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this morning, ivan just woke up and checked weibo, and was surprised by the video of the j-20 fighter jet conducting a simulated air combat confrontation released by the chinese military. through this video, we know for the first time that the j-20 fighter jet has begun to conduct confrontations between stealth fighter jets of the same generation. in just over 30 seconds of video, there are so many details that can be interpreted that it is a book full of books, so today we will start with a special article to talk about this video.

video analysis

the video starts out by stating that a unit with the call sign "sky eye" transmits information and provides target guidance to the j-20 pair 01 and 02 via voice. the targets are numbered group 3, in column formation, 90 degrees from the j-20 pair in direction, 150 degrees away, and 80 degrees at an altitude.

to facilitate understanding of this article, watch the video first (35 seconds)

this is a relatively standard voice command format: command object number + aircraft number + target number + target formation + target direction + target distance + target altitude. there are strict regulations on which information should be in the front and which information should be in the back. for example, the command object is in the front, so that the predetermined command object can receive the information at the first time. the direction, distance and altitude of the target are reported in sequence, which is convenient for the command object to allocate attention, give priority to the maneuver to contact the enemy, turn the course to the direction of the target and then perform altitude maneuvers, etc.

through this group of voice notification information, we know that the unit commanding the twin j-20s is called "sky eyes". in a literal sense, this should be an early warning command and control aircraft, or a ground radar system, etc. in short, it is a situational awareness/combat support unit responsible for air combat command and control. the twin j-20s commanded by them have no meaning, they are just normally numbered 01 and 02.

the so-called azimuth 90 refers to the 90-degree direction relative to the current heading of the j-20, located to the right of the j-20 fighter. there is a slight debate online about the distance 150 and the altitude 80. some people think that 150 is nautical miles, some think it is kilometers, and big ivan thinks it is kilometers. at present, the habit of nato, led by the united states, to report distance in air combat is still to use nautical miles. the russian aerospace forces are accustomed to expressing it in kilometers, and big ivan of the chinese air force tends to use kilometers to express distance.

the 80 is generally considered to be 8,000 meters, which is in line with the convention of multiplying by 100 in altitude reports, and 8,000 feet is indeed too low for the target (also a stealth fighter). accordingly, since our altitude is in metric units, there is no need to use imperial units for distance, so big ivan prefers that the unit of this 150 distance is kilometers.

therefore, before the air battle began, the situation faced by the two j-20 formations was three groups of unidentified targets in column formations located to the side of the aircraft (could these three groups be three aircraft? three two-aircraft formations? three batches of targets?), 150 kilometers away from the aircraft and 8,000 meters high. after receiving the target indication, the two j-20 fighters turned on their radars, and the pilots reported to the command unit "sky eye" in seven words: "there is an alarm, and the radar is clean." a faint "ding, ding" long sound can be heard in the cockpit sound, which is also worth noting.

judging from the situation before the fighter enters the air combat, it should ensure that all systems of the fighter are operating normally. if there is an airborne system warning sound, it must be turned off to avoid affecting the pilot's attention and the truly important warnings. this proves that the "warning" reported by the pilot is a verifiable radar warning, and proves that the radar warning sound of the j-20 fighter is a medium-volume "ding ding" sound. and from the design of the radar warning, interception and scanning are different, scanning and locking are different, and locking and active radar bomb radar startup are also different. generally speaking, the more urgent the situation, the higher the volume of the warning sound and the more urgent the frequency. the volume of this warning is not high and not urgent, proving that it is just a fire control radar search.

of course, what is even more amazing is the four words "radar clean". the air situation awareness of the fifth-generation aircraft is implemented by multiple systems, including active search by fire control radar, passive direction finding by airborne esm and rwr, and search by eodas/eots optoelectronic radar, etc. "radar clean" means that the esm system intercepts the radio frequency signal scattered by the target, but the radar does not intercept the target. this is undoubtedly a performance of a stealth fighter, so the j-20 fighter pilots quickly determined that they were fighting against the same generation of aircraft, that is, the opponent was also a group of j-20s.

after the 01 (lead) pilot reported, the 02 (wingman) pilot followed up with a sentence "02 is the same". this does not necessarily prove that the dual fire control radars of the j-20 fighter jets were turned on for search in an alternating burst manner, but it does prove that the j-20 should have a dual-aircraft coordination and cross-check and judgment procedure for the lead and wingman in its engagement procedure against stealth fighters. if the dual-aircraft cross-check does not find enemy aircraft on the fire control radar, then it is judged that they are facing a stealth fighter. this detail allows us to glimpse the rules of engagement between stealth fighters.

