Diver6 User Manual
Section 2: Page 12 of 87
Section 2: System Overview
How does it work?
The Diver6 System uses acoustic modems to transmit data between Topside and Diver Modems. The
single Topside Modem is both an acoustic modem and also an Ultra Short Base Line (USBL) acoustic system
that uses multiple transducers packed into a single housing to detect the range and bearing to the diver.
The acoustic component of the Diver6 System has the following signal path (Figure 1):
Figure 1: System Communication
1.
The Diver6 System Software transmits a signal to the Topside Modem to query a Diver Modem. Each
Diver Modem has an individual address (diver modem will show address on boot up via the LCD on
the bottom of the modem).
2.
The Topside Modem transmits an acoustic signal to the Diver Modem.
3.
The Diver Modem then responds with a message to the Topside Modem. These messages may
contain data (e.g. diver depth, battery voltage, cylinder pressure etc.).
4.
On reception of the message from the Diver Modem, the Topside Modem can resolve the following:
a.
The distance between the Topside Modem and the Diver Modem (this is known as the slant
range and is based upon the speed of sound in water).
b.
The compass bearing to the Diver Modem (this is based upon the angle of approach of the
signal from the Diver Modem message).
5.
Based upon the information received the Diver6 System Software then:
a.
Calculates the absolute geo-position by combining the relative position of the diver to the
Topside Modem and the GPS position of the Topside Modem.
b.
Updates the status of the diver based upon the data received from the Diver Modem.
