摘要
针对机载气象雷达在存在幅相误差影响时,杂波抑制性能下降,低空风切变风速估计不准确的问题,提出了基于组合空时主通道自适应处理(combined space-time main channel adaptive processing,CMCAP)的低空风切变风速估计方法。该方法首先对待测距离单元的雷达回波数据利用构造的降维联合空时变换矩阵进行自适应降维处理,然后构造降维处理器的最优权矢量对降维处理后的数据进行自适应滤波,进而在存在幅相误差的情况下实现风场速度的准确估计。后续仿真结果证明了所提方法的有效性。
Due to the presence of amplitude and phase errors in airborne weather radar,the performance of clutter suppression is reduced,and the estimation of low-altitude wind-shear wind speed is not accurate.Considering these problems,this paper presents a low-altitude wind-shear speed estimation method based on combined space-time main channel adaptive processing(CMCAP).This method first reduces the dimension of the radar echo data of the measured range unit by constructing a dimension-reduced joint space-time transform matrix,and then constructs the optimal weight vector of the dimension-reducing processor to adaptively filter the reduced-dimensional data.Furthermore,accurate estimation of the speed of the wind field is achieved in the presence of amplitude-phase error.Simulation results prove the effectiveness of the proposed method.
引文
[1]DESHPANDE M D,STATON L.Determination of windspeed within a weather storm using airborne Doppler radar[C]∥Proc.of the IEEE Southeastcon,1991:508-519.
[2]WILSON J W,WAKIMOTO R M.The discovery of the downburst:T.T.Fujita’s Contribution[J].Bulletin of the American Meteorological Society,2001,82(1):49-62.
[3]RTCA/DO-220.Minimum operational performance standards for airborne weather radar with forward-looking windshear capability[S].Washington D.C:RTCA Inc,2016.
[4]秦娟,吴仁彪,苏志刚,等.基于DEM的机载气象雷达地杂波剔除方法[J].信号处理,2011,27(10):1484-1488.QIN J,WU R B,SU Z G,et al.Ground clutter censoring algorithm for airborne weather radar employing DEM[J].Signal Processing,2011,27(10):1484-1488.
[5]闫修林,阮增苗.杂波图技术在雷达终端信号处理中的应用[J].现代雷达,2004,26(5):34-36.YAN X L,RUAN Z M.Application of the clutter-map technology to signal processing in radar terminals[J].Modern Radar,2004,26(5):34-36.
[6]WOODELL D L.Method and system for suppressing ground clutter returns on an airborne weather radar[P].US:6603425,2003.
[7]SIGGIA A D,PASSARELLI R E J.Gaussian model adaptive processing(GMAP)for improved ground clutter cancellation and moment calculation[C]∥Proc.of the European Conference on Radar,2004:67-73.
[8]KLEMM R.Principles of space-time adaptive processing[M].2nd ed.Boston,London:Aretch House Press,2002.
[9]王永良,彭应宁.空时自适应处理[M].北京:清华大学出版社,2000:26-81.WANG Y L,PENG Y N.Space-time adaptive signal processing[M].Beijing:Tsinghua University Press,2000:26-81.
[10]GUERCI J R.Space-time adaptive processing for radar[M].Norwood,MA:Artech House Press,2003:3-55.
[11]WARD J.Space-time adaptive processing for airborne radar data systems[R].Lexington,Massachusetts:Lincoln Laboratory of MIT,1994:25-45.
[12]BRINGI V N,CHANDRASEKAR V.Polarimetric Doppler weather radar:principles and applications[M].UK,Cambridge University Press,2005:1-100.
[13]BOYER E,LARZABAL P,ADNET C.Parametric spectral moments estimation for wind profiling radar[J].IEEE Trans.on Geoscience and Remote Sensing,2003,41(8):1859-1868.
[14]姚晖.分布式信号源参数估计技术研究[D].郑州:解放军信息工程大学,2013.YAO H.Research on parameter estimation method for distributed sources[D].Zhengzhou:Information Engineering University of PLA,2013.
[15]刘青光,彭应宁.机载雷达自适应杂波抑制的联合通道变换方法[J].电子学报,1994(6):1-9.LIU Q G,PENG Y N.Adaptive clutter suppression in airborne radar by a combined channel transformation approach[J].Acta Electronica Sinica,1994(6):1-9.
[16]LAPIERRE F D,VERLY J G.Registration-based solutions to the range-dependence problem in stap radars[C]∥Proc.of the Adaptive Sensor Array Processing Workshop,2003:1-6.
[17]张彪.基于STAP的机载气象雷达低空风切变检测方法研究[D].天津:中国民航大学,2015:38-46.ZHANG B.Detection of low-altitude wind-shear with airborne weather radar based on STAP[D].Tianjin:Civil Aviation University of China,2015:38-46.