The curvature of the earth's surface and the unevenness of the terrain greatly limit the capabilities of ground and ship-based air defense systems to detect and defeat low-flying air attack weapons (LAS). How can you effectively ensure the possibility of firing an air defense system at low-flying targets?
Climb higher
One of the options is to place the radar on a lifting and mast device (PMU). If we place the radar at a height of 15 meters, then the range of visibility of an aircraft moving at an altitude of 50 meters above the surface will be 41 km. Increasing the height of the PMU to 50 meters will increase the theoretical visibility range by only 13 km (up to 54 km), while the complexity and bulkiness of such equipment will grow to a much greater extent.
It would seem that it is quite normal for a short-range air defense system of the Pantsir-SM type? But in practice, the unevenness of the terrain, forests, buildings and other natural and artificial obstacles will reduce this value several times.
What is the minimum height to raise the radar in order to ensure the detection of low-flying targets?
The height to which it is necessary to raise the detection means to compensate for the unevenness of the terrain can be changed in each case. In most cases, the difference in elevation on the flat territory of Russia within a range of 100-200 km is no more than 100-200 meters. In mountainous areas, the difference can be significantly greater, and it is difficult to indicate any specific value.
Conventionally, for a short-range air defense system (up to 40-50 km), it is possible to take the height required to compensate for the unevenness of the terrain of 100 meters, for a medium-range air defense system (up to 50-150 km), the height required to compensate for the unevenness of the terrain will be 200 meters.
Thus, the minimum height of the radar, for detecting low-flying targets, for short-range air defense systems will be about 200 meters, for medium-range air defense systems, about 700 meters. The altitude of the radar station to ensure the over-the-horizon operation of the long-range air defense missile system should be comparable to the flight altitude of the AWACS aircraft, about 10,000 m, in this case the terrain is of much lesser importance
The indicated heights make the use of PMU impossible, but there are several other ways to "look beyond the horizon".
Aerostat radar
One of these methods is the use of balloons. The JLENS project is being implemented in the USA. Within the framework of this project, it is planned to deploy radar and optical reconnaissance equipment on balloons fixed in certain points of the country, and designed to detect low-flying cruise missiles. The altitude of the balloons is 3 - 4, 5 km, the payload mass is about three tons. The detection range of air targets should be about 550 km, ground targets about 225 km. In addition to detection, the JLENS balloon should provide over-the-horizon target designation for surface-to-air missiles. To hold the balloon in position and exchange data, it is proposed to use a cable that includes power cables and fiber-optic data transmission cables in a carbon braid.
Within the framework of the task we are considering, this project has several drawbacks: the balloon is not very convenient for constant movement by motor transport, and, if possible, should be tied to a certain point, which excludes the possibility of changing position with mobile air defense systems and is unacceptable. In addition, the huge size of the balloon (over 70 meters in length) can theoretically impede its operation in conditions of strong gusty winds.
On the other hand, the concept itself is quite promising. Radar stations placed on balloons can protect stationary objects from impact by low-flying EHV, primarily such as mines for intercontinental ballistic missiles (ICBMs), submarine bases, ballistic missile carriers, strategic bombers airfields, nuclear power plants and other critical elements of the country's armed forces and infrastructure. …
Thus, despite the fact that balloons are not the optimal means for providing air defense systems with the possibility of hitting targets beyond the horizon, they can play an important role in covering especially important stationary objects from a surprise strike by enemy low-flying air defense systems. Their main advantage is the possibility of quasi-continuous stay in the air without significant consumption of fuel and electricity
In Russia, such balloons are developed by RosAeroSystems. In particular, you can consider the large-volume tethered balloon "PUMA". The Puma balloon was developed as a radar carrier for round-the-clock radar surveillance from an altitude of up to 5 km for 30 days without landing.
The estimated radius of detection and tracking of air targets will be 300-350 km. The balloon must withstand hurricane winds up to 46 m / s and direct lightning strikes. The aerostat is held by a cable-rope during ascent, descent and parking at a working height, it also provides power supply for on-board systems and payloads with a power of up to 40 kW, as well as for lightning and static electricity removal. The payload of the PUMA balloon is up to 2250 kg.
Apparently, the armed forces of the Russian Federation are working on this direction:
In July 2015, Vladimir Mikheev, Advisor to the First Deputy General Director of the Concern "Radioelectronic Technologies" (KRET), told RIA Novosti about the start of work on an airship project for the needs of the country's antimissile defense. It can become a full-fledged element of the missile attack warning system (EWS), which today consists of two echelons - an orbital satellite constellation and ground-based radar stations.
