3,548 research outputs found
Making vision into power : Britain's acquisition of the world's first radar-based integrated air defence system 1935 - 1941
No full textThis thesis represents the first application of a current conceptual model of defence acquisition to analyse the historical process, the 1935 - 1941 British acquisition of an integrated air defence system pivoted upon the innovative technology of radar. For successful acquisition of a military capability, the model posits that balanced attention must be focused acoss eight 'lines of developmen' - not only equipment, but also doctrine and concepts, logistics, structures, personnel, organisation, training and information with an overarching requirement for interoperability. This thesis contrasts what turned out to be a successful acquisition, of radar to achive air interception capability by day in the Battle of Britain, with less successful acquisition, or radar to achieve the same capability at night, where an effective system arrived too late to ward off the Blitz. The results establish the validity of the model and its attendant lines of development concepts, and furnish new insights into acquisition processes and military history. Acquisition lessons are derived for the capability-based involvement of industry, for the experience and personality necessary for key managers at different 'life stages' of an acquisition and for the avoidance of over-rapid 'dysfunctional diffusion' of innovative technologies. Historical insights for the Battle of Britain include the sub-optimal performance, for trivial reasons, of key South Coast radars, and the critical importance of the human elements of the radar-based air defence system. For the Blitz, airborne radar hardware has previously been identified as a key problem, whereas research here exposes the greater need for accurate ground control radar, the sound selection and training of pilots and operators in new tactics, and provision of equipment maintainers and test gear. New evidence illustrates that pursuit of an alternative to radar significantly delayed the optimal solution, and throws fresh light both on personalities and on development process management
Radar and ARPA manual.
No full textRadar and ARPA Manual provides essential information for professional mariners and seagoing marine engineers, including those undertaking electronic navigation system courses and marine operations qualifications internationally. This fully revised new edition serves as the most comprehensive reference on equipment and techniques for radar observers using older and newer systems. Suitable for use both as a professional reference and a training text, the book has been updated to reflect the trend away from independent to integrated equipment and now covers the inter-relationship between radar/ARPA, AIS, GPS and ECDIS. Comprising all aspects of radar, from basic principles through to target detection, operational controls, navigation techniques and collision avoidance, Radar and ARPA Manual is a practical, tried-and-tested guide to radar, ARPA and integrated bridge systems and their role in marine navigation. Covers best practice use of equipment as well as underlying principles, with essential mathematics and complicated concepts illustrated through the use of numerous clear illustrations. Includes excerpts from all relevant International Maritime Organization (IMO) safety and performance standards relating to radar and navigational technology on new and established vessels. Updated to reflect the trend away from independent to integrated equipment and cover the inter-relationship between radar/ARPA, AIS, GPS and ECDIS.Previous edition: 2005.Includes index.Radar and ARPA Manual provides essential information for professional mariners and seagoing marine engineers, including those undertaking electronic navigation system courses and marine operations qualifications internationally. This fully revised new edition serves as the most comprehensive reference on equipment and techniques for radar observers using older and newer systems. Suitable for use both as a professional reference and a training text, the book has been updated to reflect the trend away from independent to integrated equipment and now covers the inter-relationship between radar/ARPA, AIS, GPS and ECDIS. Comprising all aspects of radar, from basic principles through to target detection, operational controls, navigation techniques and collision avoidance, Radar and ARPA Manual is a practical, tried-and-tested guide to radar, ARPA and integrated bridge systems and their role in marine navigation. Covers best practice use of equipment as well as underlying principles, with essential mathematics and complicated concepts illustrated through the use of numerous clear illustrations. Includes excerpts from all relevant International Maritime Organization (IMO) safety and performance standards relating to radar and navigational technology on new and established vessels. Updated to reflect the trend away from independent to integrated equipment and cover the inter-relationship between radar/ARPA, AIS, GPS and ECDIS.Print version record.Elsevie
Mitigation of Automotive Radar Interference
No full textThis paper presents a new approach to mitigating radar interference and focuses on the application of automotive radar. Traditional interference mitigation techniques in automotive radar depend on detection and identification of the interference. With this paper, we propose a novel method based on advanced signal separation techniques which do not need any prior detection of the interference. The success of the proposed method is demonstrated into simulated and real automotive radar data sets, in the presence of Continuous Wave (CW) and Frequency Modulated Continuous Wave (FMCW) interference. Significant improvement in Signal-to-Interference-plus-Noise Ratio (SINR) is observed after range-Doppler processing.Microwave Sensing, Signals & System
Statistical Approach for Automotive Radar Self-Diagnostics
No full textIn this paper, the problem of on-the-fly estimation of the radar state (self-diagnostics) is considered. We propose to use repetitive objects of the road infrastructure, such as lampposts, for continuous diagnostics of the radar state. The selected approach allows accounting for the external factors, such as water layer or dirt on the bumper, which can significantly affect radar performance, but cannot be retrieved with the internal calibration. The statistical model for RCS of repetitive targets is considered, and the estimator of the actual radar gain from the received data is derived. It is demonstrated that observing a few tens of targets is sufficient to provide a reasonable estimation of the radar performance within the operational mode.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
