The red banner of the communists, the black-white-red of the Second Reich, and the new swastika flag of the Nazis all contended for allegiance. From 1933 to 1945 the Nazi symbols were dominant. The Federal Republic of Germany (West Germany) restored the old black-red-yellow flag on May 9, 1949, and the government made use of a similar flag with the eagle shield in the centre.
S band radars operate on a wavelength of 8-15 cm and a frequency of 2-4 GHz. Because of the wavelength and frequency, S band radars are not easily attenuated. This makes them useful for near and far range weather observation. The National Weather Service (NWS) uses S band radars on a wavelength of just over 10 cm. The drawback to this band of radar is that it requires a large antenna dish and a large motor to power it. It is not uncommon for a S band dish to exceed 25 feet in size. C band radars operate on a wavelength of 4-8 cm and a frequency of 4-8 GHz.
Second generation NEXRAD radar systems will have the capability to optically detect hailstone size down to the square mile. Base Reflectivity Base Reflectivity is a measure of the intensity of precipitation occurring, and is reported in units of DBZ. The WSR-88D emits pulses of energy into the atmosphere at regular intervals. When this energy impacts something (i.e. a raindrop, a snowflake, a mountain, etc.), some of the energy is scattered back to the radar dish. NEXRAD base reflectivity data are updated every 5, 6, or 10 minutes, depending on whether the radar is in normal precipitation mode, storm precipitation mode, or clear air mode.