Detection of a fluctuating IR target using diversity combining techniques

摘要

In telecommunication systems, the receiver diversity combining technique is used for the reliable data transmission. Among many diversity techniques, the selection combining scheme and the equal gain combining scheme are widely used due to their simplicity and high performance. In this paper, we view and analyze the imaging sensor fusion problem (for a point target detection) in terms of the diversity combining technique. We show that the intensity variance of the matched filtered image is similar to the mean of the matched filtered image, and therefore, the intensity of each pixel after the matched filtering fluctuates severely about its mean, so that the target can be missed with a high probability. Our suggestion is to use another statistically identical imaging sensor (in the same spectral band), and to combine the two images using the proposed diversity combining schemes. Under the assumptions that the additive noise is spatially white and the target shape is deterministic, the detection error probabilities are derived analytically each under no diversity combining, selection combining and equal gain combining. Furthermore, the accuracy of the derived error probabilities is verified through extensive Monte-Carlo simulations. Our results clearly reveals the superiority of the diversity combining schemes, and identify particular situations where the performance gain is especially significant for each of the diversity combining techniques.