Automotive radar interference study for different radar waveform types
No full textMutual interference between different radar waveforms used in automotive radar applications is studied. The existing interference analysis is extended to a generalised radar-to-radar interference equation that covers most of the common interference scenarios for automotive radar systems. The outcome of the generalised equation is demonstrated for a number of typical scenarios where radars with different continuously transmitting waveforms are involved. The proposed equation can be used to characterise the received interference and its features by analysing the instantaneous beat frequency of the victim radar. Moreover, an interference analysis of phase-coded frequency-modulated continuous waveforms is performed and demonstrated experimentally by using real-time automotive radars for the first time in the literature. The experimental results corroborate the interference analysis of different waveforms and validate the proposed generalised interference equation under various conditions.Microwave Sensing, Signals & SystemsElectronic
Phase-Coded FMCW Automotive Radar: Application and Challenges
No full textPhase-Coded frequency-modulated continuous-wave (PC-FMCW) radar is an emerging radar system with its unique features such as enabling joint sensing and communication or advanced interference mitigation. Even though radars with phase coding capabilities are available in the automotive radar market today, there are some challenges in phase coded radar applications. With this paper we demonstrate multiple bit coding per single transmit chirp waveform in a FMCW automotive radar system for the first time. We concentrate on the sensing aspect of PC-FMCW radar and point out the challenges due to instantaneous phase change. To overcome these issues and improve sensing performance, this paper proposes a smart filtering method which consists of rejection filtering and signal recovery steps.Virtual/online event due to COVID-19 Accepted author manuscriptMicrowave Sensing, Signals & System
3-D Ego-Motion Estimation Using Multi-Channel FMCW Radar
No full textThe problem of estimating the 3D ego-motion velocity using multi-channel FMCW radar sensors has been studied. For the first time, the problem of ego-motion estimation is treated using radar raw signals. A robust algorithm using multi-channel FMCW radar sensors to instantly determine the complete 3D motion state of the ego-vehicle (i.e., translational speed and rotational speed) is proposed. The angle information of targets is extracted, and then their phase information from different times instances is used to determine vehicle ego-motion through an optimization process. Any pre-processing steps, such as clustering or clutter suppression, are not required. The performance of the algorithm is compared with the state-of-the-art algorithms based on real-world data, and superior performance has been demonstrated. The algorithm proposed can be easily integrated into radar signal processing pipelines for other tasks relevant to autonomous driving.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
Localization and 3D Mapping Using 1D Automotive Radar Sensor
No full textThis paper establishes novel methods for vehicle localization and mapping using a 1D linear automotive radar array in conjuncture with pre-existing lidar maps, and tests if the generated radar map can be made to be 3 dimensional. The basic design of this study was to implement a SLAM (Simultaneous Localization And Mapping) system that co-registers radar data to radar data, and/or register radar data to lidar data. After the execution of experiments, it was established that it is possible to localize the car by relating observed radar data to premade lidar maps, and to continually add to a cumulative map made with the radar data that can further aid the localization process. Furthermore, the radar map created using the 1D linear automotive array can be extended to 3D with proposed processing chain, though more experiments to establish the full potential of this capability are recommended.Microwave Sensing, Signals & SystemsElectrical Engineering, Mathematics and Computer Scienc
Using Golay Sequences to Improve the Range Performance of Hybrid Codes for MIMO Radar
No full textIn this paper, waveforms for MIMO phased array radar to enhance cross-range resolution are investigated. The problem of high sidelobes in range created by the use of Hybrid Codes with a single waveform and spatial coding is considered and a method to reduce these sidelobes by the use of Golay sequences as spatial codes is proposed. It is shown that the proposed method achieves the same range performance as a phased array radar with one waveform, despite creating additional sidelobes in Doppler.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microwave Sensing, Signals & System
Radar and video multimodal learning for human activity classification
No full textCamera systems are widely used for surveillance in the security and defense domains. The main advantages of camera systems are their high resolution, their ease of use, and the fact that optical imagery is easy to interpret for human operators. However, particularly when considering application in the defense domain, cameras have some disadvantages. In poor lighting conditions, dust or smoke the image quality degrades and, additionally, cameras cannot provide range information. These issues may be alleviated by exploiting the strongpoints of radar. Radar performance is largely preserved during nighttime, in varying weather conditions and in dust and smoke. Furthermore, radar provides range information of detected objects. Since their qualities appear to be complementary, can radar and camera systems learn from each other? In the current study, the potential of radar/video multimodal learning is assessed for the classification of human activity.Accepted author manuscriptMicrowave Sensing, Signals & System
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