Contribution of nDSM derived from VHR stereo imagery to urban land-cover mapping in Sub-Saharan Africa

摘要

Mapping the urban land cover from VHR optical imagery remains a challenging task, more particularly in cities that present complex landscapes and patterns. In this study, we assessed the contribution of height data derived from WorldView-3 stereo imagery for mapping the land cover of Sub-Saharan African cities. Our case study is located in Ouagadougou, Burkina Faso. An OBIA approach was implemented using an open-source semi-automated processing chain. The use of the nDSM as input to the segmentation and/or to the classification in addition to the four VNIR WorldView-3 optical bands was evaluated. The quantitative and qualitative analysis of the results indicate an improvement for a number of classes, among which the class ‘Buildings’ that is of particular interest in many applications. Visually, this improvement is more noticeable in planned settlements and industrial areas than in unplanned settlements.