The 3000 m Aquadopp is designed for deployments down to 3000 m and it has all the capabilities of the standard Aquadopp. It is a modern, yet well-proven instrument and it is undoubtedly the most versatile single-point current meter on the market. Relative to the standard system, it has a larger diameter (about 84 mm vs. 75 mm) but it is still made of all plastic parts. As a result, the 3000 m model is lighter than the pure-titanium 6000 m model and it represents an affordable alternative for the deployment in intermediate waters.
The transducer sensor head is made from machined Delrin materials and the orientation of the beams is either symmetrical or the same as in the standard "moring head" configuration.
In the deep ocean, there are fewer particles than in the upper 500 m of the water column. Considerable work has been done with the Aquadopp to understand the factors that affect the acoustic signal strength and to improve the magnitude of the returned echo. This work is reflected in current electronics and transducer design. Verified performance in the deep ocean is documented here.
The most common application for the 3000 m Aquadopp is deep-water moorings, where one or more instruments are mounted on a cable that stretches from the bottom to a subsurface float. The instruments can either be clamped directly to the cable or a fin can be used to make sure the instrument is always oriented into the flow.
- The Aquadopp records all relevant parameters to the internal recorder, including acoustic signal strength, tilt, compass, battery voltage, and status/error code.
- The sampling strategy is very flexible. The measurement interval, the averaging interval and the exact pinging rate can all be set independently in the deployment planning menu included as part of the standard software.
- The compass includes a hard iron calibration routine that makes it possible to remove the effects of the cable and the mounting clamps on the compass measurements.
- Using the diagnostic mode, the detailed mooring motion (heave, rotation, tilt) can be measured and understood.
- The acoustic signal strength is recorded in order to provide a direct measure of the acoustic conditions.