Theory of Operation

F

F.5 Performance Characteristics

This section lists performance information for the Acutime 2000.

F.5.1 Update Rate

The Acutime 2000 updates position at one-second intervals during self-survey. The surveyed position is frozen after the survey completes.

F.5.2 Dynamic Limits

The dynamic operating limits for the various receiver designs are listed below. These operating limits assume that the smart antenna is correctly installed and that the overall system is designed to operate under the same dynamic conditions.

Table F-1 Dynamic Upper Bound

Dynamic

Operating Limits

 

 

Velocity

500 m/s

 

 

Acceleration

4 g (39.2 m/s2)

Jerk

20 m/s3

F.5.3 Re-Acquisition

When a satellite signal is momentarily interrupted during normal operation, the receiver continues to search for the lost signal at the satellite's last known Doppler frequency. If the lost signal is not re- acquired within 15 seconds, the receiver initiates a broader frequency search. The smart antenna uses the last known information about the dynamics of the receiver and the satellite to establish the center frequency and range for the search. Every 15 seconds, until the lost signal is re-acquired, a new center frequency and search range is computed. Each frequency range is searched in 500 Hz increments. The duration of the code search at a given frequency is approximately one second and switches automatically.

F-8

Acutime 2000 Synchronization Kit User Guide

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Trimble Outdoors Part Number 45005-00-ENG manual Performance Characteristics, Update Rate, Dynamic Limits, Re-Acquisition