{"title":"Autoregressive modeling of radar data with application to target identification","authors":"R. Moses, J.W. Carl","doi":"10.1109/NRC.1988.10961","DOIUrl":"https://doi.org/10.1109/NRC.1988.10961","url":null,"abstract":"The classification and identification of radar targets from frequency domain data is studied. The approach taken is to form an autoregressive (AR) model of the downrange and Doppler profiles of the target from a set of coherent stepped-frequency radar measurements. Simple, effective methods for motion compensation of the data and for averaging of the profile estimates are derived. This composite algorithm is applied to X-band radar measurements of aircraft in flight to illustrate the effectiveness of the modeling procedure. The results indicate that the AR model can be used for scattering center identification, and for discrimination between two targets.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131797609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Closed form solutions for the depth of focus of synthetic aperture radar (SAR) maps under maneuvers","authors":"J. O'Brien","doi":"10.1109/NRC.1988.10935","DOIUrl":"https://doi.org/10.1109/NRC.1988.10935","url":null,"abstract":"Conventional range-Doppler processing of SAR data places limitations on the quality of image (map) which can be achieved under maneuvering platform conditions. A closed-form solution is presented for the radar depth of focus. For the case of spotlight synthetic-aperture radar (SAR) operation using conventional (nonpolar) processing, limits are given on the depth of field achievable using variable PRF (pulse repetition rate) and using variable-range focusing with first-order range correction terms. The use of a variable PRF extends the cross-range depth of focus up to a limit which depends on the aircraft acceleration. Variable-range focusing extends the range depth of focus; implementation using a first-order correction imposes bounds on the achievable depth of focus.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134146572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Air-to-ground ranging using electronic roll stabilization of monopulse data","authors":"P.K. Zwagerman","doi":"10.1109/NRC.1988.10949","DOIUrl":"https://doi.org/10.1109/NRC.1988.10949","url":null,"abstract":"A radar operating in an air-to ground ranging mode obtains precise range measurements from the antenna to the point of intersection of the antenna boresight with the ground. If elevation monopulse data is used, the boresight range is characterized by the range at which the sign crossover occurs in the data. In mechanically scanned arrays, the monopulse axes are fixed with respect to the array. Unless roll-stabilizing gimbals are provided, the elevation monopulse channel is increasingly corrupted by azimuth data as the airframe rolls. The AN/APG-67 multimode radar, in addition to its sum channel, has a difference channel which uses quadrature multiplexing to simultaneously receive and process both elevation and azimuth monopulse data. By comparing the difference channel signal with that of the sum channel, both azimuth and elevation errors are extracted from the same set of data. The inertial elevation monopulse data component can be extracted from the multiplexed difference channel by phase rotating the multiplexed data opposite to the inertial twist of the antenna array. The resulting multiplexed data is roll-stabilized and can be used for air-to-ground ranging regardless of the airframe's orientation.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115966755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Time-domain and frequency-domain feature selection for reliable radar target identification","authors":"F. Garber, N.F. Chamberlain, O. Snorrason","doi":"10.1109/NRC.1988.10934","DOIUrl":"https://doi.org/10.1109/NRC.1988.10934","url":null,"abstract":"The authors discuss the development of useful techniques for selecting features from radar backscatter measurements. This investigation is primarily motivated by interest in the design of radar target identification (RTI) systems that utilize frequency-diverse and polarization-diverse measurements of radar backscatter. Techniques for selecting sets of features from time-domain data and frequency-domain data are presented. The performance of radar target identification systems employing the resulting sets of features is evaluated by means of Monte-Carlo simulation studies.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116537970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A synthetic aperture radar mode for the AN/APS-506 maritime search radar","authors":"G. Haslam, M.R. Vant, D. DiFilippo","doi":"10.1109/NRC.1988.10941","DOIUrl":"https://doi.org/10.1109/NRC.1988.10941","url":null,"abstract":"The modifications and additions that were necessary to incorporate spotlight and strip-map synthetic-aperture radar (SAR) modes into the AN/APS-506 radar are described. The changes include enhancing the radar's coherence and adding software for SAR control. A motion-compensation subsystem and data-recording facility were also developed. Real-time SAR and motion-compensation processors that are under development will be included in the final system. In addition to the description of the SAR system, impulse response measurements and examples of images are presented.