Hyperspectral imaging systems

Abstract

Hyperspectral imaging system and methods that may be used for imaging objects in three-dimensions are disclosed. A cylindrical lens array and/or a slit array may be used to re-image and divide a field of view into multiple channels. The multiple channels are dispersed into multiple spectral signatures and observed on a two-dimensional focal plane array in real time. The entire hyperspectral data cube is collected simultaneously.

1 . A method of forming a hyperspectral data cube, comprising the steps of:
 forming an image by imaging optics;   dividing the formed image, by a spectrometer, into multiple channels;   refocusing the multiple channels into multiple spectral signatures on a focal plane array;   associating each of the multiple spectral signatures with a respective one of multiple bars formed by a corresponding one of a cylindrical lens array of the focal plane array;   recording at least one spectral image on the focal plane array from the multiple bars; and   processing location and spectral information of the recorded at least one spectral image to form the hyperspectral data cube.   
     
     
         2 . The method of  claim 1 , further comprising the step of forming a respective pupil image from each of the multiple channels. 
     
     
         3 . The method of  claim 2 , further comprising a step of focusing each respective pupil image as a corresponding one of the multiple bars on an image plane of the focal plane array. 
     
     
         4 . The method of  claim 1 , further comprising a step of sampling the formed image by the cylindrical lens array. 
     
     
         5 . The method of  claim 1 , wherein the step of refocusing is performed in conjunction with at least one of a collimating lens, a dispersive element, and a focusing lens. 
     
     
         6 . The method of  claim 5 , wherein the multiple bars run continuously in the X-direction and are spaced in the Y-direction. 
     
     
         7 . The method of  claim 6 , wherein a spatial resolution is according to the spacing of the multiple bars in the Y-direction. 
     
     
         8 . The method of  claim 6 , wherein each of the multiple bars is dispersed in the Y-direction so as to not overlap with respective adjacent ones of the multiple bars. 
     
     
         9 . The method of  claim 8 , wherein a direction of dispersion of the multiple bars is perpendicular to an orientation of the multiple bars. 
     
     
         10 . The method of  claim 8 , wherein a length of the multiple spectral signatures is determined by a dispersive power of the dispersive element. 
     
     
         11 . The method of  claim 7 , wherein the spatial resolution is further determined by at least one of a zoom collimating lens, a relay lens, and variable dispersion prism. 
     
     
         12 . The method of  claim 1 , wherein the imaging optics image faster than f/5. 
     
     
         13 . The method of  claim 1 , wherein the cylindrical lens array is at or near to an image plane of the imaging optics. 
     
     
         14 . The method of  claim 1 , wherein the imaging optics include at least one of a Cassegrain and refractive optical elements. 
     
     
         15 . The method of  claim 1 , wherein the hyperspectral data cubes is collected at a speed of a digital detector array. 
     
     
         16 . A hyperspectral imaging system, comprising:
 a focal plane array;   a grating-free spectrometer for dividing a field of view into multiple channels as bars and for reimaging the multiple channels as multiple spectral signatures onto the focal plane array; and   a processor connected with the focal plane array for forming a hyperspectral data cube from the multiple spectral signatures.