Modern polarimetric radars offer enhanced capabilities for rain attenuation correction, rain rate... more Modern polarimetric radars offer enhanced capabilities for rain attenuation correction, rain rate estimation and precipitation classification
1. INTRODUCTION Modern Doppler weather radars are using digital receivers (DRX). The received sig... more 1. INTRODUCTION Modern Doppler weather radars are using digital receivers (DRX). The received signals are digitized at an intermediate (IF) frequency which avoids analog downconversion to baseband. A DRX has a linear characteristic which makes accurate calibration easy. An increasing number of weather radar systems are calibrated with rain sensors, see e.g. Joss (1995). The rain sensor provides only data from its particular location a linear receiver is required to transform the local calibration to the whole radar coverage with significantly varying rain rates. Even polarimetric radars which are capable to compensate the most prominent measurement errors of weather radars, rain attenuation and Z/R-relation, require sensor calibration and thus a linear receiver to bring their advantages to bear. However the most important calibration is still the accurate determination of the radar constant together with the periodic calibration of the receiver. A linear receiver makes calibration e...
This paper presents a network of inexpensive incoherent X-band radars scanning fast and a low ele... more This paper presents a network of inexpensive incoherent X-band radars scanning fast and a low elevation angle to provide high resolution rainfall estimate. Networking of X-band radars (non necessarily dual-polarized) has been the subject of many publications in the recent years. To publish a new paper on this subject, very innovative contents must be provided. In this paper some techniques adopted in a network of
VDI 3786 Part 20:2013-08 (DRAFT) Environmental meteorology - Ground-based remote sensing of precipitation - Weather radar
The draft standard specifies the monitoring of the atmosphere with ground based precipitation rad... more The draft standard specifies the monitoring of the atmosphere with ground based precipitation radar systems with wavelengths between 3 cm and 10 cm. The mainly used area of application is the quantitative determination of precipitation. An area-wide coverage of precipitation zones produces a variety of important applications. Many professional operators use radar data and set a high value on the detailed quantitative coverage. Because of this, the draft standard does not only specify the measurement technique but also the process steps of data preparation for the different applications.
The calibration and the validation or verification of the calibration of weather radar systems is... more The calibration and the validation or verification of the calibration of weather radar systems is a permanent subject of research and development. Since there is no “reference rain” a weather radar must be calibrated indirectly. Two methods are used so far: the ground truth method and the engineering calibration. The ground truth method uses an accurate ground sensor like a disdrometer (e.g. Thurai 2008) and relates the measurement of this sensor to the radar measurement of the volume above the sensor. The results presented in this paper are related to the engineering calibration method. This method is based on the calibration of factors representing the features of radar subsystems in the meteorological radar equation. (Gekat 2010). Since the accuracy of the calibration can be improved if as many factors as possible are calibrated as a product with one measurement (provided that the accuracy of this measurement is at least as accurate as the accuracy of the individual calibration o...
Uploads
Papers by Frank Gekat