Alain Bergeron - Academia.edu (original) (raw)

Papers by Alain Bergeron

Research paper thumbnail of Wideband response of a terahertz-millimeter imager based on a 384x288 pixel uncooled bolometric detector

Research paper thumbnail of Wideband response of a terahertz-millimeter imager based on a 384x288 pixel uncooled bolometric detector

International Conference on Space Optics — ICSO 2014, 2017

Research paper thumbnail of <title>Automatic inspection using correlation of range images</title>

Proceedings of SPIE, May 24, 2000

The departure between a reference range image and an acquired one is assessed using correlation. ... more The departure between a reference range image and an acquired one is assessed using correlation. Decision criteria have been defined. Performance of coding and filtering are discussed. Results obtained on a Vander Lugt correlator with two twisted nematic spatial light modulators are given.

Research paper thumbnail of Optical Correlator for Landing and Identification of Landing Sites

Research paper thumbnail of A SAR multilook optronic processor for operational Earth monitoring applications

Proceedings of SPIE, Oct 7, 2010

Synthetic Aperture Radar (SAR) is the only remote sensing technology that can provide high resolu... more Synthetic Aperture Radar (SAR) is the only remote sensing technology that can provide high resolution images in adverse weather conditions and in day or night times. It is thus is a powerful tool for Earth monitoring. Certain applications, such as disaster relief, military reconnaissance and ice-flow and ship monitoring require a continuous flow of high-resolution images covering large areas; however,

Research paper thumbnail of Satellite on-board real-time SAR processor prototype

I. INTRODUCTION A Compact Real-Time Optronic S A R P ro c e s s o r h a s b e e n s u c c e s s f... more I. INTRODUCTION A Compact Real-Time Optronic S A R P ro c e s s o r h a s b e e n s u c c e s s f u l ly d e v e lo p e d a nd t e s t e d u p t o a Technology Readiness Level of 4 (TRL4), the breadboard validation in a laboratory environment. SAR, or Synthetic Aperture Radar, is an active system allowing day and night imaging independent of the cloud coverage of the planet. The SAR raw data is a set of complex data for range and azimuth, which cannot be compressed. Specifically, for planetary missions and unmanned aerial vehicle (UAV) systems with limited communication data rates this is a clear disadvantage. SAR images are typically processed electronically applying dedicated Fourier transformations. This, however, can also be performed optically in real-time. Originally the first SAR images were optically processed. The optical Fourier processor architecture provides inherent parallel computing capabilities allowing real-time SAR data processing a n d t h u s t h e a b i l i t y f o r c o m p r e s s i o n a n d s t r o n g l y r e d u c e d c o m m u n i c a t i o n b a n d w i d t h requirements for the satellite.

Research paper thumbnail of Basis for optronic ScanSAR processing

Proceedings of SPIE, Oct 6, 2011

ABSTRACT

Research paper thumbnail of Optical Correlator for Real-Time Rendez-Vous and Docking

57th International Astronautical Congress, Oct 2, 2006

Research paper thumbnail of Recording Binary Holograms On Small Supports For Pattern Recognition

Proceedings of SPIE, May 24, 1988

ABSTRACT

Research paper thumbnail of Lightweight compact optical correlator for spacecraft docking

Proceedings of SPIE, Oct 5, 2007

Spacecraft docking, landing and star tracking are critical operations in various space missions. ... more Spacecraft docking, landing and star tracking are critical operations in various space missions. Docking provides the opportunity to joint two vehicles in order to change crews and deliver resources to a spacecraft. One of the main challenges in docking is to perform real-time tracking of the docking point for a precise and rapid feedback to the control system in order to achieve reliable operations. The same requirements are found for landing operations and star-tracking with main difference that the ground or sky is used for position and attitude tracking. Docking operations found multiple earth counterpart applications. Many of these earth-based applications concern the use of robotic devices to grab a specific object. In these cases various location parameters of the object are needed, such as rotation angle, scale and position. INO has developed a compact lightweight optical correlator prototype. This prototype provides a tool for the evaluation of various applications. In collaboration with ESA, INO studied the use of an optical correlator for selected space applications such as rendez-vous and docking, landing and star tracking operations. Optical correlator provides beyond real-time image processing capabilities and is well suited for target identification and positioning purpose. The optical correlator also shows low power consumption. In this paper, the latest analyses of the docking and landing applications are presented. For evaluation purpose, video sequences of Soyuz docking the International Space Station (ISS) were used. In the case of landing, moon images acquired in the SMART-1 mission, during its last orbits, were used. Mt. Wilson telescope images were used for star tracking examples.

