Avidyne IFD540 Pilot's Manual page 153

GPS Status Page
The "GPS" selection will provide a number of GPS status
parameters, including the GPS navigation state and GPS derived
current altitude as well as the active GPS approach (if
appropriate), and a graphical depiction of the satellite vehicles
(SV) being tracked by the IFD GPS receiver.
GPS Status Page
NOTE
Global SBAS Support
Wide area/regional satellite based augmentation
system (SBAS) support provided by the IFD include
WAAS (Continental US, Alaska, Canada and most
of Central America), EGNOS (most of Europe and
North Africa), MSAS (Japan) and GAGNAN (India).
These are regional augmentations of the GPS
satellite constellation and should not be interpreted
as meaning the IFD is compatible with other GNSS
constellation systems such as Galileo (Europe),
GLONASS (Russia), or Compass (China).
AUX Pages 4-45