nomi007
ELITE MEMBER
- Joined
- Jan 11, 2010
- Messages
- 8,538
- Reaction score
- 8
http://i2.sinaimg.cn/jc/2012-01-11/U6449P27T1D679843F3DT20120111090520.jpeg??????_?_
Editor's Note: Recently, a group of Chinese exports coming out of Pakistan's early warning network of photos, Articles for this special interview with deputy chief designer of the early warning aircraft, China Electronics Technology Group Corporation researcher Cao morning, early warning and knowledge on a request make a solution.
　　Reporter: (hereinafter referred to mind) Cao hello! Recently appeared on the World Wide Web sites such as the development of China's early-warning aircraft to Pakistan some pictures, one of which is the early warning aircraft model, the body there is a sign of CETC, which is the China Electronics Technology Group Corporation's LOGO. As the group's research staff, please briefly describe the case of groups, especially Group and China's military industries.
　　Cao morning: (hereinafter referred to CAO) China China's military power is the group of electronic and information technology team, is one of the top ten military group, established in 2002, mainly engaged in all kinds of weapons and equipment of information technology products and consumer electronics information the development. From electronic components, made basic computer hardware and software, machine, like the area until the integrated command automation systems, early warning aircraft, data link, such large-scale systems, are all Chinese military power in the field of Science major lines of business. In fact, we can note that the export of Pakistan's AWACS, called ZDK03, which "ZDK" is "in the Electric Division," the phonetic abbreviation, 03 representing the Electric Division, following China's 2000 air marshals, air marshals served after 200 chief architect of the third unit developed early warning models.
　　In addition to early warning aircraft in addition to other major projects, the China Electricity Division also played an important role. For example, in manned space program as a deputy commander unit, responsible for monitoring and control equipment, communications systems, radar detection devices, solar cells and a number of key components of development. In lunar exploration project, is also vice president of China Power Division commander unit in the satellite, launch vehicle, launch site, monitoring and control communications and ground application systems in five major research task undertaken. In the national publication of the 16 major projects, the China Electricity Division to assume special importance in a number of research tasks, especially in the first major projects, "the core devices, high-end chips and basic software (nuclear high base)," served as the main role, and in the country "very large scale integrated circuit manufacturing process equipment and complete sets of" science and technology projects undertaken in the planning and overall design.
　　Note: early warning radar is the primary sensor. The world's airborne radar development trends? China's airborne radar technology in the world belong to what level?
　　Cao: the world in general to the airborne radar active phased array direction, both on the AWACS airborne early warning aircraft on radar or airborne fire control radar, like this, these two areas is the most airborne radar The main areas. China to airborne early warning radar as a breakthrough to achieve airborne radar equipment from the mechanical to the active phased array scanning across, not to engage in passive phased array, the world's first equipment warning two-dimensional active phased array radar , that the radar beam in the horizontal direction and height direction can be electronically scanned, which also contributed to the aircraft fire control radar equipment using active phased array. From the time point of view, Israel and Sweden are the active phased array early warning radar equipment to form the country, is the familiar "Phalcon" and "balance beam", the United States was the first equipped with active phased array airborne State fire control radar and equipment on the F-22. Europe in the completion of airborne early warning radar active phased array applications, is equipped with active phased array fire control radar, such as the UK's "wind." In addition to active phased array, the airborne radar is an important development direction of digital. Now the active phased array, the transceiver generates the transmit frequency components of the device and the receiving beam processing are analog, so sending and receiving component weight and volume is too large, the aircraft platform is not of Fitness good. Digital transceiver components, firing frequency from low to high frequency digital synthesis, and in receiving and processing time, directly on the firing frequency analog to digital conversion, not only significantly reduces the weight and size, and very flexible beam processing , can interfere with the formation of the weakest direction automatically receive, thereby greatly enhancing the ability of radar anti-jamming and anti-noise capability. China's airborne early warning radar, digital standard has been an international leader.
　　Reporter: China's airborne radar components above the level of local production? For example, the transmitter amplifier tubes, as well as processor chips, software, etc. are subject to foreign?
　　Cao: China's airborne radar transceiver components including solid state power amplifier tube and the inside, including all the key components are made of, radar data processing required for high-speed processor chip is also our own research and development. In the computer, although the use of COTS is a trend, data processing machines, distributed intelligence and command and control are specially developed without the use of military computers, you can directly buy the product on the market can basically meet the need, but the coin No doubt, China's information technology for the maintenance of information security, weapons and equipment are hidden dangers. Therefore, we insist on promoting the past few years, including servers, workstations, processors, chips, operating systems and databases and other computer-based hardware and software localization. We rely on machine-made platform and come up with a set air marshals 200, ZDK03. It can be said, through the platform, the basis of the key components and computer hardware and software localization, we have the early warning aircraft development initiative firmly in their own hands.
　　Reporter: From the photographs, early warning aircraft to China's exports to Pakistan as a platform for improved transport -8, U.S. P-3 type have early warning, early C-130 is also useful to make the idea of ​​early warning platform. Propeller aircraft and jet aircraft as a platform for AWACS platform, which compared the advantages and disadvantages?
　　Cao: In principle, as long as there is enough space and aircraft aerodynamic potential to allow the installation of radar or other electronic system and a large antenna to provide enough power to make the performance of radar or electronic systems to achieve the indicator; as long as the aircraft has sufficient load capacity, can accommodate the required equipment and personnel, propeller aircraft and jets are possible. Of course, some of propeller aircraft to more fuel-efficient.
　　In fact, compared to the engine type design on the impact of early warning aircraft, the aircraft fuselage wing position relative to the impact of early warning aircraft designed to be larger. AWACS air current configuration is the main disc, balance beam and conformal array. Disc and the balance beam, whether on the wing or under the wing have this layout, their common feature is the antenna on the rear. However, compared to an airplane wing on wing, under wing monoplane, the radar antenna from the machine back closer to the radar beam blocking more serious; order to reduce the block, need to stand higher bracket, which the larger the resistance, the strength requirements of the bracket will increase the operating stability of the aircraft impact is greater. For conformal array, because the front fuselage of the most spacious, it is generally affixed to the first radar antenna installed on both sides of the fuselage. For high-wing aircraft, the engine is generally placed under the hanging, so the beam scanning to position the engine will be blocked, and because the radar antenna will always have some bumps, may also affect the engine intake. Under the wing of the plane so there will not be a serious problem, so the conformal array of foreign aircraft, including Boeing 707, "Phalcon" and "Gulf Stream" 550 "Sea Eagle", is under the wing of the. Generally speaking, it is difficult to make propeller aircraft conformal array, the main problem is the blade block.