It's up to the Almaz-Antey concern, it is necessary that balloons and airships can not only warn of the threat of an air attack, but also direct anti-aircraft guided missiles (SAMs) equipped with an active radar homing head (ARGSN) at the identified targets.
Quadrocopters and other unmanned aerial vehicles (UAVs) vertical takeoff and landing
Let's go back to the air defense system. To begin with, consider the short-range and medium-range air defense systems, for which it is required to raise the radar to a height of 200 and 700 meters, respectively.
In early 2018, Boeing unveiled a prototype of an electric unmanned cargo aircraft quadrocopter. This UAV is designed to test and debug the technologies needed to build the next generation of cargo and passenger aircraft. The length of the experienced UAV is 4.57 meters, the width is 5.49 meters, the height is 1.22 meters, the weight, including the weight of the batteries, is 339 kilograms. Payload - up to 226 kg. The design includes four electric motors with eight rotors.
Electric quadrocopters-UAVs can become an effective solution for detecting low-flying EHV for ground and sea air defense systems
An electric quadrocopter-UAV should be located on a carrier vehicle, a diesel generator set (DGU) should also be located there to provide the UAV with electricity. Unfortunately, at the moment the power of the electric motors of the experienced quadcopter, the battery charging time and the flight time are unknown.
Two options can be considered:
- in the first version, there are no batteries required to maintain a long flight, power is supplied from the carrier's vehicle, there is only a small backup battery for the emergency landing of the UAV, presumably, this option can be considered optimal;
- the second option can be used if the mass of the cable required to supply the required power to the quadcopter turns out to be too large, in this case, the quadcopter must be equipped with rechargeable batteries or supercapacitors (supercapacitors) with a fast charging function.
To ensure the continuity of being in the air on four short-range air defense systems, at least two carrier vehicles with UAVs are required. The time spent by the UAV in the air will be limited only by the availability of fuel for the diesel generator set.
Instead of an electric quadrocopter, UAVs based on gasoline or diesel piston engines can be implemented. In Russia, the development and production of such solutions is carried out by SKYF Technology, which offers the customer SKYF vertical takeoff and landing UAVs. At the moment, the carrying capacity of the SKYF UAV is 250 kilograms with the prospect of increasing it to 400 kilograms. The flight altitude of this UAV is up to 3000 meters.
Earlier, Gorizont announced a helicopter-type Gorizont Air S-100 UAV with a circular view radar based on the Austrian Schiebel Camcopter S-100. The Kolibri radar, mounted on this UAV, and installed in the lower part of the fuselage, is being developed jointly with the Moscow Scientific Research Institute of Radiophysics. The total mass of the radar equipment should be no more than 6.5 kg, the required range in the all-round viewing mode (UAV hovering) is not less than 200 km, in the synthetic aperture mode, not less than 20 km.
The payload of this UAV is too small (35 kg) in order to accommodate a radar with acceptable characteristics, but as a concept it may be interesting. The time of continuous stay in the air is 6 hours.
The above examples of drone-quadcopters cannot directly be used to place radars, since they have a relatively modest payload, but there is no doubt that their designs will be actively developed and improved. First of all, this applies to electric drone-UAVs.
The main requirements for an AWACS UAV such as a quadrocopter or a helicopter-type UAV-AWACS should be high reliability and the ability to stay in the air for a long time, ensuring the specified flight performance (LTH), as well as a high operational resource and a low cost of a flight hour
High-altitude UAVs
For long-range air defense systems, vertical take-off and landing UAVs will no longer be an effective and sufficient means of reconnaissance, since the height of the radar station, to achieve a viewing range of about 400 km, must exceed 10,000 meters.
Presumably, UAVs of long duration of flight, aircraft type, medium or large dimension can be used as a flying radar for a long-range air defense system.
One of the candidates for the role of a promising drone-AWACS can be the Altair UAV with a take-off weight of 5 tons and a payload of 1-2 tons. This UAV is being created as part of the Altius-M research and development project at the Sokol Design Bureau (Kazan) together with the Transas company. The duration of its flight should be up to 48 hours, the flight range is 10,000 km. In 2018, the Altair UAV program was transferred to JSC Ural Civil Aviation Plant (UZGA). Flight tests of the Altair UAV should begin in 2019.
Devices of this type are being developed in other countries as well. In particular, the Chinese company CETC is developing the JY-300 UAV. A medium-sized vehicle should become a carrier of conformal antennas and serve as an unmanned AWACS. According to preliminary data, the JY-300 UAV has a takeoff weight of about 1300 kg and can carry a payload of 400 kg. It is capable of performing flights for up to 12 hours, at altitudes up to 7.6 km. The radars built into the design of this drone should allow the detection of air and sea targets at long distances.
