Video rate nine-band multispectral short-wave infrared sensor

Abstract

Short-wave infrared (SWIR) imaging sensors are increasingly being used in surveillance and reconnaissance systems due to the reduced scatter in haze and the spectral response of materials over this wavelength range. Typically SWIR images have been provided either as full motion video from framing panchromatic systems or as spectral data cubes from line-scanning hyperspectral or multispectral systems. Here, we describe and characterize a system that bridges this divide, providing nine-band spectral images at 30 Hz. The system integrates a custom array of filters onto a commercial SWIR InGaAs array. We measure the filter placement and spectral response. We demonstrate a simple simulation technique to facilitate optimization of band selection for future sensors.

Increasing Resolution of Multi-Spectral Mosaic-Array Cameras

“…The approximate center wavelengths of the filters are: 999nm, 1111nm, 1431nm, 1240nm, 1512nm, 1054nm, 1601nm, short-pass cut off at about 920nm, and 1192nm. The processing results are demonstrated using imagery collected by the 9-band sensor equipped with f/4 200mm optics [1]. The diffraction limited spot of such optical system is significantly smaller than the pixel pitch allowing for the benefits of both multi-frame and multi-band SR processing.…”

“…Previously, we presented a FMV multispectral camera based on color filter array (CFA) integrated onto a focal plane array (FPA) [1]. Such sensor design requires either binning of spatial information into a reduced spatial resolution image, or additional image processing for upsampling each band's resolution to the full FPA size.…”

Demosaicking for full motion video 9-band SWIR sensor

“…The filter array, made by Pixelteq, consists of nominally 640x512 circular thin film interference filters with 13µm diameters at a pitch of 25µm. 1 An absorptive black coating covers the space between the filters. The filter array is composed of a repeating pattern of 3x3 unit cells.…”

“…One type of FMV, multispectral camera is based on color filter arrays (CFAs) integrated onto focal plane arrays (FPAs). 1 Such sensor design requires either binning of spatial information into a reduced spatial resolution image, or additional image processing to upsample each band's resolution to full FPA size.…”

Spectral Tracking Using an Oblique Looking, Video Rate, 9-Band, SWIR Multispectral Camera

“…Recent sensor development has bridged the divide between these SWIR sensor modalities, providing imagery with 9 spectral bands at video rates. This is accomplished by fixing an array of pixel sized interference filters, arranged in a repeating pattern of 3x3 unit cells, onto a commercial off the shelf SWIR sensitive InGaAs array [2]. Applying target detection algorithms to the video-rate multispectral data from this sensor could increase coverage rates compared to line-scanning imaging spectrometers and facilitate other applications such as spectral object tracking.…”