FIELD: measuring.
SUBSTANCE: invention relates to methods of evaluating linear resolution on terrain (LRT) of digital optoelectronic systems (DOES) of the Earth remote sensing (ERS). Test configurations in which it is necessary to evaluate LRT are determined. One of the test configurations is selected and aerial survey of the area on which the resolution pattern is located is performed. Wherein aircraft equipped with ERS DOES is used. Based on the results of analysing images obtained during the flight, an experimental modulation transfer function (MTF) is plotted and its analytical form is determined in the form of empirical dependence, which approximates the plotted graph by an exponential function of the form ƒ(x) = exp(-(Ax)B) taking into account the determination of the best values of the approximation parameters A and B by the least squares method. Common analytical expression for the MTF of the ERS DOES, which is equal to the product of the MTF of individual ERS DOES links, is used to calculate the MTF for the flight conditions, further reduced to a form similar to the form of an exponential function ƒ(x) = exp(-(Ax)B). Correction coefficient is determined as the ratio of the obtained expressions of the experimental MTF obtained from the flight results and the calculated MTF obtained from the general analytical MTF expression. Common analytical expression of the MTF is made taking into account the calculated correction coefficient, based on which graphs of the corrected MTF are plotted for the given test configurations. Experimental LRT value is determined based on the results of decoding the images of the resolution pattern obtained during the flight by decoder operators. Adaptive threshold contrast index (ATCI) is determined in the form of an ordinate of a point on the experimental MTF graph, the abscissa of which is equal to the value of the spatial frequency corresponding to the found value of the LRT. Further, LRT values are calculated for given test configurations without performing flights, using the constructed graphs of the corrected calculated MTFs and the obtained ATCI values.
EFFECT: high accuracy of estimating LRT when performing calculations.
3 cl, 3 dwg, 1 tbl
