Hyper-spectral imaging using an optical fiber transition element

The Bi-static optical Imaging Sensor (BOIS) is a 2-D imaging sensor that operates in the short-wave infra-red (SWIR) spectral regime over wavelengths from approximately 1.0 to 2.4 microns. The conceptual design of the sensor is based on integral field spectroscopy techniques. The BOIS sensor utilizes a fiber transition element consisting of multiple optical fibers to map the 2-D spatial input scene into a 1-D linear array for injection into a hyper-spectral imaging (HSI) sensor. The HSI spectrometer acquires fast time resolution snapshots (60 Hz) of the entire input target scene in numerous narrowband spectral channels covering the SWIR spectral band. The BOIS sensor is developed to spatially observe the fast time-evolving radiative signature of targets over a variety of spectral bands, thus simultaneously characterizing the overall scene in four dimensions: 2 spatial, wavelength, and time. We describe the successful design, operation, and testing of a laboratory prototype version of the BOIS sensor as well as further development of a field version of the sensor. The goal of the laboratory prototype BOIS sensor was to validate the proof-of-concept ability in the 4-D measurement concept of this unique design. We demonstrate the 2-D spatial remapping of the input scene (using SWIR laser and blackbody cavity sources) in multiple spectral channels from the spatial versus spectral pixel output of the HSI snapshot. We also describe algorithms developed in the data processing to retrieve temperatures of the observation scene from the hyper-spectral measurements.