Daily measurements of wind temperature radar (WTR) from 20070607 to 20070825 with some gaps. See more information on measurement times in entry "cops_sups_wtrad_info_1". Spatial granulartity varies from 100m to 60m, mostly 75m. Quality flags of wind and temperature range from 0 to 1 (0=worst 1=best). Instrument was located at Deckenpfronn, COPS-SuperSite Stuttgart, Germany. Eastward_wind, northward_wind, upward_air_velocity, quality of wind, radar_reflectivity, virtual_temperature, quality of air temperature are archived.
The WTR operates in two modes: the RASS-mode and the clear-air-mode. In the RASS-mode the WTR records the air temperature by detecting the propagation of sound pulses.
In the clear-air-mode the WTR observes the electro-magnetic refractive index, which in contrast to its acoustic counter part is mainly dominated by moisture fluctuations but much less by temperature fluctuations.
The WTR has a five-beam geometry with two bistatic radiofrequency (rf) and one acoustic (ac) antenna. The rf antenna emits continuous waves that are frequency shifted with a saw tooth modulation (FM-CW Doppler Radar) in order to provide high average transmitted power as well as a fine range gate resolution. Contrary to a pulsed Radar the height resolution
is not calculated by means of the travel time of the rf waves but is proportional to the frequency shift between the transmitted and received signal.
From the Doppler effect induced difference between the frequency of the emitted and received radiation radial velocities are derived. Physical meaning of the velocity measured depends on the effective scattering mechanism:
a) Scattering on microturbulent refraction index fluctuations. The 3D-velocity derived from radial velocities is to be equaled to the mean wind velocity in the scattering volume.
b) Scattering on hydrometeors. In case of vertical beam direction, dropping of hydrometeors is measured.
c) Scattering on artificially generated acoustic waves (RASS).