Documents techniques

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

    Paper presented at SPIE 2020 (Digital Edition) conference, by Etienne Homassel

    "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."

    Watch the full presentation:

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

    Paper presented at SPIE D&S 2018 conference, by Catherine Barrat 

    Using a blackbody is apparently easy: the emissive surface gets quickly stabilized at the defined setpoint and the controller offers a live display of its temperature with a high resolution. However, the signification of this displayed temperature may be ambiguous especially if the operator is expecting this temperature to be what the tested sensor actually sees. The new generation of HGH’s new controller removes this ambiguity by clearly displaying either the temperature measured by the sensor or the radiated temperature at usual laboratory temperature over the appropriate bandwidth or the radiated temperature over the appropriate bandwidth whatever the room temperature, compatible with demanding applications in climatic chambers. In addition to simplifying the calculation for the operator, it strongly reduces the sources of error which might be of several tenth of degrees.

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  • Influence of current and future developments in IR CMOS detectors on the performances of their testing systems

    Paper presented at OPTRO 2018 conference by Catherine Barrat

    Some significant progresses have been made in performance on Infrared Detectors over the past years. It can be assumed this performance race will never stop and testing equipment of future detectors must be in accordance with these expected results...

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  • CMOS IRFPA spectral response measurement using FTIR - Tech note

    Thanks to its long experience in IR CMOS Focal Plane Arrays testing through the BIRD bench, HGH developed a practical FTIR-based solution for relative high resolution spectral response measurement. Associated with an easy-to-use software and a universal low noise electronics, the bench provides accurate measurements of noises, non-uniformity correction, bad pixel detection and high resolution relative spectral response measurement, all these tests being processed in a few minutes. 

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  • Blackbody Calibration&Uniformity - Tech Note

    Description of the test bench calibrating and measuring the non-uniformity of IR blackbodies with high accuracy

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  • Blackbodies Uniformity - Technical Note

    HGH has developed a testing bench for accurate measurement of uniformity of infrared sources based on a low noise radiometer mounted of translating stages and using an exclusive drift correction method.

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  • Blackbodies with extended T°c ranges - Tech note

    HGH has developed two methods to improve the range of temperature of its blackbodies.

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  • Vacuum blackbodies technical note

    HGH developed tools to demonstrate performances of vacuum dedicated blackbodies, since they surpass the accuracy of usual tools.

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  • CoolSpeed technical note

    CoolSpeed speeds up the cooling time of cavity blackbody

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  • Blackbody selection white paper

    How to select the blackbody fitting your application?

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