4
1.
Introduction
The exact and real-time knowledge of the discharge is an important task in the fields of
hydrography, water storage management, irrigation and prevention of natural hazards. It is the
requirement to calculate water structures and for an economical management of water
resources. It is the base for simulations of hydrological processes with mathematical-physical
models.
The RQ-ADMS radar sensor is a continuous measurement device for the contact-free
determination of the discharge of open rivers and channels. It combines two contact-free radar
measurement methods in one system. On one hand the water level is measured by a transit
time measurement of a radar signal. On the other hand the flow velocity at the surface is
simultaneously determined by the principle of Doppler frequency shift. These two
measurements are internally combined and provide the discharge using a predefined mapping
of the measurement site.
Backwater situations caused by inflows, weirs and downstream standing water bodies show
no stable relation between water level and discharge. In many situations hysteresis effects
with different relations for rising and falling water levels occur. Therefore the determination of
such relations is affected by a substantial uncertainty. Only the additional information of flow
velocity, given by the RQ, allows the calculation of the discharge under these difficult
conditions.
Due to the contact-free measurement approach the radar sensor usually can be installed on
bridges or extension arms without expensive structural measures in the river or channel. The
radar sensor is located outside the danger area of flood events and allows a low maintenance
operation over many years.
2.
Specifications
2.1. General
General
Total weight
15,5kg (+7,4kg batteries)
Accumulator capacity / voltage
24Ah / 12V
Current consumption (@12V)
sleep
0,8-1,0mA
measure
50-80mA
transmit
50-200mA
Recommended solar panel
50W
Operating temperature
-20
…60 °C
Protection rating
IP 66
Lightning protection
Integrated protection against indirect lightnings with a
discharge capacity of 0,6 kV Ppp
Table 1: General specifications
