TeeJet RX375P Receiver - Manual (Page 10)

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RX375P
DIffeRentIal opeRatIon
The Radio Technical Commission of Marine services (RTCM) has a
differential service intended for correction services. This includes the
Space Based Augmentation Systems (SBAS), such as the Wide Area
Augmentation System (WAAS) and the European Geo-stationary
Navigation Overlay System (EGNOS). The RX375P is compatible with
each of these differential services in addition to e-Dif.
SBAS
The SBAS enabled RX375P operates automatically anywhere within
the coverage areas of WAAS, EGNOS, or other SBAS programs.
The Basics
WAAS is a free services of the FAA that allows regular GPS positions
to be improved to a DGPS level of accuracy. Tests using an RX375P
have shown better than 3 ft (1 m) accuracy. WAAS is available
everywhere in the United States, including Alaska, Hawaii, and Puerto
Rico. It can also be picked up in some of the border areas of Mexico
and Canada. There are no subscription charges incurred when using
WAAS. EGNOS is a similar service that is available in Europe and
Western Russia.
Automatic SBAS Tracking
The RX375P will automatically scan and track the satellite signals. This
automatic tracking allows the operator to focus on other aspects of
differential operation without the need to tune the receiver. The RX375P
features two-channel SBAS tracking that provides an enhanced ability
to maintain a lock on a SBAS satellite when more than one satellite is
in view. This redundant tracking approach results in more consistent
tracking of an SBAS signal when in an area where signal blockage of a
satellite is possible.
e-Dif
An RX375P that is equipped with e-Dif capabilities can operate
anywhere in the world where normal GPS signals can be viewed.
e-Dif can be used anywhere on the globe where a GPS lock can be
achieved. e-Dif was developed for customers who are not able to
receive other types of differential signals due to location or budget.
e-Dif requires a subscription. Once the e-Dif capable RX375P
computes a differential correction, the user can operate for unlimited
time and provide good relative accuracy. Alternatively, the operator can
regularly update e-Dif to maintain absolute accuracy (typically less than
3 ft (1 m) over 40 minutes).
appenDIX a - tRoUbleshootIng
The following table provides a checklist to troubleshoot common
problems and their solutions for the RX375P.
Table 7: Troubleshooting
Problem Possible Solution
Receiver fails to
power
• Verify polarity of power leads
• Check integrity of power cable connections
• Check power input voltage (7 - 32 VDC)
• Check current restrictions imposed by
power source
(maximum is 250 mA)
No data from
RX375P
• Check receiver power status (LED)
• Check integrity and connectivity of power
and data cable connections
• The volume of data requested to be output
by the RX375P could be higher than what
the current baud rate supports. Try using
19,200 or higher as the baud rate for all
devices.
No GPS lock
• Check integrity of cable connections
• Verify RX375P’s unobstructed view of the
sky
No SBAS lock
• Check integrity of cable connections
• Verify RX375P’s unobstructed view of the
sky
• Check SBAS visibility map