Section 6 - Gps/Beacon Combination Receivers; About The Northstar 8901; Northstar 8900 Series; Features - NorthStar 8700 Technical Reference Manual

Section 6 - GPS/beacon combination receivers

6.1 Northstar 8900 series

6.1.1 About the
Northstar 8901

6.1.2 Features

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The Northstar 8900 GPS/DGPS position sensor system has a unique com-
bination of performance and operational features, including 12-channel
GPS with fully automatic, dual-channel beacon performance for the ulti-
mate in position accuracy. The 8900 sensor combines the Northstar 8700
GPS sensor and the Northstar 8800 differential sensor to create a product
ideal for applications requiring a high level of position accuracy, such as
vehicle tracking, yield monitoring, field mapping, and other specialized
OEM applications.
The 8900's advanced DGPS system provides greater accuracy than GPS
alone by accepting differential signal corrections from strategi-
cally-located transmitters, or beacons. DGPS corrections remove the
errors caused by atmospheric variations and Selective Availability, or SA.
SA is the intentional degradation of satellite signals by the U.S. Depart-
ment of Defense. Once set up and configured to your application's
requirements, the 8900 sensor needs only minimal supervision. By virtu-
ally eliminating any attention needed to operate the unit, you can devote
more time to other aspects of your work.
To add worldwide positioning capability, you can easily interface the
8900 to other sources of differential corrections using the SC-104 correc-
tions format. For further information, see Section 8, "Input/Output Con-
figurations." See Section 4, "GPS Receivers," and Section 5, "Beacon
Receivers," for a description of the operation of the 8900's GPS receiver
and beacon receiver, respectively.
The 8900 and 8901 sensors are functionally identical; the only difference
is their configuration. Like the 8900, the 8901 is a 12-channel GPS with
dual-channel, automatic differential. The 8900 can use either two sepa-
rate antennas (GPS and beacon receiver), or a combo antenna and exter-
nal signal splitter; however, the 8901 is configured to operate only with
the Northstar AN200 combination antenna (a Northstar AN190 antenna
with a 20-foot cable). Accordingly, the 8901 features a convenient inter-
nal splitter for quick connection.
The 8901 is primarily used for precision agricultural applications, includ-
ing soil sampling, field mapping, and yield monitoring. Because the two
units are functionally identical, this section uses the common term 8900
to refer to both models.
12-channel, high-performance GPS precision and dependability
•
Two-channel, fully automatic DGPS beacon receiver for accuracy as
•
good as three meters 95 percent of the time
Speed measurements accurate to about 0.1 m.p.h.
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Course-over-ground (COG) measurements to about 0.5 accuracy
•
Accurate, worldwide position data in any weather, 24 hours a day
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Section 6 - GPS/beacon combination receivers
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