Displaying the RSSI in SkyView:
Click on expand sidebar:
Click the column head of RSSI twice so the numbers closer to zero are first:
(from this post Positions Reported - #6 by wiedehopf)
If you want to have the rssi column displayed while the map is present you need to change the web interface a bit, it is explained in this post: Announcing PiAware 3! (Latest version: 3.8.0) - #910 by wiedehopf