We developed new real-time algorithm, based on the correlation function, for concealed object detection using computer processing of the passive THz images without their viewing. This algorithm allows us to make a conclusion about presence of forbidden objects on the human body. To increase the THz image quality we propose a new algorithm in comparison with algorithms which have developed by us early. It allows to increase a temperature resolution of the passive THz camera at least 20 times. This approach is based on a correlation function application for computer processing of the raw THz image. The correlation computing occurs between characteristics of the raw THz image, produced by the passive THz camera, and characteristics of a standard image corresponding to one of the detecting objects (knife, gun,…). The standard image moves in two directions along a image under analysis. As a result, 2 D correlation function is obtained. Multiplying this function by color number belonging to a grey scale, we restore the image under the analysis. This allows to suppress a noise on a new image. This algorithm is very convenient for using and has a high performance. Developed approach opens also new type of algorithms for the passive THz image quality enhancing.
{"title":"New way for concealed object detection using passive THz images without their viewing","authors":"V. Trofimov, V. V. Trofimov","doi":"10.1117/12.2195810","DOIUrl":"https://doi.org/10.1117/12.2195810","url":null,"abstract":"We developed new real-time algorithm, based on the correlation function, for concealed object detection using computer processing of the passive THz images without their viewing. This algorithm allows us to make a conclusion about presence of forbidden objects on the human body. To increase the THz image quality we propose a new algorithm in comparison with algorithms which have developed by us early. It allows to increase a temperature resolution of the passive THz camera at least 20 times. This approach is based on a correlation function application for computer processing of the raw THz image. The correlation computing occurs between characteristics of the raw THz image, produced by the passive THz camera, and characteristics of a standard image corresponding to one of the detecting objects (knife, gun,…). The standard image moves in two directions along a image under analysis. As a result, 2 D correlation function is obtained. Multiplying this function by color number belonging to a grey scale, we restore the image under the analysis. This allows to suppress a noise on a new image. This algorithm is very convenient for using and has a high performance. Developed approach opens also new type of algorithms for the passive THz image quality enhancing.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123470290","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}
Yanhua Lu, Guo-bin Fan, Huaijin Ren, Lei Zhang, Xiafei Xu, Wei Zhang, Min Wan
An 81 W average-power all-solid-state sodium beacon laser at 589 nm with a repetition rate of 250 Hz is introduced, which is based on a novel sum frequency generation idea between two high-energy, different line widths, different beam quality infrared lasers (a 1064 nm laser and a 1319 nm laser). The 1064 nm laser, which features an external modulated CW single frequency seed source and two stages of amplifiers, can provide average-power of 150 W, beam quality M2 of ~1.8 with ultra-narrow line width (< 100 kHz). The 1319 nm laser can deliver average-power of 100 W, beam quality M2 of ~3.0 with a narrow line width of ~0.3 GHz. By sum frequency mixing in a LBO slab crystal (3 mm x 12 mm x 50 mm), pulse energy of 325 mJ is achieved at 589 nm with a conversion efficiency of 32.5 %. Tuning the center wavelength of 1064 nm laser by a PZT PID controller, the target beam’s central wavelength is accurately locked to 589.15910 nm with a line width of ~0.3 GHz, which is dominated mainly by the 1319 nm laser. The beam quality is measured to be M2 < 1.3. The pulse duration is measured to be 150 μs in full-width. To the best of our knowledge, this represents the highest average-power for all-solid-state sodium beacon laser ever reported.