　　Note: the relatively simple early warning that air targets, but targets on the ground or in the mountains and so on, how to accurately determine the target, filter out the clutter?
　　Cao: AWACS main goal is to see the air, especially in low-flying air targets. Movement on the ground or stationary targets, early warning is not read. Americans have engaged in the E-8 "co-star" system, in fact, is not called early warning aircraft. Aerial targets can be both in the sea, over land may also, from sea or land clutter is the radar echo. Although the sea clutter is weaker than the land clutter, but their strength may be stronger than the echo from the target of hundreds of thousands of times or even more, if by echo intensity to distinguish between clutter will cover the target. In order to have anti-noise ability, have adopted the modern early-warning radar pulse Doppler technology, the use of targets and clutter (ground or sea) relative to the speed of the different early warning aircraft to the target and clutter separate. For the E-8 such a system, and early warning aircraft contrary, the echo from the aircraft is to be filtered out, the echo from the ground is needed. It does this by synthetic aperture radar system on the ground imaging, early warning aircraft is on the pulse Doppler radar system.
　　Note: in the development of early warning aircraft and other military electronic equipment, more time, EMC is a major problem, how to handle this problem? China doing?
　　Cao: about electromagnetic compatibility problems, people first thought is probably the EP-3 electronic reconnaissance aircraft. But in fact on the early warning aircraft electromagnetic compatibility problems are more complex, mainly on the early warning radar early warning aircraft, such high-power, high sensitivity of the device. In addition, the AWACS electronic surveillance tasks than more, so the types of electronic equipment is also more. It should be said to the troops of air marshals on behalf of 2000, shows that we have completely overcome this problem. 200 air marshals back to go in and ZDK03, so it is not a technical problem the. From the technical means, the roughly frequency isolation, spatial isolation, polarization isolation and temporal isolation 4 main ways. Frequency of isolation is to try different electronic devices work at different frequencies. Because different when you have electronic devices in the receiver frequency selectivity, that is, the signals of different frequencies have different amplification or inhibition, therefore, may be weakened signal into an electronic device to another electronic device causing the interference. Spatial isolation refers to the different electronic devices in space as a sufficient distance apart. As the radio signal attenuation of power with distance, so even if there is interference, then the interference signal interference device into the receiver, its strength has been very weak. Polarization isolation is a different antenna polarization to maximize the use of different parameters. Polarization refers to the electromagnetic field propagation in the direction of the electric field changes. Different receivers for different polarization of electromagnetic radiation may have a different reception. Time isolation, it is so different devices sharing the work, which is the most thorough method of electromagnetic compatibility. However, each device can not work, will definitely affect the overall combat effectiveness of the electronic system to play.
　　Note: this seems to solve the problem of electromagnetic compatibility is still a lot of ways, then, why do we have agreed that this issue is a major engineering difficulties early warning?
　　Cao: The most important reason is that the application of these methods may often suffer a variety of factors. Such as the frequency of isolation, many of the existing early warning electronic equipment on its working band often has been designed not modifiable. HF radio communication is often or V / UHF bands, secondary radar and "TACAN" navigation system is L-band. Even if Li Lunshang band can choose equipment, such as radar, the frequency band of choice is often limited by many other conditions, may not only from the perspective of electromagnetic compatibility selected. Furthermore, early warning aircraft is very limited on space, and a lot of equipment and layout can not be everywhere at random and, therefore, a variety of sources to make certain the layout of spatial isolation is very difficult. In the polarized segregation, a common restriction is that the radar, for example, it observed the ground or sea, in a polarized, its reflective properties weaker, less easy to clutter the radar receiver, but This feature may be in conjunction with the electromagnetic compatibility conflict. It is even so many conflicting factors interact to increase the early-warning aircraft electromagnetic compatibility issues to resolve the difficulty. This requires good computer simulation in the design prediction and calculation and analysis, electrical properties of devices made many specific regulatory requirements, and fully carry out the test, adjust the parameters of the system and so on.
　　Note: radar and other equipment cooling is an important issue, especially in Pakistan or the Middle East as a hot environment, the means might be taken to improve what? Space and cooling equipment accounted for the weight of life?
　　Cao: Radar is a big power, airborne early warning radar transmitter peak power of up to several hundred kilowatts. For phased array early warning radar, if a passive phased array, the heat from the bulk of two parts: one is concentrated on the early warning aircraft cabin-style transmitter, the other is on the top of the hood of the phase shift device. Placed in the cabin of the centralized transmitter as much heat, such as forced air cooling fan hair is not enough, the general method of liquid cooling. The top cover of the phase shifter can be used to force air cooling, liquid cooling can also be used. For active phased array early warning radar, cabin fever is basically no large, decentralized on hundreds of transmitters in the transceiver components. These components are in the top cover, if the power is larger, definitely use the liquid, such as air marshals 2000. If power is not, you can use air-cooled, for example, 200 air marshals. We can see the front and rear balance beam has holes, that is used to send and receive components of the cooling air inlet and outlet. In addition to the use of appropriate cooling method, the research or the use of the new equipment must be to make the device's storage temperature and operating temperature must be able to adapt to the local user requirements. The cost of the equipment cooling, the cooling system to current technology level, the heat probably increased by 1.2 per kilowatt to 1.5 kg of weight. If you need to heat 200 kilowatts, you need to gain weight around 300 kg.
　　Q: You mentioned earlier, phased array radar has become the trend, but the phased array radar antenna and the antenna than the traditional mechanical scanning, there are some inherent disadvantages. The disadvantages?
