Research On Accuracy Of Double ICCD Gain Modulation Laser Radar

Double ICCD gain modulated imaging laser radar is a type of gain modulated scannerless imaging laser radar. It is based on a single ICCD gain modulated imaging laser radar for improvement. Compared with single ICCD gain modulated imaging laser radar, it can remove the error which is brought by the target motion. Thus, double ICCD gain modulation imaging laser radar can perform 3D imaging for moving targets and give the geometrical morphology of moving targets. By analyzing the geometrical shape we can determine the target state and moving trend and detect more effectively. In the research of imaging laser radar, improvement of ranging accuracy is the key to demonstrating its application value. This paper research the ranging accuracy of double ICCD gain modulated imaging laser radar from theory and experiment.This paper introduces the principle of double ICCD gain modulated imaging laser radar, in which the receiver has two ICCD. The gain of one ICCD increases with time and the other decreases with time monotonically. We can obtain the running time by dividing the two gray-scale images in the gain modulation. First, we deduced the distance equation of the double ICCD linear gain modulation imaging laser radar and deduced ranging accuracy according to the error transfer formula. The parameters of two linear modulated functions are researched by MATLAB. The ranging accuracy of double ICCD gain modulation imaging laser radar are compared with single ICCD. When the initial of double ICCD linear gain function is equal to the initial of single ICCD linear gain function, the results show that the ranging accuracy of double ICCD linear gain modulated imaging laser radar is always higher than the single ICCD linear gain modulated imaging laser radar.Secondly, using the similar methods, distance equation and ranging accuracy of the double ICCD sine, exponential gain modulated imaging laser radar are deduced. For linear, sine, and exponential of three kinds of modulation mode, the ranging accuracy of exponential modulated gain is only dependent upon our SNR and the time constant. Under the MATLAB software to gain double ICCD index modulation the ranging precision of the simulation analysis and contrast with single ICCD. The ranging accuracy of exponential modulated gain is studied by the MATLAB. When the time constants of the double ICCD and single ICCD exponential gain is same, the ranging accuracy of double ICCD exponential gain modulated imaging laser radar is always higher than the single ICCD exponential gain modulated imaging laser radar.Finally, according to the principle of imaging, indoor experiment are designed and built to demonstrate the ranging accuracy of the double ICCD and single ICCD exponential gain modulated imaging laser radar. We test the ranging accuracy of two targets whose distance is 45 m, 45.5 m and 45 m, 46 m in different time constant. Based on the experiment, we make a conclusion that ranging accuracy of double ICCD exponential gain modulated imaging laser radar is higher than that of single ICCD. The ranging accuracy even can reach millimeter magnitude and increase when the time constant decrease.