scholarly journals Requirements Justification to Digital Signal Synthesizers for Various Types of Radar Systems

2020 ◽  
pp. 818-828
Author(s):  
Dmitriy S. Viktorov ◽  
Ekaterina V. Plastinina ◽  
Elena V. Samovolina
Keyword(s):  
Digital Signal ◽  
Reference Frequency ◽  
Delay Compensation ◽  
Digital Readout ◽  
Uniform Sampling ◽  
Probability Of False Alarm ◽  
Radar Systems ◽  
Number Of Factors ◽  
Continuous Radiation ◽  
Time Delay Compensation

The paper justifies the requirements for the level of distortion of radar stations with pulse and quasi-continuous radiation, built on the basis of digital signal synthesizers of four types: digital synthesizers of voltage counts and digital synthesizers of phase counts with uniform sampling, digital synthesizers of voltage counts and digital synthesizers of phase counts with uneven sampling. When building a radar master device, the question arises about choosing the type of digital signal synthesizer. The main initial criteria are the maximum operating range of the digital synthesizer and the level of in-band distortion. When choosing the type of digital signal synthesizer, you have to take into account a large number of factors, the main of which are the complexity of the execution of the digital readout shaper, the possibility of implementing a digital readout shaper with the required speed and number of digits [1, 2]. When making requirements for the total level of distortion, the criterion of acceptable reduction of the probability of correct detection in comparison with its potential value for a fixed probability of false alarm is used. Based on this criterion, in pulse radars, the maximum relative RMS value of the distortion of the intercorrelation function of a signal with angular modulation generated by a digital synthesizer should not exceed Dδx ≤ –(51...67) dB. In a radar with quasi-continuous radiation, the maximum relative mean-square value of the distortion of the autocorrelation function of the signal with angular modulation should not exceed Dδ ≤ –(80...120) dB. The number of bits of phase quantization, voltage and time delay compensation in digital signal synthesizers depends not only on the maximum relative RMS value of the distortion of the intercorrelation function, but also on the number of samples of the signal with angular modulation. Therefore, initially you need to select the reference frequency of the digital signal synthesizer, setting the type of modulation and the effective spectrum width of the signal with angular modulation based on the tactical and technical characteristics radar

scholarly journals Justification of requirements for digital signal synthesizers for various types of radar

2020 ◽  
pp. 43-55
Author(s):  
Дмитрий Сергеевич Викторов ◽  
Екатерина Владимировна Пластинина ◽  
Елена Валерьевна Самоволина
Keyword(s):  
Digital Signal ◽  
Reference Frequency ◽  
Delay Compensation ◽  
Digital Readout ◽  
Uniform Sampling ◽  
Probability Of False Alarm ◽  
Number Of Factors ◽  
Continuous Radiation ◽  
Time Delay Compensation ◽  
Uneven Sampling

