FM Multi-Path Cancellation

Cancellation can be defined as follows:
^ It is caused by the line-of-sight characteristic and exists when the radio waves are reflected from objects or structures.
^ The noise produced by cancellation is similar to flutter, with the addition of distortion in the program.
^ A more familiar description of cancellation is its similarity to the multiple ghosts and picture jumping that occurs on television when a low flying plane passes. The same condition exists in the vehicle, except that the vehicle is moving and the reflecting structure is stationary. The reflected signal cancels the normal signal, causing the antenna to pick up noise and distortion.
^ Cancellation effects are most prominent in metropolitan areas, but can also become quite severe in hilly terrain and depressed roadways.