An Analog and Digital Airborne Data Acquisition System

Abstract

A highly flexible analog and digital airborne data acquisition system has been designed and developed by Radiation, Inc., for the General Electric Company Flight Test Facility at Edwards Air Force Base, Calif. The acquired data is recorded on one-inch tape. The format may be fourteen tracks of analog or seven tracks of analog with sixteen tracks of digital data. Ampex AR-200 equipment is used on the analog subsystem. Complete analog system reference data are recorded on one track. The digital system has extreme flexibility. From ten to ninety channels may be programmed for individual word rates of from 1.25 samples per second to 2×103 samples per second. System word rates are 20 kc, 10 kc, 5 kc, and 2.5 kc. The analog-to-digital converter performs up to 2×104 conversions per second, depending on the selected sampling rate of the multiplexer. Time-history and system marker data are also recorded. Provision for acceptance of Gray code digital input data has been made. The input on any channel may be lowlevel (±10 mv full scale) or high-level (±5 volts full scale). Signal conditioning and automatic calibration are provided. Multiplexer channel capacity can be extended by the addition of more modules. Flexibility of programmiang is provided with pluggable program boards. The system is designed using all transistorized components and is constructed to withstand vehicular environmental extremes. Detailed descriptions of the low-level gate circuit, programming, accumulating, and coding techniques are made.