摘要:

The paper describes a new technique for adaptive antenna beamforming. By analysing the adaptive antenna as a least-squares problem, it is possible to organise the control processor around a recursive minimisation procedure operating in the data domain. This avoids the explicit computation of the covariance matrix estimate as required by the method known as sample matrix inversion (SMI). The paper further shows how the least-squares processing algorithm may be implemented in an efficient pipeline architecture using a triangular systolic array. Computer simulation results are presented which show the performance of this new technique compared with sample matrix inversion.

DOI:10.1049/ip-f-1.1984.0098

出版商:IEE    

年代:1984

数据来源: IET

摘要:

Maximum entropy has proved to be an enormously powerful tool for reconstructing images from many types of data. It has a privileged position as the only consistent method for combining different data into a single image. It has been used most spectacularly in radio astronomical interferometry, where it deals routinely with images of up to a million pixels, and high dynamic range. We also give examples of optical deconvolutions and tomographic reconstructions to illustrate the generality of application and the quality of maximum entropy images. Some types of data, a such as Fourier intensitites, are inadepquate in themselves to produce a good image. The maximum entropy method allows us to incorporate extra, Prior knowledge about the object being imaged, and we give examples of this technique being used in specectroscopy. The nonlinearities inherent in the a state-of-the-art example of ‘blind’ deconvolution in which an unknown object is blurred with an unknown point-spread-function: maximum entropy can recover both.

DOI:10.1049/ip-f-1.1984.0099

出版商:IEE    

年代:1984

数据来源: IET

摘要:

A powerful technique for the solution of a number of experimental in verse problems, described by an underlying first-kind Fredholm equation is presented. Such problems include, for example, diffraction-limited imaging and the analysis of laser light scattering data. The technique requires the construction of the ‘singular system’ of the propblem which then provides exact orthonormal bases both for the description of sampled and truncated measured data and for the reconstructed continuous object ‘solution’ of the inversion. The singular-system approach may ber regarded as a theory of information which generalises in several directions the well known classical concepts of Shannon and Nyquist.

DOI:10.1049/ip-f-1.1984.0100

出版商:IEE    

年代:1984

数据来源: IET

DOI:10.1049/ip-f-1.1984.0101

出版商:IEE    

年代:1984

数据来源: IET