Trends concerning real-time, high-quality airborne 3D computer image generation systems and flat panel displays are reviewed. It is pointed out that the rapid trend toward the use of full-color display devices and raster graphics image generation systems in the cockpit is in part due to advances in sensors, programmable graphics generators, and electrooptics. Although many newer display and control system technologies have yet to reach maturity for flight applications, the rate of improvement in recent years suggests many new technologies will overcome the present shortcomings during the 1995-2000 time frame. High-performance graphics engines, powerful floating point processors, and massively parallel graphics architectures will be used to increase the rendering speed, functionality, and reliability, while reducing power, space requirements, and cost of cockpit display processors. Flat panel displays will replace dedicated instruments and traditional cathode ray tubes in the cockpit and enhance maintainability, reliability, and crew-system performance.<>
{"title":"The advanced cockpit environment: computer image generation systems and flat panel displays","authors":"A. Bridges","doi":"10.1109/NTC.1991.147988","DOIUrl":"https://doi.org/10.1109/NTC.1991.147988","url":null,"abstract":"Trends concerning real-time, high-quality airborne 3D computer image generation systems and flat panel displays are reviewed. It is pointed out that the rapid trend toward the use of full-color display devices and raster graphics image generation systems in the cockpit is in part due to advances in sensors, programmable graphics generators, and electrooptics. Although many newer display and control system technologies have yet to reach maturity for flight applications, the rate of improvement in recent years suggests many new technologies will overcome the present shortcomings during the 1995-2000 time frame. High-performance graphics engines, powerful floating point processors, and massively parallel graphics architectures will be used to increase the rendering speed, functionality, and reliability, while reducing power, space requirements, and cost of cockpit display processors. Flat panel displays will replace dedicated instruments and traditional cathode ray tubes in the cockpit and enhance maintainability, reliability, and crew-system performance.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128615151","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}
Several new terms denoting new types of radar waveforms (e.g. impulse, nonsinusoidal, monocycle, baseband, and ultra-wideband) have recently emerged. The author attempts to set all of these waveform types in a consistent perspective and to assess the potential performance available from each. The perspective chosen for the waveform cataloging process is the measure of carrier cycles per pulse, or, alternatively, the percent bandwidth. This approach allows all the waveform types to be viewed on the single-parameter scale of percent bandwidth. The potential performance advantages (or disadvantages) of each waveform are discussed in terms of basic radar performance criteria: target detection, target imaging/identification, clutter rejection, and the influence of interference and the propagation medium. These characteristics are reviewed for each of the waveform cases and the relative merits of each are discussed with the intent of discovering which of these capabilities would require a large percent-bandwidth waveform. Implications for unusual component requirements are also addressed.<>
{"title":"Systems considerations for large percent-bandwidth radar","authors":"H. Engler","doi":"10.1109/NTC.1991.148001","DOIUrl":"https://doi.org/10.1109/NTC.1991.148001","url":null,"abstract":"Several new terms denoting new types of radar waveforms (e.g. impulse, nonsinusoidal, monocycle, baseband, and ultra-wideband) have recently emerged. The author attempts to set all of these waveform types in a consistent perspective and to assess the potential performance available from each. The perspective chosen for the waveform cataloging process is the measure of carrier cycles per pulse, or, alternatively, the percent bandwidth. This approach allows all the waveform types to be viewed on the single-parameter scale of percent bandwidth. The potential performance advantages (or disadvantages) of each waveform are discussed in terms of basic radar performance criteria: target detection, target imaging/identification, clutter rejection, and the influence of interference and the propagation medium. These characteristics are reviewed for each of the waveform cases and the relative merits of each are discussed with the intent of discovering which of these capabilities would require a large percent-bandwidth waveform. Implications for unusual component requirements are also addressed.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121145269","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}
A novel stepped frequency chirp waveform concept for increasing the range resolution of an existing pulse compression radar is presented. The stepped frequency chirp technique is ideally suited to obtaining high range resolution in a radar system that has a limited instantaneous bandwidth, but a large tunable bandwidth. To achieve high range resolution using these given bandwidths, two or more chirp waveforms are sequentially transmitted and received at selected carrier frequencies in the tunable bandwidth, and attached together using signal processing techniques to simulate a chirp signal covering up to the entire tunable bandwidth. In contrast to conventional or hybrid stepped frequency methods, the technique achieves both unambiguous range coverage and good range sidelobes without requiring a large number of frequency steps.<>
{"title":"A stepped chirp technique for range resolution enhancement","authors":"F. Mcgroary, K. Lindell","doi":"10.1109/NTC.1991.147999","DOIUrl":"https://doi.org/10.1109/NTC.1991.147999","url":null,"abstract":"A novel stepped frequency chirp waveform concept for increasing the range resolution of an existing pulse compression radar is presented. The stepped frequency chirp technique is ideally suited to obtaining high range resolution in a radar system that has a limited instantaneous bandwidth, but a large tunable bandwidth. To achieve high range resolution using these given bandwidths, two or more chirp waveforms are sequentially transmitted and received at selected carrier frequencies in the tunable bandwidth, and attached together using signal processing techniques to simulate a chirp signal covering up to the entire tunable bandwidth. In contrast to conventional or hybrid stepped frequency methods, the technique achieves both unambiguous range coverage and good range sidelobes without requiring a large number of frequency steps.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123795023","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}
