Sorted Pulse Data (SPD) Format: a new file structure for storing and processing LiDAR data.

This paper presents a new generic method and format for storing and processing airborne and terrestrial LiDAR pulse data within a HDF5 file. The format is specifically designed to support both traditional discrete return and full waveform data, uses a pulse (rather than point) based data model and has been developed and applied successfully using a wide range of disparate airborne and terrestrial LiDAR datasets. The format is proposed as an alternative to existing solutions as it includes support for full waveform data, explicit pulse based data structures and flexible spatial indexing using cartesian, spherical and polar coordinate systems and projections. The HDF5 format supports compression but in part due to the more complex data structures used the amount of compression that can be achieved is limited. However, it compares favourably with the file size of uncompressed LAS files and is able to accommodate a much wider range of LiDAR datasets.