we are using your ‘Ping Sonar Altimeter and Echosounder’ to detect the
underground while measuring on a moving boat.
Back from the site of the measurement campaign we have trouble with the
interpretation of the recorded data. Our intension was to manually
analyse the echo data of the underground where the confidence wasn’t
To achieve this, we successfully read distance, confidence, scan_length,
scan_start and profile_data and created plots for each ping of the
profile_data. After that, we calculated backwards the index where the
underground was detected. We are using this formula:
scale_factor = (scan_length - scan_start)/199
index_underground = distance / scale_factor
(we converted each length from mm to m, for better usage)
After that, the obtained index is added as a red line to the plot.
Additionally we used a color-map to validate the plotted data with the
given confidence. In our case ‘red’ means 0% confidence and ‘dark blue’
100%. Please see the attached file.
Looking at a row of e.g. 100 pings, we do not see any adjustment of
index_underground even though the intensity of the data clearly does
not match the index_underground. The confidence is always 100%.
Did we do something wrong during the calculation of the
index_underground? Could you please help us to interpret the echo data
We are very grateful for any help.