Raw Data Digitizing and Recording System for the Omega-Sonde Wind Finding Ground Station

This paper describes a low cost Omega-sonde data acquisition system consisting of a portable shipboard raw data recording package and a minicomputer interface used in the data reconstruction. The Omega phase is detected against a crystal controlled reference signal. The detected relative phase is recorded in digital form using timing signals controlled by the same crystal oscillator. The meteorological information is recorded in analog form. The data are stored on two-track audio tape cassettes which are processed via the interface and a minicomputer to yield IBM compatible computer tapes. The interface converts both the phase and the meteorological data to parallel-bit format. The recorded meteorological data (frequency) is counted and digitized using a clock signal which is phase-locked to the recorded phase data timing signal. The effects of tape wow and flutter on the meteorological data are thus reduced considerably. Samples of recovered phase and meteorological data are included.