Trimble Outdoors 132 - Manual (Page 22)

2 Overview
2 2 DSM 132/132RS Receiver User Guide
Position Output Format
The DSM 132 receiver outputs positions in Degrees, Minutes, and
Decimal Minutes (DDD°MM.m'). This is the NMEA (National
Marine Electronic Association) standard format and is commonly
used worldwide for data transfer between electronic equipment.
23.4
Receiving beacon DGPS
To obtain free radiobeacon differential signals, the DSM 132 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
• Sky wave interference with ground wave