Video surveillance at stadiums.
Stadiums are considered to be among the most dangerous facilities in our time.
The number of police involved in protecting individual events often exceeds the most violent rallies.
Turnstiles and portable fences are set up at distant approaches to the stadium.
Of course, video surveillance equipment is also used to maintain order.
In England, notorious for its football fans, back in the 90s, the issues of using video surveillance at stadiums were studied and systematized by the scientific center of the Ministry of Internal Affairs of Great Britain.
It was as a result of these studies that methods for monitoring the quality of coverage of the surveillance zone using special dummies became widespread.
What is the main purpose of video surveillance at the stadium?
The primary task during a match is the early detection of illegal actions and the coordination of security forces during the suppression of riots.
To do this, it is necessary to visually constantly monitor the situation in all stands and especially in potentially dangerous areas.
A secondary, but important task is to provide evidence for subsequent legal proceedings.
By the way, although it sounds cynical, this is sometimes what justifies all the investments in the surveillance system, because the club whose fans are guilty of the incident will have to pay for the damage.
Having a system that allows you to prove the guilt of the other party can save significantly more than the cost of the system, at least on paying for the repair of broken benches.
The third task is the usual task of protecting property. Well, there are no special features here.
How to solve these problems?
Ideally, it would be necessary to constantly record a video signal with high detail.
In practice, this is only possible in certain compact high-risk zones: exits/entrances/lobbies, where the flow of fans of opposing sides may cross.
Today's practice of security management at stadiums is such that possible crossings of opponents are excluded.
But this is not always 100% possible, because the stadium buildings themselves were built at a different time, when this problem was not so acute.
Sometimes some corridors for passages are used alternately, sometimes some flows pass in dangerous proximity, separated by insufficiently high partitions.
Almost the only solution for monitoring the stands is to install a number of controlled high-speed dome cameras in each sector.
Similarly, it is necessary to monitor the extended spaces of the territory adjacent to the stadium.
When a suspicious situation arises, the operator manually points the nearest dome camera at the dangerous area and, by controlling it, finds key points and gives guiding recommendations to the police officers.
In the absence of manual control, the cameras slowly return to their original positions.
The signal from all cameras is recorded continuously with high quality and can subsequently be presented to identify the culprits.
That is, the essence of the solution is that due to active control of the camera, the possibility of high resolution of details is provided throughout the entire area and, thus, these details will be recorded with high quality.
Ease of control is extremely important for the successful implementation of such a solution.
If the operator at a critical moment gets confused with the controls or loses time aiming at the desired area, the recording will be useless for clarifying the question of “who is to blame”.
For ease of control, to increase the speed of reaction, computer systems are often used that allow you to quickly select a pre-set position for the dome camera on the touch screen, after which the operator can manually fine-tune the direction and angle of view.
The “background” of such a touch screen is sometimes a “top view” plan, but more often an image of a fixed overview camera is used, coinciding with the image of a rotating camera in its “parking position”.
Important point:the movement of the PTZ camera, despite the amazing speed capabilities of modern dome cameras, must be carried out with a forced speed limitation so that the operator does not feel a gap in perception between the overview image and the image of the area on the high-speed PTZ camera.
How to achieve this?
Some cameras have a function (household video cameras often have it in the zoom control) of smooth acceleration and deceleration.
On cameras that do not have such a function, you can use the method of moving not immediately to the selected area, but through a sequence of intermediate stops.
All these measures slow down getting into the specified area with maximum zoom, but they allow the operator to get his bearings faster, and also to understand earlier that the movement is not going exactly where it should, and to correct the camera movement.
When changing the selected area, it is recommended to adjust the camera movement with an intermediate stop in the overview mode, at least in a position where both the previous area and the target area where it is moving are visible.
Similarly, with manual control, you should limit the speed of the camera. Try to rotate a modern dome camera yourself: if you just gape, it will have already made a couple of turns, and you are frantically trying to figure out where to turn it.
The main thing is that all this is done for the convenience of the operator.
Therefore, the control method should be chosen taking into account the specific habits of the operators.
For example, at one of the stadiums, a special mechanical remote control was installed with many keys located on the stadium plan.
The security staff found this remote control more convenient and reliable than a computer (they did not know that in fact there was still a computer there, processing keystrokes and generating the necessary commands for the PTZ cameras).
