A multiplex technique is described that can be used in photoelectric observations of dispersed spectra. The encoding pattern is a set of pseudo-random binary sequences. The data processing requires a minimum possible number of operations. A special purpose device could give the spectral intensity distribution on-line. An application at the solar eclipse (Mexico, 1970) is described.
Th. de Graauw and B. P. Th. Veltman, "Pseudo-Random Binary Sequences for Multiplex Codes," Appl. Opt. 9, 2658-2660 (1970)