2695 Series Operation Manual
EZT-2695-8000/1
Page
9
of
124
2. Basic Theory
Easytrak Nexus Lite is an Ultra Short Base Line (USBL) Acoustic Navigation System. The system
uses a single compact transducer containing multiple receiving ceramics and an interrogate
ceramic.
The receiving ceramics are so arranged that each can detect an acoustic signal from a target’s
transmission. The acoustic signals may arrive at slightly different times due to their different signal
paths. From these time differences, the bearing and depression angle
*
to the target are computed.
For a TRANSPONDER, time taken from the vessel’s interrogating transmission through the water
to the reception of the target acoustic signal provides the range:
Range = VOS x Travel-time (m)
2
The divide by 2 is because sound has to travel to and from the target i.e. twice the distance.
For a RESPONDER, time taken from the vessel electrical interrogate signal through a cable to the
reception of the target acoustic signal provides the range:
Range = VOS x Travel-time (m)
Given range, bearing, and the depression angle, the relative position of the target beacon to the
vessel transducer can be determined.
*
The vertical angle between the horizon and the target
Summary of Contents for Easytrak Nexus Lite 2683
Page 1: ...Easytrak Nexus Lite 2695 Series Operation Manual ...
Page 13: ...2695 Series Operation Manual EZT 2695 8000 1 Page 13 of 124 ...
Page 85: ...2695 Series Operation Manual EZT 2695 8000 1 Page 85 of 124 Summary Report ...
Page 86: ...2695 Series Operation Manual EZT 2695 8000 1 Page 86 of 124 Complete Listing of Dataset ...
Page 88: ...2695 Series Operation Manual EZT 2695 8000 1 Page 88 of 124 ...
Page 89: ...2695 Series Operation Manual EZT 2695 8000 1 Page 89 of 124 ...
