Crop Circles?

[Gramac]

Can anyone explain the following coloured circles around my aircraft on a recent flight? I was desperately looking for another aircraft but none were visible.

The rings around the top two images highlight a call sign 76EB00 and the bottom two GIPGL.  The Images have become blurred due to the very small sized image stipulation on the forum.

Thanks

Graham

[Admin]

Bearingless targets
Thx
Lee

[Gramac]

Thanks. What do the call signs mean ? They are not displayed as the usual G-XXXX etc.

Thanks

Graham