[ePMP2000] For "Antenna Selected", what do the "V" and "H" values represent?

In the ePMP 2000 Access Point's Monitor -> Wireless -> Registered Subscriber Modules table, the Antenna Selected column indicates which antenna is currently used for uplink radio transmission (Sector or Smart Antenna).  

When Smart Antenna is displayed as the antenna in-use for a subscriber,  an indicator of the azimuth angle (in degrees) of the antenna pattern is displayed. The V value represents vertical polarity and the H value represents horizontal polarity, both relative to boresight.  H and V can have different values.