{"title":"High-average-power narrow-line-width sum frequency generation 589 nm laser","authors":"Yanhua Lu, Guo-bin Fan, Huaijin Ren, Lei Zhang, Xiafei Xu, Wei Zhang, Min Wan","doi":"10.1117/12.2194900","DOIUrl":"https://doi.org/10.1117/12.2194900","url":null,"abstract":"An 81 W average-power all-solid-state sodium beacon laser at 589 nm with a repetition rate of 250 Hz is introduced, which is based on a novel sum frequency generation idea between two high-energy, different line widths, different beam quality infrared lasers (a 1064 nm laser and a 1319 nm laser). The 1064 nm laser, which features an external modulated CW single frequency seed source and two stages of amplifiers, can provide average-power of 150 W, beam quality M2 of ~1.8 with ultra-narrow line width (< 100 kHz). The 1319 nm laser can deliver average-power of 100 W, beam quality M2 of ~3.0 with a narrow line width of ~0.3 GHz. By sum frequency mixing in a LBO slab crystal (3 mm x 12 mm x 50 mm), pulse energy of 325 mJ is achieved at 589 nm with a conversion efficiency of 32.5 %. Tuning the center wavelength of 1064 nm laser by a PZT PID controller, the target beam’s central wavelength is accurately locked to 589.15910 nm with a line width of ~0.3 GHz, which is dominated mainly by the 1319 nm laser. The beam quality is measured to be M2 < 1.3. The pulse duration is measured to be 150 μs in full-width. To the best of our knowledge, this represents the highest average-power for all-solid-state sodium beacon laser ever reported.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122193399","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}
S. Bigotta, K. Diener, T. Ibach, L. Geiss, G. Stöppler, J. Schöner, M. von Salisch, M. Eichhorn
The Er3+:YAG Solid State Heat-Capacity Laser (SSHCL) as a source for medium and high energy laser systems in the “eye-safe” range is currently under investigation at ISL. The aim is to obtain a robust laser source with low complexity, high beam quality (M2 < 3) and scalable to 100 kW and beyond. In a SSHCL the laser medium is cooled only after the laser action has ended, resulting in low temperature gradients in the laser medium itself during operation. Previous investigations demonstrated the scalability of the SSHCL and up to 4.65 kW and 440 J in less than 800 ms have been achieved. Optical-to-optical efficiencies of more than 41% and slope efficiencies of over 51% has been obtained. The residual thermal gradients, due to non perfect pumping homogeneity, negatively affect the performance in terms of laser pulse energy, duration and beam quality. Using an intra-cavity adaptive optics system, beam aberrations were limited to less than 1/10 of the wavelength for each of the considered Zernike polynomials, and the shot duration lengthened by about 50%. In this paper we investigate how to further increase the SSHCL pulse duration. The influence of the crystal geometry on the pump distribution homogeneity and the pulse duration are analysed. We consider the use of a mechanical crystal changer for extending the laser pulse duration. By using a revolver with several crystals, we demonstrated that crystals can be correctly positioned in less than 100 ms, allowing a quasi-cw operation that can largely exceed the time constraints imposed by the heating of the crystal. Finally, we address the problem of measuring the laser beam quality. Since the current standard techniques are suitable only for stable cw lasers, they cannot be used for the SSHCL. A new kind of device, capable of measuring the M2 at intervals of less than 100 ms, is presented.
