The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform
Dieter Nagel - One of the best experts on this subject based on the ideXlab platform.
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Tracking airborne targets through windmill areas and Rain Clutter with ground based radar
2016 17th International Radar Symposium (IRS), 2016Co-Authors: Dieter Nagel, Christoph NeumannAbstract:Due to the growing number of wind farms, one of the most important tasks for ground based radars is the suppression of windmill returns which might cause spurious target detections [5]. The detection of targets in the presence of strong Rain Clutter would also be desirable. The usual waveform for ground based radars is LPRF (low pulse repetition frequency) with PRFs below ~1000Hz, resulting in unambiguous range measurements exceeding 150km. This waveform has many advantages for ground based radars, even with regard to Clutter and small targets from near-in ground area around the radar. However, with growing signal processing capabilities, modern radars can now be extended from 3D-operation (range-azimuth-elevation) to 4D-operation (range - azimuth - elevation - Doppler). The parameters of the fourth dimension can be measured by interleaving MPRF (medium pulse repetition frequency) waveforms with the standard LPRF waveform. When targets need to be tracked through windmill areas or Rain Clutter, the regions concerned can be detected by an LPRF waveform. If it is predictable that one or more targets will traverse windmill or Rain Clutter areas, the waveform can be switched to MPRF, where targets can easier be detected in such environments.
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SDF - MPRF waveform for ground based radars to suppress returns from windmills and Rain Clutter
2015 Sensor Data Fusion: Trends Solutions Applications (SDF), 2015Co-Authors: Dieter NagelAbstract:Renewable energy sources such as wind parks are more and more shaping our environment. In the vicinity of radars, however, they often pose a serious problem, due to degradation of radar performance [6]. This paper deals with a new MPRF waveform capable of suppressing returns from wind parks and strong Rain Clutter and thus mitigating this performance degradation. Most ground based radars use low PRF (LPRF) waveforms with pulse repetition frequencies (PRF) below ~1000Hz, allowing unambiguous range measurements out to more than 150km. The advantage of this waveform for ground based radars is that, assuming a duty ratio of approx. 10%, the near-in ground Clutter less than 15km from the radar falls into the eclipsed transmit blind zones. A further advantage is the large unambiguous range measurement interval and the possibility of using Sensitivity-Time Control (STC) [1] to suppress low radar cross section returns. A disadvantage of LPRF is the small unambiguous Doppler velocity interval which, e.g., for S-band radars, is less than ~50m/s. In the case of windmill farms, it is possible that, due to the maximum velocity of the rotor tips of ~50m/s the whole Doppler velocity region for the affected range intervals is occupied by rotor blade returns. Also, in the case of heavy Rain, the whole Doppler region over a range interval of several miles could be occupied by Rain Clutter. This paper presents a MPRF waveform which can mitigate the effects of windmills and Rain Clutter on the detectability of true targets.
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MPRF waveform for ground based radars to suppress returns from windmills and Rain Clutter
2015 Sensor Data Fusion: Trends Solutions Applications (SDF), 2015Co-Authors: Dieter NagelAbstract:Renewable energy sources such as wind parks are more and more shaping our environment. In the vicinity of radars, however, they often pose a serious problem, due to degradation of radar performance. This paper deals with a new MPRF waveform capable of suppressing returns from wind parks and strong Rain Clutter and thus mitigating this performance degradation. Most ground based radars use low PRF (LPRF) waveforms with pulse repetition frequencies (PRF) below ~1000Hz, allowing unambiguous range measurements out to more than 150km. The advantage of this waveform for ground based radars is that, assuming a duty ratio of approx. 10%, the near-in ground Clutter less than 15km from the radar falls into the eclipsed transmit blind zones. A further advantage is the large unambiguous range measurement interval and the possibility of using Sensitivity-Time Control (STC) to suppress low radar cross section returns. A disadvantage of LPRF is the small unambiguous Doppler velocity interval which, e.g., for S-band radars, is less than ~50m/s. In the case of windmill farms, it is possible that, due to the maximum velocity of the rotor tips of ~50m/s the whole Doppler velocity region for the affected range intervals is occupied by rotor blade returns. Also, in the case of heavy Rain, the whole Doppler region over a range interval of several miles could be occupied by Rain Clutter. This paper presents a MPRF waveform which can mitigate the effects of windmills and Rain Clutter on the detectability of true targets.
