Currently available remote sensing methods for forest degradation monitoring can be coarsely grouped into four categories:
(1) detection of direct degradation indicators (e.g. canopy cover percentage) on single date or composite image
(e.g. Souza et al., 2003); (2) detection of direct degradation indicators by time series analysis (e.g. Healey et al., 2005);
(3) mapping of secondary indicators (e.g. logging roads, log landings, villages) and assuming certain degradation buffers
around them (e.g. Potapov et al., 2008); and (4) direct estimation of forest parameters (e.g. stem volume and biomass),
nowadays most typically performed with radar or LiDAR systems in tropical forests (e.g. Jubanski et al., 2013). We describe
and analyse the current status of know-how in each of these four categories from the perspective of Southeast Asia. Note
that, the category 4 methods are not particularly designed for degradation monitoring. Therefore, we do not attempt to
comprehensively cover this category, but merely highlight some of the latest developments which may be of interest from
the perspective of forest degradation monitoring.