flight radar 24 and the police helicopter ?

[Minus1]

I lived nextdoor to a police station and never picked up a tetra signal (I dont think) in the 2 years I lived there, even with close call on.

I doubt Close Call will ever work. I did once get a Close Hit on an Airwave freq, but it wasn't a freq used around here, so I think it was just a fluke/intermodulation.

Try using WFM modulation on your local mobile transmit freqs.

[rogerbeep]

Glamdring, from your profile pic it seems tha you have some interests in ATC

First of all.
Police helicopters do not share their position if/when not needed.

All flight operators can choose not to share any information at Flightradar24 or similar commercial sites/networks, this in order to give a certain anonymity to the different operators in the air.

This is incorrect. For the vast majority of equipment ADS-B data cannot be switched off separately. If the transponder is on then so is the transmission of ADS-B. Even for the few transponders that do allow the separate switching of ADS-B (Mostly small addon units used by PPL pilots), pilots are required to transmit ADS-B unless requested otherwise by ATC.

This is incorrect. Of course tail numbers can be blocked if you want privacy, how many VIP flights are visible on ordinary web sites or apps?
Flightradar24 even has in their FAQ how you can unblock your tail number if you want to do the opposite with your company - to show your airplanes in public - i.e. be visible on the website/apps. If you can unblock flight info, obviously it can be blocked. If you have a blocked tail number still you must send ADS-B transimissions, but it shall not be "relayed" outside the ATC organisation.
For reference: http://flightaware.com/commercial/unblocking

The main reason for the airline companies to share flight status is to give information to their own teams that run different kinds of ground operations.

This is also incorrect. ADS-B is a pretty new technology and as such the data isn't really used for anything by the operators or ATC at the moment. There is plans in the future to integrate the data into ATC surveillance systems but nothing concrete yet. Flight status is currently fed back to airline operators by ATC surveillance systems using purely the Mode C/S transponder data.

This is also incorrect. I referred to airline companies and their ground organizations. As you most probably know ATC is owned by the government in each country and they (obviously) have more flight info available on their desks. "ATC owned" data is not available for private companies.
A friend of mine is working at the OCC (Operation Control Center) in one of Europe's leading airline companies. They use public information (as found in Flightradar24) to plan everything related to a flight. And believe me, he can't see VIP flights either.
All flight operations are planned in advance, but what happens when/if a plane is delayed? Then everything must be planned again.
The OCC's basically takes care of everything related to a flight operation and they need to plan everything within just some minutes of time frame. They have to order gates or parking for the planes at the airport and crew for the next flight. Arrange food, beverages for the next flight, order fuel delivery. They have to tell when their own or hired-in airport employees has to work overtime or maybe call in an extra shift.
Also they must forward updated delays to the company's booking office so transit passengers can be rebooked (during the delayed flight) if they miss their original flight because of a delay. The list goes on

Where can the OCC's find running information about updated ETA if they don't want do bother the flight deck officers with a lot of unneccesary ACARS-transmissions ?

[Glamdring]

If you have a blocked tail number still you must send ADS-B transimissions, but it shall not be "relayed" outside the ATC organisation.

I agree with you that operators can request that their flights are not shown on these websites. But the above is just wrong. Anybody with equipment can pick up ADS-B transmissions, they don't need to be "Relayed outside the ATC Organisation".

This is also incorrect. I referred to airline companies and their ground organizations. As you most probably know ATC is owned by the government in each country and they (obviously) have more flight info available on their desks. "ATC owned" data is not available for private companies.
A friend of mine is working at the OCC (Operation Control Center) in one of Europe's leading airline companies. They use public information (as found in Flightradar24) to plan everything related to a flight. And believe me, he can't see VIP flights either.

First off, ATC in the UK is not owned by the government. The government have a share, along with some major airlines and other companies.
Secondly, I seriously doubt that any airlines would use information from amateurs sharing ADS-B data on the internet to organise their operations. If you can prove that they do then I'll be surprised.

Also, how did airlines manage before FlightRadar24? Or before ADS-B? Or before Mode-S? Or before Mode-C? Or before Mode-A? Or before Radar?

Where can the OCC's find running information about updated ETA if they don't want do bother the flight deck officers with a lot of unneccesary ACARS-transmissions ?

In the UK at least it works like this....

We have a system called NAS (National Airspace System) that is basically a database of all UK flights showing, Reg, Callsign, Operator, Route, Squawk, EOBT, ETA, ATD, ATA etc. This system is kept up to date using various sources including feeds from the CFMU (Central Flow Management Unit) in Brussels and feeds directly from the controllers electronic strip displays. There is also a system in use at the airports called Chroma which uses a feed from the radar to "Fine Tune" the ETA and then feed it back to NAS (Chroma is where the airport public display systems get their information from). The information from NAS is provided to the airline operators as part of their route charges.

For private operators or for airlines wanting more information (Like flight tracking via ADS-B) they will use a third party website like Flight Aware (which you linked earlier), to gain access to the information. Flight Aware is in no way like FlightRadar24 however. For a start Flight Aware does not rely on amateur operators to provide data, they have their own ADS-B receiver stations. The data provided by Flight Aware is still only a nicety though, airlines and other companies in no way "rely" on it.

If ADS-B were to disappear tomorrow, believe me, air transport operations would continue on as if nothing had happened.

[BK]

If operators can request that their flights are not shown on these websites, then presumably four of us in the Edinburgh area could buy expensive GPS equipped Mode-S receivers and feed the timestamped data to flightradar24 for them to perform multilateration, and they could just refuse to display the information anyway.

ADS-B is a pretty new technology and as such the data isn't really used for anything by the operators or ATC at the moment. There is plans in the future to integrate the data into ATC surveillance systems but nothing concrete yet.

ATC might not be making much use of ADS-B yet, but surveillance radars (e.g. coastguard, military search and rescue, border patrol) are starting to integrate ADS-B, as they've been doing with AIS for years. In addition to the obvious benefit of being able to identify vessels, it also has the advantage that it helps draw attention to radar returns that are not associated with an AIS/ADS-B contact which may be for example debris in the water, or an uncooperative vessel such as a smuggler. I do wonder if some of the more advanced pirates are using fake AIS information as it's fairly simple to for example feed in synthesised GPS data into the AIS to create a 'phantom' vessel that isn't really there. Presumably the same thing can be done with ADS-B too.

[Glamdring]

Presumably the same thing can be done with ADS-B too.

Indeed. Which is the main reason that ADS-B data isn't yet used by ATC. The accuracy of the data relies on the equipment aboard the aircraft and is therefore outside of ATCs control. Most ANSPs aren't completely comfortable with that. Once it becomes law that ADS-B must be transmitted and some standards are introduced this will change.