In this post I will explain the limited data available to the crew of the BUK TELAR. This plus the assumption from other sources made the crew decide to shot down the target, fully convinced they shot down an Ukraine transport aircraft.
MH17 was shot down by a missile launched from a BUK TELAR. The BUK TELAR was highly likely operating in autonomous mode. This means the TELAR has no data link to a seperate radar and control post vehicle and has very limited tools to identify aircraft.
A very comprehensive description of the BUK systen, missile types, warheads and much more can be read here.
The crew has a primary radar screen which is used to search for targets. Crew just sees a moving dot on the screen. No information on type of aircraft, flightnumber like an air traffic controller has.
The radar shows the radial speed of the target. That is the speed of the object relative to the radar antenna. As MH17 flew almost exactly towards the BUK, the radial speed was such the crew must have been able to understand the target was not a slow flying aircraft like a SU-25.
Lets see what information the BUK TELAR has which the crew could use to identify the target :
- direction of the target
- distance of the target to the TELAR
- radial speed of the target
- altitude of the target
- identification friend or foe (IFF)
Distance of the target and the radial speed is shown in the image below. This info is not shown on the radarscreen but on a seperate display. Speed is indicated in units of 10 m/s
The speed of a Boeing 777 (900 km/h) will be displayed as “25”. The speed of an Antonov An-26 which is about 450 km / h will be displayed as “13”.
Operators of the BUK are probably trained to identify targets based on the speed range. Anything below the speed indicator 33 is regarded as subsonic. Anything above 33 is a fighterjet or cruise missile flying a supersonic speeds.
So this is one of the reasons a B777 could be mistaken for an Antonov26.
The altitude of the target is also not so clearly presented. Below the distance and speed indicators there is the height indicator. On the scale you see 0,5, 1, 1,5 and 2. The altitude needs to be multiplied by 10 to get the altitude of the target in kilometers. So 1 is target at 10 km. An Antonov would fly at around 7 km. So on the scale 0,7.
It is clear there is hardly any difference on the scale between 0.7 and 1.
Mind speed and altitude, two values to identify a target, become only available after the target has been selected on the radar screen. (lock and track mode).
Identification friend or foe
To identify enemy aircraft the BUK TELAR is equiped with a system called Silicon-2M ((Кремний-2). This identify friend of foe system shows on the radar screen if the target is a friendly aircraft, an enemy aircraft or a civilian aircraft. Silicon-2M was replaced a few years ago by a new IFF system called Password (Пароль). All of the military aircraft were upgrade to Password but part of the civil aircraft in Russia still use the old system. Silicon-2M is also used by Ukraine military and some older former Sovjet civil aircraft. Aircraft in all other countries do not have a IFF transponder. These aircraft like the Malaysian B777 will be displayed as an unknown/enemy aircraft on the radar of the BUK.
The photo below shows some toggles to select IFF mode. A military aircraft not operating for the Russian Air Force would be displayed on the large radarscreen as enemy. The same applies for any civil airliner.
The switch on the right is labeled “Диап. III” (rus “Диапозон III”). The switch and button is used to interrogate the target. When the button is pressed the, IFF system sends a code to the transponder of the target. If the IFF transponder does not respond with the correct “password” the target is considered enemy. You also see the label 1Л24 . This is the ground radar interrogator which is mounted in radar equipment for air defence systems. Probably a device like the one on the right is installed in the BUK for IFF.
The IFF identification could have caused another couple of seconds which were not used to really check speed and altitude to see if these match an Antonov.
The big circle on the left is the radar screen. It shows the aircraft flying within reach of radar. Type is R4-SA
The rectangle screen is the missile guidance (станция наведения) screen R4-V. I guess this screen can be used to adjust the illumination beam which guides the missile to its target. It has nothing to do with identification of the target.
BUK’s radar search target by 6 degrees sectors (for vertical position). The radar has 3 radar’s positions: “низ” (down, vertical sector degrees 0-6), “ручной режим” (manual mode by lines — 1 degrees — see below) and “верх” (up, vertical sector degrees 6-12).
You can see buttons from left of the screen — it’s a search “line”. One line is 1 degree sector (total 6 degrees). You can search auto (need 4 seconds for 1 cycle) or set search line manually.
target’s zone of destruction (or affected area — it’s a target zone (distance/height) there we can launch missile and hit the target with a given accuracy). That’s zone will be different for every target and depends on many parameters.
Besides radar the BUK also has an optical system. The TOV (tv-optical visor) is used by the crew to visually check the target. However in cloudy conditions the target cannot be seen by the eye and operator has radar only.
Below a screenshot of the information at the R4-V screen. It just shows some dots. (taken from this video).
non-cooperative target recognition
There is also NCTR or non-cooperative target recognition. This systems analyses the pattern of the radar returns. It can determine the type of aircraft by a typcial footprint of the radar return Also jet engine modulation, or the analysis of beats and harmonics in the radar return that are caused by engine fan or compressor blades is used to determine type of target. The return is kind of unique for each type of aircraft because of its size, number of engines, speed etc.
I am not sure in what way NCTR is used. My guess one of the two operator has a headset and listens to the sound of the radar returns.
A BUK missile cannot be launched by pressing a button. The commander in the TELAR needs to insert a special key before the launch button can be used. This photo shows the launch keys. The keys are attached to a chain which is attached to the BUK TELAR.
To prevent detection of the BUK TELAR by enemy aircraft, the radar is switched off as much as possible. The radar signal can easily be detected by aircraft. Once detected, a BUK TELAR is an easy target for ground attack aircraft like the SU-25.
BUK operations include the usage of so called spotters. These are people who are located in a distance of about 30-50 from the BUK baterry. If these spot a target using their eyes and binoculars, the give a phone call or radio call to the BUK crew. The BUK crew will then switch on the radar and start searching for the target.