A method is introduced to derive integral properties of the aerosol
size distribution, like e.g. aerosol mass, from tropospheric multi-wavelength
Raman lidar aerosol extinction and backscatter data, using an adapted
form of the Principle Component Analysis (PCA) technique. Since the
refractive index of general tropospheric aerosols is variable and aerosol
types can vary within one profile, an inversion technique applied in the
troposphere should account for varying aerosol refractive index. Using
PCA, if a sufficiently complete set of appropriate refractive index
dependent kernels is used, no a priori information about the aerosol
type is necessary for the inversion of integral properties. In principle,
the refractive index itself can be retrieved, but this quantity is more
sensitive to measurement errors than the various integral properties
of the aerosol size distribution. Here, the PCA technique adapted for
use in the troposphere is introduced, the refractive index information
content of the kernel sets is investigated and error analyses are presented.
The technique is then applied to actual tropospheric Raman
lidar measurements.