American Meteorological Society;Boston: American Meteorological Society
摘要:
摘要： AbstractMultifrequency range imaging (RIM) used with the atmospheric radars at ultra- and very high-frequency (VHF) bands is capable of retrieving the power distribution of the backscattered radar echoes in the range direction, with some inversion algorithms such as the Capon method. The retrieved power distribution, however, is weighted by the range-weighting function (RWF). Modification of the retrieved power distribution with a theoretical RWF may cause overcorrection around the edge of the sampling gate. In view of this, an effective RWF that is in a Gaussian form and varies with the signal-to-noise ratio (SNR) of radar echoes has been proposed to mitigate the range-weighting effect and thereby enhance the continuity of the power distribution at gate boundaries. Based on the previously proposed concept, an improved approach utilizing the range-oversampled signals is addressed in this article to inspect the range-weighting effects at different range locations. The shape of the Gaussian RWF for describing the range-weighting effect was found to vary with the off-center range location in addition to the SNR of radar echoes—that is, the effective RWF for the RIM was SNR and range dependent. The use of SNR- and range-dependent RWF can be of help to improve the range imaging to some degree at the range location outside the range extent of a sampling gate defined by the pulse length. To verify the proposed approach, several radar experiments were carried out with the Chung-Li (24.9°N, 121.1°E) and middle and upper atmosphere (MU; 34.85°N, 136.11°E) VHF radars. 出版者： Boston: American Meteorological Society 出版日期： 2014-01-01 出處： Journal of Atmospheric and Oceanic Technology, 2014-01, Vol.31 (1), p.47-61 資源來源： EBSCOhost OmniFile Full Text Select 版權： Copyright American Meteorological Society Jan 2014 版權： Copyright American Meteorological Society 2014 識別號： ISSN: 0739-0572 識別號： EISSN: 1520-0426 識別號： DOI: 10.1175/jtech-d-12-00236.1
