1. In optical measurements or specifications, a pair of usually straight contiguous stripes of equal width and having a defined degree of contrast, and which are used as one means of defining or determining resolution. Note 1: Resolution may be expressed in terms of line pairs per unit distance, or line pairs per unit angle. Note 2: Optical "targets," consisting of many contiguous line pairs, are sometimes used to measure optical resolution. Such targets may have line pairs of high contrast, in which one stripe is "white," or highly reflective, at the wavelength (s) of interest, and the adjacent one, "black," or highly absorbent at the wavelength (s) of interest. Other such targets may have line pairs of lower contrast ("shades of gray". ) Resolution may be specified or measured with respect to either or both kinds of target. 2. In raster-scanned television technology, two adjacent scanning lines (traces. )