Submarine underwater communication is a quite technical task.
Because the sea water is equivalent to a huge conductor and has a good electromagnetic shielding effect, submarines underwater can hardly receive any short wave signals. All kinds of electromagnetic waves common in the air almost disappear as long as they enter the sea water for one or two meters.
Therefore, at the beginning, because there was only radio, the submarine had to risk floating up to receive and send messages. This was quite dangerous, but it was good to say that if it sent a telegram, as long as it radiated electromagnetic waves, it would immediately attract a large number of anti submarine aircraft.
In the late World War II, Hans' wolf pack tactics were smashed.
In order to solve this problem, buoy antenna or buoyancy antenna appears, that is, the antenna is placed on the water surface, so that the submarine can also transmit signals underwater. In fact, there is still a problem of submarine self exposure, because when the submarine communicates with short wave at a long distance, its signal itself is not confidential, it may be intercepted and decoded by the enemy, and the submarine's position may be measured, and the buoy antenna exposed to the water may also be detected by the enemy's radar.
Therefore, after years of research, long wave communication has been recognized as the most suitable underwater communication mode.
Seawater has a strong absorption effect on electromagnetic wave energy, but it is different for electromagnetic waves with different wavelengths. The shorter the wavelength and the higher the frequency, the more severe the attenuation in seawater. But electromagnetic waves with longer wavelengths can penetrate a little water. The longer the wavelength, the stronger the penetration of electromagnetic wave.
The signals sent by very long wave and ultra long wave radio stations can enter the water of tens of meters to more than 100 meters.
However, this kind of communication requires a huge antenna, which is often hundreds of kilometers. At the same time, the data transmission speed is also quite slow. Dozens of bytes of messages have to be transmitted for half an hour. Therefore, it can only be used during the war to ensure absolute secrecy.
Now there are communication satellites. Chinese submarines routinely carry out satellite communication every day, briefly contact the base, and then dive into the water again.
As long as the anti submarine aircraft is not flying everywhere and has been searching for the status, it is not very difficult to find this short satellite communication and locate.
"Report, I got a message from boat 320. Behind them, there is a bear submarine tracking." when I returned to the bridge, I heard the report.
Sure enough, Xiong Guoren followed him. Fortunately, his side sent 320 boats, which attracted the tracking of a Xiong Guo submarine. In this way, his side's real submarine ready to launch mission ensures better safety.
"Yes, let them wander around at sea first. When our launch mission is completed here, we will avenge Xiong Guo submarine!" General Zhao patted the table and said.
I was humiliated by xiongguo submarine last time. This time, I must revenge.
The 320 submarine was at the depth of the vent pipe and continued to sail silently at a speed of five knots.
"Xiong's submarines have been following us. These Xiong's submarines are really skilled pursuit experts!" Captain Lei couldn't help sighing when listening to the sonar report.
The submarine of our side has very good mute performance and runs at a low speed. The other side is right behind our side and pursues at a distance of more than 30 nautical miles. It's an old expert.
On the ocean, the submarines of bear and Eagle often engage in this silent confrontation underwater. They have rich experience.
Originally, Captain Lei could not suppress his excitement and wanted to compete with the submarines behind him. But now, his own experiment has not started and cannot change, otherwise losing the other party will be detrimental to the task.
"Eh, strange, there's a sound." the sonar whispered. He closed his eyes, listened carefully, and carefully rotated the knob of the sonar device for several times. Finally, when he opened his eyes, he had a judgment: "behind the bear submarine, there's a Los Angeles class submarine!"
In the mid-1970s, Los Angeles class nuclear submarines began to enter service gradually, rapidly updating the underwater power of the eagle Navy and becoming the backbone.
In the ocean, Los Angeles class nuclear submarines have quickly become the main force against bear submarines. Now bear submarines are chasing their own side. Unexpectedly, behind them, Eagle submarines are also chasing them.
The mantis catches cicadas and the Yellow finches are behind.
"Continue to monitor." Captain Lei was more excited. When his superiors decided to do it, what should he do to force all these submarines out of the water?
Well, think about it.
Underwater is a silent world. At this time, hundreds of nautical miles away from them, Great Wall 200 is also sailing smoothly.
At this time, it is floating on the water. The bow of the boat splits the spray and rolls over constantly. On both sides of it, there are two fishing boats, accompanied by left and right, moving forward together.
Yes, the warships in the military port are the object of the enemy's attention, and there are submarines under the water. Now, after quietly coming out, they meet with two fishing boats and drive all the way to the predetermined sea area without anyone finding them.
This large submarine has a displacement of more than 2000 tons on the surface and 3000 tons underwater, which is the same level as the brigade level. The huge hull, nearly 100 meters long, is like a whale. During the voyage, several crew members are carefully checking on the deck.
They were wearing white navy shirts, behind sailors' hats, and black hat bands were fluttering with the sea wind.
The submarine's deck is not flat. It's a streamlined deck. It's easy to fall. If you fall into the sea, the consequences are unpredictable. However, no one is afraid. Everyone is checking carefully.
"After inspection, the launcher is in good condition." a young man raised his head and shouted loudly. His face was serious but also green. It was the young man who wrote the suicide note met by Qin Guan.
He is in charge of inspection.
"Return to the boat." on the command tower, the captain of the car gave orders loudly with a dignified expression.
A famous submarine soldier drilled back into the submarine. The last young man skillfully closed the hatch cover. This simple action was once neglected. As a result, the submarine sank completely as soon as it was launched.
"Report to the superior that we are ready for launch test at any time." the captain shouted to the political commissar below.
Waves of radio waves flew to the satellite and the fleet. Soon, news came from all aspects. The splash area was ready to start fishing at any time!
"Ready to launch, three hour countdown!"