A fuzzy logic method for improved moment estimation from Doppler spectra

A new method for estimating moments from wind measurement devices that meas ure Doppler spectra as a function of range is presented. Quite often the sp ectra are contaminated by a wide variety of sources, including (but not lim ited to) birds, aircraft, velocity and range folding, radio frequency inter ference, and ground clutter. These contamination sources can vary in space, time, and even in their basic characteristics. Human experts analyzing Dop pler spectra can often identify the desired atmospheric signal among the co ntamination. However, it is quite difficult to build automated algorithms t hat can approach the skill of the human expert. The method described here r elies on mathematical analyses, fuzzy logic synthesis, and global image pro cessing algorithms to mimic the human expert. Fuzzy logic is a very simple, robust, and efficient technique that is well suited to this type of featur e extraction problem, These new moment estimation algorithms were originall y designed for boundary layer wind profilers; however, they are quite gener al and have wide applicability to any device that measures Doppler spectra as a function of range (e.g., lidars, sodars, and weather radars).