Non-contact Discharge Radar Sensors
safe, continuous, machine-learning discharge measurements of open channels with known cross-section profiles

Measuring velocity, water level and discharge
Mount the RQ-30a and RQ-30a-30m from bridges, canal roofs, channel superstructures or cableways for safe, continuous recording of discharge measurements of rivers, channels or canals with known cross-section profile.
Radar innovation ensures the collection of reliable data without structural work or staff in the water. Locate the sensor outside the water to avoid debris, driftwood and other disruptions to take accurate measurements. Ensure fail-safe operation especially during high water or flooding.
This radar also detects the direction of water flow, affirming its use in tide-influenced rivers.
This monitoring instrument is both easy to install and very low maintenance.
The measurable velocity range is 0.10 m/s – 15 m/s. The RQ-30a is recommended for water levels 0-15m (49 ft) and the RQ-30a-30m for 0-35 m (115 ft).
Your benefits
How it works
Product Highlights
24 GHz (K-band) radar
24 GHz (K-band) radar
A 24 GHz (K-band) radar sensor measures the velocity of the water surface. Radar impulses are transmitted at an angle towards the water surface where ripples and waves induce a Doppler frequency shift detected by the RQ-30.
The same radar technology measures the water level by registering the travel time of an impulse sent from the sensor to the water surface.
Then the RQ-30 automatically computes the discharge by vm ∙ A(h), where the mean velocity vm is derived in real time from the surface velocity and additional dynamic factors using a complex hydraulic model with multiple dynamic k-factors. The cross-sectional area A(h) is computed from the water level and the stored profile.
Site-specific machine learning
Site-specific machine learning
The RQ-30 is programmed to perform machine learning, in order to make compensation of environmental influences and early detection of errors at a given monitoring site.
In addition, a self-test function reports any abnormal operation and malfunction. Quality indicators ease maintenance and ensure the ongoing, reliable collection of data.
Compact, light & weatherproof construction
Compact, light & weatherproof construction
The size of the sensor is 338 x 154 x 333 mm (13.31 in x 6.06 in x 13.11 in) and weighs just over 5 kg (<12 lb).
Operating temperature -40 °C – 60 °C (-40°F – 140 °F)
Storage temperature -40 °C – 60 °C (-40 °F – 140 °F)
Relative humidity 0 – 100 %
Protection rating IP 67Sensor housing is a powder-coated aluminum, vandalism-proof. A stainless steel option is available.
Integrated protection against indirect lightning features a discharge capacity of 0.6 kW Ppp.