Help with vectors in the HUD

[Seether1980]

I'm a DCS Hornet beginner.

I've got a question about the HUD in the Hornet. In some missions a few vectors appeared but I can't find an explanation for it. It would be nice if somebody could help. I don't know what to do with it. Thanks.  

[Frederf]

Radar warning indications. 12 o'clock is ahead, 6 o'clock behind. See the traditional RWR green gauge in the lower right of the panel to see how it's a repeater. Can be turned on/off on the "EW" DDI page.

[Seether1980]

Thanks for your fast help.

[Fropa]

Ah Frederf beat me to it. Happy flying!