On Modern Developments in Radar
On Modern Developments in Radar
I felt it fitting to create my own piece on radar. Even though this topic is well covered, this article provides a handbook for understanding some major radars from the three big super powers.
In this article, I plan to compare the most popular and effective radar systems from the three global superpowers. But to begin, I will first give a brief overview of radar systems - how they work- and what function they serve.
Radar is a system of searching or tracking using electromagnetic waves. Search radar is made up of two important parts. The first part, is the transmitter. The transmitter shoots out these electromagnetic waves, using an oscillator, which is basically an electrical circuit that produces a sine or square wave. The wave is then magnified to increase its power and the antenna, which is most commonly seen as a little dish, aims the wave in a specific direction. If the wave hits an object through which it cannot get through (depending on the length of the period of the wave), then it will deflect back to the receiver. The receiver is usually very close to the transmitter. It uses the same dish or antenna used by the transmitter to capture any electromagnetic waves on the same output wavelength and then focuses the energy from these into a receiver circuit. This circuit will amplify and filter out any radio noise that is unwanted. Then it will also use a mixer which often contains a secondary oscillator to create an intermediary frequency (IF) that will create a frequency lower than the original one. This allows the radar to easily reduce the background noise and amplify the signal for the stuff they want to track.
Radar came around in the build-up to World War Two, and by the start of the Cold War radar had already become an important staple in military technology and was used globally to for tracking and search purposes. Radars came in all shapes and sizes. Handheld radar guns could only search a couple of hundred meters away. While massive early warning systems for ICBM attacks could detect objects hundreds, even thousands, of kilometers away. These systems were known as over-the-horizon radar. But the ability of a radar system depends on two main things. The range of the radar, and the radar cross section (RCS) it can detect. The radar cross section is the measurement of the smallest object a radar could detect if it was hit from one of its waves. Usually, the RCS ability of a radar system increases the farther the object is from the system. Note that the smaller the detectable RCS, the better. This brings me to aircraft and radar stealth. There are four main ways to hide from radar: Radar Absorbant Materials, Shaping (e.g, faceting, angling), Terrain (hiding behind stuff), and electronic countermeasures. There are ways to confuse radar systems like radar decoys but that's for another time.
Early stealth aircraft like the American F-117 were based on the principles first brought up by Soviet scientist Pyotr Ufimtsev and his paper “Method of Edge Waves in the Physical Theory of Diffraction.” This importantly proved that radar detection was not based on the size of the radar, but rather the angle of the edges it came into contact with. The F-117’s development was prompted by the massive losses suffered by American Bombers in the Vietnam War, due to advanced Soviet SAMs. Early designers of the F-117 thought that the best design would be to use rounded edges But, later evidence proved that flat surfaces with sharp edges, would provide a much smaller RCS. But the issue was, this design was extremely aerodynamic. So designers had to balance the issue of stealth with still making a plane that could fly. The first flight ended up with both prototypes crashing, but the radar detection results were promising enough. 1970s computers were able to calculate the diffraction of each facet on the plane, and that was used to calculate its total RCS which was about 0.003 meters squared. Or about the size of a hummingbird in flight. This may seem tiny but consider one of the most advanced radars in the 1980’s (the decade which the F-117 flew in active service), the SA-10A which could detect still detect this plane but only in a range of about 15nmi. Modern-day stealth aircraft is much, well, stealthier. As the plane design progressed throughout the Cold War and into the 21st century, speed and agility took some more precedence over maximum stealth. For example, the B-2 Spirit Bomber while being six times bigger than the F-16. Has an RCS of 0.0001, and a dBSM of -40. dBSM is representative the ease that a radar array could track or lock onto the target. The F-16, in comparison, has an RCS of 5 meters squared and a dBSM of ~5. Very few modern radar systems have the ability to track or even detect planes with an RCS of such a slim size. The RCS of a B-2, while being six times larger, is over 50,000 times smaller than an F-16. Now that you have an understanding of how radar systems work, and a comparison between some of the earliest and most advanced stealth planes; we can now get into the nitty gritty of some of the best radar sensors on the market. Starting with the United States.
