Digital sentry bandwidth algorithm how to#
The algorithm is inspired by the HRR approaches used in HRR radar systems on how to exploit multiple nonadjacent broadcast channels or bands in the PBR range correlation to achieve higher range resolution while maintaining Doppler resolution from relatively long integration times. The performance of a mathematical processing scheme has been presented. The former happens due to the joint exploitation of multiple broadcasted channels for detection, while the latter occurs when independent returns are received from one target over different frequency channels. In addition to the reliable detection performance, a multiband PBR system offers advantages in terms of combined diversity gain and frequency diversity gain as compared with a single band PBR system. A thorough performance assessment is also given, and the results show the robustness of the proposed multiband detector against the time-varying program content of FM radio channels. Closed-form expressions for calculating false alarm probability and detection probability for the target models of Swerling 0 and Swerling 1 are derived. To address this, we derive a multiband uniformly most powerful invariant (UMPI) test as an optimal invariant detector. In this case, we formulate the problem of detecting a target in the presence of interference signals such as receiver noise, direct signal, multipath/clutter echoes and interfering targets as a composite hypothesis test. To circumvent this matter, it is a viable idea to exploit multiple broadcasted channels from a single transmitter for detection. This approach is validated with simulated and experimental data from a passive radar system tracking a commercial airline using two digital television (DTV) broadcast transmitters.įM-based passive bistatic radars (PBRs) exploiting a single broadcasted channel suffer from time-varying detection performance due to the time-varying program content of the transmitted signal as well as the propagation condition of that channel. A compressive sensing‐based algorithm is used to combine the calibrated non‐contiguous frequency data, and is shown to mitigate the grating lobe artefacts that occur when using a back‐projection algorithm. A calibration method is developed to align the downrange responses and coherently combine the two signals. Additionally, these signals may originate from transmitters not located at the same position. These signals are usually separated in the frequency domain (non‐contiguous), which causes large unwanted grating lobe artefacts in the image when using back‐projection or Fourier transform based imaging.
Multiple signals of opportunity can be coherently combined to increase the overall bandwidth of the system, and therefore create finer resolution images. The signals of opportunity have lower bandwidth than dedicated active radar systems, leading to poor downrange resolution. Passive radar systems use illuminators of opportunity to illuminate targets instead of dedicated radar transmitters. Simulation results show that a multiband PBR system offers advantages in terms of coherent combined diversity gain and target range resolution improvement as compared to a single band PBR system. Finally, they provide some simulation examples to validate the authors' theoretical analysis. The false alarm rate and detection probability of the proposed detector are also derived in the closed-form expressions. In the proposed detector, they analytically show how the exploitation of the multiple broadcasted channels can improve the target range resolution. So, they derive a multiband uniformly most powerful invariant test. To reach these goals, the authors formulate the problem of detecting a target in the presence of interference signals, such as receiver noise, direct signal, multipath/clutter echoes, and interfering targets, as a composite hypothesis test. This may be alleviated by exploiting multiple broadcasted channels from a single transmitter. FM-based passive bistatic radars (PBRs), exploiting a single broadcasted channel, have limited range resolution due to low modulation bandwidth and high dependence on the content broadcasted from an FM station.
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