Domestic High-Precision "Ultra Short Baseline Positioning System" Breaks the Foreign Monopoly
On October 23, Reporters learned from Harbin Engineering University that the Jiao Long first used domestic high-precision ultra short baseline positioning system independent produced by HEU when it carried out scientific research task which has completed recently in the first segment of the experimental application of voyage in 2014. The application breaks the pattern of the overseas technical monopoly.
In the deep sea, it's not easy to know the position of the submersible, because the radio waves will decrease quickly,which make GPS not work . So far sound waves are the most effective information carrier of underwater remote transmission. Acoustic positioning system is divided into three types: long baseline, short baseline and ultra short baseline. Receiving sensor of ultra short baseline is just like the human ear, the distance between the two ears is equivalent to the baseline. The distance between the beacons of Long baseline system between is only a few kilometers to a few tens of kilometers apart. The longer the baseline is, the higher the precision is. But when submersible does the underwater accuracy work, it needs to dispose at the bottom of the ocean, which is complex and limited. While at this time, they used ultra short baseline system for testing, whose distance between each receiving sensors is only tens of centimeters apart. So the biggest advantage of the system is easy to install and flexible to use.
The ultra-short baseline positioning system works like this: install the acoustic beacon on the target which has been fixed underwater, and fix ultra-short baseline array on the overwater hull. When the acoustic beacon sends signals, ultra short baseline system can receives them, and then the position and distance of the object can be measured. Take the Jiao Long for an example, when it is in the bottom of sea, it will send the acoustic signals to the mother ship every 8 seconds. But the signals which reach to each receiving sensor of ultra-short baseline positioning system follow the sequential order. Using the time-delay deviation, the location, depth and distance from the mother ship of Jiao Long can be calculated by ultra short baseline system. Since 2002, the team of professors lead by Professor da-jun Sun has done related research. In 2013 they successfully developed the first domestic positioning system product, which changed passive situation of the vessel in positioning system maintenance, upgrading and export licensing restrictions, etc. Now the system is installed in the domestic ships like "Dayang Yihao", "Science" and "Xiangyanghong 9"