velocity of propagation in water, stylus speed error, pythagoras error, multiple echoes, thermal and density layers, zero line adjustment error, cross noise, Aeration.
The angle of repose or, more precisely, the critical angle of repose,[1] of a granular material is the steepest angle of descent or dip of the slope relative to the horizontal plane when material on the slope face is on the verge of sliding. This angle is given by the number (0°–90°).
