Introduction to Profilers

• Profilers use the same principles and theory as Doppler radars (such as the 88-D) to derive information about the atmosphere.  
• The primary difference between profilers and Doppler radars is that the wavelength for profilers is much longer.  
• Hence, profilers should be much more sensitive to clear-air echoes created by Bragg scattering.  Recall that the radar reflectivity is proportional to 1/l ^1/3 for Bragg scattering.  

Historically, two types of profilers have been typically used for research and operational purposes.  They are:

1. UHF profilers (300-3000 Mhz)

2. VHF profilers (30-300 Mhz)

• The VHF profilers were those that comprised the now decommissioned Wind Profiler Demonstration Network located primarily over the midwest and Great plains region of the US.  
• The UHF profilers are located all over the country and are primarily used in boundary layer studies.