Spotter Platform delivers highly accurate measurements of subsurface currents in field comparison with ADCP

In a 24-day field comparison, Sofar’s Spotter Platform made observations of subsurface current speed and direction that were nearly identical to those made by an ADCP, the industry standard.

Overview

At Sofar, we reduce the cost and complexity of collecting ocean data at scale. Our flexible Spotter Platform helps ocean scientists, engineers, and other marine professionals easily gather and transmit data at and below the surface. These real-time ocean insights accelerate research, power sustainable commercial solutions, and save time and money.

Spotter makes it easier and more affordable to gather ocean data without compromising on hardware durability or data accuracy. To test Spotter’s robustness and precision, we commissioned a field study comparing its subsurface current measurement capability to that of an Acoustic Doppler Current Profiler (ADCP), widely viewed as the industry standard for subsurface current measurement.

The field comparison found that Spotter’s observations of current speed and direction were nearly identical to those made by the ADCP access the full study here. Anecdotally, Spotter was easier to deploy and recover than the ADCP, and the data it collected was significantly easier to access. These results validate Spotter as a more cost-effective, accessible, and deployable alternative to an ADCP.

A Sofar team member deploys a Spotter Platform with a Spotter buoy, Smart Mooring, and integrated Aanderaa 4830 ZPulse® Doppler Current Sensor. Deploying a Spotter is a simple process that can be conducted from a small boat with limited personnel.

Key parameters and results of field study comparing Spotter and ADCP

The field study was conducted by Integral Consulting, Inc. (Integral) off the coast of Santa Barbara, California, in the Pacific Ocean. Integral deployed:

A Spotter Platform with a Spotter buoy, Smart Mooring, and integrated Aanderaa 4830 ZPulse® Doppler Current Sensor
A Teledyne RDI Sentinel Workhorse ADCP

The Spotter and ADCP collected data concurrently for 24 days prior to recovery. Integral’s analysis of the subsurface current data collected by each platform found that:

Observations of current speed and direction were nearly identical. Figure A below shows the strong agreement between Spotter and the ADCP’s measurements during the 24-day deployment.

Figure A. Observations of current speed (top) and direction (bottom) made by Spotter (blue, “Aanderaa ZPulse”) and the ADCP (red, “RDI Workhorse”) were nearly identical during the 24-day deployment.

A regression model (Figure B) identified a strong linear curve fit (R2 = .904) for measurements of current speed.

Figure B. Regression model for current speed data collected by Spotter (y-axis, "Aanderaa ZPulse Speed") and the ADCP (x-axis, "RDI Workhorse Speed"). The model identifies strong linear curve fit.

Overall, the observations made by Spotter closely aligned with the observations made by the ADCP with low bias and low root-mean-square difference.

How the Spotter Platform combines ease of use with data accuracy and accessibility

Collecting current data — or any data — in the ocean is historically an expensive and difficult process. Sofar’s Spotter Platform is helping change that, empowering marine professionals to make surface and subsurface observations of waves, temperature, water level, and more, with less cost and complexity.

Access the full field study here to learn more about the Spotter Platform, please contact our Sales team.