Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Pulse-echo power spectra were obtained from aluminum block reflection at a depth of 2.8 mm in a water tank. (a) Frequency spectrum for Volcano Visions prototype with a peak at 8 MHz. (b) Frequency spectrum for Volcano Eagle Eye Platinum prototype with a peak at 20.5 MHz.
