1317 Webster Avenue 
Fort Collins, Colorado 80524 




Mobile Wireless Streambed Profiler

ETI's mobile, light-truck-mounted, wireless streambed profiler uses an active sonar sensor that measures distance from the sonar transducer to the streambed.

A wireless data link transmits sonar data to a receiver in the truck. A winch-boom assembly  tethers and controls the sonar sensor assembly, and is designed to be mounted on a ½-ton to 1-ton long-bed pickup truck.



The boom is comprised of two sections: (1) the main boom, which is positioned and attached over the truck bed; (2) the extension boom, which is attached to the main boom by a hinge and swings out over the bridge for taking measurements. For transporting the system to the site, the extension boom is folded in and secured to the main boom. The truck is maneuvered adjacent to the bridge rail to conduct measurements.

Two winches are mounted on the main boom over the truck bed. The top winch controls the position of a trolley along the length of the boom, thus determining how far out from the bridge rail the sonar sensor is to be suspended. The bottom winch tethers the sonar assembly, lowering it into the water and hoisting it back to the boom. Both winches are operated by pistol-grip controllers.

Mounted also on the main boom is a water stage sensor that measures the distance from the stage sensor to the water surface. Two other sensors provide additional necessary information to determine the location of the streambed point being measured in relation to a known point on the bridge. These two sensors are (1) a truck wheel position sensor and (2) a trolley position sensor. The truck wheel position sensor provides the relative position of the truck from a known point on the bridge, and the trolley position sensor provides the distance that boom’s trolley extends over the bridge rail.

The three-dimensional location of the streambed point being measured is therefore determined from (1) the distance from the sonar sensor to the streambed, (2) the distance from the boom to the water as determined by the stage sensor, (3) the distance of the suspension trolley from its home position as determined by the trolley position sensor, and (4) the position of the truck from a known point on the bridge as determined by the truck wheel position sensor.

A sonar profiler electronics module is mounted to the sonar sensor assembly. The module’s enclosure houses the sonar sensor’s electronics interface and cabling to the sonar sensor, a battery, and a wireless data link transmitter. The wireless data link transmits the distance from the sensor to the streambed once each second to a receiver in the portable attaché case described next.

Included with the system is a portable attaché case that includes a wireless data link receiver; a data controller electronics module; a control panel with a power switch, a push button (labeled Data Marker) for resetting the system reference points, receptacles for cables from the stage, trolley, and truck wheel sensors; a 9-pin RS232 port; and a Personal Data Assistant (PDA) PC.

Sonar sensor data is transferred via the wireless data link to the electronics module. The stage sensor, the trolley sensor, and the truck wheel position sensor are all directly cabled to receptacles on the attaché case’s control panel.

A push-button controller is provided that has a button which, when pressed, causes an additional sequential data field to be written to the system’s data record. This controller is cabled to the attaché case control panel receptacle marked "Manual." This will assist in marking a specific location at which the streambed depth is measured

The electronics module outputs data records to the PDA via the 9-pin RS232 port, which displays the data in tabular form on the screen and stores the data on a 32 meg memory card. Upon completion of a survey the data can be downloaded from the memory card to a PC for final reduction and analysis. The PC program, provided by the user, must have software routines that will (1) convert truck wheel rotations from the trolley position sensor and the truck wheel sensor to distances, and (2) integrate all data from the sonar, stage, trolley, and truck wheel sensors to a point in three dimensional space.

The Mobile Wireless Streambed Profiler is one of a family of electronic measurement systems designed and distributed by ETI Scour Measurement Systems that accommodate a variety of requirements and environments.



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