## 1 Introduction  
Hyperspectral images (HSI) are defined as images containing fine spectra of reflected light with a spectral resolution of 1-10 nm per image pixel [1]. Providing both spectral and spatial information, HSI has the abilities to discriminate objects with a high degree of confidence and has been used in many areas, such as target detection [2; 3; 4], environment monitoring [5; 6] and disease detection [7; 8; 9]. However, traditional HSI is a passive imaging technology, depending on sunlight to measure the reflected light from objects. Useful HSI data requires available sun for no more than 7 hours every day, depending on the location and time of year. Cloud cover also reduces illumination and limits the use of the passive HSI data. Besides, in scenarios such as shadows, caves or underwater, passive HSI system has difficulty detecting the optical information of objects effectively, and thus, applications of passive HSI are strictly limited [10]. In order to operate in environments with limited or even no sunlight, a broadband light source must be aligned with the field of the view of the hyperspectral imager to record the reflected spectra from objects, which can extend the operating envelope of HSI to 24 hours and eliminate the shadows that alter the measured spectral signature. So far, there are two choices of the light sources to illuminate targets: halogen lamps and supercontinuum (SC) lasers. Compared to halogen lamps, SC lasers not only can produce broad continuous spectrum, but can produce a spatially coherent, nearly diffraction-limited beam with high brightness that can extend the working distance up to kilometers [2, 11, 12]. So far, a few explorations have been done. In 1999, the first active HSI system with a SC laser was put forward by MIT Lincoln Laboratory [13]. The authors concluded that SC laser could provide HSI system with great promise in concealed and obscured target detection. Limited by the output power of SC lasers, active HSI witnessed a slow development [14]. Until 2013, [PERSON] et al. used a 5 W all-fiber SC laser to illuminate the targets placed 1.6 km away from the laser. The spectra of different targets were seen to be in good agreement with in-lab measurements under a lamp source [11]. Most recently in our previous work [2], a 4.5 W all-fiber SC laser was used to illuminate different objects and record their hyperspectral image data. The work demonstrated that the Gaussian-like distribution of the SC illuminator can still be used for accurate reflected spectrum measurement once the illuminator was characterized in advance, and it also indicates that an active HSI system illuminated by a SC laser with tailored spectrum has advantages over passive HSI system. Compared with the progress of the active HSI hardware, active image processing methods do not receive enough attention. It is worth noting that, for various applications of HSI, object classification lays a crucial foundation and significant part, which aims for identification of those objects depicted in HSI by analyzing spectral and spatial features [15]. So far, only a few methods have been used to deal with the active HSI classification tasks. In the first active HSI system [13], Spectral Angel Mapper (SAM) was used to detect the man-made targets contained in the scene, which computed the angles in \(n\) dimensional (\(n\) is the number of spectral bands) spectral space between the reference spectra and the spectrum of each pixel. In [1, 16], Support Vector Machine (SVM) method was applied to perform the classification, which separates classes by selecting a set of hyperplanes that maximize the distance between the nearest training samples and the hyperplanes. At present, these methods still cannot achieve high classification performance for active HSI.