ABSTRACT: 
In order to provide a wider field of view and higher spatial resolution to meet requirement for a typical earth observation mission, 
the project to developing wide field of view hyperspectral imager is applied. The widener of field of view of the hyperspectal imager 
composed of one objective aperture and one dispersing element, not only is limited by the difficulty that the large area detector 
arrays is got, but also is limited by the difficulty of optical coupling efficiency's aspect of the optical system. This paper addresses 
the difficulty of developing wide field of view imaging sensor and presents the project to developing wide field of view 
hyperspectral imager. The project adopts one wide field of view objective lens and one long slit, but more dispersing element and 
detector arrays. The lens images a ground belt onto the long entrance slit, the slit acts as a field stop and allow only light from a 
linear belt in the scene to enter the imager. The light passing through the long slit is divided more equal parts using a special skill 
and it is separated and imaged on the area detector arrays by the more spectrometer. An optical head of wide field of view 
hyperspectral imager is composed of a large field of view lens, a long entrance slit, two spectrometers and two area detector arrays 
and has a cross-track field of view of 60 degrees. The lens is used to a camera lens and images a ground belt onto the long entrance 
slit. The above half of long silt is the entering silt of one dispersing element and the below half of the long silt is the entering silt of 
the other dispersing element. The light passing through the entering silt is collimated by the collimator and is separated into some 
parallel monochromatic lights with different angle by the dispersing element. Finally, these monochromatic lights are focused on the 
detector area array. By image preprocessing, the hyperspectral image of the wide field of view can be got. The main specialty of the 
development is: 1) the model is only composed a objective, it will reduce the difficulty and the workload of image preprocessing; 2) 
the model’s plasticity is very strong, if the hyperspectral imager composed of two dispersing elements will have been developed, it 
can be extended to imager composed of more than two dispensing elements. 
1. INTRODUCTION 
Hyperspectral remote sensing technology, which is called 
image spectral remote sensing, is one of the most important 
progresses on remote sensing in last 20 years of the 20’Th 
century. Imaging spectrometry for Earth observation was 
developed over the last decades by different government 
agencies, together with industries and universities for different 
countries. It has many names in the remote sensing community, 
including imaging spectrometry, hyperspectral, and 
ultraspectral imaging. Imaging spectrometry combines the 
image technology of traditional remote sensing and spectrum 
analysis technology. Taking advantage of combination, we can 
identify and investigate the physical character of the terrene, 
analysis the compound element, and detect the spatial character 
simultaneously [U2 \ Hyperspectral imagers, as known as 
imaging spectrometers, are powerful tools for collecting 
spectral information of object. With the development of 
airborne and spacebome hyperspectral imaging instrument, 
hyperspectral remote sensing image data became more and 
more popular, more and more researcher found it’s unique 
function in resource management, agriculture, forestry, mining 
investigation, environment inspection, etc 11 ' 91 . 
Hyperspectral Imagers can not only know spectral distribution 
of disparate materials, but also identify geometry of observation 
area [3 l An airborne pushbroom hyperspectal imager is usually 
composed of an objective aperture, an entrance slit, a collimator, 
a dispersing element and a rectangular detector array. As figure 
1 shown, the objective aperture is used to a camera lens and 
images a ground belt onto the entrance slit. The slit acts as a 
field stop and allow only light from a linear belt in the scene to 
enter the imager. The light passing through the slit is collimated 
by the collimator and is separated into some parallel 
monochromatic lights with different angle by the dispersing 
element. Finally, these monochromatic lights are focused on 
different pixels on the detector area array by the imager. 
The spectrum of each spatial pixel is dispersed along the 
spectral dimension of the detector area array (the along-track 
airplane direction) and the image of the scene projected through 
the slit is aligned along the spatial dimension of the detector 
area (the cross-track airplane direction). As the aircraft move 
forward, the along-track spatial dimension of the scene is 
constructed. Image projected on the slit change and the imager 
acquires new frames of data continuously. At last, a three- 
* hzping@mail.sitp.ac.cn; phone: +86-21-65420850-43403; Fax: +86-21-65169925; http://www.sitp.ac.cn; Shanghai Institute of 
Technical Physics, Chinese Academy of Sciences, Shanghai 200083