Abstract
The recent free availability of Landsat historical data provides new potentials for land-cover change studies. Multi-temporal studies require a previous radiometric and geometric homogenization of input images, to better identify true changes. Topographic normalization is one of the key steps to create consistent and radiometricly stable multi-temporal time series, since terrain shadows change throughout time. This paper aims to evaluate different methods for topographic correction of Landsat TM-ETM+ data. They were assessed for 15 ETM+ images taken under different illumination conditions, using two criteria: (a) reduction of the standard deviation (SD) for different land-covers and (b) increase in temporal stability of a time series for individual pixels. We observed that results improve when land-cover classes where processed independently when applying the more advanced correction algorithms such as the C-correction and the Minnaert correction. Best results were obtaining for the C-correction and the empiric-statistic correction. Decreases of the SD for bare soil pixels were larger than 100% for the C-correction and the empiric-statistic correction method compared to the other correction methods in the visible spectrum and larger than 50% in the IR region. In almost all tests the empiric-statistic method provided better results than the C-correction. When analyzing the multi-temporal stability, pixels under bad illumination conditions (northern orientation) improved after correction, while a deterioration was observed for pixels under good illumination conditions (southern orientation). Taken this observation into account, a simple but robust method for topographic correction of Landsat imagery is proposed.
Original language | English (US) |
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Pages (from-to) | 691-700 |
Number of pages | 10 |
Journal | International Journal of Applied Earth Observation and Geoinformation |
Volume | 13 |
Issue number | 5 |
DOIs | |
State | Published - 2011 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Global and Planetary Change
- Earth-Surface Processes
- Computers in Earth Sciences
- Management, Monitoring, Policy and Law