Signal‐processing gain by digital beamforming in Doppler sonar

1974 ◽  
Vol 56 (S1) ◽  
pp. S7-S7 ◽  
Author(s):  
H. S. C. Wang
Keyword(s):  
Signal Processing ◽  
Digital Beamforming ◽  
Processing Gain ◽  
Doppler Sonar

scholarly journals Signal Processing for Digital Beamforming FMCW SAR

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Qin Xin ◽  
Zhihong Jiang ◽  
Pu Cheng ◽  
Mi He
Keyword(s):  
Signal Processing ◽  
Continuous Wave ◽  
Single Channel ◽  
Pulse Repetition Frequency ◽  
Sampling Frequency ◽  
Synthetic Aperture ◽  
Signal Model ◽  
Digital Beamforming ◽  
Processing Gain ◽  
Detailed Imaging

According to the limitations of single channel Frequency Modulation Continuous Wave (FMCW) Synthetic Aperture Radar (SAR), Digital Beamforming (DBF) technology is introduced to improve system performance. Combined with multiple receive apertures, DBF FMCW SAR can obtain high resolution in low pulse repetition frequency, which can increase the processing gain and decrease the sampling frequency. The received signal model of DBF FMCW SAR is derived. The continuous antenna motion which is the main characteristic of FMCW SAR received signal is taken into account in the whole signal processing. The detailed imaging diagram of DBF FMCW SAR is given. A reference system is also demonstrated in the paper by comparing with a single channel FMCW SAR. The validity of the presented diagram is demonstrated with a point target simulation results.

Comparison of Meteorological Radar Signal Detectability with Noncoherent and Spectral-Based Processing

2016 ◽  
Vol 33 (4) ◽  
pp. 723-739 ◽  
Author(s):  
James B. Mead
Keyword(s):  
Signal Processing ◽  
False Alarm ◽  
False Alarm Rate ◽  
Time Domain ◽  
Spectral Width ◽  
Probability Of Detection ◽  
Spectral Domain ◽  
Processing Gain ◽  
Meteorological Radar ◽  
The Time Domain

AbstractDetection of meteorological radar signals is often carried out using power averaging with noise subtraction either in the time domain or the spectral domain. This paper considers the relative signal processing gain of these two methods, showing a clear advantage for spectral-domain processing when normalized spectral width is less than ~0.1. A simple expression for the optimal discrete Fourier transform (DFT) length to maximize signal processing gain is presented that depends only on the normalized spectral width and the time-domain weighting function. The relative signal processing gain between noncoherent power averaging and spectral processing is found to depend on a variety of parameters, including the radar wavelength, spectral width, available observation time, and the false alarm rate. Expressions presented for the probability of detection for noncoherent and spectral-based processing also depend on these same parameters. Results of this analysis show that DFT-based processing can provide a substantial advantage in signal processing gain and probability of detection, especially when the normalized spectral width is small and when a large number of samples are available. Noncoherent power estimation can provide superior probability of detection when the normalized spectral width is greater than ~0.1, especially when the desired false alarm rate exceeds 10%.

scholarly journals The high frequency surface wave radar solution for vessel tracking beyond the horizon

2020 ◽  
Vol 33 (1) ◽  
pp. 37-59
Author(s):  
Dejan Nikolic ◽  
Nikola Stojkovic ◽  
Pavle Petrovic ◽  
Nikola Tosic ◽  
Nikola Lekic ◽  
...  
Keyword(s):  
Signal Processing ◽  
Surface Wave ◽  
High Frequency ◽  
Constant False Alarm Rate ◽  
Process Data ◽  
Digital Beamforming ◽  
Moving Platforms ◽  
Microwave Radar ◽  
Wave Radar ◽  
Processing Techniques

With maximum range of about 200 nautical miles (approx. 370 km) High Frequency Surface Wave Radars (HFSWR) provide unique capability for vessel detection far beyond the horizon without utilization of any moving platforms. Such uniqueness requires design principles unlike those usually used in microwave radar. In this paper the key concepts of HFSWR based on Frequency Modulated Continuous (FMCW) principles are presented. The paper further describes operating principles with focus on signal processing techniques used to extract desired data. The signal processing describes range and Doppler processing but focus is given to the Digital Beamforming (DBF) and Constant False Alarm Rate (CFAR) models. In order to better present the design process, data obtained from the HFSWR sites operating in the Gulf of Guinea are used.

scholarly journals Optimization of searching for moving targets of a multifunctional radar station

2021 ◽  
pp. 85-88
Author(s):  
С.М. Піскунов ◽  
Д.С. Роменський ◽  
В.Ю. Бабич
Keyword(s):  
Signal Processing ◽  
Antenna Array ◽  
Antenna Arrays ◽  
Adaptive Signal Processing ◽  
Search Process ◽  
Moving Targets ◽  
Digital Beamforming ◽  
Stochastic Uncertainty ◽  
Radar Station ◽  
Adaptive Signal

A method for optimizing the process of searching for an unknown number of moving targets in conditions of stochastic uncertainty is proposed, which allows to significantly reduce the average time of their finding by a multifunctional radar device equipped with an antenna array. More effective is the optimal managed search, in which the order of viewing different directions is determined in the search process depending on the results of already performed views. One of the important areas of further improvement of radar technology is the transition to antenna arrays with digital beamforming based on adaptive signal processing directly in the elements of the digital antenna array (DAA).

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