steradian
(ster)立体弧度，球面度(立体角单位)

• twinkling
• twin laser
• twin lens reflex camera
• twin lens reflex viewing finder
• twin photogrammetric camera
• twin-prism separator
• twin pulse code
• twin serial camera
• twin wave
• twisted mode
• twisted wire
• twist pitch
• two-beam interferometry
• two circle goniometer
• two-colour detector array
• two-colour hologram
• two-cup edging machine
• two-dimensional
• two-dimensional array
• two-dimensional convolution
• two-dimensional display
• two-dimensional focusing
• two-dimensional grating
• two-dimensional laser scnning system
• two-dimensional sampling theory