Trimble Outdoors aggps 332 Benutzerhandbuch

AgGPS 332 GPS Receiver User Guide     9

Overview     2

GPS positioning systems are used in different ways to provide different 
levels of accuracy. Accuracy is measured in absolute terms (you know 
exactly where you are in a fixed reference frame).

Table 2.1 summarizes the GPS positioning methods. Imperial units in 
this table are rounded to two decimal places. The values shown are 
2 sigma.

For more information about each positioning method,

 

see below.

The AgGPS 332 receiver uses the RTK positioning method to achieve 
centimeter-level accuracy. To use the RTK method, you must first set 
up a base station. The base station uses a radio link to broadcast RTK 
corrections to one or more rover receivers. The AgGPS 332 receiver is a 
rover receiver, so another compatible receiver, such as a Trimble 
MS750

™

 or AgGPS 214 GPS receiver, must be used as the base station.

Real-Time Kinematic 
(RTK) GPS

Trimble CMR 
corrections broadcast 
by a local base station

2.5 cm (0.98 in) + 2 ppm horizontal accuracy, 
3.7 cm (1.46 in) + 2 ppm vertical accuracy

OmniSTAR HP 
Differential GPS

OmniSTAR HP

10 cm (3.94 in) after the signal has fully 
converged

1

1

Convergence time can vary, depending on the environment. Time to the first fix (submeter accuracy) is 

typically <30 seconds; time to the first high accuracy fix (<10 cm accuracy) is typically <30 minutes.

OmniSTAR XP 
Differential GPS

20 cm (7.87 in) after the signal has fully 
Differential GPS converged

Satellite Differential GPS OmniSTAR VBS

78 cm (30.71 in)

Radio Beacon

Coast Guard radio 
beacon towers

.4 inch through 12 inch
(10 cm through 30 cm) RMS 15 min

Satellite Differential GPS WAAS/EGNOS

95 cm (37.40 in)