AWR1642BOOST: set angle in visualizer (awr 1642 boost)?

Hello,  I'm HJ.  First time I use awr 1642 EVK.

I set 15 degree(Antenna Config azimuth res-deg) in visualizer for detect object.
But object detect over 15 degree.
Is it set of azimuth resolution that detect object angle?
If it is not, how do I set angle for detect object 15 degree?

Regards,

HJ