　　Cao: Phased array radar antenna and conventional antenna compared to the main problem is that the antenna performance will increase with the beam scan angle worsened, while the traditional antenna will not have this problem. This is because, for the phased array antenna, the antenna array when the scan angle deviation from the surface normal, the beam is not perpendicular to the surface with the antenna array, and play a decisive role on the antenna performance and the beam is perpendicular to the antenna area, known as the effective area. Partial scan angle normal to the front on both sides of 60 °, the effective area is only half of the whole area, the antenna performance will seriously deteriorate to the extent not used, this is a phased array antenna is generally only around the 60 ° scan range truth. And because the traditional antenna and antenna array beam is always perpendicular to the surface, so the antenna performance has always played a decisive role in all of the antenna area. Deterioration of the antenna performance includes two aspects, one main lobe of fat, which is the antenna gain reduction, because the main lobe is emitted from the antenna wave energy in space the most concentrated area, the wider the main lobe, indicating that this region more energy less, which are crucial for the radar beam is projected onto the farther detrimental. Second, the side lobe is too high, Ye Hao understand this, because the total energy emitted from the antenna is certain, contained in the main lobe in less energy, natural energy to go on the side lobe in more.
　　Reporter: So, phased array antennas in these two areas there are ways to overcome the lack of it? So, is the traditional antennas will not be fully eliminated?
　　Cao: the performance worsening in these two areas, the main lobe of fat can also be prone to make up for a few radar pulses. Because phased array radar beam scanning can be electronically controlled, allowing the beam sweep faster, you can scan more slowly. Sweep more slowly when the beam scan passing the target, the longer the time to stay, that is, the more pulses emitted, the energy will come back more, so that the antenna gain to make up due to falling energy reduction. However, the sidelobe elevation can not solve this problem, but its impact will be more serious, because sidelobe distribution in all directions, will be irradiated to the ground, it will increase the intensity of ground clutter, which the anti-clutter negative. So, in general, anti-mechanical scanning radar clutter capability will be better. As the traditional antenna will not be eliminated, I think not as it lies in two aspects: First, not all radar tasks are required to solve the phased array, mechanical scanning radar, low cost, easy to use, many cases have been enough; second, can the advantages of the traditional antenna combined with phased array.
　　Reporter: You just mentioned can be traditional phased array antenna and antenna combined, the European C-295 AWACS Radar design is by rotating radome integrated with phased array antenna design, the diameter radome certain circumstances, an antenna can be installed along the diameter, length can be increased accordingly, in order to install more transmit / receive modules, and therefore has more power, more flexible scanning, improved version of the U.S. E-2C has the idea. You speak with such a vision is not a meaning?
　　Cao: Yes. C-295 and E-2C are disc form. If the use of phased array to achieve full coverage, at least three front, can these two AWACS aircraft carrier aircraft are small, allowing the disc size is not significant, C-295 was 6 m, E -2C and its improved version of E-2D was 7 meters. Cover the same size circular arrangement of three antennas in the front, compared to the layout of a front only, that is, rotating antenna, there is no doubt that three front antenna size will be smaller. The small size of the antenna after the detection range is not enough. Rotating antenna has the advantage of antenna size can be larger, and anti-noise performance, but can not scan as fast as flexible phased array. So, what can the combination of both? Yes, this combination is called "machine-phase scanning." As a result of the phased array scanning mode, multiple pulses can reduce the scan cycle, detection range can be further increased.
　　Q: Can you further explain how the mechanical scanning is combined with phased array scan work?
　　Cao: The E-2D, for example, rotating radar antenna in the process, if there are threats that target a certain direction, you need to immediately re-target irradiated with a beam, the beam can be used for computer-controlled flyback, to overcome the mere mechanical scan observed the target again in a circle until only after weaknesses. Of course, the angle of sweep back to normal on both sides of the antenna will not exceed 60 ° range. And if you only need to observe, rather than the whole 120 ° airspace airspace, the antenna can not rotate, only phased array manner.
　　Q: After listening to your introduction, we know that the disc-shaped AWACS radar there are three, one is like an air marshal 2000 so that only phased array scanning, and one is like the United States and Russia, E-3 A-50 only mechanical scan, there is a C-295 and E-2D phase sweep of this machine. So why use such a common type of radar disc? Conformal array proposed for many years, why so far only in the development of Israel's own?
　　Cao: I think the problem involves disc-shaped, balance beam conformal array and the three main air AWACS configuration of choice. My general view is that the radar detection range to meet the requirements of the premise, the disc may be the best choice. If the distance in order to meet the requirements of the antenna can provide disk size is not enough, it would have to take some other form of radome. For example, the balance beam in the form, you can like the C-295 aircraft of this size to do the balance beam 9 meters in length, the use of conformal array form, can be in the "Gulf Stream" 550 aircraft of this size on the surface of the antenna array size to achieve 10 m × 2 m, this is the disc size can not be achieved. But do the large size of the antenna and may be at the expense of full performance for the price. Balance beam head and tail are blind; conformal array head and tail even though it can cover, but the distance is much closer. As for the disc, whether it is transferred, or does not turn, are able to meet the full requirements of uniform coverage, and disc compatibility is very good, as a disc, not only do the turn, but do do not turn, has two advantages.
　　Note: In order to make up the balance beam orientation blind, E-737 to install a cap, this can solve the problem the balance beam? Also, you mentioned that there are conformal array direction detection uneven, can you explain again?
　　Cao: E-737 to increase the cap above the balance beam antennas, which beam injection direction is towards the nose and tail, and the work performance of the antenna beam, is the antenna in the direction of the nose and tail size, the size large, rather than the size of the wingspan direction, so better able to compensate for blind spots. This antenna beam injection direction and the plane parallel to the antenna, rather than the side of the radio antenna as the plane perpendicular to the antenna, known as the end-fire antenna. Our early when cable is not yet universal Yagi antenna is used in the first end-fire antenna. However, this antenna in the current technical level, the gain and the maximum scan angle can be achieved are still not the same side of radio antenna matching, so the nose and tail of the detection range will still be closer. The conformal array, the position detection was mainly due to uneven nose and tail that can be allowed to install the antenna size is much smaller than in the fuselage sides to the Boeing 707 "Phalcon" for example, the nose area of ​​the antenna only 3 square meters and more, only the side of the antenna area of ​​1 / 6. Of course, in the case of smaller antennas, the radar can work up to make up for the shorter wavelengths, so that is also able to gain the post. So, then Israel has engaged in a "sea eagle" conformal array early warning radar antenna at the head end, the operating wavelength of 10 cm, while the fuselage on both sides of the radar wavelength of 25 cm. But even if to do so, as a multiple of the wavelength difference is not entirely compensate for differences in a multiple antenna area, so the full range of detection is not balanced.
