Dust particles are not homogeneously spread over our Solar System, because they are often associated with an ancient comet, fallen into debris. Such a dusty region causes enhanced meteor activity, called a "meteor shower". Famous meteor showers are the Perseids (in August), the Geminids (in December), etc. Knowledge of these meteor showers, together with their intensity and duration, allows one to obtain additional information about the dust distribution in our Solar System.
Unfortunately, peaks in the signal strength of the receiver can also be caused by local interference sources, such as PC's, ingition motors, lightnings, etc. Therefore, it is of the utmost importance to incorporate a control mechanism. To this end, a second setup is used which is tuned on a nearby but unused frequency. Meteor reflections will only influence the first station (which is tuned to the distant transmitter). On the other hand, peaks which simultaneously ocurr in the signal strength of both setups must be considered as local interference (which is broadbanded).
A radio setup can be used during the day as well as during the night, and is not influenced by the presence of clouds. Therefore, it is of great value for long-time monitoring projects, particularly because the system is completely automated.
This picture shows a typical observation of the hourly meteor rate during the period 01/01/95 to 16/01/95. On the 3th of January, enhanced activity, due to the presence of the Bootide meteor shower, is clearly visible. The strong daily variation (with a maximum at 6h UT and a minimum at 18hUT) is called apex effect, and is caused by the rotation of the Earth around the Sun.