The military-industrial scientific research system of the academic master.

It is actually normal for superiors to have concerns in this regard.

In fact, the passive positioning radar deployed on land is not necessarily a high-end product in itself.

For example, the 70M6 "Volga" early warning radar has a passive detection function, and it can even be regarded as a model close to shelf products.

But in the past, the common function of this kind of thing was to provide mid-course early warning of ballistic missiles, anti-stealth and anti-radiation, which can only be said to be secondary functions.

Not only will the software system not be optimized in this direction, but corresponding tactics have not been considered in terms of hardware.

Therefore, in order to ensure the detection distance and prolong the reaction time of one's own nuclear counterattack, a radar antenna is generally deployed permanently like a building or even a hillside.

China has also researched similar early warning equipment in the past, and the sizes are basically similar.

It is indeed extremely difficult to "smuggle" something of this size to another country without crossing a third country.

Therefore, when people of this generation first heard that Chang Haonan wanted to change an ordinary vehicle-mounted fixed radar into a passive positioning radar, their first reaction was definitely confused.

It is also natural to subconsciously think that this may be a project with a very heavy workload.

However, the algorithm Chang Haonan developed previously focused on "multi-point distribution."

If you want to achieve passive positioning with a single array, you will naturally need a huge size to calculate a sufficiently accurate angle difference.

But because the whole idea was originally intended to be used on an aircraft and two missiles, after transplanting it to the ground, the signal source and at least two receiving sources can be separated.

This is why he and the 14th Institute of Electrical Engineering chose the P18 radar, which is not familiar to China, as the target of transformation.

This type of early warning radar is extremely common in the countries of the original Warsaw Pact camp. Even more than 20 years later, you can easily take out a lot of them, and even out a few of them and modify them into passive radars, which will not affect the early Early warning capability will not produce too noticeable movements.

Therefore, facing Ding Gaoheng's question, Chang Haonan looked outside and after confirming that his family was not nearby, he answered:

"The specific hardware operations related to radar modification are carried out by the 14th Institute of Electrical Engineering, so if you need to compile a specific transportation list for Lao Wu, you have to contact them."

"But from the perspective of the basic algorithms and signal processing principles that I am responsible for, since it basically does not involve changes to the antenna itself, the total components required to improve the two radars are mainly the feed and filtering equipment at the back end of the antenna, as well as the output end Digital signal processing chips such as DSP and FPGA required for data processing.”

"There are indeed a large number of components such as chips and circuit boards, but they can be shipped directly in the name of personal computer accessories, even with great fanfare. After all, it is not easy to distinguish these components without taking them apart and inspecting them one by one. The difference between military-spec chips and desktop products."

"The main trouble is those things related to analog signal processing and conversion. Because they are relatively large, if a knowledgeable person can see them almost at a glance, you need to be particularly careful..."

"Need to modify two radars?"

The questions on the other end of the phone were significantly more in-depth and detailed.

"At least two, actually preferably three."

For Chang Haonan, these technical route questions have been repeated countless times in his mind, and he can naturally answer them fluently:

"However, one of them only needs to transmit signals as usual. The improvement is very small. At least two of them need to be changed to passive radars. This can only be achieved by forming these three radars with exactly the same antenna parameters into a whole and then deploying them dispersedly. Signal detection in various environments.”

"Of course, if there is a relatively strong and stable signal source within the airspace itself, such as a relatively close early warning aircraft or a naval ship with regional air defense capabilities, then it does not matter if there is one less radar that actively transmits signals. After all, this radar It is very dangerous in itself and is likely to be destroyed by the opponent's air defense suppression operations."

"The reason why I suggest retaining it is because I am worried that the other party will adopt stricter electromagnetic signal discipline. After all, the party we want to help probably does not have a strong air force or long-range strike force, so the opponent does not necessarily need to maintain a high level of electromagnetic signal discipline all the time. Air warning level..."

After all, it was a confidential insider exclusively for high-level leaders, and he had already communicated with the other party before, so Chang Haonan did not go through all the twists and turns and directly analyzed the actual situation of both parties in the conflict.

His suggestions are naturally not just speculations, but have been verified by "future history".

