释义 |
helical scanning
helical scanning[′hel·ə·kəl ′skan·iŋ] (communications) A method of facsimile scanning in which a single-turn helix rotates against a stationary bar to give horizontal movement of an elemental area. (electronics) A method of recording on videotape and digital audio tape in which the tracks are recorded diagonally from top to bottom by wrapping the tape around the rotating-head drum in a helical path. (engineering) A method of radar scanning in which the antenna beam rotates continuously about the vertical axis while the elevation angle changes slowly from horizontal to vertical, so that a point on the radar beam describes a distorted helix. helical scanning
helical scanning Spiral computed tomography, see there. |