Lidar data format (Level 1)

The lidar data provided at level 1 would consist of parameters such as range-corrected attenuated backscatter coefficient at the various wavelengths, and depolarisation ratio. Attenuated backscatter coefficient should be calibrated if possible, and in the units (m sr)-1. Molecular and multiple scattering effects should not be removed, but there is a case for subtracting the instrument noise if it can be distinguished from the molecular signal. As with the radar, instrumental artifacts should be removed if possible, including correction for the overlap function of the laser and telescope.

As with radar, sensitivity can be improved by averaging, so averaging the data to somewhere between 5 and 30 second resolution would seem appropriate. It may be desirable to provide a beta_raw parameter, containing the data without instrument noise and artifacts removed, and without the correction for the overlap function.