Research paper thumbnail of Introducing Real-Time On-Board SAR Image Generation using an Optronic SAR Processor

Synthetic Aperture Radar (EUSAR), 2010 8th European Conference on, Jun 7, 2010

ABSTRACT

Research paper thumbnail of A global review of optronic synthetic aperture radar/ladar processing

Proceedings of SPIE, May 31, 2013

ABSTRACT

Research paper thumbnail of Optical SAR processor for space applications

Proceedings of SPIE, Apr 3, 2008

Synthetic Aperture Radar (SAR) systems typically generate copious amounts of data in the form of ... more Synthetic Aperture Radar (SAR) systems typically generate copious amounts of data in the form of complex values difficult to compress. Processing this data provides real-valued images that are easier to compress, however comprehensive processing capabilities are required. Optical processor architectures provide inherent parallel computing capabilities that could be used advantageously for SAR data processing. Onboard SAR image generation would provide local access to processed information paving the way for real-time decisions. This could also provide benefits to navigation strategy or automatic instruments orientation. Moreover, for interplanetary missions or unmanned aerial vehicles (UAVs), onboard analysis of images could provide important feature identification clues and could help select the appropriate images to be transmitted to the ground (Earth). This would reduce the data throughput requirements and the related transmission bandwidth. This paper reviews the preliminary work performed for the analysis of SAR image generation using an optical processor and describes the set-up of an optical SAR processor prototype. Results of optical reconstruction of SAR signals acquired with a state-of-the-art SAR satellite are presented. Real-time processing capabilities and dynamic range calculations for a tracking optical processor architecture are also discussed.

Research paper thumbnail of Improved 2x2 pixel computer-generated holographic matched filters

Proceedings of SPIE, 1990

Improved 2x2 pixel computer-generated holographic matched filters for spatial light modulators. [... more Improved 2x2 pixel computer-generated holographic matched filters for spatial light modulators. [Proceedings of SPIE 1211, 267 (1990)]. Alain Bergeron, Gilbert V. April, Henri H. Arsenault. Abstract. An improved computer-generated ...

Research paper thumbnail of Reconfigurable real-time optronic processor for altitude and look angle adaptability for ENVISAT/ASAR scene observation

Research paper thumbnail of Real-time optical processor prototype for remote SAR applications

Proceedings of SPIE, Sep 17, 2009

A Compact Real-Time Optical SAR Processor has been successfully developed and tested. SAR, or Syn... more A Compact Real-Time Optical SAR Processor has been successfully developed and tested. SAR, or Synthetic Aperture Radar, is a powerful tool providing enhanced day and night imaging capabilities. SAR systems typically generate large amounts of information generally in the ...

Research paper thumbnail of Extended capability overview of real-time optronic SAR processing

Research paper thumbnail of Introducing sub-wavelength pixel THz camera for the understanding of close pixel-to-wavelength imaging challenges

Proceedings of SPIE, May 1, 2012

ABSTRACT Conventional guidelines and approximations useful in macro-scale system design can becom... more ABSTRACT Conventional guidelines and approximations useful in macro-scale system design can become invalidated when applied to the smaller scales. An illustration of this is when camera pixel size becomes smaller than the diffraction-limited resolution of the incident light. It is sometimes believed that there is no benefit in having a pixel width smaller than the resolving limit defined by the Raleigh criterion, 1.22 λ F/#. Though this rarely occurs in today&#39;s imaging technology, terahertz (THz) imaging is one emerging area where the pixel dimensions can be made smaller than the imaging wavelength. With terahertz camera technology, we are able to achieve sub-wavelength pixel sampling pitch, and therefore capable of directly measuring if there are image quality benefits to be derived from sub-wavelength sampling. Interest in terahertz imaging is high due to potential uses in security applications because of the greater penetration depth of terahertz radiation compared to the infrared and the visible. This paper discusses the modification by INO of its infrared MEMS microbolometer detector technology toward a THz imaging platform yielding a sub-wavelength pixel THz camera. Images obtained with this camera are reviewed in this paper. Measurements were also obtained using microscanning to increase sampling resolution. Parameters such as imaging resolution and sampling are addressed. A comparison is also made with results obtained with an 8-12 μm band camera having a pixel pitch close to the diffractionlimit.

