A clock signal is deskewed relative to a data signal by sweeping a sampling point in time and sweeping an amplitude offset. In this state, a rotation casing is rotated 90 degrees to be in a lock state, and a fixing casing is firmly adsorbed to the magnetic base such that magnetic force of the permanent magnet inside it permeate to the magnetic base side. In contrast, the inventive system scans and displays the high resolution image in about 37 seconds, some 7-30 seconds faster than a conventional scanner. The receiver is configured to determine the signal to noise ratio of a first signal received at the first receive antenna and the signal to noise ratio of a second signal received at the second receive antenna; and to combine the first and second signals based on the respective signal to noise ratios such that interference due to multi-path signals in the spherical cavity is reduced. A plurality of tethers are provided to selectively restrain the valve during deployment.