Directional Wave Spectra Drifter (DWSD)™

Technical Description

  • 35 cm sphere surface float
  • GPS-based tracking and wave engine
  • Iridium Short Burst Data (SBD) telemetry
  • Onboard datalogger with up to 16 GB of storage
  • Fourier coefficients a0, a1, b1, a2, b2
  • 1/256 Hz bandwidth from 0.03–0.50 Hz
  • User-programmable sampling window
  • Sea surface temperature (±0.05 K accuracy)
  • Freely drifting or restrained mooring configurations
  • One-year lifespan

> Download technical illustration (312 KB pdf)

Wave Engine

The heart of the Directional Wave Spectra Drifter (DWSD) sensor is a high-performance GPS engine paired with in-house developed software algorithms for onboard computation of the directional wave spectrum.

The DWSD sensor is designed as a turnkey solution for all wave monitoring requirements.


Hardware Concept

The DWSD hardware utilizes the same concept as the SVP drifter but without a drogue. The DWSD utilizes a field-serviceable buoy hull that can be restrained for shallow water near-coastal applications or freely drift at the surface for open-ocean applications. All measurements collected can be logged onboard an optional microSD card and/or relayed to a shore station using Iridium SBD.


Data Quality

Onboard processing enables computation of First-5 Directional Fourier coefficients a0, a1, b1, a2, b2. First-5 coefficients can be used to compute wave parameters such as significant wave height, swell direction, and directional spread, among others.

Intercomparison studies have been conducted in San Diego, California (mooring vs. Datawell DWR3), the Gulf of Naples in Naples, Italy (mooring vs. RDI ADCP), and the equatorial Pacific (spheres vs. Wave Watch III) and are ongoing.