FIELD: technical physics.
SUBSTANCE: invention relates to technical physics and can be used for qualimetry of aviation digital optoelectronic systems (SOES) with optical radiation receivers that provide registration of digital images with a bit depth of 8 bits. The substance of the claimed method for determining the modulation transfer function (MTF) of aviation SOES is as follows. Linear worlds of the visible range are placed on the ground, then aerial photography of the area with the line worlds located on it is performed at a priori given values of the altitude and flight course of the aircraft. Next, the obtained images are decoded, the numerical values of the spatial frequencies of the stroke world corresponding to the recognized groups of strokes are determined. At the same time, image contrasts are determined for each spatial frequency based on measurements by each decoder of pixel illuminations in tone level values from 0 to 255, which make up images of light and dark strokes of recognized groups of stroke targets. The modulation transfer coefficients for each spatial frequency are calculated as the ratio of the obtained image contrasts to the actual modulation contrast of the stroked world. Next, a graphical view of the MTF is determined in the form of a graph of the dependence of the calculated modulation transfer coefficients on the spatial frequency and an analytical form of the MTF in the form of an empirical dependence, approximating the constructed dependence of the modulation transfer coefficients on the spatial frequency by an exponential function using LSM.
EFFECT: reducing the time for flight tests of the SOES due to the reduction in the number of flight experiments necessary to obtain an estimate of the linear resolution on the ground, through the use of the MTF obtained in accordance with the claimed method.
1 cl, 1 dwg, 1 tbl