　　Note: now disc-shaped AWACS radar is still widely used, and the nascent disc-shaped AWACS phased array in direction to the development, then the mechanical scanning of US-Russian early warning aircraft, there may be disc shaped by technological innovation to make up some of the disadvantages of modern ?
　　Cao: Let me talk about the United States. Disc-shaped early warning aircraft from the U.S. Navy's E-2C mechanical scanning to improve the E-2D, which is the active phased array with mechanical scanning of new things, a great influence on E-2C can no longer be seen as an upgrade, and is a new model. U.S. Air Force E-3 AWACS, radar, have not seen its like to change the active phased array of reports, but it also made some improvements, such as increasing the transmission power, improved waveform design, the use of new devices to reduce processing losses, etc. measures to increase the detection range of more than 80%. At the same time the system has also done a lot of improvements, including the use of new broadband data link, enhanced battlefield situational multi-source data fusion and the formation of software improvements, etc., the latest upgrade model E-3G. Russian A-50 early warning aircraft will have to be replaced by A-100, IL-76 from its carrier aircraft Il-476 instead, will use radar active phased array.
　　Note: the Russian A-100 will use what kind of configuration it?
　　Cao: There is no more to see the relevant reports. I personally think that the possibility of using disk configuration to be larger. On the one hand, Il-476 and IL-76 in the basic aerodynamic layout similar to the high wing aircraft is not likely to use conformal array. On the other hand, IL-76 on the disc-shaped configuration is very mature, IL-76 Israeli exports to India, "Phalcon" and Russia's own A-50, all of this configuration. The array is made of three sides made of single or array, depending on how much power is required. If you want to meet for small aircraft is about 400 kilometers away from the discovery request, even if the array should be enough on three sides, and this distance is compared to A-50 has improved a lot. If you want to improve the discovery of the ability of stealth aircraft, the possibility of using machine-phase scanning large. Of course, if the power increase again, you should use another type of structure.
　　Reporter: Now everyone is concerned about aircraft carriers early warning aircraft. China's existing fixed-wing aircraft platforms, slippery little for flying leaps, like the transport -12 as the maximum takeoff weight of 5.3 tons, a maximum payload of 1.7 tons of aircraft carrier-based AWACS could change it? Win -7 maximum takeoff weight of 21 tons that, load 4.7 tons of aircraft can serve as early warning aircraft carrier catapult to carry it?
　　Cao: E-2 maximum takeoff weight of 26 tons, is equipped with the first 80,000-ton aircraft carrier. China is now the platform for the 60,000-ton aircraft carrier, but even so, transport -12 is still too small. China-made aircraft in operation and is more close to -7 E-2. But to note that the maximum takeoff weight shipped -7 is 21 tons, E-2 C-2A carrier machine to light a lot, have to a large number of captains and wingspan. Therefore, the carrier transport -7 and adaptation of them to be more difficult to achieve. And C-2 is specifically developed for the early warning aircraft on the ship, the fitting with the carrier to do a lot of special design, such as folding wings, radomes leg lift, and so highly. If the operation -7 as a ready-made AWACS aircraft to change, probably had to use these designs, along with other measures of the modification, the resulting design changes may be less than the workload developed a new type of adapter carrier aircraft, the basic parameters may be changed greatly. Nevertheless, in the absence of better conditions for the platform, I personally think -7 operation may still be an important choice.
　　Reporter: equipment for various reasons can not be the case of fixed-wing AWACS, the use of performance on the early warning helicopters and fixed-wing AWACS much difference?
　　Cao: carrier-based early warning helicopter ceiling is much lower than fixed-wing AWACS. If the fixed-wing AWACS ceiling in 8,000 meters of sea-flying aircraft affixed, the maximum sight distance of 370 km or so; and early warning helicopters ceiling of 4,000 meters, the maximum sight distance is only 250 km or so. And because it is the body is small, fewer personnel, command and control capabilities should be much weaker. But its fundamental value is that the ground was able to overcome or shipboard radar line of sight from the past, low-flying target detection for only three to four kilometers from the defects, the effective low-level raid against the enemy, which is important for fleet air defense. In addition, it uses a flexible, space requirements for the carrier's relatively low, the cost is cheap, equipment, number of fixed-wing AWACS can be a lot more than that. Also, a variety of tactical operations from the sea to be considered, the helicopter's radar early warning function of the general functions than a simple early-warning radar to many, including imaging of the sea, beacon, anti-submarine and meteorological early warning. Therefore, early warning helicopters and fixed wing AWACS with one hand, the completion of some areas of the low-altitude warning radar command guidance and a small amount of the task, the other can perform in addition to radar warning and command guidance other than the Navy's unique operational mission.
　　Note: There are three radar early warning helicopters mounted way, namely, the British "Neptune," the Ministry of the machine body side retractable tube, the Russian card -31 abdomen retractable panels, France's "Super Puma" retractable rear cylinder. The layout of each of these three characteristics?
　　Cao: three on the whole layout is retractable, because if we adopt the fixed antenna structure may be difficult to have the installation conditions. For example, as did the fixed-wing AWACS antenna fixed to the upper body and elevated obviously not, because the rotor. The idea of ​​trying to get a large enough area of ​​the antenna in the case, in the end what kind of mounting means need to combine all aspects of machine set to set. The layout of these three aircraft to compare card -31 abdomen obtained retractable antenna plate area is the largest, reaching 6 m × 1 m. Of course, the antenna can do much, but also the size of the helicopter itself.
　　Reporter: Thank you for the interview.