R.m. O'donnell - One of the best experts on this subject based on the ideXlab platform.
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Adaptive Doppler Filtering Applied to Modern Control Radars
2020Co-Authors: K.j. Anderson, J. Ward, R.m. O'donnell, Lexington MassachusettsAbstract:Abszruct - This paper presents an analysis of the Doppler processing technology currently ini use in the nation's terminal airport surveillance radars, and examines possibilities for performance improvement, particuhrly in the presence of moving Clutter. The research focuses on live- and eight-pulse waveform methodologies and their respective detection capabilities given clearly defined Rain Clutter scenarios. Performance with fixed coefficient fdters similar to those used in the existing radars is calculated, followed by performance using an adaptive Doppler fdtering technique. Performance k quantified in terms of signalto-interference ratio at the output of the Doppler filters and resultant probability of detection given a specified probability of false alarm. The results Win show that a substantial improvement in detection in the vicinity of Rain Clutter is realized for both the fn.e and eight-pulse waveforms when using the adaptive coefficient Doppler filters as compared to the performance observed with the fued coefficient filters. For constant filter weights, the eight-pulse Doppler fdters give significantly better performance in most diverse Rain Clutter than the fwepulse Doppler filters.
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The Radar Equation
The Radar Equation, 2012Co-Authors: R.m. O'donnellAbstract:The Radar Systems Engineering Series consists of seventeen lectures; each lecture is offered as an individual tutorial. The goal of this series is to provide an advanced introduction to radar systems subsystem issues for first year graduate students, advanced senior undergraduates or professionals new to the field. The material will be most accessible to university graduates with a Bachelor of Science degree in Electrical Engineering, Physics, Mathematics, Computer Science / Engineering, or Mechanical Engineering and who have a solid understanding of Electromagnetism and their fields, Probability, and Calculus through Differential Equations, Vector Calculus, and Linear Algebra. Each tutorial consists of a screen-captured PowerPoint lecture narrated by Dr. O'Donnell. In each tutorial Dr. O'Donnell has broken his lecture into one or more separate segments for ease of viewing. All of the material in these tutorials is subject to copyright laws. In the first segment of this lecture Dr. O'Donnell reviews the specific copyright information for these materials. Following this brief video, the first segment of this lecture will begin.You may also access copyright information by viewing the video listed below on this course page. In this fourth lecture, Dr. O'Donnell provides an in depth discussion of the radar equation. He considers the surveillance and tracking forms of the radar equation as well as the radar equation for Rain Clutter. He also examines radar losses with specific examples. This lecture is divided into two parts.
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Adaptive Doppler filtering applied to modern air traffic control radars
Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509), 2004Co-Authors: K.j. Anderson, J. Ward, R.m. O'donnellAbstract:This paper presents an analysis of the Doppler processing technology currently in use in the USA's terminal airport surveillance radars, and examines possibilities for performance improvement, particularly in the presence of moving Clutter. The research focuses on five- and eight-pulse waveform methodologies and their respective detection capabilities given clearly defined Rain Clutter scenarios. Performance with fixed coefficient filters similar to those used in the existing radars is calculated, followed by performance using an adaptive Doppler filtering technique. Performance is quantified in terms of signal-to-interference ratio at the output of the Doppler filters and resultant probability of detection given a specified probability of false alarm. The results show that a substantial improvement in detection in the vicinity of Rain Clutter is realized for both the five- and eight-pulse waveforms when using the adaptive coefficient Doppler filters as compared to the performance observed with the fixed coefficient filters. For constant filter weights, the eight-pulse Doppler filters give significantly better performance in most diverse Rain Clutter than the five-pulse Doppler filters.
Michael Ludwig - One of the best experts on this subject based on the ideXlab platform.
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Rain Impact on Sensitivity of Ka-band Scan-on-Receive Synthetic Aperture Radars
IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008Co-Authors: Salvatore D'addio, Michael LudwigAbstract:This paper analytically analyses the radiometric performance of a spaceborne Ka-band SAR based on scan-on-receive Rx antenna beam. The analysis outlines the major limiting factors for the design of this instrument. The instrument radiometric sensitivity is evaluated considering a figure of merit that includes the signal-to-noise ratio and the signal-to-Rain Clutter ratio as well as. In the simulations, different Rainfall rates are considered, and the instrument availability for given performance is evaluated. Potential instrument configurations and geometric options are traded-off in order to find the optimal configuration. The analyses show the scan-on-receive technique as a potential solution leading to spaceborne Ka-band synthetic aperture radars with sufficient availability.
