HEATHROW DIRECTOR
Using SBS, there is nothing uncommon in seeing aircraft "land" several miles away from Heathrow. Similar inaccuracies can be seen from visual observations.
I hope they sort it before it is ever used for ATC purposes.
To be fair, the aircraft that are reporting the gross errors are also invariably reporting "minimum integrity" for the data. In other words they send the data with a qualifier that says the accuracy is not guaranteed to anything better than 20NM!
However I take your point, the data integrity issue does need to be fully resolved before ADS-B is used for ATC and this is very much part of the thinking of the current European mandate for aircraft equippage.
It is now recognised on both sides of the Atlantic that Version 2 aircraft equppage is the minimum requirement for ADS-B to be used for ATC. And currently aircraft are still mainly equipped with Version 0 and a very few with Version 1.
The Australians, who have been very much the front runners in using ADS-B, have taken a different approach in that installations were approved on an aircraft-by-aircraft basis (the so called "white list"). However even they would acknowledge that this was difficult to manage and I think will be happy to abandon it with the coming of Version 2.