The US strategic doctrine for radar, has been the following: to maximize range and situational awareness in the context of the US airforce and Navy. Since the US dominates the sky in terms of raw number of aircraft. Having lots of ground-based SAMs do not provide much of an advantage when it comes to air superiority. This is why the US specializes in aircraft radar. Arguably the best aircraft radar is the AN/APG-81 which can detect targets with an RCS as small as 0.01 square meters at a range of at least 150 kilometers. This radar system is currently used on the F-35 Lightning II. This radar system is the evolution of the AN/APG-77 used in the F-22 Raptor. This radar also includes an MIRFS system which includes its role in EW and ELINT. Its search and track feature scans in the I band. The AN/APG-81. The most advanced radar systems tend to be AESA radar. Northrop-Grummans program has produced some of the most advanced systems in the world. Including the AN/APG-63(v)2/3 on the F-15C/D and the AN/APG-79 systems which were developed separately by Raytheon for the F/A-18E/F. The AN/APG-77 should be particularly noteworthy because of its range, in which it can detect aircraft at 300kms away and bombers 500 kms away. AESA radar in the United States has always been a strong point. AESA radar is different from PESA radar. AESA (Active Electronically Scanned Array) uses a wider range of scanning frequencies and spreads out their signal emissions. While this makes AESA much, much harder to jam or block, and allows for the ability to track more target in a higher resolution; AESA does not have the same range as many of its PESA counterparts. For example, the main operator of PESA in the modern day is Russia. Russian aircraft have continuously be fitted with PESA up until some upgraded variants of the SU-30 and now the SU-57. PESA is considered to be an inferior active radar system because it provides few benefits. Countries like Russia use them, simply because their AESA programs are not good enough to compete with their existing PESA programs.
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Estimated characteristics of the Western fighter radars are following (from an internet source):
Some of these radar I have not and will not discuss in this article. This includes the Swedish and Italian NORA AESA and France’s CAESAR.
A. Style of antenna:
1. APG-63V3/V4: AESA, 1,500 T/R (Transmitters/Receivers)
2. APG-77: AESA, 2,000 T/R
3. APG-79: AESA, 1,100 T/R
4. APG-80: AESA, 1,000 T/R
5. APG-81: AESA, 1,200+ T/R
6. CAPTOR: Mechanic
7. CAESAR: AESA, 1,200~1,500+ T/R
8. RBE-2: PESA
9. RBE-2AA: AESA, 1,000~1,200 T/R
10. PS-05A: Mechanic
11. NOAR: AESA, 1,000 T/R
B. Effective tracking range for RCS = 1 m2 target
1. APG-63V3/V4: 144~185 km
2. APG-77: 200~230 km
3. APG-79: 120~130 km
4. APG-80: 110~120 km
5. APG-81: 140~160 km+
6. CAPTOR: 110~125 km
7. CAESAR: 165~220 km
8. RBE-2: 65~80 km
9. RBE-2AA: 110~130 km
10. PS-05A: 50~60 km
11. NOAR: 100~120 km+
C. Horizontal tracking angles
1. APG-63V3/V4: +/- 60 degrees
2. APG-77: +/- 60 degrees (May equip conformal lateral AESA in the future)
3. APG-79: +/- 60 degrees
4. APG-80: +/- 60 degrees
5. APG-81: +/- 60 degrees (May equip conformal lateral AESA in the future)
6. CAPTOR: +/- 70 degrees
7. CAESAR: +/- 60 degrees ~ +/- 100~110 degrees
8. RBE-2: +/- 60 degrees
9. RBE-2AA: +/- 70 degrees
10. PS-05A: +/- 60 degrees
11. NOAR: +/- 100~110 degrees
D. Target number of TWS at the same time:
1. APG-63V3/V4: > 20 targets
2. APG-77: 100 targets
3. APG-79: > 20 targets
4. APG-80: 20 (now) ~ 50 (potential in the future) targets
5. APG-81: unknown
6. CAPTOR: 20 targets
7. CAESAR: unknown
8. RBE-2: 40 targets
9. RBE-2AA: unknown
10. PS-05A: 14 targets
11. NOAR: unknown
E. Performing A-A and A-G modes at the same time:
1. APG-63V3/V4: Yes