В работе обосновываются требования к уровню искажений радиолокационных станций с импульсным и квазинепрерывным излучением, построенных на основе цифровых синтезаторов сигналов четырех типов: цифровых синтезаторах отсчетов напряжения и цифровых синтезаторах отсчетов фазы с равномерной дискретизацией, цифровых синтезаторах отсчетов напряжения и цифровых синтезаторах отсчетов фазы с неравномерной дискретизацией. При построении задающего устройства РЛС возникает вопрос о выборе типа цифрового синтезатора сигналов. Основными исходными критериями при этом являются максимальный рабочий диапазон цифрового синтезатора и уровень внутриполосных искажений. При выборе типа цифрового синтезатора сигналов необходимо учитывать большое количество факторов, основными из которых являются сложность исполнения формирователя цифровых отсчетов, возможность реализации формирователя цифровых отсчетов с требуемым быстродействием и количеством разрядов [1, 2]. При предъявлении требований к суммарному уровню искажений используется критерий допустимого снижения вероятности правильного обнаружения по сравнению с её потенциальным значением при фиксированной вероятности ложной тревоги. Исходя из данного критерия в импульсных РЛС максимальное относительное среднеквадратическое значение искажений взаимокорреляционной функции сигнала с угловой модуляцией, формируемого цифровым синтезатором, не должно превышать $D_{\\delta x}\\le $-(51...67) дБ. В РЛС с квазинепрерывным излучением максимальное относительное среднеквадратическое значение искажений автокорреляционной функции сигнала с угловой модуляцией не должно превышать $D_{\\delta }\\le $-(80...120) дБ. Количество разрядов квантования фазы, напряжения и компенсации временной задержки в цифровых синтезаторах сигналов зависит не только от максимального относительного среднеквадратического значения искажений взаимокорреляционной функции но и от количества отсчетов сигнала с угловой модуляцией. Поэтому первоначально необходимо выбрать эталонную частоту цифрового синтезатора сигналов, задаваясь видом модуляции и эффективной шириной спектра сигнала с угловой модуляцией исходя из ТТХ РЛС. The paper substantiates the requirements for the level of distortion of radar stations with pulsed and quasi-continuous radiation, built on the basis of digital signal synthesizers of four types: digital synthesizers of voltage counts and digital synthesizers of phase counts with uniform sampling, digital synthesizers of voltage counts and digital synthesizers of phase counts with uneven sampling. When building a radar master device, the question arises about choosing the type of digital signal synthesizer. The main initial criteria are the maximum operating range of the digital synthesizer and the level of in-band distortion. When choosing the type of digital signal synthesizer, you must take into account a large number of factors, the main of which are the complexity of the execution of the digital readout shaper, the possibility of implementing a digital readout shaper with the required speed and number of digits [1, 2]. When making requirements for the total level of distortion, the criterion of acceptable reduction of the probability of correct detection in comparison with its potential value for a fixed probability of false alarm is used. Based on this criterion, in pulse radars, the maximum relative RMS value of the distortion of the intercorrelation function of a signal with angular modulation generated by a digital synthesizer should not exceed $D_{\\delta x}\\le $-(51...67) dB. In a radar with quasi-continuous radiation, the maximum relative mean-square value of the distortion of the autocorrelation function of the signal with angular modulation should not exceed $D_{\\delta }\\le $- (80...120) dB. The number of bits of phase quantization, voltage and time delay compensation in digital signal synthesizers depends not only on the maximum relative RMS value of the distortion of the intercorrelation function, but also on the number of samples of the signal with angular modulation. Therefore, initially you need to select the reference frequency of the digital signal synthesizer, setting the type of modulation and the effective spectrum width of the signal with angular modulation based on the tactical and technical characteristics radar.

Designing Time Delay Compensation Methods for Functional Modes Using Sensory Evaluation

2015 ◽  
Vol 135 (7) ◽  
pp. 755-764 ◽  
Author(s):  
Shuhei Shimizu ◽  
Yoshiki Ohno ◽  
Takahiro Nozaki ◽  
Kouhei Ohnishi
Keyword(s):  
Time Delay ◽  
Sensory Evaluation ◽  
Delay Compensation ◽  
Compensation Methods ◽  
Time Delay Compensation

Concurrent Monitoring for Multiple Critical Signals in a Complex Display: A Vigilance Perspective

2005 ◽  
Vol 49 (17) ◽  
pp. 1518-1522
Author(s):  
Nathan R. Bailey ◽  
Mark W. Scerbo
Keyword(s):  
Task Demands ◽  
Complex Environment ◽  
Vigilance Performance ◽  
Digital Readout ◽  
Monitoring Task ◽  
Number Of Factors ◽  
Different Types ◽  
Effort Regulation ◽  
Monitoring Performance ◽  
Complex Display

The present study was designed to examine the monitoring performance of operators in a complex environment requiring concurrent monitoring of multiple displays with different types of critical signals. Participants performed a manual flight task concurrently with three monitoring tasks over three separate 2-hour sessions. The monitoring tasks required operators to detect deviations in the gauge, mode, and digital readout portions of a simulated EICAS display. Results indicated that while performance on the primary flight task degraded within each session, monitoring performance remained constant. Further, intrasession monitoring performance did not degrade across trials. These findings suggest that vigilance performance for complex displays may be influenced by a number of factors including compensatory strategies related to mental effort regulation, the complexity of monitoring task demands, the duration of the monitoring session, and the nature of additional operator responsibilities.

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