Camouflaged target recognition realized by AOTF multispectral imaging system

The multispectral imaging system taking an acousto-optic tunable filter (AOTF) as the spectrometer is proposed to overcome the weak points of the traditional spectrometers which have some moving parts and can not perform the real-time wavelength selection. The system is composed of lens, AOTF, AOTF driver, CCD camera and image acquisition unit, and can obtain images in the spectral range of 500nm～1000nm. The spectrum is selected at random by controlling the AOTF, thus the wavelengths at different bands that have typical target characteristics are purposefully chosen, and the different images for the same targets are acquired at different wavelengths. Several tests for the recognition of the target characteristics were performed in lab and field environment with camouflage pattern, helmet and plants. Reflectance characteristics of objects were obtained at different spectral bands, and images of the discriminating targets were acquired from their backgrounds. The experiments confirm that the multispectral imaging system based on AOTF can change and select the spectral band quickly in real time, it has the ability of detecting and recognizing camouflaged targets, and can discriminate the camouflaged targets from backgrounds. Moreover, the system has many merits, such as compact and high-speed spectral sensitivity as well as without moving parts.