2. APG-77: Yes
3. APG-79: Yes
4. APG-80: Yes
5. APG-81: Yes
6. CAPTOR: Perhaps
7. CAESAR: Yes
8. RBE-2: Yes
9. RBE-2AA: Yes
10. PS-05A: No
11. NOAR: Yes
F. LPI capability:
1. APG-63V3/V4: Yes
2. APG-77: Yes
3. APG-79: Yes
4. APG-80: Yes
5. APG-81: Yes
6. CAPTOR: No
7. CAESAR: Yes
8. RBE-2: Yes
9. RBE-2AA: Yes
10. PS-05A: No
11. NOAR: Yes
G. High speed capability of Data-link/communication:
1. APG-63V3/V4: Perhaps
2. APG-77: Yes
3. APG-79: Yes
4. APG-80: No
5. APG-81: Yes
6. CAPTOR: No
7. CAESAR: Perhaps
8. RBE-2: No
9. RBE-2AA: No
10. PS-05A: No
11. NOAR: Perhaps
H. Advanced functions for Microwave-weapon / CPU virus spreader/ Net-Hacker:
1. APG-63V3/V4: Perhaps
2. APG-77: Yes
3. APG-79: Yes
4. APG-80: No
5. APG-81: Yes
6. CAPTOR: No
7. CAESAR: Perhaps
8. RBE-2: No
9. RBE-2AA: No
10. PS-05A: No
11. NOAR: Perhaps
I. MTBF (mean time between failures)
1. APG-63V3/V4: 800~1,000 hrs
2. APG-77: 800~1,000 hrs
3. APG-79: 1000 hrs
4. APG-80: 500~800 hrs
5. APG-81: 2000 hrs+
6. CAPTOR: 194~300 hrs
7. CAESAR: Unknown
8. RBE-2: Unknown
9. RBE-2AA: Unknown
10. PS-05A: 250~300 hrs
11. NOAR: Unknown
Now onto Russian AESA. Which is still relatively new compared to its western counterparts. Although not as mature as Western AESA programs, Russian radar technology has supposedly made significant progress in the recent years. Russia has tried to close the gap between itself and the west to try and maintain aunty competitive edge. The most advanced Russian AESA system is the N036 Byelka, which is mounted on the SU-57, Russia’s so-called 5th generation stealth fighter. The Byelka features three X-band AESA radar arrays, with the main one on the nose cone and the two smaller ones on the side of plane and one of the back. The nose cone array has a maximum range of 215 nm, while the sides 80nm, and the rear, 120 nms. This radar has NTCR and JEM. NTCR-JEM (Non-Cooperative Target Recognitions and Joint Emiter Matrix) is a technique that combines the capabilities of radar systems and ELINT to classify radar signals based on their emissions. This can help identify target without needing their cooperation. This system used on the N036 Byelka involved a proces of collecting data from the radar returns. Then comparing these returns to a database containaing known radar signatures and the characteristics of various targets. By matching the signal with one of these entries, the system can alert the pilot of the plane that they are facing with high confidence. This can be done for multiple targets. Note that the N036B-1-01 Byelka on the nose cone scans in the I band, while the rear scans in the D band. D band radar scans in longer wave lengths which makes it more suitable for ground and foliage penetrations, and more resistant to EW. I band is standard for detecting modern fighter jets, due to the balance of short wavelengths and clear resolution and range.
Zhuk-AE:
Now, let's talk about the Zhuk-AE. This AESA radar is designed specifically for the Mikoyan MiG-35, which is the latest variant of the renowned MiG-29 fighter. Operating in the X-band frequency range, the Zhuk-AE is mounted right in the MiG-35's nose cone. With this radar, targets having an RCS of 3 square meters can be detected up to 160 km away, while those with an RCS of 1 square meter can be detected at a distance of up to 120 km. What's really impressive about the Zhuk-AE is that it can track up to 30 targets at once and engage with 6 targets simultaneously.
The Zhuk-AE comes in handy when dealing with multiple adversaries or in congested airspace. Its ability to track numerous targets allows the MiG-35 pilot to maintain situational awareness and effectively prioritize threats. Moreover, the radar's advanced air-to-ground and air-to-sea capabilities make the MiG-35 a versatile platform for various mission types.