{"title":"Recent advances in Er3+:YAG solid-state heat-capacity technology","authors":"S. Bigotta, K. Diener, T. Ibach, L. Geiss, G. Stöppler, J. Schöner, M. von Salisch, M. Eichhorn","doi":"10.1117/12.2197681","DOIUrl":"https://doi.org/10.1117/12.2197681","url":null,"abstract":"The Er3+:YAG Solid State Heat-Capacity Laser (SSHCL) as a source for medium and high energy laser systems in the “eye-safe” range is currently under investigation at ISL. The aim is to obtain a robust laser source with low complexity, high beam quality (M2 < 3) and scalable to 100 kW and beyond. In a SSHCL the laser medium is cooled only after the laser action has ended, resulting in low temperature gradients in the laser medium itself during operation. Previous investigations demonstrated the scalability of the SSHCL and up to 4.65 kW and 440 J in less than 800 ms have been achieved. Optical-to-optical efficiencies of more than 41% and slope efficiencies of over 51% has been obtained. The residual thermal gradients, due to non perfect pumping homogeneity, negatively affect the performance in terms of laser pulse energy, duration and beam quality. Using an intra-cavity adaptive optics system, beam aberrations were limited to less than 1/10 of the wavelength for each of the considered Zernike polynomials, and the shot duration lengthened by about 50%. In this paper we investigate how to further increase the SSHCL pulse duration. The influence of the crystal geometry on the pump distribution homogeneity and the pulse duration are analysed. We consider the use of a mechanical crystal changer for extending the laser pulse duration. By using a revolver with several crystals, we demonstrated that crystals can be correctly positioned in less than 100 ms, allowing a quasi-cw operation that can largely exceed the time constraints imposed by the heating of the crystal. Finally, we address the problem of measuring the laser beam quality. Since the current standard techniques are suitable only for stable cw lasers, they cannot be used for the SSHCL. A new kind of device, capable of measuring the M2 at intervals of less than 100 ms, is presented.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121870677","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}
C. Pargmann, T. Hall, F. Duschek, T. Fischbach, Karin Grünewald, Kirsten Klaffki, J. Thieser, J. Handke
The transmission of high power laser radiation through the air is influenced by atmospheric turbulence. As a result the beam experiences variations regarding its position and its distribution, which increase with increasing propagation length. In order to analyze the atmospheric influence on the laser beam propagation a disk laser with a maximum output power of 6 kW and a wavelength of 1.03 μm is operated on the 130 m long free transmission laser test range at Lampoldshausen. The test range is equipped with a variety of sensors, which continuously monitor the current status of the weather conditions. Power sensors and camera systems at the beginning and the end of the test range measure the laser beam parameters before and after propagation. First measurements of atmospheric power transmission, diameter change of the laser beam and deviation of its center of gravity are performed on a sunny and on a rainy day and are compared with turbulence strength, visibility and rainfall. The results show good correlation between the optical parameters and the weather conditions. Following measurements will be performed at different weather conditions and seasons. Experimental results will be compared to a numerical analysis.
{"title":"Experimental and numerical analysis of atmospheric propagation of high energy laser","authors":"C. Pargmann, T. Hall, F. Duschek, T. Fischbach, Karin Grünewald, Kirsten Klaffki, J. Thieser, J. Handke","doi":"10.1117/12.2194783","DOIUrl":"https://doi.org/10.1117/12.2194783","url":null,"abstract":"The transmission of high power laser radiation through the air is influenced by atmospheric turbulence. As a result the beam experiences variations regarding its position and its distribution, which increase with increasing propagation length. In order to analyze the atmospheric influence on the laser beam propagation a disk laser with a maximum output power of 6 kW and a wavelength of 1.03 μm is operated on the 130 m long free transmission laser test range at Lampoldshausen. The test range is equipped with a variety of sensors, which continuously monitor the current status of the weather conditions. Power sensors and camera systems at the beginning and the end of the test range measure the laser beam parameters before and after propagation. First measurements of atmospheric power transmission, diameter change of the laser beam and deviation of its center of gravity are performed on a sunny and on a rainy day and are compared with turbulence strength, visibility and rainfall. The results show good correlation between the optical parameters and the weather conditions. Following measurements will be performed at different weather conditions and seasons. Experimental results will be compared to a numerical analysis.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124990428","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}
Ship defense system with a pulsed COIL (Chemical Oxygen-Iodine Laser) has been considered. One of the greatest threats for battle ships and carriers in warfare are supersonic anti-ship cruise missiles (ASCMs). A countermeasure is considered to be a supersonic RAM (Rolling Airframe Missile) at first. A gun-type CIWS (Close-In Weapon System) should be used as the last line of defense. However since an ASCM can be detected at only 30-50km away due to radar horizon, a speed-of-light weapon is desirable as the first defense especially if the ASCM flies at >Mach 6. Our previous report explained several advantages of a giant pulse from a chemical oxygen laser (COL) to shoot down supersonic aircrafts. Since the first defense has the target distance of ~30km, the use of COIL is better considering its beam having high transmissivity in air. Therefore efficient operation of a giant-pulsed COIL has been investigated with rate-equation simulations. The simulation results indicate that efficient single-pass amplification can be expected. Also a design example of a giant-pulsed COIL MOPA (master oscillator and power amplifier) system has been shown, in which the output energy can be increased without limit.