Research paper thumbnail of THz imaging and radiometric measurements using a microbolometer-based camera

A THz VOx-based 160×120 microbolometer FPA camera with 52 μm pixel pitch has been developed at IN... more A THz VOx-based 160×120 microbolometer FPA camera with 52 μm pixel pitch has been developed at INO. Radiometric NEP values have been measured at different wavelengths. Real-time video-rate reflectance imaging using large beam area from a high-power FIR optically pumped THz laser has been also performed, demonstrating high sensitivity for stand alone applications.

Research paper thumbnail of Catadioptric optics for high-resolution terahertz imager

Proceedings of SPIE, May 1, 2012

ABSTRACT INO has developed infrared camera systems with microscanning capabilities in order to in... more ABSTRACT INO has developed infrared camera systems with microscanning capabilities in order to increase image resolution. It has been shown in previous works that the image quality may be improved even if the pixel pitch is smaller than the point spread function. This paper introduces a catadioptric optics system with fully integrated microscan for improved resolution in the THz band. The design, inspired by the INO&#39;s HRXCAM infrared camera core and adapted for terahertz wavelengths, includes two mirrors and one refractive element. It has a 11.9 degree full field of view and an effective F-number of 1.07 over a wide spectral range, from 100 μm to 1.5 mm wavelength. This diffraction limited optics is used to provide video rate high quality THz images. A THz camera, with 160 x 120 pixel and 52 μm pitch detector, is combined with the microscan objective to provide a 320 x 240 pixel image with a 26 μm sampling step. Preliminary imaging results using a THz illumination source at 118 μm wavelength are presented. A comparison between standard and microscanned images is also presented.

Research paper thumbnail of Wideband response of a terahertz-millimeter imager based on a 384x288 pixel uncooled bolometric detector

Research paper thumbnail of Wideband response of a terahertz-millimeter imager based on a 384x288 pixel uncooled bolometric detector

International Conference on Space Optics — ICSO 2014, 2017

Research paper thumbnail of <title>Automatic inspection using correlation of range images</title>

Proceedings of SPIE, May 24, 2000

The departure between a reference range image and an acquired one is assessed using correlation. ... more The departure between a reference range image and an acquired one is assessed using correlation. Decision criteria have been defined. Performance of coding and filtering are discussed. Results obtained on a Vander Lugt correlator with two twisted nematic spatial light modulators are given.

Research paper thumbnail of Optical Correlator for Landing and Identification of Landing Sites

Research paper thumbnail of A SAR multilook optronic processor for operational Earth monitoring applications

Proceedings of SPIE, Oct 7, 2010

Synthetic Aperture Radar (SAR) is the only remote sensing technology that can provide high resolu... more Synthetic Aperture Radar (SAR) is the only remote sensing technology that can provide high resolution images in adverse weather conditions and in day or night times. It is thus is a powerful tool for Earth monitoring. Certain applications, such as disaster relief, military reconnaissance and ice-flow and ship monitoring require a continuous flow of high-resolution images covering large areas; however,

Research paper thumbnail of Satellite on-board real-time SAR processor prototype

I. INTRODUCTION A Compact Real-Time Optronic S A R P ro c e s s o r h a s b e e n s u c c e s s f... more I. INTRODUCTION A Compact Real-Time Optronic S A R P ro c e s s o r h a s b e e n s u c c e s s f u l ly d e v e lo p e d a nd t e s t e d u p t o a Technology Readiness Level of 4 (TRL4), the breadboard validation in a laboratory environment. SAR, or Synthetic Aperture Radar, is an active system allowing day and night imaging independent of the cloud coverage of the planet. The SAR raw data is a set of complex data for range and azimuth, which cannot be compressed. Specifically, for planetary missions and unmanned aerial vehicle (UAV) systems with limited communication data rates this is a clear disadvantage. SAR images are typically processed electronically applying dedicated Fourier transformations. This, however, can also be performed optically in real-time. Originally the first SAR images were optically processed. The optical Fourier processor architecture provides inherent parallel computing capabilities allowing real-time SAR data processing a n d t h u s t h e a b i l i t y f o r c o m p r e s s i o n a n d s t r o n g l y r e d u c e d c o m m u n i c a t i o n b a n d w i d t h requirements for the satellite.