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| Zhuk-AE Schema |
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| Zhuk-AE mounted on MiG-35 |
Irbis-E:
Next up is the Irbis-E, a passive electronically scanned array (PESA) radar system used in the Sukhoi Su-35S, a 4++ generation fighter. Although it's not an AESA radar, the Irbis-E still packs a punch with its impressive performance. Operating in the X-band frequency range and mounted in the nose cone of the Su-35S, this radar can detect targets with an RCS of 3 square meters at ranges up to 400 km.
When it comes to long-range air-to-air engagements, the Irbis-E radar gives the Su-35S early warning of incoming enemy aircraft, allowing the pilot to make informed decisions about engagement tactics. In air-to-ground missions, the radar can identify and track ground targets for precision strikes. The Irbis-E's powerful capabilities make the Su-35S a formidable aircraft in various combat scenarios.
While Russia has made significant advancements in radar technology, with systems like the N036 Byelka, Zhuk-AE, and Irbis-E showcasing the country's growing capabilities, China has also made strides in developing its own indigenous AESA radars. These radar systems, mounted on platforms such as the Su-57, MiG-35, and Su-35S, demonstrate Russia's commitment to enhancing its military technology and narrowing the gap with Western counterparts. As we transition to discussing Chinese radar systems, it is evident that both Russia and China are focused on research and development to refine and expand their AESA radar capabilities in the coming years.
China has made significant progress in developing AESA radar technology for its military aircraft and systems. In this expanded discussion, we will cover several Chinese radar systems, their technical specifications, and the platforms they are mounted on.
KLJ-7A:
The KLJ-7A radar is mounted on the Chengdu J-20, China's 5th generation stealth fighter. It operates in the X-band frequency range, providing a balance between resolution, range, and resistance to atmospheric attenuation. The radar is housed in the nose cone of the J-20 and has approximately 1,856 transmit/receive (T/R) modules. The KLJ-7A can scan angles up to ±60° in azimuth and elevation, offering the J-20 a wide field of view for target detection and tracking.
In terms of stealth aircraft detection, the KLJ-7A is believed to have improved performance compared to earlier Chinese radar systems. The exact capabilities in detecting stealth aircraft remain classified, but its advanced signal processing techniques and high-resolution imaging allow it to better distinguish between real targets and decoys or radar clutter.
The KLJ-7A radar is also expected to be integrated into the upcoming Chengdu J-35, a naval variant of the J-20. This would provide the Chinese Navy's carrier-based aircraft with advanced radar capabilities.
JY-27A:
The JY-27A is a long-range early warning radar designed for ground-based air defense applications. It operates in the VHF band, which is effective at detecting stealth aircraft due to lower frequencies being less affected by radar-absorbent materials and shaping techniques used in stealth designs. The radar has a claimed detection range of up to 500 km for conventional aircraft and up to 300 km for stealth aircraft.
The JY-27A radar can track up to 100 targets simultaneously and can rapidly switch between multiple operating modes to adapt to various combat scenarios. It is resistant to electronic warfare and jamming, enhancing its survivability in contested environments. This radar system is utilized by China's ground-based air defense units to protect critical installations and support early warning for the Chinese air defense network.
Type 346:
The Type 346 is an advanced AESA radar system developed for the Chinese Navy's Type 052D destroyer (Luyang III-class) and Type 055 cruiser (Renhai-class). It operates in the S-band, which offers improved performance in maritime environments due to its lower susceptibility to clutter from sea surfaces and weather. The radar is mounted in four fixed arrays, providing 360° coverage around the ship.
The Type 346 has a detection range of up to 450 km for aircraft and 200 km for sea-skimming missiles. It can track and engage multiple targets simultaneously, making it a versatile and powerful radar system for Chinese naval vessels. The radar also supports long-range surface-to-air missiles, such as the HHQ-9 series, providing robust air defense capabilities.
In conclusion, both Russia and China have made significant strides in radar technology, enhancing their military capabilities and narrowing the gap with Western counterparts. AESA radar systems like the Zhuk-AE, Irbis-E, KLJ-7A, JY-27A, and Type 346 showcase the commitment of these countries to ongoing research and development in this field. As the global landscape of radar technology continues to evolve, it is likely that Russia and China will continue to refine and expand their radar capabilities in the coming years. Stay tuned for an upcoming article on Iran.
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