A mathematical model of the airborne light detection and ranging (LiDAR) system based on the GM-APD arrays is established in the behavioral level. The model adopts Poisson probability distribution to calculate the intensity of the echo-laser-signal. After the detection, the range of the target is obtained by the time-of-flight (ToF) method. Then, the system outputs the range and intensity images taking advantages of the peak-value algorithm. The sources and the impact of the noise are analyzed in the model. In condition of 3km distance, 33uJ laser pulse energy, 20 KHz repetition frequency and 200 accumulations each period, the simulation results show that the system is capable to get clear pictures of the target in distance with 1 miscount per frame time. The standard deviation of the calculated range is 0.0219m. The model also demonstrates the validity of capturing the moving target. The proposed model is suitable in systematic design of the airborne LiDAR, which is promising in civil and military applications.
Polarization imaging focuses on degrees of linear polarization (DoLP) and angles of polarization (AoP). This paper introduces a polarization imaging set which employs a LWIR polarization imaging system along with a set of cooperative self-made target panels to acquire polarized radiation. The sampling flowchart is given and the process of polarization acquisition demonstrated. The experiment shows that larger the observation angle, stronger DoLP signal and weaker radiance lowers the contrast of polarization image.
Equivalent extinction ratio and polarization orientation are two significant parameters representing the performance of a polarized pixel in an integrated micropolarizer array camera. With manufacturing and integrating errors of the micropolarizer array, equivalent extinction ratios are nonuniform and polarization orientations of polarized pixels deviate from their nominal values. Measuring the equivalent extinction ratio and the polarization orientation of each polarized pixel by rotating a polarizer at a tiny step is extremely time-consuming and even inaccurate. Therefore, this paper proposes a calibration method for the equivalent extinction ratio and the polarization orientation of each polarized pixel. Its principle is derived by theorizing the relationship between an orientation of a linearly polarized incident light and its digital output of a polarized pixel. In experiment, this derived principle is applied to an integrated micropolarizer array camera. Experimental result proves that calibrated equivalent extinction ratios generally vary from 4.5 to 10, with a mean of 7.939 and a standard variation of 1.053.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.