I spent a happy few hours trying to get the Beeb report corrected, with reference to which bit of the military had been involved, and which kit had been deployed.
MoD did confirm to me that it was indeed the Rocks involved (not the Pongoes). I also understand that the Rafael 'Drone Dome' kit has not yet been delivered - so presumably it was Horizon, or somesuch.
If you check the latest version of the Beeb report (3 Jan), you'll see they have made the corrections.
https://www.bbc.co.uk/news/uk-england-sussex-46741687
airsound