Weak Signal Detection Method in a Stronger Noise Background

2014 ◽  
Vol 568-570 ◽  
pp. 260-264
Author(s):  
Jun Wang ◽  
Jian Ming Bai
Keyword(s):  
Detection Method ◽  
Detection System ◽  
Feasibility Analysis ◽  
Weak Signal ◽  
Weak Signal Detection ◽  
Error Angle ◽  
Noise Background ◽  
Photoelectric Detection ◽  
Detection Technology ◽  
Detection Principle

When we use the laser auto collimation theodolite to measure the azimuth error angle of air target, the strong noise background reduces the spot imaging quality and seriously influences the measuring angle ability of the theodolite. In order to solve the problem, a photoelectric detection system used to detect the weak signal is designed based the correlation detection principle and the principle of correlation detection technology is introduced. We use Simulink software presenting a simulation to the detection system and do a feasibility analysis. Finally, it’s proved that the photoelectric detection system could suppress the strong noise background, improve the SNR greatly and detect the weak signal effectively.

Exploration on Applying Non-Contact Photoelectric Detection Method for Double-Enveloping Hourglass Worm

2010 ◽  
Vol 97-101 ◽  
pp. 4287-4292
Author(s):  
Shu Yuan Zhang ◽  
Xiao Jing Chen ◽  
Song Kun Yu ◽  
Ting Chen Chen
Keyword(s):  
Light Source ◽  
Detection Method ◽  
Detection System ◽  
Image Sensor ◽  
Tooth Surface ◽  
Rotary Table ◽  
Ccd Imaging ◽  
Photoelectric Detection ◽  
Manufacturing Accuracy ◽  
Work Table

According to the principle of processing, a non-contact photoelectric detection method for double-enveloping hourglass worm is investigated. The structure of the detection system is designed. It consists of solid-state image sensor CCD and light source. The parallel light source is installed on a sliding-board which is fixed on the rotary table. There is an inclination angular β between the parallel light source and the plane of the work table. The industrial CCD lens is mounted on the other side of the worm through a frame. The plane of the CCD is vertical to the parallel light source. Therefore CCD imaging is along with the direction of the generating process surface. By comparing the measured spiral tooth surface with the standard spiral tooth surface, the manufacturing error of worm can be calculated. Manufacturing accuracy of the worm can be obtained. Based on the four-axis CNC grinder, Non-contact photoelectric detection method is studied through preliminary experimental study. The experimental results indicate that this method is feasible in the precise detection of the double-enveloping hourglass worm.

Weak Signal Detection System Based on Lock-in Amplifier Technology

2013 ◽  
Vol 389 ◽  
pp. 489-493
Author(s):  
Yong Lv ◽  
Chun Hui Niu ◽  
Yue Qiang Li ◽  
Qing Shan Chen ◽  
Xiao Ying Li ◽  
...  
Keyword(s):  
Signal Detection ◽  
Detection System ◽  
Signal To Noise Ratio ◽  
Weak Signal ◽  
Weak Signal Detection ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Phase Sensitive ◽  
Lock In

In order to detect the weak signal deeply buried in the noise, a weak signal detection system based on lock-in amplifier is proposed. The system includes the preamplifier circuit, active low pass filter circuit, AC amplifying circuit and phase sensitive demodulation circuit. Test results show that it can greatly increase the signal-to-noise ratio (SNR) up to 12.7db.

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