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 Wysłany: Nie 7:48, 09 Sty 2011 Temat postu: belstaff outlet Ship monitoring and alarm systems |
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Ship monitoring and alarm systems wireless video
Detector is based on the Doppler effect. High-frequency electromagnetic waves sent by the transmitter. The scope of monitoring to establish three-dimensional space in the alternating electromagnetic field. Receiver and transmitter installed in the same housing, for receiving reflected back from the region to monitor the reflected wave, and the frequency of the reflected wave compared with the emission wave frequency to make judgments. Responsive to temperature changes, air flow and noise disturbance are not sensitive to interference, can penetrate walls, glass and other objects. Microwave motion detectors detect the direction of radial motion direction, the direction of lateral motion detection of objects is relatively poor. Disadvantage is that the metal surface or solid concrete and are particularly vulnerable to reflection. The above analysis. Just a passive infrared detection of defects detected by the microwave can make: Microwave detection of infrared detection can just make up for shortcomings, especially for ambient temperature changes, water flow of complex environments. The anti-theft alarm system, target recognition. Complex in the marine environment is in need of towels work. Is in need of passive infrared and microwave detectors complement each other's role, because only when the detected infrared and microwave signals occur when the alarm signal is triggered. Passive infrared detectors made in this environment, both the high alarm capabilities, and will not produce false alarms. Passive infrared detection direction is horizontal, and radial direction of microwave detection, around the ship to form a complete three-dimensional space, greatly improve the monitoring alarm effect. When the pirate ship into the alert zone, arranged in the alarm monitoring points around the probe - passive infrared / microwave detectors will be sensitive to the pirates body. And generate the related signals, transmitted to the main controller, automatic alarm action. Meanwhile, the duty room control panel also through infrared night camera. Display images surrounding the ship, always monitor the situation in and around the ship. Wireless video surveillance and security system Main technical parameters: Video Input Multiple Input Multiple input video alarm output Alarm sensor input multiple audio and video synchronization alarm alarm transmission frequency from the 30-meter modular system 2.4G transmission power 12V/220V3 signal transmission using wireless transmission. Namely the use of a wireless transmitter and receive images, sound transceiver functions in order to free space as the transmission medium, by way of wireless transmission for data transmission. Wireless monitoring system to solve the traditional wired lines, monitoring the project to be delayed cost. Now commonly used for wireless video transmission frequency are: 0.9G1.2G1.3G2.4G and so on, which 0.9G system frequency and G (phone) system, the frequency of close, it is not commonly used; 1.2G system applications The most popular, and the ability to penetrate obstacles, diffraction performance is better than the 2.4G system, so commonly used in the power transmission system; 2.4G ~ 2.4835GHz are S-band, the band also called I (industrysciencemedica1), is industrial free radiation frequency,[link widoczny dla zalogowanych], will not cause harm to human health. Less interference in this band. Better image quality transmission, the current is more and more common. The disadvantage is the short distance transmission,[link widoczny dla zalogowanych], but for the average transmission of the ship's anti-theft system has been adequate. The system uses 2.4G wireless operating frequency, the transmission shown in Figure 3. Slave l. 4G transceiver modules \ 2 countries. \ - One. . Ru} _ a few metal cap: audio and video transmission effective distance 150mI. Bu - Figure 3 wireless transmission structure to have a dedicated wireless video transmitters and receivers can see the picture and sound performance of confidentiality and will not interfere with regular TV reception. The operating frequency is generally microwave section, paragraph microwave transmission characteristics of radio waves is generally straight line of sight transmission, if the middle of the occluder or the general diffuse diffraction by transmission, it will greatly reduce the transmission distance, so use the receiver and between the transmitter block better. If you can not avoid the occlusion can be fired by raising the transmitter power of the method of compensation. 4,[link widoczny dla zalogowanych], the practical application of the system was installed in a ship,[link widoczny dla zalogowanych], the actual effect is good. The application shows the development of wireless video surveillance ship and anti-theft system, can fully control the situation in and around the ship, once the abnormal invasion to automatic alarm,[link widoczny dla zalogowanych], the crew can reduce the security burden, and improve maritime security of ships. This system needs no drag line, easy to install. $ Author: Xu Manping Guangzhou Maritime College, Professor, Doctor of Engineering
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