Spectral Background Subtraction Errors in Infrared Field Measurements Made with Fourier Transform Spectrometers

摘要

The measurement of infrared spectra of tactical aircraft has been a mainstay in providing signatures for both analysis and simulation to missile seeker designers for many years. Whereas many modern air vehicles have seen their intrinsic infrared signatures reduced over time, the variation in atmospheric backgrounds remains a natural phenomenon which has placed limitations on both operational characteristics of field measurement and the accuracy with which weak targets may be characterized. This paper presents a heuristic method for reducing errors introduced by natural variations in backgrounds in spectral background subtraction. The motivation behind the new technique is discussed as well as the theoretical development of the new technique to reduce spectral background induced errors. An example showing measurements of a small model aircraft are presented with both corrected and uncorrected results. These results are contrasted with apriori expectations of the aircraft signature to provide specific instances when uncorrected background induced errors can limit the measurement accuracy of weak or suppressed air vehicles.