I have an array of 1600 rows x 1000 columns
Each row is an A-scan time trace of ultrasonic data
The A scans look like:
Note the difference in arrival time at the detector, this is due to Tx and Rx being closer or further from each other.
The large amplitude signals are SAW signals that I want to filter out.
I have used:
FMC(FMC < -2e-4)=0;
FMC(FMC > 2e-4)=0;
It works ok, however, I want to refine it based on the calculated arrival time of the SAW (t = d/v) with t = time, d = distance and v = velocity of the ultarsonic signal.
I can calculate the arrival time based on the distance of each Tx and Rx combination for each row, however, some arrival times are between the time intervals of 20ns. Is it possible to round up 3.95270270270270e-06 to 3.96e-06 as this would correspond exactly with one of the time stamps.
I want to convert that time stamp, with n to the left and to the right to zero.