rAbstmet-The low bandwidth of curre

rAbstmet-The low bandwidth of current ultrasonic transducers
for range measurements in air produces waveforms with
relatively high rise and fall times. This is a cause of errors when
echoes are detected by simple threshold-crossing techniques.
To overcome this drawback, several digital signal-processing
algorithms are considered, including L1, L2 norm, and correlation
with different approaches for envelope extraction. The
influence of different factors such as S/N ratio, sampling frequency,
and digitizing resolution on measurement errors are
analyzed using a synthetic approach through nearly 40 000
simulations. Results show different performance levels involving
accuracy, computing time, and cost for the studied methods,
although all of them allow us to reduce errors by several
orders of magnitude.
I. INTRODUCTION