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129409271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low probability of intercept (LPI) techniques and implementations for radar systems","authors":"E.J. Carlson","doi":"10.1109/NRC.1988.10930","DOIUrl":"https://doi.org/10.1109/NRC.1988.10930","url":null,"abstract":"After a brief overview of optimal low-probability of intercept (LPI) radar design criteria, it is shown that for a given radar signal code length, many more codes are available by using higher-order Galois fields; that is, polyphase coding will supply the required diversity. Various aspects of polyphase coding are described because Doppler compensation of the returned signal is a polyphase process. It is shown that radiated spectral components are minimized if the code modulation is restricted to codes that have two-level autocorrelation functions. In addition, polyphase code modulation assignments allow the peak correlation sidelobes to be minimized in contrast to biphase coding that relies only on the best choice for the starting code element. The RMS sidelobe values are likewise reduced, so clutter rejection is actually improved with polyphase coding.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128333748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R.V. Jones, V. D. Vaughn, R. L. Frost, D. M. Chabries
{"title":"The effect of codebook size on the vector quantization of SAR data","authors":"R.V. Jones, V. D. Vaughn, R. L. Frost, D. M. Chabries","doi":"10.1109/NRC.1988.10945","DOIUrl":"https://doi.org/10.1109/NRC.1988.10945","url":null,"abstract":"The effect of the vector quantization (VQ) codebook (and codevector) size on the quality of synthetic-aperture radar (SAR) images formed from the compressed phase history data are shown. The reconstructed SAR images are compared to the original SAR image using the terrain and contrast ratios as measures of quality. Experiments indicate that image quality improves monotonically with increasing codevector size. The authors infer that compression ratios of 10:1 may be feasible for many applications.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121409012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New radar pulse compression waveforms","authors":"F. Kretschmer, K. Gerlach","doi":"10.1109/NRC.1988.10956","DOIUrl":"https://doi.org/10.1109/NRC.1988.10956","url":null,"abstract":"Pulse compression waveforms are described which have low sidelobe levels. Emphasis is on individual waveforms or multiple dissimilar waveforms. Processing the single waveforms consists of matched filtering while the multiple waveforms are individually matched, filtered, time-aligned, and summed. The multiple waveforms consist of complementary waveforms whose compressed pulses sum to zero in the sidelobes. These waveforms, in turn, were related to the underlying theory of orthogonal matrices. Multiple waveforms are discussed that, when filtered using a filter matched to a different waveform of the set, have a small output or cross-correlation response after combination of the individual responses. These waveforms have potential applications in reducing ambiguous range stationary clutter returns.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121680276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Target tracking in maneuver centered coordinates","authors":"J. A. Roecker, C. McGillem","doi":"10.1109/NRC.1988.10932","DOIUrl":"https://doi.org/10.1109/NRC.1988.10932","url":null,"abstract":"Aircraft targets normally maneuver on circular paths which has led to tracking filters based on circular turns. The authors introduce a new coordinate system to track circular maneuvers with a simple Kalman filter. When the maneuver is detected the tracker switches to a polar coordinate system located at the center of the maneuver. The state vector will then have radius, angle, and angular velocity as its components. This makes the process equation linear, allowing a simple Kalman filter to be used throughout the turn. The center of maneuver is estimated with each new measurement to adjust for possible changes. This investigation also examines maneuver detection methods and how they apply to the circular tracking problem. The method is then compared to the methods of Y. Bar-Shalom and K. Birmiwal (1982) and P.L. Bogler (1987) on various circular paths. The resulting algorithm displays improved performance over methods based on constant x-y accelerations when tracing circular turns.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126363437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reduction of SAR digital processing time using vector quantization","authors":"D. Arnold, D. M. Chabries, P. Jackson","doi":"10.1109/NRC.1988.10946","DOIUrl":"https://doi.org/10.1109/NRC.1988.10946","url":null,"abstract":"A procedure is presented to directly process synthetic-aperture radar (SAR) phase history data in a vector-quantized form. The procedure is particularly valuable when SAR has previously been vector-quantized to reduce bandwidth for downlink or other purposes. The vector quantization (VQ) process necessarily degrades the image, the degradation being generally a direct function of VQ compression ratio. However, the individual quality measures are affected differently. The computation compression technique (CCT) described is faster because only addition is required, as contrasted with both multiplication and addition for the FFT. The fact that preprocessed segments are overlapped and summed lends itself to parallel processing. Parameters for using CCT are the size of each vector, whether 1-D or 2-D, the number of entries in the codebook, and the address bits. These parameters influence the amount of time savings, image degradation, and amount of required memory.<<ETX>>","PeriodicalId":237192,"journal":{"name":"Proceedings of the 1988 IEEE National Radar Conference","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1988-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123428278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}