{"title":"Considerations of a ship defense with a pulsed COIL","authors":"K. Takehisa","doi":"10.1117/12.2197523","DOIUrl":"https://doi.org/10.1117/12.2197523","url":null,"abstract":"Ship defense system with a pulsed COIL (Chemical Oxygen-Iodine Laser) has been considered. One of the greatest threats for battle ships and carriers in warfare are supersonic anti-ship cruise missiles (ASCMs). A countermeasure is considered to be a supersonic RAM (Rolling Airframe Missile) at first. A gun-type CIWS (Close-In Weapon System) should be used as the last line of defense. However since an ASCM can be detected at only 30-50km away due to radar horizon, a speed-of-light weapon is desirable as the first defense especially if the ASCM flies at >Mach 6. Our previous report explained several advantages of a giant pulse from a chemical oxygen laser (COL) to shoot down supersonic aircrafts. Since the first defense has the target distance of ~30km, the use of COIL is better considering its beam having high transmissivity in air. Therefore efficient operation of a giant-pulsed COIL has been investigated with rate-equation simulations. The simulation results indicate that efficient single-pass amplification can be expected. Also a design example of a giant-pulsed COIL MOPA (master oscillator and power amplifier) system has been shown, in which the output energy can be increased without limit.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131094036","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}
Manpads offer a severe threat to both civilian and military airborne platforms. The present countermeasure systems include platform maneuver, flares and DIRCM systems. Recently an increasing interest is aimed at preemptive measures e.g. to detect, identify and counter the threat before any missile has been launched. This will emphasize the importance of detecting and analyzing other signatures than those treated in conventional DIRCM systems. These may include laser emission from the target, detection of retro-reflections from optical sights and seekers as well as the optical signatures of the weapon and operator including the aiming and tracking activity. We will exemplify some of the concepts by experimental results and discuss some of the system and technology challenges.
{"title":"Potential of preemptive DIRCM systems","authors":"O. Steinvall","doi":"10.1117/12.2201133","DOIUrl":"https://doi.org/10.1117/12.2201133","url":null,"abstract":"Manpads offer a severe threat to both civilian and military airborne platforms. The present countermeasure systems include platform maneuver, flares and DIRCM systems. Recently an increasing interest is aimed at preemptive measures e.g. to detect, identify and counter the threat before any missile has been launched. This will emphasize the importance of detecting and analyzing other signatures than those treated in conventional DIRCM systems. These may include laser emission from the target, detection of retro-reflections from optical sights and seekers as well as the optical signatures of the weapon and operator including the aiming and tracking activity. We will exemplify some of the concepts by experimental results and discuss some of the system and technology challenges.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129956998","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}
D. Seiffer, C. Eisele, M. Henriksson, L. Sjöqvist, Sebastian Möller, F. Togna, M. Velluet
The performance of electro-optical platform protection systems can be degraded significantly by the propagation environment around the platform. This includes aero-optical effects and zones of severe turbulence generated by engine exhausts. For helicopters rotor tip vortices and engine exhaust gases that are pressed down by the rotor airflow form the so called downwash phenomena. The downwash is a source for perturbations. A wide range of spatial and temporal fluctuations in the refractive index of air can occur. The perturbations from the turbulent flow cause detrimental effects on energy delivery, angle of arrival fluctuations, jam-code transmission, tracking accuracy and imaging performance in general. Therefore the effects may especially have a severe impact on the performance of laser-based protection systems like directed infrared countermeasures (DIRCM). The chain from passive missile detection and warning to obtaining an optical break-lock by the use of an active laser system will be influenced. To anticipate the installed performance of an electro-optical defensive aids suite (DAS) for helicopter platforms it is necessary to develop models for the prediction of the perturbations. Modelled results have to be validated against experimental findings. However, the data available in open literature on the effects of rotor downwash from helicopters on optical propagation is very limited. To collect necessary data and to obtain a first impression about the magnitude of occurring effects the European defence agency group (EDA) on “airborne platform effects on lasers and warning sensors (ALWS)” decided to design and perform a field trial on the premises of the Italian Air Force Flight Test Center in Pratica di Mare, Italy. ALWS is a technical arrangement under the Europa MoU among France, Germany, Italy, Sweden and the United Kingdom.