Summary form only given. Lincoln Laboratory is developing an ultra-wideband imaging radar that will be capable of two- and three-dimensional imaging at very close range to a synthetic aperture. The radar is fully coherent over two bandwidths (0.1 to 2 GHz and 2 to 18 GHz) and will be used for target imaging at X and Ku band, and for foliage penetration measurements over the VHF, UHF, and L bands. The radar is a portable scatterometer based on a Hewlett-Packard HP 8510C network analyzer combined with an HP 8360 frequency synthesizer and a Digital MicroVAX III computer. The characteristics of the radar are described, and technical issues arising in the analysis of the close-range imaging techniques are discussed.<>
{"title":"Two- and three-dimensional radar imaging at close range to a synthetic aperture","authors":"S. Verbout, D. Blejer","doi":"10.1109/NTC.1991.148007","DOIUrl":"https://doi.org/10.1109/NTC.1991.148007","url":null,"abstract":"Summary form only given. Lincoln Laboratory is developing an ultra-wideband imaging radar that will be capable of two- and three-dimensional imaging at very close range to a synthetic aperture. The radar is fully coherent over two bandwidths (0.1 to 2 GHz and 2 to 18 GHz) and will be used for target imaging at X and Ku band, and for foliage penetration measurements over the VHF, UHF, and L bands. The radar is a portable scatterometer based on a Hewlett-Packard HP 8510C network analyzer combined with an HP 8360 frequency synthesizer and a Digital MicroVAX III computer. The characteristics of the radar are described, and technical issues arising in the analysis of the close-range imaging techniques are discussed.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116040726","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}
The authors describe how a 265-beam MBA (multibeam antenna) may be used to emulate the performance of a 37-beam MBA. A study of the gain characteristics of a cluster of beams of a 265-beam MBA is performed, and a comparison is made with the gain of a single beam of a 37-beam MBA. It is shown that the composite beam formed by thirteen beams of a 265-beam MBA will provide better gain and coverage characteristics than that of a single beam of a 37-beam MBA.<>
{"title":"Emulation of a 37-beam MBA using a 265-beam MBA","authors":"P. Iversen, L. Ricardi","doi":"10.1109/NTC.1991.148006","DOIUrl":"https://doi.org/10.1109/NTC.1991.148006","url":null,"abstract":"The authors describe how a 265-beam MBA (multibeam antenna) may be used to emulate the performance of a 37-beam MBA. A study of the gain characteristics of a cluster of beams of a 265-beam MBA is performed, and a comparison is made with the gain of a single beam of a 37-beam MBA. It is shown that the composite beam formed by thirteen beams of a 265-beam MBA will provide better gain and coverage characteristics than that of a single beam of a 37-beam MBA.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131408551","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}
An estimation technique based on the autoregressive (AR) modeling of field probe data is used to locate and quantify spurious signals in a compact range. In this technique, the probe aperture is divided into a number of overlapping subapertures such that the far-field criterion for each subaperture is satisfied. Then the subaperture data are modeled as an AR process, and the AR parameters are derived using the principal component forward-backward linear prediction technique. Directions of the incident signals relative to each subaperture are then determined from the poles of the prediction filters. Using a series of subapertures, the locations of the scatterers are estimated by triangulation. After estimation of the spatial frequencies of the probe data for any subaperture, the magnitude of each component is determined by a least squares algorithm. Examples of probe measurements and analysis for the Ohio State University compact range are given.<>
{"title":"Imaging of a compact range using autoregressive spectral estimation","authors":"E. Walton, A. Moghaddar","doi":"10.1109/NTC.1991.148011","DOIUrl":"https://doi.org/10.1109/NTC.1991.148011","url":null,"abstract":"An estimation technique based on the autoregressive (AR) modeling of field probe data is used to locate and quantify spurious signals in a compact range. In this technique, the probe aperture is divided into a number of overlapping subapertures such that the far-field criterion for each subaperture is satisfied. Then the subaperture data are modeled as an AR process, and the AR parameters are derived using the principal component forward-backward linear prediction technique. Directions of the incident signals relative to each subaperture are then determined from the poles of the prediction filters. Using a series of subapertures, the locations of the scatterers are estimated by triangulation. After estimation of the spatial frequencies of the probe data for any subaperture, the magnitude of each component is determined by a least squares algorithm. Examples of probe measurements and analysis for the Ohio State University compact range are given.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124239006","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}
The various ways that high range resolution operation can be achieved in a radar system are reviewed. Both simple pulse and pulse compression techniques are discussed. For the simple approach, monocycle radar, a form of ultra-wideband radar, is emphasized. For the pulse compression approach, both phase and frequency coding of the carrier is considered. for phase coding, the multiplicity of codes and sidelobe suppression filtering techniques are emphasized. For frequency coding, the emphasis is placed on correlational compression, nonlinear frequency modulation, and stepped frequency approaches. Performance analyses are presented, and the strengths and potential drawbacks of each technique are discussed.<>