Throughout the entire Allied operation, due to the relatively complex ground environment and proper preparations for electromagnetic countermeasures, the efficiency of the coalition's air defense suppression operations was extremely low, and the defending side's radar could remain switched on for a long time even until the middle and late stages of the conflict. without being destroyed.

In this context, deploying an additional controllable friendly signal source is basically a harmless thing.

"okay I know……"

Ding Gaoheng replied in a "That's it" tone.

In fact, according to Chang Haonan's understanding of him, the step of communicating on the phone should be over here.

But today, Ding Gaoheng seemed particularly interested:

"Also, Xiao Chang, I remember you said two days ago that in addition to detecting invisible targets, you can also directly shoot them down?"

"Well... you can at least give it a try."

Chang Haonan naturally has this idea, but the stealth fighter has never been used yet, and his equipment has not even been tested, so it is definitely not easy to say too harshly:

"In my work over the past few years, I have found that many people, even comrades in the aviation industry system, deify stealth aircraft and even fear difficulties. In fact, our opponents often think so too. It has even become part of their strategic intimidation."

"If we can take advantage of this opportunity to get some kills or even injuries before they become more vigilant about anti-stealth methods, I think it will be a huge positive incentive for the perception and confidence of our entire society. .”

Ding Gaoheng seemed to be shocked by Chang Haonan's righteous statement. It took almost half a minute before he replied:

"However, the nature of electromagnetic waves of long-range warning radar determines that whether it is signal accuracy or data update frequency, it is unlikely to support terminal attacks by air defense weapons. If you really want to achieve a shootdown, you will need a hard-kill method. "

"Or are you planning to smuggle in the new missile developed by the Aerospace Technology Research Institute?"

Chang Haonan was stunned by this question.

Of course I didn't stop him.

But Ding Gaoheng, as a leader with a technical background and a background in guidance and navigation technology, had almost never asked such detailed tactical questions in the past.

However, he quickly came to his senses:

"It is definitely inconvenient to smuggle missiles."

"First of all, the nature of this thing is different from radar components and self-defense interference systems. In any case, it is a serious weapon and equipment. We still have to be just in case. It would be really bad if we were stopped on the road. explain."

"Secondly, even if you don't consider the risks, that model is still in the development stage, and even the sample bomb has just been built. After all, missiles are pyrotechnics and different from radars. It is absolutely impossible to use them without a test launch... "

After hearing that Chang Haonan was not planning to send out the missiles as well, Ding Gaoheng seemed to be relieved:

"Then what do you think..."

For Chang Haonan, this is a complete question:

"They should have a lot of S125 "Pechora" air defense missile systems themselves. The most important thing about stealth aircraft is its suddenness. If the early warning radar can continue to effectively detect the target, even if it cannot lock, it can also let the fire control radar of the air defense missile To indicate the direction, as long as you grab the opponent's aircraft and open the magazine, or turn at a large angle, the time window increased by RCS is still enough to complete a shot."

"Taking a step back, even if the opponent uses electromagnetic interference to invalidate the missile's command guidance, we can still return to the most primitive method, through voice reporting and manual work, and try our luck with large and medium-caliber anti-aircraft artillery. Anyway, we are ahead It’s not like I haven’t considered similar tactics in recent years…”

"Modern warfare is artillery warfare...anything that can pull out pus is a good ointment, not shabby."

At the end of the sentence, he even had a bit of a joking tone:

"Rather, if the stealth fighter is really shot down by anti-aircraft artillery, it will be embarrassing for the world to circle around..."

After Operation Desert Storm, China, which was frightened by the coalition's electronic warfare, realized that the existing old-fashioned anti-aircraft missiles were probably not much different from fire sticks, so it rushed to import S300 anti-aircraft missiles and dragged out several more divisions of them. 100mm and 57mm large and medium caliber anti-aircraft guns emergency.

Among them, the 57mm anti-aircraft gun was finally used until about 2018 before it completely bid farewell to the stage of history.

Returning to nature, this kind of thing is the least affected by electronic interference.

Of course, it was definitely not used in the end.

However, the ideas can still be used for reference...