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Directional Waverider DWR-G

Measuring waves with GPS

The DWR-G wave buoy measures waves with help of the Global Positioning System (GPS) only. It features a patented algorithm and custom-made GPS receiver. With a single stand-alone GPS receiver it can measure directional waves, up to 100 s periods, without any calibration ever, and even in the middle of the ocean.

  • Sensor
    wave motion sensor based on GPS.
  • Measures
    – wave height for wave periods of 1.6 to 100 seconds
    1 cm precision in all directions (free floating)
    – wave direction
    – water temperature
  • Additional features
    – GPS for buoy monitoring and tracking through HF link
    – internal logger
    – power switch
    – LED flash antenna
    – 0.9 m (0.7 m) diameter spherical hull of AISI 316
    – optional Cunifer hull, warranted not to corrode
    – 2 years (1 year) battery life
    – Intelligent Test Box
Wave motion sensor
Sensor single GPS (not differential)
Precision
0.01 to 0.02 m free floating, all directions (1σ)
0.01 to 0.02 m + 0.5% moored, vertical (1σ)
moored, horizontal, depends on current and wave frequency (excluding GPS antenna pitch and roll motion)
Periods 1.6 s to 100 s
Calibration not required ever
Exclusion GPS signals do not penetrate through water, occasional data gaps may occur
Exclusion measurements fail at position changes greater than 100 m in less than 100 s, e.g. when used free floating or towed at constant velocities greater than 1 m/s.
Wave data
Data north, west, vertical
Resolution 0.01 m (north 0.02 m, LSB of north is GPS data gap indicator)
Range -20 m to +20 m
Rate 1.28 Hz
Reference WGS84
Spectral data
Frequency resolution 0.005 Hz below 0.10 Hz and 0.01 Hz above
Frequency range 0.025 Hz to 0.60 Hz
Direction resolution 1.5°
Direction range 0° to 360°
Standard features
Integrated data logger Compact flash module 2 Gb
LED flashlight Antenna with integrated LED flasher, colour yellow (590 nm), standard length 35 cm, “Standard pattern”: 5 flashes every 20 s, “Increased pattern”: 5 flashes every 15 s.
GPS position every 30 minutes, precision < 5 m
Intelligent Test Box enables the sequential discharge of individual battery strings
Water temperature range -5 °C to +46 °C, resolution 0.05 °C, accuracy 0.2 °C
General
Material Stainless steel AISI 316 or Cunifer 10
Hull diameter 0.7 m or 0.9 m (excluding fender)
Weight Approx 96 kg 0.7 m AISI 316
Approx 211 kg 0.9 m AISI 316
Batteries 0.7 m operational life 14 months, 2 sections of 16 batteries
0.9 m operational life 28 months, 5 sections of 13 batteries
Type: Datacell RC27G (270 Wh green)
Power switch Data files are closed and secured
Hull painting Brantho-Korrux “3 in 1” paint system (no anti-fouling)
Compatibility DWR-G hatchcovers are compatible with MkIII buoys
Optional features
HF link
Flashlight antenna (1.95 m)
frequency range 25.5 MHz to 35.5 MHz (35.5 to 45.0 MHz on request)
transmission range 50 km, for use with Datawell RX-C receiver.
Air Temperature
Measuring height: 2 m above sea surface
Temperature range: -20 °C to +70 °C
Resolution: 0.01 °C
Exposed accuracy: ±0.5 °C (±1.0 °C when solar induced uncertainty detected)
Argos/Iridium satellite communication
GSM mobile communication
A picture of a CAT4 antenna with a background of the sea

Compact Air Temperature (CAT4)

The CAT4 is a meteorological air temperature sensor integrated in the HF-antenna of the Directional Waverider. It consists of four individual sensors that have different radiative properties and will therefore measure different temperatures. The actual air temperature is derived from these different temperatures. External influences that might affect the measurements, such as evaporative cooling, are detected for validation.

FAQ