{"title":"An overview of high range resolution radar techniques","authors":"M. Cohen","doi":"10.1109/NTC.1991.147997","DOIUrl":"https://doi.org/10.1109/NTC.1991.147997","url":null,"abstract":"The various ways that high range resolution operation can be achieved in a radar system are reviewed. Both simple pulse and pulse compression techniques are discussed. For the simple approach, monocycle radar, a form of ultra-wideband radar, is emphasized. For the pulse compression approach, both phase and frequency coding of the carrier is considered. for phase coding, the multiplicity of codes and sidelobe suppression filtering techniques are emphasized. For frequency coding, the emphasis is placed on correlational compression, nonlinear frequency modulation, and stepped frequency approaches. Performance analyses are presented, and the strengths and potential drawbacks of each technique are discussed.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"256 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123284917","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}
Lightweight BFN (beamforming network) implementation based on a hybrid mode technology is described and shown to provide dramatic weight and size reduction relative to waveguide-implemented designs. The hybrid mode technology refers to an integration of microstrip and guided wave media. The basic control element is a ferrite phaser which is significantly reduced in size and weight and which incorporates microstrip input/output circuits. This phaser design, in combination with microstrip circuit components and microstrip transmission line elements, yields a substantial size and weight reduction of the BFN with only a small increase in RF insertion loss. The author provides an overview of this technology, highlighting its features and performance characteristics. Some examples are given.<>
{"title":"Lightweight beamforming networks","authors":"R.W. Kreutel","doi":"10.1109/NTC.1991.148003","DOIUrl":"https://doi.org/10.1109/NTC.1991.148003","url":null,"abstract":"Lightweight BFN (beamforming network) implementation based on a hybrid mode technology is described and shown to provide dramatic weight and size reduction relative to waveguide-implemented designs. The hybrid mode technology refers to an integration of microstrip and guided wave media. The basic control element is a ferrite phaser which is significantly reduced in size and weight and which incorporates microstrip input/output circuits. This phaser design, in combination with microstrip circuit components and microstrip transmission line elements, yields a substantial size and weight reduction of the BFN with only a small increase in RF insertion loss. The author provides an overview of this technology, highlighting its features and performance characteristics. Some examples are given.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122483098","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}
The basic theory of polarimetric radar and various decomposition theories are briefly reviewed. A novel decomposition of the scattering matrix is then presented with special reference to high-resolution imaging. By decomposing the scattering matrix into three different components, it is possible to resolve different types of scatterers even if they are within the same resolution cell of the image. This allows for a better resolution of the target scattering properties as well as a better characterization of the type of scattering for the individual contributions. The usefulness of this decomposition and the advantage in general of utilizing full polarimetric data in connection with radar target imaging are demonstrated by applying the decomposition to simulated images of a complex target model composed of a number of individual scatterers. The extra information contained in the full polarimetric data as compared with single polarization data should greatly improve the possibility of noncooperative target recognition by radar.<>
{"title":"Decomposition of the radar target scattering matrix with application to high resolution target imaging","authors":"E. Krogager","doi":"10.1109/NTC.1991.147990","DOIUrl":"https://doi.org/10.1109/NTC.1991.147990","url":null,"abstract":"The basic theory of polarimetric radar and various decomposition theories are briefly reviewed. A novel decomposition of the scattering matrix is then presented with special reference to high-resolution imaging. By decomposing the scattering matrix into three different components, it is possible to resolve different types of scatterers even if they are within the same resolution cell of the image. This allows for a better resolution of the target scattering properties as well as a better characterization of the type of scattering for the individual contributions. The usefulness of this decomposition and the advantage in general of utilizing full polarimetric data in connection with radar target imaging are demonstrated by applying the decomposition to simulated images of a complex target model composed of a number of individual scatterers. The extra information contained in the full polarimetric data as compared with single polarization data should greatly improve the possibility of noncooperative target recognition by radar.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122971688","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}
Several concepts and formulae are presented that are useful in the examination of the signal-to-noise performance of phased array antennas with dissimilar signal paths or subarray sizes. It is demonstrated that, in most such cases, aperture illumination efficiency remains an accurate indication of array antenna noise performance.<>
{"title":"Phased array noise considerations","authors":"E. Nelson","doi":"10.1109/NTC.1991.148016","DOIUrl":"https://doi.org/10.1109/NTC.1991.148016","url":null,"abstract":"Several concepts and formulae are presented that are useful in the examination of the signal-to-noise performance of phased array antennas with dissimilar signal paths or subarray sizes. It is demonstrated that, in most such cases, aperture illumination efficiency remains an accurate indication of array antenna noise performance.<<ETX>>","PeriodicalId":320008,"journal":{"name":"NTC '91 - National Telesystems Conference Proceedings","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116638646","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}
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