---------- Post added at 01:57 PM ---------- Previous post was at 01:57 PM ----------
http://i2.sinaimg.cn/jc/2012-01-11/U6449P27T1D679843F3DT20120111090520.jpeg??????_?_
Editor's Note: Recently, a group of Chinese exports coming out of Pakistan's early warning network of photos, Articles for this special interview with deputy chief designer of the early warning aircraft, China Electronics Technology Group Corporation researcher Cao morning, early warning and knowledge on a request make a solution.
　　Reporter: (hereinafter referred to mind) Cao hello! Recently appeared on the World Wide Web sites such as the development of China's early-warning aircraft to Pakistan some pictures, one of which is the early warning aircraft model, the body there is a sign of CETC, which is the China Electronics Technology Group Corporation's LOGO. As the group's research staff, please briefly describe the case of groups, especially Group and China's military industries.
　　Cao morning: (hereinafter referred to CAO) China China's military power is the group of electronic and information technology team, is one of the top ten military group, established in 2002, mainly engaged in all kinds of weapons and equipment of information technology products and consumer electronics information the development. From electronic components, made basic computer hardware and software, machine, like the area until the integrated command automation systems, early warning aircraft, data link, such large-scale systems, are all Chinese military power in the field of Science major lines of business. In fact, we can note that the export of Pakistan's AWACS, called ZDK03, which "ZDK" is "in the Electric Division," the phonetic abbreviation, 03 representing the Electric Division, following China's 2000 air marshals, air marshals served after 200 chief architect of the third unit developed early warning models.
　　In addition to early warning aircraft in addition to other major projects, the China Electricity Division also played an important role. For example, in manned space program as a deputy commander unit, responsible for monitoring and control equipment, communications systems, radar detection devices, solar cells and a number of key components of development. In lunar exploration project, is also vice president of China Power Division commander unit in the satellite, launch vehicle, launch site, monitoring and control communications and ground application systems in five major research task undertaken. In the national publication of the 16 major projects, the China Electricity Division to assume special importance in a number of research tasks, especially in the first major projects, "the core devices, high-end chips and basic software (nuclear high base)," served as the main role, and in the country "very large scale integrated circuit manufacturing process equipment and complete sets of" science and technology projects undertaken in the planning and overall design.
　　Note: early warning radar is the primary sensor. The world's airborne radar development trends? China's airborne radar technology in the world belong to what level?
　　Cao: the world in general to the airborne radar active phased array direction, both on the AWACS airborne early warning aircraft on radar or airborne fire control radar, like this, these two areas is the most airborne radar The main areas. China to airborne early warning radar as a breakthrough to achieve airborne radar equipment from the mechanical to the active phased array scanning across, not to engage in passive phased array, the world's first equipment warning two-dimensional active phased array radar , that the radar beam in the horizontal direction and height direction can be electronically scanned, which also contributed to the aircraft fire control radar equipment using active phased array. From the time point of view, Israel and Sweden are the active phased array early warning radar equipment to form the country, is the familiar "Phalcon" and "balance beam", the United States was the first equipped with active phased array airborne State fire control radar and equipment on the F-22. Europe in the completion of airborne early warning radar active phased array applications, is equipped with active phased array fire control radar, such as the UK's "wind." In addition to active phased array, the airborne radar is an important development direction of digital. Now the active phased array, the transceiver generates the transmit frequency components of the device and the receiving beam processing are analog, so sending and receiving component weight and volume is too large, the aircraft platform is not of Fitness good. Digital transceiver components, firing frequency from low to high frequency digital synthesis, and in receiving and processing time, directly on the firing frequency analog to digital conversion, not only significantly reduces the weight and size, and very flexible beam processing , can interfere with the formation of the weakest direction automatically receive, thereby greatly enhancing the ability of radar anti-jamming and anti-noise capability. China's airborne early warning radar, digital standard has been an international leader.
　　Reporter: China's airborne radar components above the level of local production? For example, the transmitter amplifier tubes, as well as processor chips, software, etc. are subject to foreign?
　　Cao: China's airborne radar transceiver components including solid state power amplifier tube and the inside, including all the key components are made of, radar data processing required for high-speed processor chip is also our own research and development. In the computer, although the use of COTS is a trend, data processing machines, distributed intelligence and command and control are specially developed without the use of military computers, you can directly buy the product on the market can basically meet the need, but the coin No doubt, China's information technology for the maintenance of information security, weapons and equipment are hidden dangers. Therefore, we insist on promoting the past few years, including servers, workstations, processors, chips, operating systems and databases and other computer-based hardware and software localization. We rely on machine-made platform and come up with a set air marshals 200, ZDK03. It can be said, through the platform, the basis of the key components and computer hardware and software localization, we have the early warning aircraft development initiative firmly in their own hands.
　　Reporter: From the photographs, early warning aircraft to China's exports to Pakistan as a platform for improved transport -8, U.S. P-3 type have early warning, early C-130 is also useful to make the idea of ​​early warning platform. Propeller aircraft and jet aircraft as a platform for AWACS platform, which compared the advantages and disadvantages?
　　Cao: In principle, as long as there is enough space and aircraft aerodynamic potential to allow the installation of radar or other electronic system and a large antenna to provide enough power to make the performance of radar or electronic systems to achieve the indicator; as long as the aircraft has sufficient load capacity, can accommodate the required equipment and personnel, propeller aircraft and jets are possible. Of course, some of propeller aircraft to more fuel-efficient.
　　In fact, compared to the engine type design on the impact of early warning aircraft, the aircraft fuselage wing position relative to the impact of early warning aircraft designed to be larger. AWACS air current configuration is the main disc, balance beam and conformal array. Disc and the balance beam, whether on the wing or under the wing have this layout, their common feature is the antenna on the rear. However, compared to an airplane wing on wing, under wing monoplane, the radar antenna from the machine back closer to the radar beam blocking more serious; order to reduce the block, need to stand higher bracket, which the larger the resistance, the strength requirements of the bracket will increase the operating stability of the aircraft impact is greater. For conformal array, because the front fuselage of the most spacious, it is generally affixed to the first radar antenna installed on both sides of the fuselage. For high-wing aircraft, the engine is generally placed under the hanging, so the beam scanning to position the engine will be blocked, and because the radar antenna will always have some bumps, may also affect the engine intake. Under the wing of the plane so there will not be a serious problem, so the conformal array of foreign aircraft, including Boeing 707, "Phalcon" and "Gulf Stream" 550 "Sea Eagle", is under the wing of the. Generally speaking, it is difficult to make propeller aircraft conformal array, the main problem is the blade block.
