Phenomenological Model of Scintillation of Infrared Radiation from Point Targets over Water and Measurements of the Model Parameters

摘要

As part of a study of the long range detection of antiship missiles (ASMs) by infrared search and track (IRSI) systems using staring sensors, measurements of scintillation of an infrared source have been made. Scintillation of IR radiation from ASMs is one of a few features which may enhance ASM detectability by IRST systems. The measurements were made in the 3-5 micron band at ranges of 17 km and 19.9 km over water. The data were used to provide values for parameters of a phenomenological model of scintillation for use in development of detection algorithms. The parameters were the magnitude of irradiance, blurring effects and image location, and the correlation coefficients of these parameters. It was found that the probability distribution for the irradiance fluctuations was log-Gaussian, as predicted by theory. There was a temporal correlation for each of the parameters which was quantified by a correlation time, but none of the parameters were correlated with any other. Approximate methods were developed for correcting the data for the finite pixel size effects of the camera and the blurring effect of the optics.