Ms. Catherine Barrat Profile

Catherine Barrat

at HGH Systèmes Infrarouges

SPIE Involvement:

Author

Proceedings Article | 20 September 2020 Presentation + Paper

Improved modulation transfer function evaluation method of a camera at any field point with a scanning tilted knife edge

Etienne Homassel, Catherine Barrat, Frédéric Alves, Gilles Aubry, Guillaume Arquetoux

Proc. SPIE. 11537, Electro-Optical and Infrared Systems: Technology and Applications XVII

KEYWORDS: Modulation, Cameras, Diagnostics, Collimators, Modulation transfer functions, Algorithm development, Optics manufacturing, Prototyping, Device simulation, Design for manufacturability

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Modulating Transfer Function (MTF) has always been very important and useful for objectives quality definition and focal plane settings. This measurand provides the most relevant information on the optimized design and manufacturing of an optical system or the correct focus of a camera. MTF also gives out essential information on which defaults or aberrations appear on an optical objective, and so enables to diagnose potential design or manufacturing issues on a production line or R&D prototype. Test benches and algorithms have been defined and developed in order to satisfy the growing needs in optical objectives qualification as the latter become more and more critical in their accuracy and quality specification. Many methods are used to evaluate the Modulating Transfer Function. Slit imaging and scanning on a camera, MTF evaluation thanks to wavefront measurement or imaging fixed slanted knife edge on the detector of the camera. All these methods have pros and cons, some lack in resolution, accuracy or don’t enable to compare simulated MTF curves with real measured data. These methods are firstly reminded in this paper. HGH has recently developed an improved and mixed version of a scanning technique used on a slanted knife edge giving a more accurate, ergonomic, high resolution and precise Line Spread Function (LSF) and one axis MTF measurement of a camera. A selected single pixel corresponding to a precise field point of the camera is scanned with sub pixelic resolution by the tilted knife edge thus enabling an optimized accuracy for LSF and MTF curves. The experimental protocol which requires a high-performance collimator, a scanning wheel device and a camera set up is detailed in this paper. Explained simulations are done to prove the under 1% accuracy of this method with regards to the different characteristics of the camera. All the parameters of this improved measurement technique are described and their effect criticized to give out all the result influence of these variables. These simulations and the algorithms used are then confronted to real measurements on a camera thanks to a mirror-based collimator and a scanning wheel device equipped with a slanted knife edge target.

Proceedings Article | 20 June 2019 Presentation + Paper

Advancing the performance of extended area blackbody sources in order to stay ahead of the IR camera improvements

Stephen Scopatz, Catherine Barrat

Proc. SPIE. 11001, Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XXX

KEYWORDS: Staring arrays, Infrared cameras, Nonuniformity corrections, Infrared sensors, Infrared imaging, Cameras, Sensors, Black bodies, Electro optics, Temperature metrology

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Proceedings Article | 9 October 2018 Presentation + Paper

Influence of ambient temperature on the radiation of IR reference sources: effect on the calibration of IR sensors and method of compensation

Catherine Barrat, Alex Audouin, Gauthier Auvray

Proc. SPIE. 10795, Electro-Optical and Infrared Systems: Technology and Applications XV

KEYWORDS: Infrared sensors, Sensors, Calibration, Black bodies, Infrared radiation, Sensor calibration, Temperature metrology

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Proceedings Article | 6 October 2017 Presentation + Paper

Extension to NIR and visible ranges of high-resolution relative spectral response measurement using Fourier Transform Infrared Spectrometer (FTIR) of CMOS FPAs

Catherine Barrat, Thierry Lepot, Michael Ramamonjisoa, Sébastien Fradcourt

Proc. SPIE. 10433, Electro-Optical and Infrared Systems: Technology and Applications XIV

KEYWORDS: Staring arrays, Near infrared, Visible radiation, FT-IR spectroscopy, Sensors, Spectroscopy, Fourier transforms, Spectral resolution, Helium neon lasers, Signal detection

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Proceedings Article | 21 October 2016 Presentation + Paper

A practical implementation of high resolution relative spectral response measurement of CMOS IRFPAs using Fourier Transform Infrared Spectrometer (FTIR)

Catherine Barrat, Thierry Lepot, Michael Ramamonjisoa, Sébastien Fradcourt

Proc. SPIE. 9987, Electro-Optical and Infrared Systems: Technology and Applications XIII

KEYWORDS: Infrared sensors, Mirrors, FT-IR spectroscopy, Sensors, Spectroscopy, Infrared spectroscopy, Black bodies, Spectral resolution, Monochromators, Signal detection

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Proceedings Article | 13 October 2015 Paper

Evaluating uniformity of IR reference sources

Catherine Barrat, Sébastien Violleau

Proc. SPIE. 9649, Electro-Optical Remote Sensing, Photonic Technologies, and Applications IX

KEYWORDS: Infrared cameras, Thermography, Infrared sensors, Cameras, Sensors, Calibration, Black bodies, Infrared radiation, Radiometry, Temperature metrology

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Proceedings Article | 7 October 2014 Paper

Evaluating performances of vacuum dedicated blackbodies

Catherine Barrat, Vincent Leboucher

Proc. SPIE. 9241, Sensors, Systems, and Next-Generation Satellites XVIII

KEYWORDS: Thermography, Infrared sensors, Reflection, Sensors, Calibration, Satellites, Ray tracing, Black bodies, Infrared radiation, Temperature metrology

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Proceedings Article | 25 October 2013 Paper

Improving cooling of cavity blackbodies

Catherine Barrat, Gildas Chauvel

Proc. SPIE. 8896, Electro-Optical and Infrared Systems: Technology and Applications X

KEYWORDS: Infrared sensors, Infrared imaging, Calibration, Coating, Manufacturing, Black bodies, Infrared radiation, Convection, Infrared technology, Temperature metrology

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Showing 5 of 8 publications

Conference Committee Involvement (1)

SPIE Security + Defence

9 September 2019 | Strasbourg, France

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