　　Note: the relatively simple early warning that air targets, but targets on the ground or in the mountains and so on, how to accurately determine the target, filter out the clutter?
　　Cao: AWACS main goal is to see the air, especially in low-flying air targets. Movement on the ground or stationary targets, early warning is not read. Americans have engaged in the E-8 "co-star" system, in fact, is not called early warning aircraft. Aerial targets can be both in the sea, over land may also, from sea or land clutter is the radar echo. Although the sea clutter is weaker than the land clutter, but their strength may be stronger than the echo from the target of hundreds of thousands of times or even more, if by echo intensity to distinguish between clutter will cover the target. In order to have anti-noise ability, have adopted the modern early-warning radar pulse Doppler technology, the use of targets and clutter (ground or sea) relative to the speed of the different early warning aircraft to the target and clutter separate. For the E-8 such a system, and early warning aircraft contrary, the echo from the aircraft is to be filtered out, the echo from the ground is needed. It does this by synthetic aperture radar system on the ground imaging, early warning aircraft is on the pulse Doppler radar system.
　　Note: in the development of early warning aircraft and other military electronic equipment, more time, EMC is a major problem, how to handle this problem? China doing?
　　Cao: about electromagnetic compatibility problems, people first thought is probably the EP-3 electronic reconnaissance aircraft. But in fact on the early warning aircraft electromagnetic compatibility problems are more complex, mainly on the early warning radar early warning aircraft, such high-power, high sensitivity of the device. In addition, the AWACS electronic surveillance tasks than more, so the types of electronic equipment is also more. It should be said to the troops of air marshals on behalf of 2000, shows that we have completely overcome this problem. 200 air marshals back to go in and ZDK03, so it is not a technical problem the. From the technical means, the roughly frequency isolation, spatial isolation, polarization isolation and temporal isolation 4 main ways. Frequency of isolation is to try different electronic devices work at different frequencies. Because different when you have electronic devices in the receiver frequency selectivity, that is, the signals of different frequencies have different amplification or inhibition, therefore, may be weakened signal into an electronic device to another electronic device causing the interference. Spatial isolation refers to the different electronic devices in space as a sufficient distance apart. As the radio signal attenuation of power with distance, so even if there is interference, then the interference signal interference device into the receiver, its strength has been very weak. Polarization isolation is a different antenna polarization to maximize the use of different parameters. Polarization refers to the electromagnetic field propagation in the direction of the electric field changes. Different receivers for different polarization of electromagnetic radiation may have a different reception. Time isolation, it is so different devices sharing the work, which is the most thorough method of electromagnetic compatibility. However, each device can not work, will definitely affect the overall combat effectiveness of the electronic system to play.
　　Note: this seems to solve the problem of electromagnetic compatibility is still a lot of ways, then, why do we have agreed that this issue is a major engineering difficulties early warning?
　　Cao: The most important reason is that the application of these methods may often suffer a variety of factors. Such as the frequency of isolation, many of the existing early warning electronic equipment on its working band often has been designed not modifiable. HF radio communication is often or V / UHF bands, secondary radar and "TACAN" navigation system is L-band. Even if Li Lunshang band can choose equipment, such as radar, the frequency band of choice is often limited by many other conditions, may not only from the perspective of electromagnetic compatibility selected. Furthermore, early warning aircraft is very limited on space, and a lot of equipment and layout can not be everywhere at random and, therefore, a variety of sources to make certain the layout of spatial isolation is very difficult. In the polarized segregation, a common restriction is that the radar, for example, it observed the ground or sea, in a polarized, its reflective properties weaker, less easy to clutter the radar receiver, but This feature may be in conjunction with the electromagnetic compatibility conflict. It is even so many conflicting factors interact to increase the early-warning aircraft electromagnetic compatibility issues to resolve the difficulty. This requires good computer simulation in the design prediction and calculation and analysis, electrical properties of devices made many specific regulatory requirements, and fully carry out the test, adjust the parameters of the system and so on.
　　Note: radar and other equipment cooling is an important issue, especially in Pakistan or the Middle East as a hot environment, the means might be taken to improve what? Space and cooling equipment accounted for the weight of life?
　　Cao: Radar is a big power, airborne early warning radar transmitter peak power of up to several hundred kilowatts. For phased array early warning radar, if a passive phased array, the heat from the bulk of two parts: one is concentrated on the early warning aircraft cabin-style transmitter, the other is on the top of the hood of the phase shift device. Placed in the cabin of the centralized transmitter as much heat, such as forced air cooling fan hair is not enough, the general method of liquid cooling. The top cover of the phase shifter can be used to force air cooling, liquid cooling can also be used. For active phased array early warning radar, cabin fever is basically no large, decentralized on hundreds of transmitters in the transceiver components. These components are in the top cover, if the power is larger, definitely use the liquid, such as air marshals 2000. If power is not, you can use air-cooled, for example, 200 air marshals. We can see the front and rear balance beam has holes, that is used to send and receive components of the cooling air inlet and outlet. In addition to the use of appropriate cooling method, the research or the use of the new equipment must be to make the device's storage temperature and operating temperature must be able to adapt to the local user requirements. The cost of the equipment cooling, the cooling system to current technology level, the heat probably increased by 1.2 per kilowatt to 1.5 kg of weight. If you need to heat 200 kilowatts, you need to gain weight around 300 kg.
　　Q: You mentioned earlier, phased array radar has become the trend, but the phased array radar antenna and the antenna than the traditional mechanical scanning, there are some inherent disadvantages. The disadvantages?