Don't forget: in addition to the controlled ones, fixed cameras are required to provide an overview image.
It is on them, constantly displayed on overview monitors, that operators must detect the first signs of an incident.
They provide constant coverage of all areas, even if operators are distracted by individual areas.
You need to monitor visually – no computer systems can yet detect danger against the backdrop of a raging crowd of fans.
Therefore, you need a lot of operators. The consolation is the fact that many operators are only needed during matches.
Additional operators can be hired for this time, part-time.
However, the system must provide work places for them, and these operators must be trained in advance.
The task of monitoring the behavior of fans has some peculiarities, and some significantly simplify this task.
For example, voluntary bright coloring of potential violators of order. A designer's dream.
If only the terrorists around the chemical plant were dressed as brightly and contrastingly as the fans at the football stadium.
However, the consequence of this feature is the necessity of a color system, otherwise we will lose such a rare fortunate circumstance.
On a black and white monitor, it will be quite difficult to distinguish red and white jerseys from yellow and blue ones.
The second happy circumstance is good lighting in the stadium as a whole, and therefore in the stands.
There are some problems with possible backlighting from powerful floodlights, but they are easy enough to avoid by carefully choosing the location of the cameras.
Please note that in foggy conditions, the use of smoke bombs or similar means (which is not surprising in the case of riots) the light from the floodlights is strongly scattered, so the cameras should be aimed with a fair margin in angle from the backlight.
In case of emergency, many stadiums have special floodlights aimed at the stands – check the system when they are turned on.
The consequence of the need to take into account possible illumination is that, despite the theoretical possibility of rotating cameras in all directions, in reality they should only be used to monitor those sectors for which they are intended.
Despite the above about the benefits of color cameras, one should not neglect highly sensitive black and white cameras or even rotating black and white cameras on heavy turrets with their own spotlights.
Emergency situations come in all shapes and sizes.
The standard lighting system may fail, and if your video surveillance system is designed only to work in greenhouse conditions “like in a TV studio”, it will be a shame.
Depending on the design decisions for emergency lighting, it may be sufficient to install a few monochrome dome cameras in a pinch, or it may be necessary to install a number of heavy, slow PTZ cameras with fast lenses and spotlights on the same turret.
Of course, such kits are expensive and today seem anachronistic, but they are still effective in such difficult cases.
Finally, a few words about recording means.
Be extremely careful when using digital systems with interframe compression.
MPEG, MJPEG are great algorithms, but with fast movement of the PTZ camera the recording will almost certainly be completely unintelligible.
Take comfort in the fact that you do not need multi-month archives.
It is enough to record several hours of material (true, from many cameras and in the highest quality), after the match all this can be erased, only exporting a few interesting clips for transmission to the court, sports association or scandalous television newsreel.
By the way, in all these cases it is extremely important to provide evidence of the authenticity of the recording.
There are all sorts of patented mechanisms of “watermarks”, “digital signatures”, etc., but the main mechanism is organizational measures.
The recording together with the corresponding “digital signatures” should as quickly as possible get to a place where independent witnesses can confirm its immutability.
For example, to a prosecutor's investigator as material evidence or to a bank safe, if the bank is ready to testify that no one touched this safe until the moment of presentation of the certificate.
Finally, you can simply give several copies to different people who are independent and respected enough for their testimony to be accepted by the court (it does not matter – regular or sport arbitration).
Any digital signature can be forged, at least with the original equipment, if you have enough time at your disposal.
It is extremely important to confirm that the presented recording was out of control of independent witnesses for a very limited time.
As a rule, one or two hours out of control are acceptable, even if the recording is not protected at all.
If you bring the recording a year after the event, no watermarks will remove suspicion.
Don't limit the exported portion of the recording to the bare minimum.
The more that gets onto the recording, the less likely it is that it was tampered with in advance (yes, there can be such suspicions).
Remember that digital signatures, in order to be genuine, must be properly guarded.
In the case of digital video recorders, this usually means properly guarding the recorder itself, especially after it has recorded a controversial incident.
It is advisable to check the readiness of the equipment with the participation of representatives of the police or the inter-club sports association and seal it before the match.
In general, it is better to agree on organizational measures in advance, before a serious incident occurs.
Perhaps you will agree the presence in the operator's office of representatives of the association or other clubs or other measures that increase the confidence of all interested parties.
