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“Save Concord” or a report from the tests of the Russian radar system for searching for foreign objects on the runway

View of the runway a / p "Orlovka" from the radar SKVPP-76

This photo of the modest Orlovka airfield (ICAO code: UUTO) in the Tver Region is actually very symbolic. For the first time in history, Russia joins a club of technological leaders capable of designing and producing radar systems for monitoring the runway for the presence of foreign objects.

It is not easy to buy such a system from a foreign manufacturer (these are piece projects) and expensive. In addition to the price of equipment, the contract requires payment for design for a specific airport, installation supervision services, and then - payment of authorized service for the entire life of the system.

The garbage problem is invisible, but very relevant


In the history of aviation, there are many cases where debris that fell out of the structure of aircraft or airfield equipment appeared on the runway and caused damage to aircraft during take-off or landing. The Concorde catastrophe that occurred in 2000 was a tragedy that showed the urgency of this problem.

The European Commission estimates the annual damage to world aviation from debris on the runways in amounts close to $ 13 billion. This includes flight delays and damage to aircraft tire covers, each of which costs up to $ 5,000 and must be replaced with a new one after damage.
At Pobeda Airlines, the problem of garbage on Russian runways is also called very relevant.

The problem of foreign objects on the runway and taxiways is relevant in Russia. Although, unlike the EU, we do not give grants for the development of systems, but there are complaints from airlines. For example, the director of the Pobeda airline, in an interview with the Kommersant newspaper, speaks of at least one hundred cases in 2019, when the landing gear of this company was damaged. At the same time, the director of Pobeda calls the check of the runways formal: “Officials simply drive by car and inspect the surface.” The article notes that in Vnukovo in the summer, an inspection is carried out every three hours, and in winter - at least six times a day.

What kind of trash happens on the runway


In international practice, foreign objects on the runway are called FOD, Foreign Object Debris (foreign debris). Among these items, bolts, nuts, tie rods, tools that have fallen from car repair services, scraps of tires, hoses, etc. are most often found.

The FAA report (Federal Avaition Agency, the American aviation regulator) shows that more than 60% of garbage is made up of metal items, and 18% - scraps of rubber. At the same time, the main share of objects is quite small, about 3x3 cm. So, the FAA created a methodology for assessing the ability of airfield equipment to find foreign objects on a runway using a standard metal cylinder with a diameter of 38 mm and a height of 31 mm (unpainted). Now this type of test is used all over the world.

Reference cylinder Ø38 mm and height 31 mm
Ø38 31 ( / )


What can I say - a narrow circle of these manufacturers, the total number of which around the world can be counted literally on the fingers. Four leaders include Stratech Group, UK Qinetiq / USA Moog Inc., Xsight Systems Ltd. and Trex Aviation Systems Inc, which account for nearly two-thirds of market revenue (source: FactMr ). This is a high-tech area where competencies in radiolocation and optoelectronics, mathematics, and machine data processing are required from a manufacturing company.

Modern systems capable of detecting foreign objects on the runway and taxiways use two physical principles, including in the form of joint solutions:
• Millimeter-band radars;
• Cameras of visible and infrared spectrum, incl. with pattern recognition system;
• Hybrid radar + camera systems.

Both radars and cameras have their advantages and disadvantages, however, there is one common property - such systems are very expensive both by themselves and by the cost of their implementation in the infrastructure of airports.

For example, the Xsight FODetect System (made in Israel, used at Ben Gurion Airport), when implemented, requires the complete replacement of signal lights at the edges of the runway, as In their place, an integrated design is installed, including a flashlight, a video camera and a short-range radar. The functioning of such a system requires the laying of underground utilities along the runway and throughout the territory of the airport, and this voluminous work is best done with a complete modernization or construction of a new runway.

Tarsier FOD Radars at Heathrow Airport
Location of Tarsier FOD radars at Heathrow Airport. Source: Moog Inc

It is generally accepted that the optimal solution for active and heavily loaded runways is a solution in the form of a stand-alone radar with a large radius of action, with which you can monitor the presence of foreign objects in the entire strip. Those. one radar for short lanes at regional airports, or 2-3 radars per lane at international airports. This is how the Tarsier Runway FOD Detection System (manufactured in the USA) works at Heathrow Airport, using only 4 radars to the entire airport - 2 radars per strip with a length of 3.7 km.

Foreign manufacturers of FOD systems and basic equipment specifications
Foreign manufacturers of FOD-systems and the main characteristics of the equipment (compiled by the author)

Tests of the SKVPP-76 radar at the Orlovka flight experimental base


Now we turn to the experiment on the basis of the flight-experimental center of the MANS concern at the Orlovka aerodrome in the Tver region. In March 2020, the DOK company, a manufacturer of millimeter-wave radars from St. Petersburg, in collaboration with the MANS concern, conducted full-scale tests of the SKVPP-76 radar control system (76 GHz FOD radar) in Orlovka .

The radar operates at a frequency of 76 GHz (wavelength 3.9 mm) in the regime of quasi-continuous linear frequency modulation (FMCW). The principle of operation - the radar determines the distance to the target (object FOD) by the difference in frequencies between the emitted and received radar signals. The advantage of the FMCW DOC radar is in small 60 cm antennas with a high gain (up to 50 dB). The spot spot on the strip allows for a single pass beam to view the area up to 2 km long.

