Note that ultrasonics can be used for rangefinding to interrogate a remote environment in a number of ways: https://www.tdcommons.org/dpubs_series/1832/ https:/

Note that ultrasonics can be used for rangefinding to interrogate a remote environment in a number of ways: https://www.tdcommons.org/dpubs_series/1832/ https://www.tdcommons.org/dpubs_series/1832/