing the best available version of the longest continuously-collected record of Earth surface conditions in existence.

Landsat Collection 2: an upgrade that makes Landsat data easier to use alongside other satellite data sources, namely Europe’s Sentinel-2 satellites.

NOTE: These Landsat Collections are different to the Geoscience Australia Landsat Collections mentioned in the CMI.

The data that comes from the Landsat satellites is subject to a number of limitations. 

The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the USGS. 

In cooperation with NASA, the Earth Resources Technology Satellite (later renamed Landsat 1, LS1) was launched in 1972. Additional Landsat satellites were launched in the 1970s and 1980s, followed by Landsat 7 (LS7) in 1999. Landsat 8 (LS8) was  launched on 11 February, 2013. Landsat 9 (LS9) was successfully launched 27th September 2021.  

The instruments aboard the Landsat satellites have acquired millions of images through the course of the missions, and the data is a valuable resource for global change research and applications in agriculture, forestry, geology, regional planning, and education. 

For more information, see Landsat Science.