Real-time current profiles and directional waves for shallow water

The AWAC 1 MHz ADCP has become the standard reference technology in submerged wave-

measurement applications. Thousands of these ADCPs have been deployed to capture the full wave

spectrum in combination with current profiles. With a 35 m maximum range for wave measurements

and 4 Hz sampling of the surface elevation, the AWAC 1 MHz is the optimal tool for shallow current

and wave measurements.

ACOUSTIC WAVE AND CURRENT PROFILER

AWAC - 1 MHz

Highlights

Real-time current profiles to 30 m range

Real-time directional waves to 35 m range

Acoustic surface tracking (AST) with

vertical beam

Can be used both with fixed frames and

subsurface buoys

Applications

Online measurements of currents and

waves

Design data for planning of new

coastal structures

Site studies for offshore wind

platforms

Coastal erosion studies

Measurement campaigns where the

full wave spectrum is needed

Monitoring of transient waves for

channel wall protection

Studies of tidal currents

ACOUSTIC WAVE AND CURRENT PROFILER

AWAC - 1 MHz

Technical specifications

Water velocity measurements

Maximum profiling range 30 m

Cell size 0.25-4.0 m

Number of cells Typical 20-40, max. 128

Velocity range ±10 m/s horizontal, ±5 m/s along beam

Accuracy ±1% of measured value ±0.5 cm/s

Velocity precision Consult instrument software

Maximum output rate 1 Hz

Internal sampling rate 7 Hz

Echo intensity (along slanted beams)

Sampling Same as velocity

Resolution 0.45 dB

Dynamic range 90 dB

Transducer acoustic frequency 1 MHz

Number of beams

3 beams 120° apart, one vertical beam (90° apart, one at 5° for

platform mount)

Beam width 1.7°

Beam width vertical beam 1.7°

Wave measurement option (AST)

Maximum depth 35 m

Data types Pressure, one velocity along each beam, AST

Sampling rate velocity (output) 2 Hz

Sampling rate AST (output) 4 Hz

No. of samples per burst 512, 1024 or 2048

Wave estimates

Range -15 to 15 m

Accuracy/resolution (Hs) < 1% of measured value / 1 cm

Accuracy/resolution (Dir) 2° / 0.1°

ACOUSTIC WAVE AND CURRENT PROFILER

AWAC - 1 MHz

Wave estimates

Period range 0.5-50 s

Cut-off period (Hs) 5 m depth: 0.5 sec, 20 m depth: 0.9 sec, 60 m depth: 1.5 sec

Cut-off period (dir) 5 m depth: 1.5 sec, 20 m depth: 3.1 sec, 60 m depth: 5.5 sec

Sensors

Temperature: Thermistor embedded in housing

Temp. range -4 to +40 °C

Temp. accuracy/resolution 0.1 °C/0.01°C

Temp. time response < 5 min

Compass: Magnetoresistive

Accuracy/resolution 2°/0.1° for tilt <15°

Tilt: Liquid level

Accuracy/resolution 0.2°/0.1°

Maximum tilt 30°,AST requires <10° instrument tilt

Up or Down Automatic detect

Pressure: Piezoresistive

Range 50 m

Accuracy 0.5% of full scale (optional 0.1% of full scale)

Resolution 0.005% of full scale

Analog inputs

No. of channels 2

Supply voltage to analog output devices

Three options selectable through firmware commands: Battery

voltage/500 mA, +5V/250 mA, +12V/100 mA

Voltage input 0-5 V

Resolution 16-bit A/D

Data Recording

Capacity 9 MB standard, 4/16 GB (Prolog)

Profile record Ncells*9 + 120 bytes

Wave record Nsamples*24 + 1k bytes

Mode Stop when full (default and Prolog) or wrap mode

ACOUSTIC WAVE AND CURRENT PROFILER

AWAC - 1 MHz

Real Time Clock

Accuracy ±1 min/year

Backup in absence of power 1 year

Data Communications

I/O

RS-232 or RS-422. Software supports most commercially

available USB– RS-232 converters

Communication baud rate 300- 115200 Bd

Recorder download baud rate 600/1200 kBd for both RS-232 and RS-422

User control

Handled via "AWAC AST" software, or ActiveX® controls.

"Seastate" for online systems

Output formats

NMEA, Binary. Prolog provides same types also for processed

wave and current data.

Connectors

Bulkhead

MCBH-2-FS, MCBH-8-FS, optional Souriau M-series metal

connector for online use

Cable

PMCIL-8-MP on 10 m polyurethane cable, metal connector

optional

Software

Functions

Deployment planning, instrument configuration, data retrieval

and conversion. (for Windows®)

Power

DC input 9- 18V DC

Maximum peak current 3 A

Avg. power consumption 0,65 W

Sleep current < 100 μA

Transmit power 1-30W, 3 adjustable levels

Environmental

Operating temperature -4 to +40 °C

Storage temperature -20 to +60 °C

Shock and vibration IEC 721-3-2

EMC approval IEC 61000

ACOUSTIC WAVE AND CURRENT PROFILER

AWAC - 1 MHz

Environmental

Depth rating 300m

Materials

Standard model POM and polyurethane plastics with titanium fasteners

Dimensions

Maximum diameter 210 mm

Maximum length 175 mm

Weight

Weight in air 6.1 kg

Weight in water 2.9 kg

Online cable

Polyurethane jacket, Shore D hardness, 13mm in diameter, max 2km. Inquire for longer cables

ACOUSTIC WAVE AND CURRENT PROFILER

AWAC - 1 MHz