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The accuracy of the direction of the target depends on how far the three surface station
sonar transducers are spaced apart. If they are 3 meters apart, the accuracy is about +/-
5 degrees. If they are 30 meters apart, direction accuracy is about +/- 0.5 degrees
For best accuracy, concentrate target operations broadside to the longer of the two baselines that
are formed by surface transducers #1 and #2, and #1 and #3 respectively.
PILOT Performance Characteristics and Limitations
Short baseline tracking is very convenient. Once the system is set-up, just 'flip the power switch' to
start tracking. The PILOT™ Short Baseline (SBL) technology also lets you choose the accuracy of
tracking by spacing the surface station transducers further apart. When operating from a larger
vessel or the shore, you can often obtain survey (sub-meter) accuracy. In addition, tracking is
available with PILOT even if the target is some distance away but just a fraction of a meter below the
surface.
Yet, despite these capabilities and our customer’s use of PILOT for precision tasks such as
surveying pipelines or serving as a ‘gold standard’ against which other navigation systems are
compared against, the SBL technology does have limits:
The further you move away from the location of your surface station transducers, the further the
tracking accuracy (expressed in meters) will decline. In addition, if you are using GPS and heading
sensor integration in order to operate in a geo-referenced (lat/lon or UTM) frame of work, the error
inherent in those sensors will add to the overall positioning error.
Therefore, requirements that call for consistent sub-meter accuracy over a large area of the sea floor
remain the domain of long baseline (LBL) systems such as Desert Star’s AquaMap system. Due to
our system modularity, your PILOT system is readily upgradeable for precision LBL AquaMap™
work. Check on our web site or call for details.
Geo Referenced Tracking Operations
The main part of this manual describes the basic system operation, which yields target positions
relative to the location of your surface transducers or vessel. Refer to the Appendix for a description
of georeferenced operations and other advanced functions such as chart integration, image
annotations and real-time data export to surveyor’s software such as Hypack™.
2. List of Operational Tasks
The five sections of the installation and operation process contain the following steps.
Installing
1.
Charge the batteries if necessary
2.
Install software
3.
Mount the mobile station
