A Data Acquisition System for a Coarse Optical Power Spectrum Estimator.

Abstract : The system consists of the detector, an electronic sub-system and software for a NOVA 1200 mini-computer and Xerox Sigma 9 computer using nine track magnetic tape. The user has a choice of several gains and biases, log or linear mode of operation, automatic or manual sampling and a variable sampling frequency. The signals coming from the 64 photo-diodes in the detector are first multiplexed onto one channel. The multiplexed signal is amplified, biassed and amplified again before it is sampled and digitized. The digital samples are then stored on the magnetic tape for later processing. The major components of the system are described below. The implementation of the system to estimate optical power spectra will be reported in subsequent publications.