Power calibration of VHF Stratospheric-Tropospheric radars

Radar calibration is a central issue that must be addressed before attempting any quantitative interpretation of precipitation radar measurements in the VHF band. Therefore, this study presents a method for the calibration of VHF Stratosphere-Troposphere (ST) radars. Combining previous applications of noise-generator hardware and surveys of VHF emissions from the stars, this method allows a correct measurement of the received power (by converting the arbitrary units of the Analog-to-Digital-Converter into Watts). Derivations of particular antenna and receiver parameters, such as efficiency and noise, as well as their corresponding errors, are also provided. An expression to obtain calibrated power densities is given as well. The calibration method is applied to McGill VHF radar measurements, which thus gives the hardware parameters for this particular site at Montreal, Canada. An example of calibrated Doppler spectra in rain is also discussed, which shows the application of this method towards cloud physics research.