Trimble Outdoors AgGPS 332 - Manual (Page 27)

AgGPS 332 GPS Receiver User Guide 17
Overview 2
24.9
Receiving Beacon DGPS
To obtain free radiobeacon differential signals, the AgGPS 332 receiver
uses dual-channel, fully-automatic beacon receiver electronics and
tracks broadcasts that conform to the IALA (International Association
of Lighthouse Authorities) Standard. When you use beacon DGPS, the
receiver selects the closest of the 10 most powerful radiobeacons in the
vicinity. You can configure the receiver to search for particular station
frequencies, or use the EZ beacon feature to select local beacons.
The receiver continuously monitors the integrity of the data received
from the differential radiobeacons. If it finds unacceptable errors in the
data stream, the receiver automatically switches to a different
radiobeacon, if one is available.
Radiobeacon signal reception is generally not affected by:
• hilly or mountainous terrain
• tree canopy
• location of the receiver inside a canyon (the signal reception
depends on the proximity of the receiver to the transmitter)
Radiobeacon signal reception is affected to varying degrees, by:
• natural “noise”, such as lightning
• human-made “noise”, such as alternators, electric fan motors,
radio speakers, and high voltage power lines
Multipath
environment Low Multipath errors are caused when GPS signals are reflected
off nearby objects and reach the receiver by two or more
different paths. The receiver incorporates the EVEREST
multipath reduction option.
RTCM-
compatible
corrections These corrections are broadcast from a Trimble 4000RSi™ or
equivalent reference station.
Table 2.6 DGPS accuracy (continued)