Creating multi-sensor time series using data from Landsat-5 TM and Landsat-7 ETM+ to characterise vegetation dynamics

The Landsat series of satellites provide the longest contiguous earth observation record of the Earth´s surface. This provides the unique capacity to track changes in vegetation over multiple decades. This paper illustrates how standardized Landsat data can be combined to create a time series of sensor independent observations. The impact of side-lap and cloud frequency on observation frequency are also examined with reference to two adjacent path/rows of data in southern Australia. The generation of Landsat scale time series provides the opportunity to track both subtle and dramatic changes in vegetation cover in much higher levels of detail than previously possible. However the approach presents new challenges associated with developing time series analysis techniques to characterize time series that have uncertain observation frequencies.