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Abstract
Vaisala has recently released new versions of the wind profiler LAP-XM® signal processing software. New features include an experimental boundary layer top determination module; a wind and temperature quality control module that has been modified to detect inhomogeneity between the radar beams; and a new module for archiving and distributing wind and virtual temperature data in XML format. Another new feature allows the integration of surface wind and temperature data from the Vaisala Weather Transmitter WXT520 with Vaisala Wind Profiler data.
A new melting layer software automatically determines the peak radar reflectivity level within the melting layer. The module is useful in estimating rainfall, freezing level and river runoff. A graphical display software includes the ability to display the data output from the boundary layer algorithm and melting layer module on top of normal reflectivity data.
Another new algorithm is the Gabor filtering module, which implements an advanced method for the suppression of intermittent clutter in wind profiler time-series data. The method is intended especially for profilers that experience significant problems during the seasonal bird migration. The module analyzes time series data using the discrete Gabor frame expansion, which forms a time-frequency presentation of the signal. The intermittent clutter signals can be separated and removed from the Gabor frame expansion using a statistical filtering technique. The algorithm has been developed and published by V. Lehmann and G. Teschke (2008): “Advanced Intermittent Clutter Filtering for Radar Wind Profiler: Signal Separation Through a Gabor Frame Expansion and its Statistics”, Annales Geophysicae, 26, pp. 759-783.