EO/IR sensor model for evaluating multispectral imaging system performance

Abstract

This paper discusses the capabilities of a EO/IR sensor model developed to provide a robust means for comparative assessments of infrared FPA's and sensors operating in the infrared spectral bands that coincide with the atmospheric windows - SW1 (1.0-1.8mm), sMW (2-2.5mm), MW (3-5mm), and LW (8-12mm). The applications of interest include thermal imaging, threat warning, missile interception, UAV surveillance, forest fire and agricultural crop health assessments, and mine detection. As a true imaging model it also functions as an assessment tool for single-band and multi-color imagery. The detector model characterizes InGaAs, InSb, HgCdTe, QWIP and microbolometer sensors for spectral response, dark currents and noise. The model places the specified FPA into an optical system, evaluates system performance (NEI, NETD, MRTD, and SNR) and creates two-point corrected imagery complete with 3-D noise image effects. Analyses are possible for both passive and active laser illuminated scenes for simulated state-of-the-art IR FPA's and Avalanche Photodiode Detector (APD) arrays. Simulated multispectral image comparisons expose various scene components of interest which are illustrated using the imaging model. This model has been exercised here as a predictive tool for the performance of state-of-the-art detector arrays in optical systems in the five spectral bands (atmospheric windows) from the SW to the LW and as a potential testbed for prototype sensors. Results of the analysis will be presented for various targets for each of the focal plane technologies for a variety of missions.