SonTek/YSI Argonaut-XR Technical Manual - HydroScientific West

Section 1. Argonaut Components, Terminology, and Sampling
SonTek/YSI
1.1. Argonaut Components
The Argonaut includes several components depending on the exact instrument configuration. The
list below gives a brief description of all major system components and their function.
• Argonaut sensor - The sensor consists of two or three acoustic transducers (for 2D or 3D
measurements) permanently mounted in the transducer head. The head is mounted to the
pressure housing; the size and material used for construction vary with system configuration.
• Receiver electronics - The receiver electronics consist of a circuit board mounted directly to
the inside of the transducer head. The receiver provides the primary conditioning of the return
signals from the acoustic transducers.
• Argonaut processor - The Argonaut processor consists of two printed circuit boards inside the
pressure housing. The processor is mounted on an internal mounting frame supported from
the transducer head (§5.2). The processor sends and receives signals from the sensor,
performs Doppler calculations to compute velocity, controls the operation of all other
sensors, and outputs the data over the serial port and to the internal recorder.
• Power and communication cable - This cable carries DC input power and serial communication
between the processor and the controlling computer. The Argonaut can be configured for
RS232 serial communication for cable lengths to 100 m (300 ft) or RS422 for cable lengths
to 1500 m (4500 ft).
• Splitter cable - This cable connects the Argonaut XR or SL to an external battery pack for
autonomous operation. The cable has one connector to the Argonaut, a second to the battery
pack, and a third to the power and communication cable (sealed with a dummy plug during
deployment). See §5.5.2 for details.
• Temperature sensor - The temperature sensor, standard on all Argonaut systems, is mounted
on a titanium pin in the Argonaut transducer head. Temperature data are used to
automatically compensate for changes in sound speed; sound speed is used to convert
Doppler shift to water velocity. See §6.6 for details on the temperature sensor.
• Compass/tilt sensor - This sensor measures magnetic heading and 2-axis tilt (maximum
tilt ±50°). It comes standard with the Argonaut MD and XR, and is optional for the
Argonaut SL. It allows the Argonaut to report velocity measurements in Earth coordinates
(East / North / Up or ENU). The compass includes a built-in calibration feature to
compensate for ambient magnetic fields. See Section 4 for more details.
• Pressure sensor - The pressure sensor (standard on the XR; optional on the MD and SL) is
mounted in the Argonaut transducer head between the acoustic transducers. In addition to its
more general function of measuring deployment depth and surface elevation, data from the
pressure sensor can be used by the Argonaut XR to automatically adapt operation for
changing water level. See §6.6 for more details on the pressure sensor, see §3.8 for more
details about the Argonaut XR dynamic boundary adjustment.
• Battery power - The Argonaut can include battery power for autonomous deployment or to
act as a backup in the event of shore power failure. For the Argonaut MD, the batteries are
enclosed with the processor in a single pressure housing. For the Argonaut XR and SL, the
batteries are housed in a separate underwater canister and are connected using a special
splitter cable (§5.5.2). See Section 7 for details on autonomous operation from battery power.
Argonaut Operation Manual Firmware Version 7.9 (May 1, 2001) 1