Multiscale Approach for Ground Filtering from Lidar Altimetry Measurements

This chapter presents a filtering method based on a multiscale signal decomposition termed the multiscale Hermite transform (MHT), which has been formulated in the context of the scale-space theory for signal processing. The chapter discusses the theoretical basis of this method and the practical aspects of its operation. It presents an extension of the original method by revising the erosion operation and testing its performance with the International Society for Photogrammetry and Remote Sensing (ISPRS) data sets. The chapter discusses the scale-space representation as the theoretical foundation of the MHT. Next, the ground filtering method is presented. The chapter shows how the multiscale erosion operation, which is the main mechanism to estimate the MHT coefficients of the bare terrain from the MHT expansion of the digital surface model (DSM), can be generalized to higher order coefficients through a scale-space shifting operation.