　　Cao: Phased array radar antenna and conventional antenna compared to the main problem is that the antenna performance will increase with the beam scan angle worsened, while the traditional antenna will not have this problem. This is because, for the phased array antenna, the antenna array when the scan angle deviation from the surface normal, the beam is not perpendicular to the surface with the antenna array, and play a decisive role on the antenna performance and the beam is perpendicular to the antenna area, known as the effective area. Partial scan angle normal to the front on both sides of 60 °, the effective area is only half of the whole area, the antenna performance will seriously deteriorate to the extent not used, this is a phased array antenna is generally only around the 60 ° scan range truth. And because the traditional antenna and antenna array beam is always perpendicular to the surface, so the antenna performance has always played a decisive role in all of the antenna area. Deterioration of the antenna performance includes two aspects, one main lobe of fat, which is the antenna gain reduction, because the main lobe is emitted from the antenna wave energy in space the most concentrated area, the wider the main lobe, indicating that this region more energy less, which are crucial for the radar beam is projected onto the farther detrimental. Second, the side lobe is too high, Ye Hao understand this, because the total energy emitted from the antenna is certain, contained in the main lobe in less energy, natural energy to go on the side lobe in more.
　　Reporter: So, phased array antennas in these two areas there are ways to overcome the lack of it? So, is the traditional antennas will not be fully eliminated?
　　Cao: the performance worsening in these two areas, the main lobe of fat can also be prone to make up for a few radar pulses. Because phased array radar beam scanning can be electronically controlled, allowing the beam sweep faster, you can scan more slowly. Sweep more slowly when the beam scan passing the target, the longer the time to stay, that is, the more pulses emitted, the energy will come back more, so that the antenna gain to make up due to falling energy reduction. However, the sidelobe elevation can not solve this problem, but its impact will be more serious, because sidelobe distribution in all directions, will be irradiated to the ground, it will increase the intensity of ground clutter, which the anti-clutter negative. So, in general, anti-mechanical scanning radar clutter capability will be better. As the traditional antenna will not be eliminated, I think not as it lies in two aspects: First, not all radar tasks are required to solve the phased array, mechanical scanning radar, low cost, easy to use, many cases have been enough; second, can the advantages of the traditional antenna combined with phased array.
　　Reporter: You just mentioned can be traditional phased array antenna and antenna combined, the European C-295 AWACS Radar design is by rotating radome integrated with phased array antenna design, the diameter radome certain circumstances, an antenna can be installed along the diameter, length can be increased accordingly, in order to install more transmit / receive modules, and therefore has more power, more flexible scanning, improved version of the U.S. E-2C has the idea. You speak with such a vision is not a meaning?
　　Cao: Yes. C-295 and E-2C are disc form. If the use of phased array to achieve full coverage, at least three front, can these two AWACS aircraft carrier aircraft are small, allowing the disc size is not significant, C-295 was 6 m, E -2C and its improved version of E-2D was 7 meters. Cover the same size circular arrangement of three antennas in the front, compared to the layout of a front only, that is, rotating antenna, there is no doubt that three front antenna size will be smaller. The small size of the antenna after the detection range is not enough. Rotating antenna has the advantage of antenna size can be larger, and anti-noise performance, but can not scan as fast as flexible phased array. So, what can the combination of both? Yes, this combination is called "machine-phase scanning." As a result of the phased array scanning mode, multiple pulses can reduce the scan cycle, detection range can be further increased.
　　Q: Can you further explain how the mechanical scanning is combined with phased array scan work?
　　Cao: The E-2D, for example, rotating radar antenna in the process, if there are threats that target a certain direction, you need to immediately re-target irradiated with a beam, the beam can be used for computer-controlled flyback, to overcome the mere mechanical scan observed the target again in a circle until only after weaknesses. Of course, the angle of sweep back to normal on both sides of the antenna will not exceed 60 ° range. And if you only need to observe, rather than the whole 120 ° airspace airspace, the antenna can not rotate, only phased array manner.
　　Q: After listening to your introduction, we know that the disc-shaped AWACS radar there are three, one is like an air marshal 2000 so that only phased array scanning, and one is like the United States and Russia, E-3 A-50 only mechanical scan, there is a C-295 and E-2D phase sweep of this machine. So why use such a common type of radar disc? Conformal array proposed for many years, why so far only in the development of Israel's own?
　　Cao: I think the problem involves disc-shaped, balance beam conformal array and the three main air AWACS configuration of choice. My general view is that the radar detection range to meet the requirements of the premise, the disc may be the best choice. If the distance in order to meet the requirements of the antenna can provide disk size is not enough, it would have to take some other form of radome. For example, the balance beam in the form, you can like the C-295 aircraft of this size to do the balance beam 9 meters in length, the use of conformal array form, can be in the "Gulf Stream" 550 aircraft of this size on the surface of the antenna array size to achieve 10 m × 2 m, this is the disc size can not be achieved. But do the large size of the antenna and may be at the expense of full performance for the price. Balance beam head and tail are blind; conformal array head and tail even though it can cover, but the distance is much closer. As for the disc, whether it is transferred, or does not turn, are able to meet the full requirements of uniform coverage, and disc compatibility is very good, as a disc, not only do the turn, but do do not turn, has two advantages.
　　Note: In order to make up the balance beam orientation blind, E-737 to install a cap, this can solve the problem the balance beam? Also, you mentioned that there are conformal array direction detection uneven, can you explain again?
　　Cao: E-737 to increase the cap above the balance beam antennas, which beam injection direction is towards the nose and tail, and the work performance of the antenna beam, is the antenna in the direction of the nose and tail size, the size large, rather than the size of the wingspan direction, so better able to compensate for blind spots. This antenna beam injection direction and the plane parallel to the antenna, rather than the side of the radio antenna as the plane perpendicular to the antenna, known as the end-fire antenna. Our early when cable is not yet universal Yagi antenna is used in the first end-fire antenna. However, this antenna in the current technical level, the gain and the maximum scan angle can be achieved are still not the same side of radio antenna matching, so the nose and tail of the detection range will still be closer. The conformal array, the position detection was mainly due to uneven nose and tail that can be allowed to install the antenna size is much smaller than in the fuselage sides to the Boeing 707 "Phalcon" for example, the nose area of ​​the antenna only 3 square meters and more, only the side of the antenna area of ​​1 / 6. Of course, in the case of smaller antennas, the radar can work up to make up for the shorter wavelengths, so that is also able to gain the post. So, then Israel has engaged in a "sea eagle" conformal array early warning radar antenna at the head end, the operating wavelength of 10 cm, while the fuselage on both sides of the radar wavelength of 25 cm. But even if to do so, as a multiple of the wavelength difference is not entirely compensate for differences in a multiple antenna area, so the full range of detection is not balanced.
