More information on sound velocity and dynamic draft corrections can be read below. When you are not going to use either draft or sound velocity corrections, make sure both check boxes are unchecked and click the "Next" button to proceed to the data correction page.
When applicable, setup sound velocity and dynamic draft corrections on this page.
An echosounder calculates depth by sending a pulse and measuring the time it takes to get to the ocean floor and back.
With this time and the speed of sound through the water, the depth is calculated.
For fresh water, the speed of sound is 1500 meters per second, however, for salt water this speed depends on the salinity, temperature and depth (pressure). Using the sound velocity correction option you can correct your sounding for salt water. Please do not use this function if this correction is already used in the echosounder. To generate a sound velocity correction file, click the "Editor..." button to start the sound velocity file editor.
Use the sound velocity editor to generate or alter sound velocity profile files when applicable.
Dynamic draft corrections can be used to correct the downwards motion of the ship.
For instance, when using a speedboat, you may notice that when the speed increases, the rear of the ship lowers while the front raises. This is what we call dynamic draft, and depends on the speed of the vessel. You can correct for this motions by creating dynamic draft correction table (speed versus draft). To generate a dynamic draft correction file, click the "Editor..." button to start the dynamic draft correction file editor.
Use the dynamic draft editor to generate or alter dynamic draft profile files when applicable.
