STAP compensation technique based on homomorphic filtering in GPS

2010 ◽  
Author(s):  
Renbiao Wu ◽  
Rulan Xu ◽  
Dan Lu ◽  
Jianpin Yu
Keyword(s):  
Homomorphic Filtering ◽  
Compensation Technique

Influence of the Aperture Edge Diffraction Effects on the Mutual Coupling Compensation Technique in Small Planar Antenna Arrays

2011 ◽  
Vol 57 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Mariusz Zamłyński ◽  
Piotr Słobodzian
Keyword(s):  
Antenna Arrays ◽  
Mutual Coupling ◽  
Planar Antenna ◽  
Sidelobe Level ◽  
Edge Diffraction ◽  
Narrow Angle ◽  
Compensation Technique ◽  
Diffraction Effects ◽  
Linear Antenna Arrays

Influence of the Aperture Edge Diffraction Effects on the Mutual Coupling Compensation Technique in Small Planar Antenna Arrays In this paper the quality of a technique to compensate for mutual coupling (and other phenomena) in small linear antenna arrays is investigated. The technique consists in calculation of a coupling matrix, which is than used to determine corrected antenna array excitation coefficients. Although the technique is known for more than 20 years, there is still very little information about how different phenomena existing in a real antenna arrays influence its performance. In this paper two models of antenna arrays are used. In the first model the effect of mutual coupling is separated from the aperture edge diffraction. In the second model antenna both mutual coupling and aperture edge diffraction effects are included. It is shown that mutual coupling itself can be compensated very well and an ultralow sidelobe level (i.e. -50 dB) could be achieved in practice. In the presence of diffraction effects -46.3 dB sidelobe level has been attained, but radiation pattern can be controled only in narrow angle range (i.e. up to ±60°).

PERBANDINGAN METODE HOMOMORPHIC FILTERING DAN METODE CONTRAST STRECHING UNTUK PERBAIKAN KUALITAS CITRA UNDERWATER

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Adi Mora Lubis ◽  
Nelly Astuti Hasibuan ◽  
Imam Saputra
Keyword(s):  
Digital Image ◽  
Water Environment ◽  
Repair Process ◽  
Image Process ◽  
Two Dimensional ◽  
Two Dimensional Image ◽  
Underwater Image ◽  
Homomorphic Filtering ◽  
Contrast Stretching

Digital imagery is a two-dimensional image process through a digital computer that is used to manipulate and modify images in various ways. Photos are examples of two-dimensional images that can be processed easily. Each photo in the form of a digital image can be processed through a specific software. In the water environment, the light factor greatly influences the results of the quality of the image obtained. With the deepening of underwater shooting, the results obtained will be the darker the quality of the underwater image. . uneven lighting and bluish tones. One of the factors that influence the recognition results in pattern recognition is the quality of the image that is inputted. The image acquired from the source does not always have good quality. The process of repairing digital images that experience interference in lighting. The lighting repair process uses homomorphic filtering and uses contrast striching and will compare the quality of both methods and test to prove the results of image quality between homomorphic filtering and contrast streching. Until later the results of both methods can be seen which is better. homomorphic filtering and contrast stretching can produce image improvements with pretty good performance.Keywords: Digital Image, Underwater Image, Homomorphic Filtering, Contrast Streching, Matlab R2010a

An instrument for the measurement of colour and turbidity in natural waters

1998 ◽  
Vol 37 (12) ◽  
pp. 263-267 ◽  
Author(s):  
Henry O. Edwards
Keyword(s):  
Water Treatment ◽  
Natural Waters ◽  
Beam Intensity ◽  
Compensation Technique

The development of a sensor to measure colour and turbidity of natural waters is described. Filtration of the water is not required, so maintenance intervals and costs will be reduced. A four-beam intensity compensation technique is used for robust measurement and resistance to fouling. Results of the operation of a prototype at a water treatment works are presented.

Recent Progress on Nonlinear Compensation Technique in Digital Coherent Receiver

2010 ◽  
Author(s):  
Takeshi Hoshida ◽  
Takahito Tanimura ◽  
Shoichiro Oda ◽  
Toshiki Tanaka ◽  
Hisao Nakashima ◽  
...  
Keyword(s):  
Recent Progress ◽  
Compensation Technique ◽  
Nonlinear Compensation ◽  
Coherent Receiver

Sonar image preprocessing method based on homomorphic filtering

2012 Oceans ◽  
2012 ◽  
Author(s):  
I. Mandhouj ◽  
F. Maussang ◽  
B. Solaiman ◽  
H. Amiri
Keyword(s):  
Image Preprocessing ◽  
Sonar Image ◽  
Preprocessing Method ◽  
Homomorphic Filtering
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