there are two more details worth mentioning:

first, the "eye of the sky" commands the stealth fighter, which must use data links. the information transmitted by the data links can be directly displayed on the j-20's integrated tactical display, but the video still includes the voice command part. big ivan believes there are two possibilities. the first is that it is required for the program effect, but the biggest possibility is that data link transmission and voice command repetition are a form of ensuring that the commanded aircraft receives the data link information and confirms the accuracy of the information, which is equivalent to another form of cross-checking;

second, the fire control radar performance of stealth fighters such as the j-20 fighter generally uses methods such as frequency hopping, spread spectrum, and adaptive waveform adjustment to achieve the so-called low probability of intercept (lpi). ordinary radar warning receivers are difficult to detect intercept signals for such advanced lpi radars. however, the radar warning receiver of the j-20 fighter can receive the search signal of the j-20 fighter's fire control radar, proving that the electronic countermeasures and electronic support equipment equipped on the j-20 fighter are advanced in performance, and should be a fourth-generation warning receiver that integrates digital reception and electronic countermeasures.

after clarifying the nature of the target, j-20 no. 01 and no. 02 immediately carried out an enemy-engaging maneuver. the subsequent engagement was more or less omitted, and it was only mentioned that the wingman no. 02 created the conditions, and no. 02 immediately opened fire after creating the conditions for firing. the directorate then determined that the three groups of j-20s on the opposite side had all been "shot down." the simulated footage from the directorate that followed also showed that a "blue army" aircraft with a j-20 appearance had been "shot down," proving that the red side's j-20 did indeed engage in a same-generation confrontation with the blue side in this exercise, and that it had won the battle.

hidden details

in fact, in big ivan's opinion, the hidden part in the video is the most crucial. the basic tactics of air combat should be that the leader opens fire, and the wingman is responsible for creating conditions for the leader to open fire. from the video footage, it can be seen that it is the wingman who creates the conditions and the wingman directly opens fire. this at least proves that in air combat between stealth fighters, the difference between the leader and the wingman may not be too critical. after engaging the enemy and maneuvering, whoever is in a favorable position will open fire.

however, how exactly the j-20 fighter jets formed this firing condition when facing the same generation of aircraft is still unclear. military fans on the internet also have different opinions. big ivan roughly summarized it:

one is that the wingman took the initiative to expose himself to lure the opponent's fire control radar to turn on, and then reversely locate. this tactic is possible but unlikely. after all, it can be seen from the video that when the battle with no. 01 and no. 02 began, the fire control radar of the j-20 fighter on the opposite side of the blue side was already turned on. there is no possibility that the fire control radar was turned on during the battle and then reversely located by the red side's electronic support system.

second, the anti-stealth radar of the early warning aircraft implemented a-shooting and b-guiding. there is such a possibility that the anti-stealth radar gives an approximate position of a target, and the j-20 fighter jet fires at the approximate position, performs mid-course correction on the launched medium-range missile, and guides it to the position where the active radar is turned on. after the active radar is turned on, it searches for the target by itself. this operation is theoretically fine, but ivan is not clear about the technical details. after all, according to our limited understanding of dcs beyond-visual-range air combat, whether it is the local fire control radar or the use of data link locking, at least the target position must be calibrated. then, whether the anti-stealth radar of the early warning aircraft can give a relatively accurate position, which can be used for the fire control system on the j-20 to calculate and bind the attack parameters and launch the medium-range missile, this is not clear technically.

third, two j-20 aircraft used eots to engage in combat. it is difficult for a single eots to measure distance. if it cannot measure distance, it cannot guide medium-range missiles. however, eots can use multi-site ranging to perform very long baseline interferometry, which roughly uses the parallax method to measure the target distance. after calibrating the distance, speed and other motion elements, the conditions for firing medium-range missiles can be formed. this requires the two j-20 fighters to be time synchronized, but this eots ranging method is very complicated. the only thing that can be confirmed is that the us navy has verified it with the f/a-18e/f legion pod. it is not clear whether the j-20 fighter has the ability to measure very long baseline interferometry in a two-aircraft formation. if it has this ability, it would be too amazing.

in general, the video of the j-20 fighter jets confronting each other with the same type disclosed this time may be just a rough demonstration, and it must have been heavily encrypted. the details we can see may not be true, and there are still a lot of details missing. big ivan believes that this video has proved two points: first, the j-20 fighter jets have been engaged in regular confrontations with the same type of fighter jets, which is of great benefit to our army's experience in accumulating combat experience with stealth fighter jets. second, when stealth fighter jets confront each other, whether there is an anti-stealth system behind them is of great significance to the outcome of the confrontation. in the end, air combat is a confrontation between systems and a confrontation between system integrity. that's about it.