A study of IRFPA camera measurement errors: radiometric artefacts

Abstract

Infrared Focal Plane Array cameras have several aberrations and measurement artefacts with different material origins: lenses, sensors, Read-Out-Circuits of the sensors. The authors' goal is to characterize each artefact separately to obtain more versatile correction procedures and improve the correction accuracy. This paper focuses on some radiometric artefacts associated with variations of measured illuminance. It presents a new correction algorithm dedicated to Narcissus and vignetting effects, which is identified and validated for two different lenses. It also proposes an innovative experimental protocol to detect low-level contrast-induced artefacts. Several R&D cameras and lenses are tested and some present such artefacts, which can not be corrected by traditional pixel-to-pixel methods. Their origins are shown to derive either from the optical system or the Read-Out-Circuit.

Experimental study by full field measurement techniques of the stress gradients effect under fretting, fretting-fatigue and notch fatigue

“…The employed infrared camera should be first of all calibrated, this process is considered as the key parameter in the termographic measurement. Several calibration techniques can be found in literature, such as the non-uniformity correction [15], and the radiometric artefact treatment [16]. A pixel to pixel calibration process was used in this work as in [17].…”

Infrared thermography coupled with digital image correlation in studying plastic deformation on the mesoscale level

“…Recently, it has become realizable thanks to the development of full-field measurement techniques, e.g., infrared thermography (IRT) for measuring temperature field [11][12][13] and digital image correlation (DIC) method for accessing displacement and strain fields [14][15][16][17][18][19]. These techniques have the advantages of non-contact, real-time, full-field measurement and high precision.…”

Unsteady data reduction techniques for QIRT: considerations of temporal and spatial resolution

“…Although the FPA systems offer many benefits over single detector system, additional sources of uncertainty and error due to the larger sensor size (sensor non-uniformity, optical aberrations) and more complicated read-out circuitry (ghosting) could be identified, causing the single detector system to remain the preferred choice for purists. For an overview of the performance and specific characteristics of FPA IR cameras the reader is referred to the papers of Pron and Bissieux (2004), Levesque et al (2005) and Poncelet et al (2011).…”