Effect of system point spread function, apparent size, and detector instantaneous field of view on the infrared image contrast of small objects

Analysis of point-target detection performance based on ATF and TSF

“…However, unlike extended object detection described above, when image size of observed object is somewhat smaller or comparable to detector size, the object cannot be resolved by system. In this case, optical blurring limits image size of object, and changes light-intensity distribution in the scope of the detector [1,2,9], shown as Fig. 1.…”

“…Its image size is much smaller than detector size. This limiting case is of much interest, where the system is viewing point-target [1][2][3]9,[11][12][13]. In point-target detection, optical blurring must be taken into account, especially when system is operated in infrared band where optics diffraction causes more distortion to point-target image [1,2,9].…”

“…Analysis of object detection performance has been developed for several decades [1][2][3][4]6], and is still a valid challenge for performance evaluation of electro-optical imaging system [1,2,[9][10]. Now technologies of object detection, to most extent, rely on object acquisition model.…”

“…In other words, in order to detect object that is of interest, it is often to use detector to collect flux emanating from objects and transmitting optical system, and to traditionally consider its output voltage as system response [1][2][3]. In spite of a large amount of literature that dedicated to object detection [1][2][3][9][10][11][12][13], it still has not been studied thoroughly due to the fact that most people consider object detection under the assumption of ideal imaging [1][2][3]10]. People often simply assume ideal imaging case, where the effects of any image-degradation factors during the object acquisition process are ignored [1][2][3]10].…”

“…This limiting case is of much interest, where the system is viewing point-target [1][2][3]9,[11][12][13]. In point-target detection, optical blurring must be taken into account, especially when system is operated in infrared band where optics diffraction causes more distortion to point-target image [1,2,9]. Mathematically, blurring degree is measured by optical response index, which is the only parameter of Gaussian Point Spread Function (PSF) [9], while its effect upon system response can be represented by Aperiodic Transfer Function (ATF) and Target Size Function (TSF) [1,2].…”