This document describes the hardware, software, and operation, of a radio/computer system for monitoring meteor activity. The radio receiver is tuned to the frequency of a television video carrier whose transmitter is located beyond the local horizon. The system normally registers only a weak signal. However when a meteor enters the atmosphere and creates an ion trail at an intermediate point between the transmitter and the receiver, more power can be reflected to the receiver.
The radio's automatic gain control voltage is sampled by a personal computer through an analog-to-digital board. The computer program is alerted to a possible meteor when the signal level jumps by a few decibels in a small fraction of a second.
Signal enhancement has been used on similar systems in the past. However, such an increase can also be triggered by lightning, electrical switching, and other forms of noise. In order to distinguish between meteors and false alerts, the system described here also samples the receiver's audio output. A meteor echo is identified by increased audio signal autocorrelation, while electrical noise is recognized by a decreased correlation.
The first data acquired from this system demonstrate the expected diurnal variation of meteor counts, where those sampled in the morning hours exceed those taken in the evening hours.