Obtaining spectral information from infrared scenarios using hyper-spectral cameras and cameras with spinning filter wheel

Abstract

In the past decades the Norwegian Defence Research Establishment (FFI) has recorded and characterized infrared scenarios for several application purposes, such as infrared target and background modeling and simulation, model validation, atmospheric propagation, and image segmentation and target detection for civilian and defence purposes. During the last year FFI has acquired several new systems for characterization of infrared radiation properties. In total, five new infrared cameras from IRCAM GmbH, Germany, have been acquired. These cameras cover both the longwavelength and extended medium-wavelength infrared spectral bands. The cameras are equipped with fast rotating filter wheels which can be used to study spectral properties and polarization effects within these wavelength bands. This option allows the sensors to operate in user-defined spectral bands. FFI has also acquired two HyperCam sensors from Telops Inc, Canada, covering the long-wavelength and extended medium-wavelength spectral bands, respectively. The combination of imaging detectors and Fourier Transform spectroscopy allows simultaneous spectral and spatial characterization of infrared scenarios. These sensors may optionally be operated as high-speed infrared cameras. A description of the new sensors and their capabilities are presented together with some examples of results acquired by the different sensors. In this paper we present a detailed comparison of images taken in different spectral bands, and also compare images taken with the two types of sensors. These examples demonstrate the principles of how the new spectral information can be used to separate certain targets from the background based on the spectral information.