Wind retrieval from multiangle backscatter lidar profiles through anisotropic aerosol structures

Abstract

A wind retrieval correlation method for backscatter lidar scanning schemes consisting of a few profiling sounding lines of sight is mathematically formulated in matrix solution form under general anisotropic atmospheric conditions and convective boundary layer scenarios. The method assumes the frozen atmosphere model and works with temporal cross-correlation functions that do not need to be maximized. The method also applies to the well-known case of slant scans based on the multiple-angle azimuth technique (horizontal wind retrievals). A first application of the method to a 1064 nm wavelength case example is presented for a 40°e levation, two-angle azimuth scan, where horizontal wind speed and wind direction are retrieved.

Set of Algorithms and Techniques for Accurate 3D, Single Beam – Single Pointing, Lidar Measurements for Slant Range Visibility, Planetary Boundary Layer Height and Wind Speed Retrieval, Atmospheric Layers Spatial Distribution and Categorization in Real Time

“…The vertical, near vertical or even slant measurements that can achieve molecular values of β aer (λ,R) (and/or α aer (λ,R)), at a molecular height above the PBLH and at any wavelength, taken from [1,2,3,7], ([8] p. 57, 58), which are recorded using the backscattering signal, are able to provide a clear view of the aerosol load located along the Line Of Sight (LOS) of the lidar beam. This aerosol load recorded as elastic backscattering signal (Eqs 1-6 already mentioned and Eqs 7-9 below), was used by these algorithms in order to have successive outcomes of processing.…”

“…For wind measurements, the most known method is based on the Doppler effect which has been used for the retrieval of the PBLH through wind measurements [10]. A different technique, but the most correlated to the one proposed here, based on single beam-single pointing measurements, is the one mentioned in [7]; it uses the wind retrieval correlation method for backscatter lidar scanning schemes consisting of a few profiles along the LOS, which is mathematically formulated in a matrix solution form under different atmospheric conditions. This method assumes the frozen atmosphere model [7] and works with temporal cross-correlation functions that do not need to be maximized.…”

“…A different technique, but the most correlated to the one proposed here, based on single beam-single pointing measurements, is the one mentioned in [7]; it uses the wind retrieval correlation method for backscatter lidar scanning schemes consisting of a few profiles along the LOS, which is mathematically formulated in a matrix solution form under different atmospheric conditions. This method assumes the frozen atmosphere model [7] and works with temporal cross-correlation functions that do not need to be maximized. It also applies for the case of slant scans based on the multiple-angle azimuth technique (horizontal wind retrievals) [7].…”

“…This method assumes the frozen atmosphere model [7] and works with temporal cross-correlation functions that do not need to be maximized. It also applies for the case of slant scans based on the multiple-angle azimuth technique (horizontal wind retrievals) [7]. The main differences with our proposed wind algorithms and technique, is that even if we simultaneously use single beam measurements at each time, we can produce wind speed in 2 dimensions (2D), by staying in one single slant pointing angle and calculate 3D wind speed profiles by using a method similar to the 2-angle azimuth scan [7].…”