Plane circling over South Grantham

[RGG]

As per heading it was circling in the dark tight 800 metre diameter constantly for 20 minutes.

Any idea what it was and what it was doing.

[MesoForm]

I guess it’s this one on Flight Radar


A police plane, can’t tell you what it was up to mind!

[Sheets Tabuer]

You mean this?

https://globe.adsbexchange.com/?icao=4077fc

It's the Rozzers.

[RGG]

Thanks

Quite a low pitch engine

[rodericb]

Could be "dirt boxing", aka DRTbox aka IMSI catcher.