The Doppler radar works by measuring an energy emission. It could be sound, light, UV, or whatever. By continually measuring over time, it can sense the change in frequency or wavelength of the energy wave. The changes in these two aspects allow the radar to figure out change in position and velocity. The basic principle is known as the Doppler shift. You can find several articles on the web, but I can't recommend one because they're all written at varying levels of academia.- The radar may help determine what type of threat that may be developing near his large farm. Example: Are the storms developing near his farm appeared to be organized in a group, cluster, or line. Or do the storms appeared on radar to be the usual afternoon 'pulse convective" widely scattered or isolated convective thunderstorms. If the storms appeared to be part of an organized system, the farmer can get the word out quickly for all those who are working on his farm and direct them to a safe shelters until the threat ends. Golf Course - With any threat of thunderstorms nearby, a golf course manager will have to determine whether to shut down operations in which his business may suffer a significant loss of revenue during that period of time.