High Speed Data Acquisition System: Burst-Type Phenomena With Wait Periods inBetween

摘要

In some aerospace applications data periodically occurs in short bursts. Highfrequency content data can be digitized and prepared for transmission at a much lower bit rate during the intervals between bursts. The analog burst signal is digitized by a high-speed analog-to-digital converter to produce binary words which are stored in a FIFO memory along with synchronization words which mark the beginning of every new frame. The stored words are then converted into a serial bit stream during the wait periods and put into a PCM format for transmission to the ground. In this thesis, the system is tested with a data collection period of 16.0 usec and a wait period of 5.136 msec. A commercial converter is used to sample at 20 MHz and produce 10-bit words which are read out at a 62.5 kilo word per second rate. Experimentally, it was found that the system developed provided accuracy with 1.2% error for signal with fast rise and fall times, signals with slow rise and fall times, e(-t)/T wave-functions, and pseudo-random signals.