Analysis of Spectral Notching in FM Noise Radar Using Measured Interference

Ravenscroft, Brandon; Blunt, Shannon D.; Allen, Christopher T.; Martone, Anthony F.; Sherbondy, Kelly D.

doi:10.1049/cp.2017.0388

Cited by 20 publications

(10 citation statements)

References 17 publications

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“…14 that likewise does not include RFI. Note that a slight spreading in range, due to higher near‐in sidelobes and not degraded resolution, is observed in the latter due to notching, which agrees with the results in [25].…”

Section: Cognitive Notching For Mtisupporting

confidence: 89%

“…The main application for the placement of spectral notches in radar waveforms is the avoidance of in‐band RFI. It was shown in [25] that a notch coinciding with the spectral location of high‐power narrowband RFI provides a direct benefit to target detection through reduction of interference in the matched filter response.…”

Section: Assessing Notch Interference Rejectionmentioning

confidence: 99%

“…While the majority of such approaches involve spectral notching of a single waveform or by extension the same waveform over the coherent processing interval (CPI), it was shown in [16] that doing so incurs a rather significant penalty in terms of increased radar range sidelobes. However, it was recently experimentally demonstrated [22, 23, 25, 26] that the spectral notching of frequency modulated (FM) noise waveforms [27, 28] largely avoids this limitation because the incoherent combining of range sidelobes across multiple distinct pulsed waveforms in the CPI serves to reduce the resulting sidelobe level by a factor commensurate with the number of pulses [29].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental demonstration and analysis of cognitive spectrum sensing and notching for radar

Ravenscroft

Owen

Jakabosky

et al. 2018

IET Radar, Sonar & Navigation

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Spectrum sensing and transmit notching is a form of cognitive radar that seeks to reduce mutual interference with other spectrum users in the same band. This concept is examined for the case where another spectrum user moves in frequency during the radar's CPI. The physical radar emission is based on a recent FM noise waveform possessing attributes that are inherently robust to sidelobes that otherwise arise for spectral notching. Due to increasing spectrum sharing with cellular communications, the interference considered takes the form of in-band OFDM signals that hop around the band. The interference is measured each PRI and a fast spectrum sensing algorithm determines where notches are required, thus facilitating a rapid response to dynamic interference. To demonstrate the practical feasibility and to understand the tradespace such a scheme entails, free-space experimental measurements based on notched radar waveforms are collected and synthetically combined with separately measured hopping interference under a variety of conditions to assess the efficacy of such an approach, including the impact of interference hopping during the radar CPI, latency in the spectrum sensing/waveform design process, notch tapering to reduce sidelobes, notch width modulation due to spectrum sensing, and the impact of digital up-sampling on notch depth.

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Section: Cognitive Notching For Mtisupporting

confidence: 89%

Section: Assessing Notch Interference Rejectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental demonstration and analysis of cognitive spectrum sensing and notching for radar

Ravenscroft

Owen

Jakabosky

et al. 2018

IET Radar, Sonar & Navigation

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“…Проте сучасні досягнення в радіоелектроніці вказують на обмеження, які виникають у зв'язку з такими особливостями (вузькосмуговість, детерміновані сигнали тощо). Значний прорив у розробленні широко-і надширокосмугової радіоелектроніки дозволив реалізовувати високоточні та надійні вимірювання радарами з використання стохастичних сигналів [11][12][13]. Такі радари досить цікаві з огляду на можливість створення радіосистем з високим ступенем захищеності від стороннього випромінювання.…”

Section: вступunclassified

Алгоритм Обробки Сигналів Для Вертолітного Широкосмугового Шумового Некогерентного Радіовисотоміру

Volosyuk¹,

Павликов²,

Zhyla³

et al. 2022

aktt

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The algorithm for a helicopter or an unmanned aerial vehicle flight altitude measuring based on the processing of broadband and ultra-wideband pulsed stochastic signals has been synthesized for the first time by the maximum likelihood method. When formulating the initial data, mathematical models of the probing signal and the received observation are given, taking into account both various options for input path implementation, which impose restrictions on the observation equation form, and the geometry of the problem. When solving the problem, the statistical characteristics of the given models were found and studied. The calculated observation correlation function contains information about both the signal delay time and the radio pulse envelope, which makes it possible to obtain the algorithm for desired altitude parameter determining by one of two ways: differentiating the likelihood functional by the delay time or by the radio pulse envelope. At the same time, for the first time, the inversion equation for the statistical characteristics of the studied non-stationary processes in the frequency domain has been obtained. Such processes arise due to the presence of a radio pulse envelope. An important feature of the solved synthesis problem is a noise pulse transmitter use that implements the function of the underlying surface sounding, as well as taking into account the fact of the signal structure destruction during its radiation, propagation and reflection. Such a destruction of the signal shape doesn’t make it impossible to synthesize a radar with internal coherent processing algorithms when working on one receiving antenna and requires the search for other signal processing options. The use of a non-deterministic signal in the system also complicates the formalization of the delay time parameter in the likelihood function, since in this case the reference signal cannot be represented as a model or an analytical equation. Following the synthesized algorithm, a simulation model of a pulsed radar with a stochastic probing signal has developed and the results of its modeling are presented. The obtained output effect of the system fully corresponds to the classical theoretical calculations.

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“…Selesnick et al [22], [23] describe iterative algorithms for creating notched and multiple notched chirp-like waveforms allowing transmissions on selected frequencies to be controlled. Spectral notching in FM noise radar in the presence of narrowband noise is analysed in [24], and experimentally demonstrated in [25]. Aubry et al [26] employ an optimisation based approach to waveform design in the spectral coexistence context, the perception element of the cognitive process relying on external environment knowledge provided by a radio environment map (REM).…”

Section: Introductionmentioning

confidence: 99%

Fast Fully Adaptive Signalling for Target Matching

Horne

Jones

Smith

et al. 2020

IEEE Aerosp. Electron. Syst. Mag.

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In this article, we discuss a novel signal processing technique for adaptive radar that permits joint target-matched illumination and interference avoidance in dynamic spectral environments. This approach allows for spectral coexistence between a radar system and a primary user of the radio frequency space. Spectral coexistence is exploited to allow use of higher bandwidths than would otherwise be available to conventional radar systems. The technique proposed exploits the relative simplicity of the error reduction algorithm, and also provides a novel use of the masking procedure to allow for target-matched illumination. Practical constraints such as constant modulus are considered in the waveform design procedure, while providing an implied signal-to-interference-plus-noise ratio improvement via the error reduction algorithm. Results for full simulation and hardware-in-the-loop experiments are presented and analyzed. We are able to show a signal-to-interference-plus-noise ratio gain of 40 dB is achieved for the target-matched waveform as compared with a linear frequency modulated waveform. However, the signal-to-interference-plus-noise ratio gain comes at a cost of degraded autocorrelation characteristics of the targetmatched illumination waveform, despite only modest levels of primary user spectrum occupancy. Spectral notch depths achieved by the modified error reduction algorithm are approximately 25 dB.

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Analysis of Spectral Notching in FM Noise Radar Using Measured Interference

Cited by 20 publications

References 17 publications

Experimental demonstration and analysis of cognitive spectrum sensing and notching for radar

Experimental demonstration and analysis of cognitive spectrum sensing and notching for radar

Алгоритм Обробки Сигналів Для Вертолітного Широкосмугового Шумового Некогерентного Радіовисотоміру

Fast Fully Adaptive Signalling for Target Matching

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