When the air defense siren sounded, Liu Xiangzhen did not return to the bridge of the commander's ship, but walked to the porthole, raised his binoculars and looked at the "Nanjiang" not far away.

At the top of the foremast, there is an object that is rotating, like a large dustpan.

That's an antenna.

However, it is not a radio antenna, and no radio antenna looks like that.

That's right, that's the antenna of the radar!

The antenna, which rotates only when it is working, is usually fixed.

For the sake of secrecy, but also to deceive and mislead, the few warships equipped with radar are not allowed to use radar when entering and leaving the port, and the antenna must be fixed at a certain angle, and then a canvas cover is put on, which looks like a device to scare and drive away birds from a distance.

In addition, the Imperial Navy has never released any radar-related information to the public.

So far, intelligence agencies in other countries have only known that the Imperial Navy is equipped with an electronic device similar to a radio that can detect aircraft from great distances. It is very likely that the position of the reconnaissance plane will be determined by listening to the radio station of the reconnaissance plane. The intelligence agencies of some countries even take it for granted that it is a large-size, high-precision high-power telescope.

In fact, what is the value of radar, Liu Xiangzhen is not sure.

It is not surprising that a few months ago, at the end of September to be precise, when the "Beihe" and "Nanjiang" began to prepare for the upcoming fleet exercises, they went to the Puzhou Shipyard and the Jianzhou Shipyard separately to install the radar during maintenance.

Since then, I have tried it a few times.

According to the arrangement, in this year's fleet exercises, in order to test the tactical value of radar, a separate exercise subject was also arranged.

It is a pity that the situation quickly deteriorated shortly after the start of the exercises.

Liu Xiangzhen only knew that the radar on the "Nanjiang" had a detection range of up to 100 kilometers for the aircraft group, and a detection distance of 40 kilometers for a single aircraft, far exceeding the visual range of the naked eye.

Of course, accuracy handicap isn't a big deal.

As long as enemy planes are discovered in time, they can command air defense fighters to intercept them, thus gaining more time and greatly improving the efficiency of air defense operations.

According to the assessment report given by the Jinlin Radio Research Institute, which developed the radar, with the assistance of the radar, the combat effectiveness of the fighter was able to increase by twenty times.

Liu Xiangzhen felt that those highly myopic engineers were bragging.

It's just that, even if it's not twenty times, it's definitely okay to increase it by a few times.

In several internal exercises conducted by the Second Air Task Force, the air defense fighters were guided by radar to discover and intercept enemy planes in a timely and accurate manner.

In the words of the pilots, it is enough just to detect the incoming enemy aircraft in time.

In past air defense operations, the biggest problem was that it was impossible to detect approaching enemy planes in a timely manner, let alone predict the direction in which enemy planes would attack. It is necessary to do everything in all aspects, at least to deploy enough fighters in the direction of the main threat, wasting valuable air defense.

With radar, it can be targeted.

That's it this time.

The "Nanjiang" was the one that issued the air defense alert, and the radar spotted a number of enemy planes flying from the northeast direction, and judged them to be carrier-based aircraft of the Sagi Navy.

One swarm, probably ten enemy aircraft.

"A hundred kilometers away, our fighters are rushing over." Major Zhuang Bisheng, an operational staff officer, rushed over and reported the situation to Liu Xiangzhen. "The enemy planes are in dense formation, separated by a distance of several tens of meters, and fly at an altitude of less than 3,000 meters, so it is inferred that they are attacked by 97 ships."

Liu Xiangzhen only nodded, indicating that he heard it.

If it is a fighter, it generally does not adopt such a dense formation, often two or three planes form a small formation, and the distance between the small formations is relatively wide, and there will be a certain height difference, to ensure that after encountering enemy aircraft, the formations can take care of each other.

In addition, fighters generally fly at an altitude of no less than five thousand meters. You can see far when you fly high, and when it comes to fighting, the side with the height advantage is often able to win.

It's just that more than one team of 97 ships attacked.

Soon, the "Nanjiang" sent a new report, and the radar detected several small groups of enemy planes, three of which were flying at high altitudes.

It's just that it is impossible to judge the nature of the enemy aircraft.

Flying at high altitudes, it may be a fighter or a dive bomber.

If the speed of the enemy aircraft can be measured, it will be able to make a judgment. The Navy made a similar request, asking the Jinlin Radio Research Institute to develop a radar capable of measuring speed. It's a pity that the development of a new radar has not yet started, and it is even more unknown when it will be developed.

Without Liu Xiangzhen's orders, the staff officer in charge of air defense operations made adjustments.

It is a bit cumbersome, first of all, it is necessary to obtain the information provided by the "Nanjiang", then mark it on the chart, and then conduct a comprehensive analysis and judgment of the overall battle situation, and the staff officer in charge of air defense operations will make a judgment on this information during this period, and finally order the adjustment of the air defense deployment.

The whole process takes about a few minutes.

It is precisely for this reason that Bai Zhizhan proposed that the fast battleship should be used as the air defense command ship, so as to free the aircraft carrier from the cumbersome air defense operations. According to the meaning of the white war, as long as necessary, a special air defense combat command will be set up on fast battleships equipped with radars. When conducting air defense operations, all the battleships in the formation had to obey the command, and the fast battleships served as the core force of air defense.

Of course, this is just a good idea.

However, it is certainly much better to delay for a few minutes than to have a black eye.

The most significant value is to give commanders a more comprehensive understanding of the battlefield situation, so that they can make the most appropriate deployment in a timely manner.

To put it simply, it is to use steel on the edge of a knife.

For example, when intercepting bombers and attack planes without fighter escort, you don't need to send too many fighters, you can force the bombers to drop the bombs and let the torpedo planes drop the torpedoes. There were no bombs or torpedoes, and even if they flew over the aircraft carrier, they could only stare dryly. If you conclude that it is a fighter jet, you don't even need to pay attention to it, after all, no carrier-based fighter can carry out a bombing mission with a bombshell. Only if it is certain that the enemy's bombers and torpedo planes are covered by fighters, it is necessary to put the air defense fighters in full force.

Of course, the key is time.

Increasing the distance at which enemy aircraft can be detected from less than 20 kilometers to 100 kilometers means that the time for air defense interception has increased by at least 20 minutes. Even if it is only raised to 60 kilometers, the extra 40 kilometers will give the fleet an extra 10 minutes of interception time.

In an air defense operation, even five minutes are invaluable.

Take a dive bomber as an example, from the acceleration sprint to the dropping of the bomb, it only takes a few minutes.

The battle has not started yet, to be precise, it has not started in front of Liu Xiangzhen, and the value of the radar has been demonstrated. All of the discovered enemy planes were intercepted, and the bombers and torpedo planes dropped their bombs and torpedoes and abandoned the assault.

It's just that radar is not omnipotent!