A comparison of visualization techniques for models created from airborne laser scanned data

摘要

The uptake of airborne laser scanned (ALS) data (commonly known as airborne lidar) for heritage landscape assessment has grown rapidly in the past decade as data have become increasingly available. Likewise there has been a recent upsurge in published techniques for modelling the ground surface from ALS data to highlight archaeological features. However, many end-users of the data are not trained in remote sensing and visualization techniques and the lack of comparative assessment of techniques has increased the complexity of interpretation of the ALS-derived models. This study quantitatively compares five visualization techniques ranging from the commonly used shaded relief model to newer local relief and sky view factor modelling for a study area in the UK. Outputs are compared with the baseline data of the English Heritage National Mapping Programme aerial photographic archive transcription and assessed with respect to percentage visibility of feature length. Ancillary aspects of the outputs are discussed, such as geospatial shift of features, suitability for profile mapping, ease of interpretation and ability to combine with other data sources. It is concluded that although the overall performance of the models in terms of feature recognition is relatively even, consideration of all factors enables more transparent modelling choices to be made and facilitates critical interpretation of the features recorded.