High definition 3D imaging lidar system using CCD

Abstract

In this study we propose and demonstrate a novel technique for measuring distance with high definition three-dimensional imaging. To meet the stringent requirements of various missions, spatial resolution and range precision are important properties for flash LIDAR systems. The proposed LIDAR system employs a polarization modulator and a CCD. When a laser pulse is emitted from the laser, it triggers the polarization modulator. The laser pulse is scattered by the target and is reflected back to the LIDAR system while the polarization modulator is rotating. Its polarization state is a function of time. The laser-return pulse passes through the polarization modulator in a certain polarization state, and the polarization state is calculated using the intensities of the laser pulses measured by the CCD. Because the function of the time and the polarization state is already known, the polarization state can be converted to time-of-flight. By adopting a polarization modulator and a CCD and only measuring the energy of a laser pulse to obtain range, a high resolution three-dimensional image can be acquired by the proposed three-dimensional imaging LIDAR system. Since this system only measures the energy of the laser pulse, a high bandwidth detector and a high resolution TDC are not required for high range precision. The proposed method is expected to be an alternative method for many three-dimensional imaging LIDAR system applications that require high resolution.