{"title":"Quantification of helicopter rotor downwash effects on electro-optical defensive aids suites","authors":"D. Seiffer, C. Eisele, M. Henriksson, L. Sjöqvist, Sebastian Möller, F. Togna, M. Velluet","doi":"10.1117/12.2195645","DOIUrl":"https://doi.org/10.1117/12.2195645","url":null,"abstract":"The performance of electro-optical platform protection systems can be degraded significantly by the propagation environment around the platform. This includes aero-optical effects and zones of severe turbulence generated by engine exhausts. For helicopters rotor tip vortices and engine exhaust gases that are pressed down by the rotor airflow form the so called downwash phenomena. The downwash is a source for perturbations. A wide range of spatial and temporal fluctuations in the refractive index of air can occur. The perturbations from the turbulent flow cause detrimental effects on energy delivery, angle of arrival fluctuations, jam-code transmission, tracking accuracy and imaging performance in general. Therefore the effects may especially have a severe impact on the performance of laser-based protection systems like directed infrared countermeasures (DIRCM). The chain from passive missile detection and warning to obtaining an optical break-lock by the use of an active laser system will be influenced. To anticipate the installed performance of an electro-optical defensive aids suite (DAS) for helicopter platforms it is necessary to develop models for the prediction of the perturbations. Modelled results have to be validated against experimental findings. However, the data available in open literature on the effects of rotor downwash from helicopters on optical propagation is very limited. To collect necessary data and to obtain a first impression about the magnitude of occurring effects the European defence agency group (EDA) on “airborne platform effects on lasers and warning sensors (ALWS)” decided to design and perform a field trial on the premises of the Italian Air Force Flight Test Center in Pratica di Mare, Italy. ALWS is a technical arrangement under the Europa MoU among France, Germany, Italy, Sweden and the United Kingdom.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128783081","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}
B. Barmashenko, I. Auslender, S. Rosenwaks, B. Zhdanov, M. Rotondaro, R. Knize
We report on a model of highly efficient static, pulsed K DPAL [Zhdanov et al, Optics Express 22, 17266 (2014)], where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams are assumed. The model shows good agreement between the calculated and measured dependence of the laser power on the incident pump power. In particular, the model reproduces the observed threshold pump power, 22 W (corresponding to pump intensity of 4 kW/cm2), which is much higher than that predicted by the standard semi-analytical models of the DPAL. The reason for the large values of the threshold power is that the volume occupied by the excited K atoms contributing to the spontaneous emission is much larger than the volumes of the pump and laser beams in the laser cell, resulting in very large energy losses due to the spontaneous emission. To reduce the adverse effect of the high threshold power, high pump power is needed, and therefore gas flow with high gas velocity to avoid heating the gas has to be applied. Thus, for obtaining high power, highly efficient K DPAL, subsonic or supersonic flowing-gas device is needed.
