Optical tomography based on nonredundant array scanning holography

A novel technique termed nonredundant array scanning holography based on the principle of optical heterodyne scanning holography and the tomographic technique of coded aperture imaging is proposed. The system designed in terms of this technique codes an object optically and decodes its coded image digitally. It can realize optical tomograms of three-dimensional objects. It also has potentially practical value due to its compact structure. The computer simulations present the principle of the technique. Some experiments at the proof-principle level are performed to test the principle.

Computer generated hologram from full-parallax 3D image data captured by scanning vertical camera array(Invited Paper)

Full-parallax light-field is captured by a small-scale 3D image scanning system and applied to holographic display. A vertical camera array is scanned horizontally to capture full-parallax imagery, and the vertical views between cameras are interpolated by depth image-based rendering technique. An improved technique for depth estimation reduces the estimation error and high-density light-field is obtained. The captured data is employed for the calculation of computer hologram using ray-sampling plane. This technique enables high-resolution display even in deep 3D scene although a hologram is calculated from ray information, and thus it makes use of the important advantage of holographic 3D display.

Terahertz Transmission Imaging with 2.52 THz Continuous Wave

In this article, two terahertz transmission imaging systems are built with a 2.52 THz continuous wave laser and two types of sensors. One is array scanning system using a 124×124 pyro-electric array camera as the detector; the other is a point-wise scanning system utilizing a Golay cell as the detector. The imaging speed and quality is briefly analyzed. Terahertz （THz） imaging results demonstrate that the array scanning system has higher imaging speed with lower resolution. The point-wise scanning system has higher imaging quality with lower speed.

Signal Acquisition and Processing Method Using Sector SSPA

Self scanning photodiode array (SSPA) is a kind of solid state imaging sensor. The signal processing method using a special sector SSPA was investigated. Based on the principle and characteristics of SSPA, a signal acquisition and processing method controlled by computer was introduced. The amplification of weak signal, the matching of time sequence, the fast peak holding with low leakage, the high speed A/D conversion and nonlinear correction were discussed. This method can acquire the peak signal of every ring of sector SSPA with high accuracy and in real time. It can be used to detect the distribution of space light energy.

Beam-pointing error compensation method of phased array radar seeker with phantom-bit technology

A phased array radar seeker（PARS） must be able to effectively decouple body motion and accurately extract the line-of-sight（LOS） rate for target missile tracking.In this study,the realtime two-channel beam pointing error（BPE） compensation method of PARS for LOS rate extraction is designed.The PARS discrete beam motion principium is analyzed,and the mathematical model of beam scanning control is finished.According to the principle of the antenna element shift phase,both the antenna element shift phase law and the causes of beam-pointing error under phantom-bit conditions are analyzed,and the effect of BPE caused by phantom-bit technology（PBT） on the extraction accuracy of the LOS rate is examined.A compensation method is given,which includes coordinate transforms,beam angle margin compensation,and detector dislocation angle calculation.When the method is used,the beam angle margin in the pitch and yaw directions is calculated to reduce the effect of the missile body disturbance and to improve LOS rate extraction precision by compensating for the detector dislocation angle.The simulation results validate the proposed method.