Results of Bottom-Tracking Test at Offshore Model Basin

Bottom-tracking accuracy of a SonTek Doppler system was tested at the Offshore Model Basin in Escondido, California in December 1999. This facility features a computer-controlled carriage that can move along the basin at speeds up to 5.5 m/s.

The SonTek Doppler instrument was installed in the middle of the carriage with its head submerged about 0.3 m into the water. Two independent runs were conducted at 11 speeds ranging from -3 m/s to 3 m/s. The results of the test are shown below. A least-squares linear fit of the velocity data to the carriage speed gives a slope of 0.9992 with a reported offset of 0.13 cm/s.

The results from this test indicate a bottom-tracking accuracy of 0.08 percent, which is well within our product specification of 0.2 percent.

• ADP
• RiverSurveyor