Research paper thumbnail of Basis for optronic ScanSAR processing

Proceedings of SPIE, Oct 6, 2011

ABSTRACT

Research paper thumbnail of Optical Correlator for Real-Time Rendez-Vous and Docking

57th International Astronautical Congress, Oct 2, 2006

Research paper thumbnail of Recording Binary Holograms On Small Supports For Pattern Recognition

Proceedings of SPIE, May 24, 1988

ABSTRACT

Research paper thumbnail of Lightweight compact optical correlator for spacecraft docking

Proceedings of SPIE, Oct 5, 2007

Spacecraft docking, landing and star tracking are critical operations in various space missions. ... more Spacecraft docking, landing and star tracking are critical operations in various space missions. Docking provides the opportunity to joint two vehicles in order to change crews and deliver resources to a spacecraft. One of the main challenges in docking is to perform real-time tracking of the docking point for a precise and rapid feedback to the control system in order to achieve reliable operations. The same requirements are found for landing operations and star-tracking with main difference that the ground or sky is used for position and attitude tracking. Docking operations found multiple earth counterpart applications. Many of these earth-based applications concern the use of robotic devices to grab a specific object. In these cases various location parameters of the object are needed, such as rotation angle, scale and position. INO has developed a compact lightweight optical correlator prototype. This prototype provides a tool for the evaluation of various applications. In collaboration with ESA, INO studied the use of an optical correlator for selected space applications such as rendez-vous and docking, landing and star tracking operations. Optical correlator provides beyond real-time image processing capabilities and is well suited for target identification and positioning purpose. The optical correlator also shows low power consumption. In this paper, the latest analyses of the docking and landing applications are presented. For evaluation purpose, video sequences of Soyuz docking the International Space Station (ISS) were used. In the case of landing, moon images acquired in the SMART-1 mission, during its last orbits, were used. Mt. Wilson telescope images were used for star tracking examples.

Research paper thumbnail of Introducing Real-Time On-Board SAR Image Generation using an Optronic SAR Processor

Synthetic Aperture Radar (EUSAR), 2010 8th European Conference on, Jun 7, 2010

ABSTRACT

Research paper thumbnail of A global review of optronic synthetic aperture radar/ladar processing

Proceedings of SPIE, May 31, 2013

ABSTRACT

Research paper thumbnail of Optical SAR processor for space applications

Proceedings of SPIE, Apr 3, 2008

Synthetic Aperture Radar (SAR) systems typically generate copious amounts of data in the form of ... more Synthetic Aperture Radar (SAR) systems typically generate copious amounts of data in the form of complex values difficult to compress. Processing this data provides real-valued images that are easier to compress, however comprehensive processing capabilities are required. Optical processor architectures provide inherent parallel computing capabilities that could be used advantageously for SAR data processing. Onboard SAR image generation would provide local access to processed information paving the way for real-time decisions. This could also provide benefits to navigation strategy or automatic instruments orientation. Moreover, for interplanetary missions or unmanned aerial vehicles (UAVs), onboard analysis of images could provide important feature identification clues and could help select the appropriate images to be transmitted to the ground (Earth). This would reduce the data throughput requirements and the related transmission bandwidth. This paper reviews the preliminary work performed for the analysis of SAR image generation using an optical processor and describes the set-up of an optical SAR processor prototype. Results of optical reconstruction of SAR signals acquired with a state-of-the-art SAR satellite are presented. Real-time processing capabilities and dynamic range calculations for a tracking optical processor architecture are also discussed.

