Conventional threshold-detecting techniques give errors in the range of several millimeters to centimeters using the low-bandwidth transducers currently available for operation in air
Correlation is the best method with low
S/N ratio
L2 norm provides better results with moderate
and low noise levels although it requires high sampling
frequency, high digitizing resolution, and higher
computing time to achieve its full performance
L1 needs both low cost
hardware and lower computing time using conventional
architectures. Also, results show that 6-8 b of resolution
are enough for most applications
while L1 and L2 norms