Partial solution:
sudo su
crontab -e
* * * * * /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I | grep BSSID > /Users/your_name/Desktop/airport_output.txt
then read this file periodically and parse the relevant bits out
BSSID: 28:e8:29:6e:c2:25
this is in case you want to automate this / need this info in your scripts