　　Note: now disc-shaped AWACS radar is still widely used, and the nascent disc-shaped AWACS phased array in direction to the development, then the mechanical scanning of US-Russian early warning aircraft, there may be disc shaped by technological innovation to make up some of the disadvantages of modern ?
　　Cao: Let me talk about the United States. Disc-shaped early warning aircraft from the U.S. Navy's E-2C mechanical scanning to improve the E-2D, which is the active phased array with mechanical scanning of new things, a great influence on E-2C can no longer be seen as an upgrade, and is a new model. U.S. Air Force E-3 AWACS, radar, have not seen its like to change the active phased array of reports, but it also made some improvements, such as increasing the transmission power, improved waveform design, the use of new devices to reduce processing losses, etc. measures to increase the detection range of more than 80%. At the same time the system has also done a lot of improvements, including the use of new broadband data link, enhanced battlefield situational multi-source data fusion and the formation of software improvements, etc., the latest upgrade model E-3G. Russian A-50 early warning aircraft will have to be replaced by A-100, IL-76 from its carrier aircraft Il-476 instead, will use radar active phased array.
　　Note: the Russian A-100 will use what kind of configuration it?
　　Cao: There is no more to see the relevant reports. I personally think that the possibility of using disk configuration to be larger. On the one hand, Il-476 and IL-76 in the basic aerodynamic layout similar to the high wing aircraft is not likely to use conformal array. On the other hand, IL-76 on the disc-shaped configuration is very mature, IL-76 Israeli exports to India, "Phalcon" and Russia's own A-50, all of this configuration. The array is made of three sides made of single or array, depending on how much power is required. If you want to meet for small aircraft is about 400 kilometers away from the discovery request, even if the array should be enough on three sides, and this distance is compared to A-50 has improved a lot. If you want to improve the discovery of the ability of stealth aircraft, the possibility of using machine-phase scanning large. Of course, if the power increase again, you should use another type of structure.
　　Reporter: Now everyone is concerned about aircraft carriers early warning aircraft. China's existing fixed-wing aircraft platforms, slippery little for flying leaps, like the transport -12 as the maximum takeoff weight of 5.3 tons, a maximum payload of 1.7 tons of aircraft carrier-based AWACS could change it? Win -7 maximum takeoff weight of 21 tons that, load 4.7 tons of aircraft can serve as early warning aircraft carrier catapult to carry it?
　　Cao: E-2 maximum takeoff weight of 26 tons, is equipped with the first 80,000-ton aircraft carrier. China is now the platform for the 60,000-ton aircraft carrier, but even so, transport -12 is still too small. China-made aircraft in operation and is more close to -7 E-2. But to note that the maximum takeoff weight shipped -7 is 21 tons, E-2 C-2A carrier machine to light a lot, have to a large number of captains and wingspan. Therefore, the carrier transport -7 and adaptation of them to be more difficult to achieve. And C-2 is specifically developed for the early warning aircraft on the ship, the fitting with the carrier to do a lot of special design, such as folding wings, radomes leg lift, and so highly. If the operation -7 as a ready-made AWACS aircraft to change, probably had to use these designs, along with other measures of the modification, the resulting design changes may be less than the workload developed a new type of adapter carrier aircraft, the basic parameters may be changed greatly. Nevertheless, in the absence of better conditions for the platform, I personally think -7 operation may still be an important choice.
　　Reporter: equipment for various reasons can not be the case of fixed-wing AWACS, the use of performance on the early warning helicopters and fixed-wing AWACS much difference?
　　Cao: carrier-based early warning helicopter ceiling is much lower than fixed-wing AWACS. If the fixed-wing AWACS ceiling in 8,000 meters of sea-flying aircraft affixed, the maximum sight distance of 370 km or so; and early warning helicopters ceiling of 4,000 meters, the maximum sight distance is only 250 km or so. And because it is the body is small, fewer personnel, command and control capabilities should be much weaker. But its fundamental value is that the ground was able to overcome or shipboard radar line of sight from the past, low-flying target detection for only three to four kilometers from the defects, the effective low-level raid against the enemy, which is important for fleet air defense. In addition, it uses a flexible, space requirements for the carrier's relatively low, the cost is cheap, equipment, number of fixed-wing AWACS can be a lot more than that. Also, a variety of tactical operations from the sea to be considered, the helicopter's radar early warning function of the general functions than a simple early-warning radar to many, including imaging of the sea, beacon, anti-submarine and meteorological early warning. Therefore, early warning helicopters and fixed wing AWACS with one hand, the completion of some areas of the low-altitude warning radar command guidance and a small amount of the task, the other can perform in addition to radar warning and command guidance other than the Navy's unique operational mission.
　　Note: There are three radar early warning helicopters mounted way, namely, the British "Neptune," the Ministry of the machine body side retractable tube, the Russian card -31 abdomen retractable panels, France's "Super Puma" retractable rear cylinder. The layout of each of these three characteristics?
　　Cao: three on the whole layout is retractable, because if we adopt the fixed antenna structure may be difficult to have the installation conditions. For example, as did the fixed-wing AWACS antenna fixed to the upper body and elevated obviously not, because the rotor. The idea of ​​trying to get a large enough area of ​​the antenna in the case, in the end what kind of mounting means need to combine all aspects of machine set to set. The layout of these three aircraft to compare card -31 abdomen obtained retractable antenna plate area is the largest, reaching 6 m × 1 m. Of course, the antenna can do much, but also the size of the helicopter itself.
　　Reporter: Thank you for the interview.
hold breath and wait for second post...
