According to the radiation intensity of the spaced-target, the SNR and detection distance of the spaced target of visible light has been study and analyzed. The relationship between SNR, detection distance and the size of the spaced-target, the reflectance, observed phase angle, as well as the entrance pupil area has been obtained. The specific formula of the detection distance of the spaced-target of detection of the visible light detection system is given. And key indicators that impact the detection distance of spaced target of visible light have been analyzed. The study provides a theoretical basis for the performance of the future space-target detection system.
According to the working principle of laser active detection system, the paper establishes the optical target laser active detection simulation system, carry out the simulation study on the detection process and detection performance of the system. For instance, the performance model such as the laser emitting, the laser propagation in the atmosphere, the reflection of optical target, the receiver detection system, the signal processing and recognition. We focus on the analysis and modeling the relationship between the laser emitting angle and defocus amount and “cat eye” effect echo laser in the reflection of optical target. Further, in the paper some performance index such as operating range, SNR and the probability of the system have been simulated. The parameters including laser emitting parameters, the reflection of the optical target and the laser propagation in the atmosphere which make a great influence on the performance of the optical target laser active detection system. Finally, using the object-oriented software design methods, the laser active detection system with the opening type, complete function and operating platform, realizes the process simulation that the detection system detect and recognize the optical target, complete the performance simulation of each subsystem, and generate the data report and the graph. It can make the laser active detection system performance models more intuitive because of the visible simulation process. The simulation data obtained from the system provide a reference to adjust the structure of the system parameters. And it provides theoretical and technical support for the top level design of the optical target laser active detection system and performance index optimization.
The resolution of the camera and the detection sensitivity is increasing day by day to make it possible to use on observing deep space small target. In order to satisfy the commercial camera observing the stars background targets in high dynamic image fusion and image matching in high precision and rapid extraction star location of the application requirements, analyzed the influence of different noise on star positioning accuracy, preprocessing, and then puts forward the star selection method for image registration applications, finally completed the star locating and used the altitude angle and azimuth of stars in actual stars map to analyze the accuracy of extraction.
Astronomical detection always need high dynamic range image, but there are problems such as underexposure or overexposure in astronomical images taken by commercial camera, this paper proposed the technique that combine establishing the first order difference quotient curve of each pixel with data feature positioning to calculate optimal exposure value of each pixel, which achieves high dynamic range fusion. In this paper, data feature positioning method was firstly utilized to establish mathematical model to calculate optimal exposure point in the first order difference quotient curve of each pixel in the target scene. Correlate optimal exposure point and camera response function to calculate optimal brightness value of each pixel, the fused high dynamic range image will be achieved. Finally, take a series of low dynamic range images with different exposure value by commercial camera, establish mathematical model and calculate to achieve high dynamic range fusion, which verifies the fusion technique proposed in this paper can obtain high dynamic range astronomical images effectively.
Proc. SPIE. 9142, Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics: Optical Imaging, Remote Sensing, and Laser-Matter Interaction 2013
In order to study the performance of the cat-eye target laser active detection system, the cat-eye target laser active detection system which includes the technology of laser emitting/receiving, data acquisition, signal processing and recognition has been established. The effective reflection area of cat-eye target and the operating range function have been given. The paper focuses on the analysis of the key indicators such as laser divergence angle, laser incident angle and focal shift, which have a great impact on the operating range. According to the calculation and the simulation, it shows that in the case of oblique incidence and focal shift, the effective reflection area of cat-eye target will change; the laser beam incidence angle, focal shift and laser divergence angle of the system will have a great impact on the operating range.