Location map of the SKVPP-76 radar in a / p Orlovka
Location map of the SKVPP-76 radar at the Orlovka airport

In the photo: SKVPP-76 radar at Orlovka airport
On the photo: the SKVPP-76 radar at the Orlovka airport

Given that the radar is designed for a range of up to 1000 m in range (and this parameter is designed as the best among similar systems on the world market), and the Orlovka runway (ICAO: UUTO) is only 800 m, the SKVPP-76 radar was placed at a distance of 40 m from the edge of the runway (course "06") on a metal support 3.5 m high, providing a total height of the center of the radar antennas 4.7 m above the runway. At the same time, the distance from the radar installation point to the far edge of the runway (course "24") was 910 m. This arrangement of equipment made it possible to test the ability of SKVPP-76 to detect objects at distances close to the maximum possible (1000 m according to the specification).

To confirm the ability of the radar to detect a calibrated test target, a reference cylinder was placed on the surface of the runway at a distance of 650 m. Why 650, not 910 m? As it turned out during the experiment, at the far end of the runway there is a downward slope and a “blind zone” arises for the radar.

The layout of the test cylinder on the runway a / p Orlovka
Layout of the test cylinder on the runway

Radar control and reading was carried out through the local aerodrome network to a computer with the installed FieldScanner test software. FieldScanner software allows you to determine on the screen the presence of marks from various objects on the runway, including the reference cylinder, and thus confirm the fact of detection of foreign objects.

Screenshot from the radar: left - empty runway, right - runway with test cylinder
Screenshot from the radar: left - empty runway, right - runway with test cylinder

Everyone who looks at this screenshot will say, “And what can you make out here?” Therefore, the engineers explained that the test software is intended only to answer the question “does the radar see the target or not” (that is, confirm that the signal from the test target is higher than the level of noise and reflections from the surface of the runway). In the test software, the image is not cleared of false targets, such as marks from the surrounding soil, patches, seams and potholes on the strip cover, etc. At the same time, to visualize the detection of the test cylinder, given its small size, the mark on the radar is increased to the number of pixels distinguishable on the monitor screen.
Industrial runway control software must be trained on a specific runway in artificial intelligence mode.

Industrial runway control software for this radar is developed on the basis of artificial intelligence (Deep Learning), and after the deployment of the system at the airport, such software should go through a training mode on a specific band. After training, the software becomes able to identify potentially dangerous objects and separate them from false targets, such as backlight elements, bumps, seams on the coating, etc. The buyer of the radar can also order revision of the software for some special conditions.

There is no good experiment without problems


A problem is always ready to intervene in field trials of complex equipment, and more often than not one. So it was in Orlovka. As already mentioned above, during the experiment it turned out that the runway profile has a depression at the far end of the strip, and therefore direct visibility with the radar beam was provided up to a length of about 720 m, counting from the edge of the runway as the “06” course. The rest of the runway length fell into the “blind zone” due to insufficient height of the radar support - there was no visibility of the concave fragment of this runway.
The visibility of the surface of the far end of the runway to the level of ~ 720 m
The direct visibility of the surface of the far end of the runway was limited at ~ 720 m (photo through binoculars)

It was an unaccounted moment, but they did not begin to remake the pedestal under the radar, because shortly before scanning the strip, the radar was checked on a flat kilometer section of the local highway and in this experiment the cylinder was successfully found. For this, the radar was installed in the back of a truck and a reference cylinder was placed 1 km from it on the asphalt. Radar easily detected this target.

Radar test on 1 km straight straight road section
Testing the radar on a 1 km section of a straight straight road

Below in the screenshot from the radar it can be seen that a significant margin remains in the target detection range - up to about 1.5 km. However, beyond 1 km the detection of a test target with linear dimensions of the order of 3 cm is no longer guaranteed.

i Road marking on a radar from a cylinder
Mark on the radar monitor from a cylinder located on the highway

How to find an engineer on a strip of dry rations


Uncalibrated Foreign Objects for Radar Search
Non-calibrated foreign objects to be searched by the radar

In addition to the reference cylinder Ø38 mm and a height of 31 mm, the experiment conducted a demonstration of the detection of a set of 10 different non-calibrated objects arranged on a strip at distances from 250 m to 650 m, counting from the edge as the “06” course. The items included two wrenches, bottles of liquids, tin cans, a coil of wire, and a rubber duck.

The wrench was easily detected on the runway.
The

Radar also found a can
radar also found a wrench easily on the runway. The radar also found a

can In order not to bore readers with pictures of bottles and cans on the strip, we can say briefly — the SKVPP-76 radar detected all 10 uncalibrated foreign objects, which further confirmed the technical characteristics of the equipment and its applicability for this class tasks.

On the left is a radar picture of an empty runway, on the right is a runway with 10 foreign objects
On the left is a radar picture of an empty runway, on the right is a runway with 10 foreign objects

How it was and will be - on video


The video shows the scanning process of the Orlovka runway with the SKVPP-76 radar. This looks a little boring, but not for specialists: the radar positioning device scans as a series of small L-shaped movements consisting of rotation in azimuth (X axis) and adjusting the antenna tilt in elevation (Y axis).


And on the bottom promo video you can see how the radar should work in "combat" mode, being built into the airport’s flight safety system.


The high range of the SKVPP-76 (the ability to control 1 km to the left and 1 km to the right = 2 km) is its important advantage in the market of this equipment, making it possible to dispense with a single radar with a single connection (including wireless) over the local network for monitoring Runways up to 2 km long. In other words, the implementation will not require significant earthworks on the infrastructure. It is believed that a runway length of at least 1830 m is sufficient to accept aircraft weighing up to 90 tons, such as Airbus 319, Airbus 320 or Boeing 737-800.

Important advantages of the Russian radar are high range, compact size, high gain antennas. The roadmap of the project provides for the sharing of the radar with a high-resolution video camera - according to world practice.

Now we are waiting for this project of domestic engineers to go through the implementation stage, and SKVPP-76 radars will arrive at Russian airports, where they will ensure flight safety.

Special thanks to the MANS concern for their help in organizing the experiments.

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