Computational Model of Radar Signal Spectrum Reflected from Rain

The article provides an assessment of the impact the dynamic structures of power systems of aircraft systems have on the spectrum of the reflected radar signal. In the conditions of autonomous actions of the fighter, the tasks of long-range detection of airborne targets are assigned directly to the onboard radar station. It is necessary to resolve the contradictions associated with increasing the detection range without changing the energy indicators of the onboard radar station. This is possible by optimizing the processing of many spectral components of the signal reflected from the propeller and turboprop engine of airborne targets. The location of propeller reflections in the spectrum of the reflected signal is determined by the technical parameters of the power plant and its mode of operation. The percent of the total energy of the reflected signal spectrum outside the main spectral component is comparable with the energy reflected from the airframe of the aviation complex, most of which is the energy reflected from the rotating elements of power plants. Therefore, the development of an algorithm for detecting a signal with a complex spectral structure that maximizes the probability of detection under time and computational resources restrictions is a very relevant scientific task. The scientific novelty lies in the development of an algorithm for detecting a signal with a complex spectral structure and its detection characteristics taking the effect of secondary modulation into account as well as in the development of practical recommendations for optimizing algorithms for detecting airborne targets. Using the developed algorithm in the fighter’s pulse-Doppler radar station will increase the detection range of an air target against the background of interfering reflections from the water surface.

Download Full-text

Methods and Algorithms for Technical Vision in Radar Introscopy

Optoelectronics in Machine Vision-Based Theories and Applications - Advances in Computational Intelligence and Robotics ◽

10.4018/978-1-5225-5751-7.ch013 ◽

2019 ◽

pp. 373-391

Author(s):

Oleg Sytnik ◽

Vladimir Kartashov

Keyword(s):

Signal Processing ◽

Processing Technique ◽

Ultra Wideband ◽

Radar Signal ◽

Signal Spectrum ◽

Signal Processing Technique ◽

Distinctive Features ◽

Technical Vision ◽

Probing Signal ◽

Radio Vision

Optimization of technical characteristics of radio vision systems is considered in the radars with ultra-wideband sounding signals. Highly noisy conditions, in which such systems operate, determine the requirements that should be met by the signals being studied. The presence of the multiplicative noise makes it difficult to design optimal algorithms of echo-signal processing. Consideration is being given to the problem of discriminating objects hidden under upper layers of the ground at depths comparable to the probing pulse duration. Based upon the cepstrum and textural analysis, a subsurface radar signal processing technique has been suggested. It is shown that, however the shape of the probing signal spectrum might be, the responses from point targets in the cepstrum images of subsurface ground layers make up the texture whose distinctive features enable objects to be detected and identified.

Download Full-text

Research on Signal "Batch-Increasing" Phenomenon of Superheterodyne Reconnaissance Receiver

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.347-350.1743 ◽

2013 ◽

Vol 347-350 ◽

pp. 1743-1747

Author(s):

Yan Zhong Hao ◽

Hong Liang Zhang ◽

Fu Chun Zhang ◽

Wang Hui ◽

Zheng Dong Xu ◽

...

Keyword(s):

Signal Processing ◽

Frequency Domain ◽

Pulse Width ◽

Radar Signal ◽

Signal Spectrum

For the superheterodyne reconnaissance receiver detected "signalBatch-increasing" phenomenon, research on radar signal sand the intercepted characteristics of reconnaissance receiver from the frequency domain, pointed out that "Pulse-width split" and "Pulse-width truncated" caused by Emitter signal spectrum loss is the reason of "Batch-increasing",On this basis, analyzed the strategies of "Batch-increasing" signal processing .

Download Full-text

An Adaptive Moments Estimation Technique Applied to MST Radar Echoes

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech1696.1 ◽

2005 ◽

Vol 22 (4) ◽

pp. 396-408 ◽

Cited By ~ 25

Author(s):

V. K. Anandan ◽

P. Balamuralidhar ◽

P. B. Rao ◽

A. R. Jain ◽

C. J. Pan

Keyword(s):

Conventional Method ◽

Signal To Noise Ratio ◽

Radar Data ◽

Adaptive Method ◽

Radar Signal ◽

Signal Spectrum ◽

Estimation Technique ◽

Low Snr ◽

Wind Speeds ◽

Mst Radar

Abstract An adaptive spectral moments estimation technique has been developed for analyzing the Doppler spectra of the mesosphere–stratosphere–troposphere (MST) radar signals. The technique, implemented with the MST radar at Gadanki (13.5°N, 79°E), is based on certain criteria, set up for the Doppler window, signal-to-noise ratio (SNR), and wind shear parameters, which are used to adaptively track the signal in the range–Doppler spectral frame. Two cases of radar data, one for low and the other for high SNR conditions, have been analyzed and the results are compared with those from the conventional method based on the strongest peak detection in each range gate. The results clearly demonstrate that by using the adaptive method the height coverage can be considerably enhanced compared to the conventional method. For the low SNR case, the height coverage for the adaptive and conventional methods is about 22 and 11 km, respectively; the corresponding heights for the high SNR case are 24 and 13 km. To validate the results obtained through the adaptive method, the velocity profile is compared with global positioning system balloon sounding (GPS sonde) observations. The results of the adaptive method show excellent agreement with the GPS sonde measured wind speeds and directions throughout the height profile. To check the robustness and reliability of the adaptive algorithm, data taken over a diurnal cycle at 1-h intervals were analyzed. The results demonstrate the reliability of the algorithm in extracting wind profiles that are self-consistent in time. The adaptive method is thus found to be of considerable advantage over the conventional method in extracting information from the MST radar signal spectrum, particularly under low SNR conditions that are free from interference and ground clutter.

Download Full-text

Joint influence of rain rate and turbulence on radar signal spectrum width

2007 European Radar Conference ◽

10.1109/eurad.2007.4405029 ◽

2007 ◽

Author(s):

Yahya S. H. Khraisat ◽

Felix J. Yanovsky

Keyword(s):

Rain Rate ◽

Radar Signal ◽

Signal Spectrum ◽

Joint Influence ◽

Spectrum Width

Download Full-text

Fractional-N PLL Synthesizer for FMCW Signal Generator with Dual-Mode Modulation Pattern

Jurnal Elektronika dan Telekomunikasi ◽

10.14203/jet.v18.46-52 ◽

2018 ◽

Vol 18 (2) ◽

pp. 46

Author(s):

R. Indrawijaya ◽

R. Sariningrum ◽

B. Edi Sukoco ◽

D. Muliawandana

Keyword(s):

Continuous Wave ◽

Signal Generator ◽

Experimental Result ◽

Radar Signal ◽

Signal Spectrum ◽

Single Chip ◽

Dual Mode ◽

Modulation Pattern ◽

Realization Process ◽

Pll Synthesizer

Radar signal generator is a critical component in radar system as it determines the best achievable resolution. Single chip Fractional-N PLL synthesizer with built-in VCO and sweep modulator become more popular as Frequency Modulated Continuous Wave (FMCW) signal generator due to the simplicity and overall cost reduction. This paper presents a realization process and experimental result of dual-mode modulation pattern FMCW signal generator using HMC769LP6CE PLL. The PLL is controlled by ATMega328 microcontroller and Altera EPM240T100C5 CPLD to operate in two difference mode: 1-way sweep mode and 2-way sweep mode. The PLL is programmed with four different sweep bandwidth from 6.75–54 MHz for different range and resolution radar purpose. The performance of FMCW signal generator is measured using the output of passband signal spectrum. The experimental results indicate that the PLL-VCO with 2-way sweep mode has clearer frequency passband compared to 1-way sweep mode.

Download Full-text