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IGARSS (3) - Rain Impact on Sensitivity of Ka-band Scan-on-Receive Synthetic Aperture Radars
IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008Co-Authors: Salvatore D'addio, Michael LudwigAbstract:This paper analytically analyses the radiometric performance of a spaceborne Ka-band SAR based on scan-on-receive Rx antenna beam. The analysis outlines the major limiting factors for the design of this instrument. The instrument radiometric sensitivity is evaluated considering a figure of merit that includes the signal-to-noise ratio and the signal-to-Rain Clutter ratio as well as. In the simulations, different Rainfall rates are considered, and the instrument availability for given performance is evaluated. Potential instrument configurations and geometric options are traded-off in order to find the optimal configuration. The analyses show the scan-on-receive technique as a potential solution leading to spaceborne Ka-band synthetic aperture radars with sufficient availability.
Fu Ying - One of the best experts on this subject based on the ideXlab platform.
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modeling and simulation of Rain Clutter for tethered aerostat borne radar
Radar Science and Technology, 2010Co-Authors: Fu YingAbstract:Tethered aerostat borne radar works in the air and faces strong ground Clutter,sea Clutter,and Rain Clutter.The detection performance of the radar will be come worse especially when the target is in the Rain Clutter region.The characteristic of Rain Clutter for tethered aerostat borne radar is studied.First,the geometry model of Rain Clutter is presented.By analyzing the factors which affect the characteristic of Rain Clutter,the Rain Clutter's expression of certain range gate is then derived.Finally,the Rain Clutter's Clutter-noise ratio of range-azimuth and range-Doppler spectrum are simulated and analyzed.The results can be used as the reference for the Clutter suppression and signal processing of tethered aerostat borne radar.
K.j. Anderson - One of the best experts on this subject based on the ideXlab platform.
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Adaptive Doppler Filtering Applied to Modern Control Radars
2020Co-Authors: K.j. Anderson, J. Ward, R.m. O'donnell, Lexington MassachusettsAbstract:Abszruct - This paper presents an analysis of the Doppler processing technology currently ini use in the nation's terminal airport surveillance radars, and examines possibilities for performance improvement, particuhrly in the presence of moving Clutter. The research focuses on live- and eight-pulse waveform methodologies and their respective detection capabilities given clearly defined Rain Clutter scenarios. Performance with fixed coefficient fdters similar to those used in the existing radars is calculated, followed by performance using an adaptive Doppler fdtering technique. Performance k quantified in terms of signalto-interference ratio at the output of the Doppler filters and resultant probability of detection given a specified probability of false alarm. The results Win show that a substantial improvement in detection in the vicinity of Rain Clutter is realized for both the fn.e and eight-pulse waveforms when using the adaptive coefficient Doppler filters as compared to the performance observed with the fued coefficient filters. For constant filter weights, the eight-pulse Doppler fdters give significantly better performance in most diverse Rain Clutter than the fwepulse Doppler filters.
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Adaptive Doppler filtering applied to modern air traffic control radars
Proceedings of the 2004 IEEE Radar Conference (IEEE Cat. No.04CH37509), 2004Co-Authors: K.j. Anderson, J. Ward, R.m. O'donnellAbstract:This paper presents an analysis of the Doppler processing technology currently in use in the USA's terminal airport surveillance radars, and examines possibilities for performance improvement, particularly in the presence of moving Clutter. The research focuses on five- and eight-pulse waveform methodologies and their respective detection capabilities given clearly defined Rain Clutter scenarios. Performance with fixed coefficient filters similar to those used in the existing radars is calculated, followed by performance using an adaptive Doppler filtering technique. Performance is quantified in terms of signal-to-interference ratio at the output of the Doppler filters and resultant probability of detection given a specified probability of false alarm. The results show that a substantial improvement in detection in the vicinity of Rain Clutter is realized for both the five- and eight-pulse waveforms when using the adaptive coefficient Doppler filters as compared to the performance observed with the fixed coefficient filters. For constant filter weights, the eight-pulse Doppler filters give significantly better performance in most diverse Rain Clutter than the five-pulse Doppler filters.
