AQUAscat® 1000LT

Suspended sediment in the field - to 200m

Ideal for sediment research and surveys

It is now even easier to measure suspended sediment concentration with the new AQUAscat 1000LT acoustic profiler. The latest addition to the well-established AQUAscat range combines cutting edge technology with economic design to give the best value solution for scientists and surveyors.

The AQUAscat transmits pulses of high frequency sound on two transducers, each of which operate at a different frequency. It measures the sound scattered by sediment or other suspended materials at 10 mm spatial intervals, giving profiles of 2.5m. Profiling allows sediment dynamics such as resuspension and entrainment to be explored, which is not possible with single point measurements. The instrument is supplied with the latest user-friendly post-processing software that allows the mean particle size and concentration to be calculated from the acoustic backscatter output.

The self-contained design and rechargeable battery make it easy to deploy and maintain. Suitable for use to 200m, the new AQUAscat can be deployed in rivers, lakes, estuaries and coastal regions. 

 

Applications

  • Academic research
  • Commercial use
  • Suspended sediment research
  • Dredge monitoring
  • Water quality monitoring

 

Features
Specs
Documents
FAQ

AQUAscat 1000LT Lite Model

Key features

  • The AQUAscat 1000LT can observe profiles of up to 2.5 m.
  • Using set frequencies of 1 MHz and 4 MHz, the AQUAscat 1000LT allows you to determine the mean grain size and concentration of suspended materials.
  • The self-contained instrument has 2 integrated transducers to give quick and simple deployment and operation. It contains a rechargeable battery making it suitable for repeat deployments.
  • With a depth rating of 200 m, the AQUAscat 1000LT is ideal for use in shallower waters.
  • The instrument also has integrated pressure and temperature sensors.

The AQUAscat 1000 range

Effective profiling of SSC

  • AQUAscat 1000 technologies can observe profiles of suspended sediment concentration over a series of depths within a water column to give you valuable knowledge on the sediment processes taking place.
  • Profiles can be observed at a single location to produce a time series, or transects taken to observe spatial variability.
  • Profiling can be done horizontally or vertically depending on your choice of deployment.
  • Profiles of SSC can provide information on sediment processes, including motion under wave, tides and currents. Applications include research, coastal zone management and flood risk management. Profiles can provide more information on dredge plumes to assist operational decisions, habitat protection and regulatory compliance.

Multiple frequencies

  • Using multiple frequencies, the AQUAscat 1000 range allows you to determine the mean grain size and concentration of suspended materials.
  • The instrument is most suitable for particle sizes between 20 μm and 500 μm radius and concentrations of 0.01 g/l to 20 g/l over 1 m, or more over a shorter range.

Use in all water environments

  • The AQUAscat 1000 can monitor sediment in both freshwater and marine water environments, including:
  • Estuaries
  • Coastal areas
  • Rivers
  • Lakes
  • Oceans
  • Polar regions
  • Laboratory studies

Concerned about biofouling?

  • Acoustic instruments have greater resistance to biofouling than optical instruments, therefore AQUAscat 1000 technologies are ideal for unattended deployments.

Effective data analysis with the AQUAscat Toolkit

  • The acoustic backscatter data is post-processed and viewed using the AQUAscat Toolkit, which is supplied with every AQUAscat 1000 instrument.
  • View the Acoustic BackScatter (ABS) data in different formats and apply bottom-detection and threshold algorithms to the data before it is processed to obtain suspended sediment concentration (SSC) profiles.

Sediment range

Sensitive to a wide range of grain sizes
Size inversion typically feasible for 20 μm to 500 μm radius
Typically 0.01 g/l to 20 g/l over 1 m, or more over shorter range

Frequencies

2 frequencies - 1MHz, 4MHz

Transducers

Typically Ø10-20mm ceramic discs (beam width according to frequency)

Transducer arrangement

2 fixed transducers

Gain

Software controlled transmitter and receiver gain adjustment

Range

150 cm (typical) at 4MHz, 255cm at 1MHz

Transmitted signal

1 W rms typical transmit CW pulse, pulse length to match cell size.

Transmission rate

128 Hz max pulse rate for each frequency (i.e. 256 pulses per second for two), subject to acoustic range limits. Minimum rate 1 Hz for calibration.

Data averaging

Cell ensembles averaged over time by powers of 2 up to 64 before storage

Range cells

256 cells, 10mm standard (at 1500 m/s speed of sound). 

Burst duration

Defined by number of profiles requested

Burst trigger

Either external hardware trigger when required or internal software trigger at regular intervals

Burst interval

Internally generated from once every minute to once every 255 minutes, user definable start time of first burst.

Trigger output

A digital output allows triggering of external instruments

Power requirement

8 V to 24 V dc. Typically 1 W when logging, and with standby of typically 1 mW when not logging.

Battery packs

Internal rechargeable Nickel Metal Hydride battery pack gives up to 5 days typical burst
deployment. External battery packs available according to deployment needs.

Additional sensors

Built-in temperature and pressure

Disk storage

Compact Flash (proprietary format), 8 GB standard

Data comms

USB 1.1 typically 2-3 Mbaud

Housing options

200m rated acetal housing. 

Q: I want to deploy the instrument in proximity to other instrumentation - will there be any interference between the signals?

A: Care should be taken in placing acoustic instruments of the same frequency as interference can occur. Please contact us with details and we can provide deployment advice.

Q: How do you trigger the instrument to start logging?

A: The software provided with the instrument allows you to set a start time for sampling. Alternatively, the AQUAscat can be triggered by third party instruments via a trigger cable.

Q: Can I deploy the instrument in the surf zone?

A: As an acoustic instrument, the AQUAscat is sensitive to entrained bubbles within the water column. If used in the surf zone where bubbles are prolific, the instrument will not be able to distinguish them from suspended sediment particles.

Q: Are the transducers affected by biofouling?

A: The transducers are acoustic sensors so are less affected by biofouling than optical sensors.