High-resolution Laser Imaging Technique

High resolution laser imaging is a new developing technique, which is applied to military scouting widely, and is attended by many military departments. The technology of high resolution laser imaging could provide high graphics with an angular resolution of nrad, thereby could satisfy the demands of the modern battlefields. So it is necessary to work on the research of this technique.Two methods of high resolution laser imaging are discussed in this paper, which is supported by the fund of the national key lab. One is the Active Fourier Telescopy (afterward named"AFT"for short), another is"Spectrum shifting". The main content of this paper as follows: First of all, The imaging principle in theory of the AFT is analyzed: The spatial spectrum of the target is extracted while the three fringes moving across the target, then the image is reconstructed use the algorithms. The technology of spectrum extracted, the phase close and the influence of atmosphere turbulence are analyzed. Deduced the elements of the"Spectrum shifting": Use the resting fringe illuminate target many times, take pictures of the illuminated target, process the pictures by algorithms, at last, abtain the high resolution image of the target. Second, The process is simulated by MATLAB. When C_n²=10¹⁴m^-2/3, C_n²= 10¹⁵m^-2/3 and C_n²=10¹⁶m^-2/3, the phase screens are produced under the Kolmogorov and the Von Karman spectrum separately. On the basis of above, the laser beam propagates through the turbulence is simulated. The AFT imaging process of one dimensional object is simulated, and the simulation of"spectrum shifting"is accomplished.At last, The results of the simulation is analyzed. When the laser beams propagate through atmosphere turbulence, the interference fringes have little distortion as the transmitter apertures become wider . The fringes are good while the laser beams propagating through the middle and the weak turbulence in horizontal path. The reconstructed image isn't distortion by the technology of AFT. The image abtained by the"Spectrum shifting"have high resolution .