Control Systems & PLC's

Transducer Module

Three Key Hydrographic Survey Equipment

Water level recorder instruments for collecting Hydrographic Survey data incorporate versions for both shore based and offshore / seabed applications together with telemetry systems for secure data exchange.

The top three essential hydrographic survey devices are outlined below.

1. Echosounder

Bathymetry: the science of calculating depth. Regardless of whether you are surveying, dredging or managing underwater operations, accurate bathymetric records is vital, be it complete water depth or the position of certain equipment within the water column.

Electronic digital signal processing methods that utilise fuzzy logic are readily available in the marketplace. These echosounders will select and lock onto the correct echo, while automatic power and gain control means that erroneous echoes are minimised and accurate readings can be made in water depths as little as 30cm. Being a stand alone altimeter, this device is suitable for integration into bathymetry equipment. Combining the technology with integral GPS receiver and on board information collection offers echosounders with the benefits of optimum versatility and minimal deployment time.

Echo sounders, both single and multi-beam need speed of sound records to correctly produce water depth measurements. If standard, small boat echosounding is necessary with single or dual frequency transducers and interface of external parameters with GPS reference then a single beam echo sounder is ideal.

The MIDAS Surveyor has been formulated to provide a low price tag answer for modest scale hydrographic surveys. The device is offered with a 210kHz transducer as standard, and uses sophisticated electronic digital signal processing systems to guarantee high accuracy and sound bottom tracking. With an integral SBAS enabled DGPS receiver, the MIDAS Surveyor will record location and depth data for in excess of 30 hours, in addition to performing on-line correction making use of external heave and tide data inputs. Options include an added 33kHz transducer, or high accuracy 16 channel DGPS receiver.

2. Sound Velocity Profiler

Sound Velocity Profilers are currently on offer on the market that will offer the following attributes

a. Genuine Accuracy of ±0.02m/s (Total Error Budget)

b. Precision (peak to peak noise) of ±0.002m/s

c. Operating range of 1375m/s to 1900m/s (covering all environments from fresh water to the Dead Sea and the Marianas Trench)

d. Data rates up to 60Hz (instrument dependent)

One such profiler is the miniSVP, a new low cost model, formulated to make the most effective Sound velocity measurements in the world available to everyone. Featuring the distinct and acclaimed "time of flight" Sound velocity sensor, the miniSVP is available in either 500m rated acetal or 6000m rated titanium versions. A single C cell and large Flash storage make it possible for hundreds of profiles to be stored, and the pre-set profiling patterns enable it to be setup and deployed quickly and easily.

3. Water Level Recorder

Tide Gauges offer perhaps one of the most fundamental of all marine readings - Accurate tidal information. This is critical for Port & Harbour Operations, Dredging, Surveying, equipment deployments, and a variety of other purposes.

Features include:-

a. logging of tidal data for historical purposes;

b. ability to provide real time information,

c. transmission of data over a variety of telemetry links,

d. network capabilities,

e. fixed displays or access through web or local intranet,

f. seabed fixing or in-line mooring.

The TideMaster is a little, cost effective Tide gauge, specifically designed for applications where the end user needs an accurate record of water height, but with the further possibility of meteorological data via an ultrasonic wind speed and direction sensor. Ideal for deployment in fresh or salt water, the TideMaster can be put into service for up to 1 year, dependant on the sampling rate, with instrument setup and data retrieval via an optional monitor panel or using the Computer application provided. Alternatively, the system can be supplied with radio modules for real time data transmission.

Established in 1969, Valeport designs and manufactures hydrographic survey instrumentation for the oceanographic, hydrographic and hydrometric communities, with a worldwide customer base that includes:environmental, defence, oil and gas, renewable energy, construction, dredging and civil engineering sectors.

To view a range of hydrographic equipment suitable for hydrographic surveys, look at Valeport at http://www.valeport.co.uk

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