The Injune landscape collaborative project: an update on research activities

Abstract

The Injune Landscape Collaborative Project (ILCP) was initiated in 1998 to evaluate the potential of airborne SAR, either singularly or in combination with optical data, for retrieving vegetation biomass and structure. With funding from the Australian Research Council (ARC) and government partners, and as part of the 2000 NASA Jet Propulsion Laboratory (JPL) PACRIM II Mission, AIRSAR C, L and P-band data were acquired over a 40 x 60 km subtropical savanna area near Injune in central southeast Queensland. Over the same period, discrete return LiDAR, hyperspectral Compact Airborne Spectrographic Imagery (CASI) and 1:4000 aerial photography were acquired over 150 500 x 150 msampling units located within the imaged area. These data have been used subsequently to advance the development of algorithms for tree crown delineation, species differentiation and biomass estimation from finer (< 1 m) spatial resolution data, radar simulation modelling and empirical methods for retrieving structural attributes and biomass, and mapping of regrowth and forest structural types using combinations of SAR and Landsat sensor data. In 2009, a second airborne campaign was undertaken to establish whether changes in the species composition, structure and biomass of forests occurring as a consequence of both natural and anthropogenic (including climate) change could be detected and quantified. Airborne datasets acquired included Riegl LMS-Q560 full waveform LiDAR, EAGLE hyperspectral and digital aerial photography. Terrestrial laser scanner and field data were obtained to provide ground truth. The ILCP has also been the focus of multiple acquisitions of Advanced Land Observing Satellite (ALOS) Phased Arrayed L-band SAR (PALSAR) and a NASA-funded project aimed at establishing the potential of the proposed DESDynI mission for retrieving biophysical attributes. As a consequence of these activities, the ILCP is now associated with one of the most comprehensive time-series of airborne and spaceborne datasets available within Australia and indeed internationally. As such, the Injune area is a potential candidate for a long-term environmental research (LTER) site and the data, algorithms and outputs generated can play a key role in addressing a wide range of scientific questions relating to future sensors, carbon cycle science, land use/cover change and conservation of biological diversity.