{"title":"Modeling of pulsed K DPAL taking into account the spatial variation of the pump and laser intensities in the transverse direction","authors":"B. Barmashenko, I. Auslender, S. Rosenwaks, B. Zhdanov, M. Rotondaro, R. Knize","doi":"10.1117/12.2193579","DOIUrl":"https://doi.org/10.1117/12.2193579","url":null,"abstract":"We report on a model of highly efficient static, pulsed K DPAL [Zhdanov et al, Optics Express 22, 17266 (2014)], where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams are assumed. The model shows good agreement between the calculated and measured dependence of the laser power on the incident pump power. In particular, the model reproduces the observed threshold pump power, 22 W (corresponding to pump intensity of 4 kW/cm2), which is much higher than that predicted by the standard semi-analytical models of the DPAL. The reason for the large values of the threshold power is that the volume occupied by the excited K atoms contributing to the spontaneous emission is much larger than the volumes of the pump and laser beams in the laser cell, resulting in very large energy losses due to the spontaneous emission. To reduce the adverse effect of the high threshold power, high pump power is needed, and therefore gas flow with high gas velocity to avoid heating the gas has to be applied. Thus, for obtaining high power, highly efficient K DPAL, subsonic or supersonic flowing-gas device is needed.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116591117","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}
In the past few decades, laser imaging has demonstrated its potential in delivering accurate range images of objects or scenes, even at long range or under bad weather conditions (rain, fog, day and night vision). We note great improvements in the conception and development of single and multi infrared sensors, concerning embedability, circuitry reading capacity, or pixel resolution and sensitivity, allowing a wide diversity of applications (i.e. enhanced vision, long distance target detection and reconnaissance, 3D DSM generation). Unfortunately, it is often difficult to dispose of all the instruments to compare their performance for a given application. Laser imaging simulation has shown to be an interesting alternative to acquire real data, offering a higher flexibility to perform this sensors comparison, plus being time and cost efficient. In this paper, we present a 3D laser imaging end-to-end simulator using a focal plane array with Geiger mode detection, named LANGDOC. This work aims to highlight the interest and capability of this new generation of photo-diodes arrays, especially for airborne mapping and surveillance of high risk areas.
{"title":"Performance assessment of simulated 3D laser images using Geiger-mode avalanche photo-diode: tests on simple synthetic scenarios","authors":"A. Coyac, L. Hespel, N. Rivière, X. Briottet","doi":"10.1117/12.2194304","DOIUrl":"https://doi.org/10.1117/12.2194304","url":null,"abstract":"In the past few decades, laser imaging has demonstrated its potential in delivering accurate range images of objects or scenes, even at long range or under bad weather conditions (rain, fog, day and night vision). We note great improvements in the conception and development of single and multi infrared sensors, concerning embedability, circuitry reading capacity, or pixel resolution and sensitivity, allowing a wide diversity of applications (i.e. enhanced vision, long distance target detection and reconnaissance, 3D DSM generation). Unfortunately, it is often difficult to dispose of all the instruments to compare their performance for a given application. Laser imaging simulation has shown to be an interesting alternative to acquire real data, offering a higher flexibility to perform this sensors comparison, plus being time and cost efficient. In this paper, we present a 3D laser imaging end-to-end simulator using a focal plane array with Geiger mode detection, named LANGDOC. This work aims to highlight the interest and capability of this new generation of photo-diodes arrays, especially for airborne mapping and surveillance of high risk areas.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114867165","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}
Damian S. Steiger, B. Heim, T. F. Rønnow, M. Troyer
In this paper, we provide an introduction to quantum annealers, which are analogue quantum computing devices, and their potential application to solve hard optimisation problems. We summarise our benchmarks performed on a "Wave Two" machine by Canadian company D-Wave Systems Inc.
在本文中，我们介绍了量子退火，这是模拟量子计算设备，以及它们在解决硬优化问题方面的潜在应用。我们总结了我们在加拿大公司D-Wave Systems Inc.的“Wave 2”机器上进行的基准测试。
{"title":"Performance of quantum annealing hardware","authors":"Damian S. Steiger, B. Heim, T. F. Rønnow, M. Troyer","doi":"10.1117/12.2202661","DOIUrl":"https://doi.org/10.1117/12.2202661","url":null,"abstract":"In this paper, we provide an introduction to quantum annealers, which are analogue quantum computing devices, and their potential application to solve hard optimisation problems. We summarise our benchmarks performed on a \"Wave Two\" machine by Canadian company D-Wave Systems Inc.","PeriodicalId":348143,"journal":{"name":"SPIE Security + Defence","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134190715","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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