Sensor reflectance of Landsat imagery before bi-directional correction (left).
Sensor reflectance after correction to nadir view and 45 degree sun elevation (right).

Large area monitoring of vegetation cover depends on relationships between field observations of cover and the spectral radiance measured by satellite image imagery sensors. Variation in measured radiance caused by factors other than variation in vegetation cover on the ground, reduce the accuracy at which vegetation cover estimates can be made from the imagery. The factors include differences in the sensor's sensitivity to incoming radiation, atmospheric conditions, and sun and sensor positions. The purpose of this project is to develop an approach to minimise the variation in measured radiance caused by atmospheric, topographic and bi-directional reflectance effects. The output imagery will represent reflectance from a flat surface a standard set of sun and sensor angles. The approach will be used to standardise Landsat TM/ETM and SPOT5 HRG imagery. The imagery will be used as the basis for vegetation monitoring programs in Queensland and New South Wales.

Project Details

Location: Queensland and New South Wales


  • Queensland DES: Peter Scarth, Neil Flood. 
  • New South Wales OEH: Tim Danaher, Tony Gill, Arndt Meier. 
  • NZ Landcare: James Shepherd), John Dymond.  


Timeframe: Ongoing


  • Queensland Department of Environment and Science
  • New South Wales Office of Environment and Heritage