Pre-measurement Tests for SonTek RSSL

Video Transcript
Download Video
Right-click and save to download

Detailed Description

In this video we will outline the pre-measurement tests conducted prior to a measurement in the SonTek RSSL software. Note: Use of trade names is for descriptive purposes only, and does not imply endorsement by the USGS. For additional videos in this series, visit the following link:


Date Taken:

Length: 00:02:37

Location Taken: Augusta, ME, US


Hi my name is Nick Stasulis and I work with the Maine Office of the New England Water Science Center. In this video we will outline the pre-measurement tests conducted prior to a measurement in the SonTek RSSL software.

Start by setting the ADCP’s clock by clicking Set Time to bring up the dialog. Simply click Set Time once you’ve verified the PC time is correct.

Next, select Compass Calibration. A compass calibration is recommended  as the compass is used for angle correction and to account for rotation of the ADCP in RSSL. Here are a few best practices when calibrating the compass. Ensure you are in the same environment as measurement transects will be collected. The ADCP should be rotated at least twice, about 1 minute per rotation, with one clockwise and one counter-clockwise. While rotating, the unit should be pitched and rolled in an amount similar to what the unit will experience during the measurement.

Begin by clicking the Start button and perform the test using the best practices we discussed. Once completed, press the stop button in the bottom left corner. On the screen, you’ll notice information on the test. Be sure to follow the comments and feedback here. In this case, the test is not acceptable and needs to be re-done. The allowable pitch and roll for the measurement based on the compass calibration is shown here. Also, notice the error reported. This error should be less than 0.2 degrees. If after three attempts the result is not better than this, note the result and proceed with the measurement. Press the OK button in the bottom right corner of the screen to store the compass file.

A system test should be run for each day of use at a minimum, but given the short duration of the test, it’s recommended you conduct it prior to each measurement. Click on the System Test link and a small box will appear, click on the start button. The test will come back with a PASS and a copy of the test will be stored with the measurement files for the day.

The BeamCheck option can be run once the instrument is in the water. It can be used to check to see if all beams are functioning and to determine depth at the start of a measurement, but is likely not an option that will be used routinely.