ABSTRACT
A fast, reliable method of spectral rectification, division of the spectrum by the spectrum itself after it has been put through a very low pass filter, is demonstrated. It is shown that this technique is superior to the other Fourier technique now in use (simple removal of the low-frequency components) for use in automatic spectral classification. The method has been used successsively at all dispersions currently available with the Mark II scanner. It fails catastrophically, however, with very late (M1 and later) type stars and sometimes on extreme emission line objects. Since the spectrum need not be wavelength calibrated, the method should be applicable to objective-prism spectra, galaxy redshift surveys, and analyses such as the radial-velocity work of Fehrenbach and Burnage (1978).