Russian UAVs of medium and large dimensions have many problems, including the lack of compact, powerful and economical domestic engines, the lack of modern avionics. One of the most important problems is the lack of high-speed satellite data transmission channels with a global reach, allowing control of the UAV and receiving intelligence information from it at a great distance from the basing point.
The use of an AWACS UAV with a long flight duration does not require the presence of such channels. In general terms, the work of a bundle of long-range air defense systems - UAVs of a long flight duration may look like this:
UAV AWACS of long duration of flight takes off from the airfield and enters the patrol zone above the positions of the layered air defense. All information from it is sent to the operators of long-range air defense systems, and then, through the combat control point, to the operators of other air defense systems that are part of the combined echeloned air defense. The UAV flight should be carried out mostly in automatic mode along a given trajectory. One long-range air defense system should include two AWACS UAVs. In this case, they can carry out in shifts combat duty over the positions of the air defense missile system for a duration of 36-48 hours, depending on the remoteness of the home airfield.
The requirements for UAVs of AWACS with a long flight duration are the same as for UAVs for short and medium-range air defense systems - a high operational resource and a low cost of a flight hour
The question may arise: in the title of the article it is said about the work of the air defense missile system on low-flying targets without the involvement of the Air Force aviation, and the UAVs of a long flight duration are clearly related to aviation. Here the question is rather in departmental affiliation. In the USA, according to the Johnson-McConnell agreement between the Army and the Air Force, helicopters do not belong to the Air Force and are directly subordinate to the US Army, they act in its interests (the division of aircraft in the United States between the Army and the Air Force is well written here). So in our case, the fact that the UAV belongs to a specific air defense system will not allow the use of its Air Force for other purposes.
Layered air defense with UAV AWACS
The use of an AWACS UAV of a quadrocopter type and an AWACS UAV of a long flight duration will create a dense radar coverage of the terrain and ensure the issuance of target designation to missiles with ARGSN and IR seeker at maximum range.
Presumably, for two short-range air defense systems, there should be one machine with a drone drone of a quadrocopter type, or two machines for four air defense systems. The medium-range air defense missile system should include two machines with a drone-type drone drone. Two UAVs of AWACS of long duration of flight should belong to air defense systems of long range.
During a threatened period or in the event of the outbreak of hostilities, UAVs of a long flight duration must carry out continuous patrols over the positions of the air defense missile systems. UAVs of a quadrocopter type, from the composition of the short and medium-range air defense systems, must be on the carrier vehicles in readiness for an immediate start. In case of detection of an air threat, the launch of a drone-type UAV should be carried out within a few minutes.
The cost of the UAVs themselves and their flight time are traditionally significantly lower than the cost of manned aircraft and helicopters, which makes this task economically attractive. Technically, the proposed concept also contains no insurmountable problems.
For stationary objects of high importance, AWACS balloons can be used. In the case of air defense of objects equipped with AWACS balloons, UAVs of long flight duration are not required and can be excluded from the long-range air defense system or can be at the airfield in readiness for departure as a backup reconnaissance and target designation means.
UAV AWACS for the fleet
Previously, only the use of UAV AWACS was considered in the interests of ground-based air defense systems. But no less, and possibly a more important task is the use of an AWACS UAV of a quadrocopter type and a UAV with a long flight duration in the interests of the air defense of the ships of the Navy. Given the fact that we have no aircraft carriers and, accordingly, AWACS aircraft on them, modern Russian ships are poorly protected from air attacks, regardless of what air defense they are on, due to physical limitations in the detection range of low-flying targets.
The use of a quadrocopter-type UAV on the ships of the Russian Navy will significantly push back the border of destruction of low-flying targets. And sending a UAV with a long flight duration and range to the area where the naval ships are located will give them additional opportunities for reconnaissance of enemy forces and issuing target designations to long-range missiles.
It is impossible to exclude the use of balloons and AWACS airships in the interests of the Navy, especially since there are historical examples of the use of balloons by the Russian fleet.
conclusions
Ground and surface air defense without the possibility of attacking low-flying targets at a great distance will be defeated.
To solve this problem, in the interests of short and medium-range air defense systems, it is necessary to create an AWACS UAV of a quadrocopter type, preferably with power supply via a cable from the carrier vehicle.
For a long-range air defense system, it is necessary to intensify the development of an AWACS UAV with a long flight duration.
For stationary objects of high importance, AWACS balloons can be used.
All of the above systems (UAVs of AWACS of a quadrocopter type, UAVs of AWACS of long duration of flight and AWACS balloons) are of great importance for increasing the efficiency and survival of not only ground-based air defense systems, but ships of the Russian Navy.
