Surface Velocity Radar (SVR) Sensor

SVR is a non-contact method for measuring surface flow velocity in open channels.  The SVR uses radar technology to measure the Doppler shift of electromagnetic waves reflected from the water surface. 

The Doppler shift is proportional to the water’s surface velocity and can calculate the velocity of water at various depths.

Technical Specifications


Measurement Range0.05 to 15 m/s. Depending on flow conditions
Speed SelectionDefault is meters / second. Feet / second is an option
Flow DirectionBi-directional | Measures backwater situations.
Measurement intervalUp to 1 measurement per second
Resolution0.1 mm/s (0.0001 ft)
Accuracy+- 2% of measured value
Radar frequency24 GHz (K-band)
Radar opening angle12 degrees Azimuth
24 degrees Elevation


Power supply4-20 mA
600 ohms @ 24 VDC
150 ohms @ 12 VDC
4-20 mA with (2) NPN outputs
Power /current consumption activeTypical 112 mA at 12 VDC
~ 5 second warmup. 30 to 60 seconds for measurement output (depending on flow conditions)
Maximum current250 mA


Serial interfaceRS-485
Vertical distance to water surface0.5 to 15 m (1.64 to 82 feet) minimum depending on wave height


Operating temperature-40°C to 85°C (-40°F to 185°F). Battery charging protected below 0°C.
HousingIP 68
Lightning protectionGas Discharge Tubes on sensor inputs


Dimensions (L x W x H)134.5 mm (5.3 in) x 114.5 mm (4.5 in) x 80 mm (3.2 in) [without mounting bracket]
Weight0.756 kg (1.67 lbs)
Surface Velocity Radar (SVR) Sensor
SVR Application


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