Description
In recent years novel, inexpensive high resolution weather radar (HRWR) systems have been developed, which can scan precipitation with spatial and temporal resolution of 60 m and 30 s respectively. Such precise information on precipitation is valuable both for research applications in hydrology, land-atmosphere exchange etc. and for operational use in flash flood warning systems. HRWR systems operate in the X-band frequency range which is affected by attenuation of the radar beam. Overlapping networks of HRWRs allow for a determination and correction of attenuation. Since precipitation rate and attenuation are closely correlated, the retrieved attenuation improves additionally the precipitation estimates. This project aims at a comprehensive evaluation of this novel technology and intends to provide a reliable proof of concept. Research goals and scientific questions in detail:
- Generation of multi-year data set of a real HRWR network consisting of four radars.
- Development and improvement of networked radar retrieval algorithms
- Accuracy of network retrieval algorithm in practice
- Exploring a novel absolute radar calibration procedure
- Assessment of the potential of HRWR on local and regional scales by a comprehensive intercomparison with other radar products and by simulation of regional HRWR studies in observation systems simulation experiment (OSSE).
- The obtained high resolution precipitation data will be used for model validation within the project
HD(CP)² - O3 Integration
For more information go to 
pattern.zmaw.de
Technology
The HRWR was developed in the frame of a cooperation project with the University Clermont Ferrand. It is based on a nautical radar type with 25kW transmit power. The original fan beam antenna was replaced by a pencil beam antenna (offset parabol with low side lobes, 0.85 m diameter). The radar has been operated since 2006 successfully in continuous mode as well as in measuring campaigns including LAUNCH and COPS.
Field Campaign
Four X-band High Resolution Weather Radars (HRWR) were installed as a network in the region around Itzehoe north of Hamburg. Neighbouring radars are at least 11 km apart, but not more than 16 km and cover an area of approximately 60 km x 80 km. Most parts of the area are covered by more than one radar and the centre of the network is covered by all four radars. At each radar site a vertically pointing Micro-Rain Radar (MRR) has been positioned for testing the callibration procedure of the radar network. Additionally, three rain stations, each consisting of a MRR, a rain gauge and a wind sensor, were installed in the centre of the network. The radar at the location 'Hungriger Wolf' is operational since June 2011. The locations 'Moordorf', 'Quarnstedt' and 'Bekmünde' are operational since January 2012. A fifth radar ('Hamburg') will be installed on the roof of the Meteorological Institute of the University of Hamburg soon as an additional location.
Within the framework of the PATTERN project a setup including three micro-rain-radars (MRR) has been build up near the DWD Observatory Lindenberg. Two MRRs directed toward eachother are measuring horizontally on a 6km long distance. This simplified, one-dimensional setup allows to analyse and improve retreavals without the additional difficulties of a two-dimensional network. The data from both horizontally oriented MRRs is used to investigate the attenuation correction. MRRs are convenient for this purpose because of the strong attenuation in the k-band region. In addition to that a method for the absolute calibration of radars in a network shall be tested by means of the verically oriented MRR.
Publications
- Lengfeld, K., Clemens, M., Feiertag, N. and F. Ament (2012): Precipitation and Attenuation Estimates from a High Resolution Weather Radar Network (PATTERN) – Design of the Experiment., Proceedings of ERAD 2012, Seventh European Conference on Radar Meteorology and Hydrology (ERAD), Toulouse, France,download
Contact
Dr. Katharina Lengfeld
| Dr. Marco Clemens
| |
Nicole Feiertag
| Claire Merker
|
katharina.lengfeld(at)zmaw.de