The construction and performance of a rapid scan spectrophotometer is described. The system uses a 1024-channel signal averager to accumulate many rapid spectral scans so as to average out slow changes in sky transparency. Wavelength programming is provided so that multicolor narrow-band photometry is possible in the signal averaging mode. Observations were made using a variety of scan speeds and sky conditions to evaluate the gains in accuracy compared to conventional slow scans. With sufficiently high scan speeds, it is possible to work on partly cloudy nights with only a factor of 2 loss in accuracy.
R. K. Honeycutt, "Signal Averaging Astronomical Spectrophotometer," Appl. Opt. 10, 1125-1128 (1971)