Paper presented at SPIE Remote Sensing 2023 by Catherine Barrat
“Low light night vision systems based on I² tubes have been expanding rapidly over the past few years, due to a combination of the growing advancement of this technology and the increased pressure in the current climate.
The design of a single optical bench able to fully characterize night vision devices is presented into this paper, focused more specifically on spot defects and goggle axes parallelism tests.
These criteria are indeed very important: misalignment between the two binocular images may be one source of visual fatigue and could degrade task performance of the night vision user, and spot defects can act as visual distractions and may be large enough to mask critical information pilots need to conduct normal night vision operations.
Thanks to HGH’s IRCOL bench, these two tests are integrated on the same support. Spot defect measurement utilizes machine vision algorithms to determine the size and location of the defects, and the parallelism measurement identifies the angular misalignment between the two channels under test. The spot defect test has also been completely automatized compared to the only visible test previously available
All these results will be compiled and directly integrated into a computer-generated report that can be easily used for quality control or for maintenance applications.”
Paper presented at SPIE 2020 (Digital Edition) conference, by Etienne Homassel, HGH, Optronics project manager
“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.”
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.
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…
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.
Description of the test bench calibrating and measuring the non-uniformity of IR blackbodies with high accuracy
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.
HGH has developed two methods to improve the range of temperature of its blackbodies.
HGH developed tools to demonstrate performances of vacuum dedicated blackbodies, since they surpass the accuracy of usual tools.
CoolSpeed speeds up the cooling time of cavity blackbody
How to select the blackbody fitting your application?
HGH is a electro-optical devices global provider. The company provides wide area surveillance, industrial thermography and electro-optical test solutions.