Research paper thumbnail of Improved 2x2 pixel computer-generated holographic matched filters

Proceedings of SPIE, 1990

Improved 2x2 pixel computer-generated holographic matched filters for spatial light modulators. [... more Improved 2x2 pixel computer-generated holographic matched filters for spatial light modulators. [Proceedings of SPIE 1211, 267 (1990)]. Alain Bergeron, Gilbert V. April, Henri H. Arsenault. Abstract. An improved computer-generated ...

Research paper thumbnail of Reconfigurable real-time optronic processor for altitude and look angle adaptability for ENVISAT/ASAR scene observation

Research paper thumbnail of Real-time optical processor prototype for remote SAR applications

Proceedings of SPIE, Sep 17, 2009

A Compact Real-Time Optical SAR Processor has been successfully developed and tested. SAR, or Syn... more A Compact Real-Time Optical SAR Processor has been successfully developed and tested. SAR, or Synthetic Aperture Radar, is a powerful tool providing enhanced day and night imaging capabilities. SAR systems typically generate large amounts of information generally in the ...

Research paper thumbnail of Extended capability overview of real-time optronic SAR processing

Research paper thumbnail of Introducing sub-wavelength pixel THz camera for the understanding of close pixel-to-wavelength imaging challenges

Proceedings of SPIE, May 1, 2012

ABSTRACT Conventional guidelines and approximations useful in macro-scale system design can becom... more ABSTRACT Conventional guidelines and approximations useful in macro-scale system design can become invalidated when applied to the smaller scales. An illustration of this is when camera pixel size becomes smaller than the diffraction-limited resolution of the incident light. It is sometimes believed that there is no benefit in having a pixel width smaller than the resolving limit defined by the Raleigh criterion, 1.22 λ F/#. Though this rarely occurs in today&#39;s imaging technology, terahertz (THz) imaging is one emerging area where the pixel dimensions can be made smaller than the imaging wavelength. With terahertz camera technology, we are able to achieve sub-wavelength pixel sampling pitch, and therefore capable of directly measuring if there are image quality benefits to be derived from sub-wavelength sampling. Interest in terahertz imaging is high due to potential uses in security applications because of the greater penetration depth of terahertz radiation compared to the infrared and the visible. This paper discusses the modification by INO of its infrared MEMS microbolometer detector technology toward a THz imaging platform yielding a sub-wavelength pixel THz camera. Images obtained with this camera are reviewed in this paper. Measurements were also obtained using microscanning to increase sampling resolution. Parameters such as imaging resolution and sampling are addressed. A comparison is also made with results obtained with an 8-12 μm band camera having a pixel pitch close to the diffractionlimit.

Research paper thumbnail of THz imaging and radiometric measurements using a microbolometer-based camera

A THz VOx-based 160×120 microbolometer FPA camera with 52 μm pixel pitch has been developed at IN... more A THz VOx-based 160×120 microbolometer FPA camera with 52 μm pixel pitch has been developed at INO. Radiometric NEP values have been measured at different wavelengths. Real-time video-rate reflectance imaging using large beam area from a high-power FIR optically pumped THz laser has been also performed, demonstrating high sensitivity for stand alone applications.

Research paper thumbnail of Catadioptric optics for high-resolution terahertz imager

Proceedings of SPIE, May 1, 2012

ABSTRACT INO has developed infrared camera systems with microscanning capabilities in order to in... more ABSTRACT INO has developed infrared camera systems with microscanning capabilities in order to increase image resolution. It has been shown in previous works that the image quality may be improved even if the pixel pitch is smaller than the point spread function. This paper introduces a catadioptric optics system with fully integrated microscan for improved resolution in the THz band. The design, inspired by the INO&#39;s HRXCAM infrared camera core and adapted for terahertz wavelengths, includes two mirrors and one refractive element. It has a 11.9 degree full field of view and an effective F-number of 1.07 over a wide spectral range, from 100 μm to 1.5 mm wavelength. This diffraction limited optics is used to provide video rate high quality THz images. A THz camera, with 160 x 120 pixel and 52 μm pitch detector, is combined with the microscan objective to provide a 320 x 240 pixel image with a 26 μm sampling step. Preliminary imaging results using a THz illumination source at 118 μm wavelength are presented. A comparison between standard and microscanned images is also presented.