title: Dayglow photometry: a new approach.
abstract: A unique photometer capable of measuring line intensities of <0.1% of the bright background continuum (5 x 10(6)/A) has been developed and successfully commissioned for the measurement of daytime OI 630.0-nm emission from the thermosphere. The photometer employs a low resolution (10(4)) Fabry-Perot etalon, temperature tuned narrowband (3-A) interference filter, radial chopper, and up/down counting system. The optimum choice of the photometer parameters and a unique method of eliminating the background enabled us to overcome the limitations of the earlier attempts to make measurements on such phenomena as dayglow and has opened up a wide range of uses. However, at present, it is being discussed only in the context of dayglow measurements.
authors.forename: R
authors.initials: R
authors.lastname: Narayanan
authors.forename: J N
authors.initials: JN
authors.lastname: Desai
authors.forename: N K
authors.initials: NK
authors.lastname: Modi
authors.forename: R
authors.initials: R
authors.lastname: Raghavarao
authors.forename: R
authors.initials: R
authors.lastname: Sridharan