Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
M. Vaccarono; R. Bechini; R. Bechini; C. V. Chandrasekar; R. Cremonini; C. Cassardo (2016)
Publisher: Copernicus Publications
Journal: Atmospheric Measurement Techniques
Languages: English
Types: Article
Subjects: TA170-171, Earthwork. Foundations, Environmental engineering, TA715-787
The stability of weather radar calibration is a mandatory aspect for quantitative applications, such as rainfall estimation, short-term weather prediction and initialization of numerical atmospheric and hydrological models. Over the years, calibration monitoring techniques based on external sources have been developed, specifically calibration using the Sun and calibration based on ground clutter returns. In this paper, these two techniques are integrated and complemented with a self-consistency procedure and an intercalibration technique. The aim of the integrated approach is to implement a robust method for online monitoring, able to detect significant changes in the radar calibration. The physical consistency of polarimetric radar observables is exploited using the self-consistency approach, based on the expected correspondence between dual-polarization power and phase measurements in rain. This technique allows a reference absolute value to be provided for the radar calibration, from which eventual deviations may be detected using the other procedures. In particular, the ground clutter calibration is implemented on both polarization channels (horizontal and vertical) for each radar scan, allowing the polarimetric variables to be monitored and hardware failures to promptly be recognized. The Sun calibration allows monitoring the calibration and sensitivity of the radar receiver, in addition to the antenna pointing accuracy. It is applied using observations collected during the standard operational scans but requires long integration times (several days) in order to accumulate a sufficient amount of useful data. Finally, an intercalibration technique is developed and performed to compare colocated measurements collected in rain by two radars in overlapping regions. The integrated approach is performed on the C-band weather radar network in northwestern Italy, during July–October 2014. The set of methods considered appears suitable to establish an online tool to monitor the stability of the radar calibration with an accuracy of about 2 dB. This is considered adequate to automatically detect any unexpected change in the radar system requiring further data analysis or on-site measurements.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Altube, P., Bech, J., Argemi, P., Rigo, T., and Pineda, N.: Weather radar online Sun-monitoring in presence of leverage outliers: five or three parameter model inversion?, in: ERAD 2014 - The eighth European conference on radar in meteorology and hydrology, 2014.
    • Altube, P., Bech, J., Argemí, O., and Rigo, T.: Quality control of antenna alignment and receiver calibration using the Sun: adaptation to mid range weather radar observations at low elevation angles, J. Atmos. Ocean. Tech., 927-942, 2015.
    • Beard, K. and Chuang, C.: A New Model for the Equilibrium Shape of Raindrops, J. Atmos. Sci., p. 16, 1987.
    • Bechini, R. and Chandrasekar, V.: A Semisupervised Robust Hydrometeor Classification Method for Dual-Polarization Radar Applications, J. Atmos. Ocean. Tech., 32, 22-47, 2015.
    • Bringi, V. N. and Chandrasekar, V.: Polarimetric Doppler Weather Radar, principles and applications, Cambridge University Press, 2001.
    • Bringi, V. N., Chandrasekar, V., Balakrishnan, N., and Zrnic, D. S.: An Examination of Propagation Effects in Rainfall on Radar Measurements at Microwave Frequencies, J. Atmos. Ocean. Tech., 7, 829-840, 1990.
    • Gabella, M., Sartori, M., Boscacci, M., and Germann, U.: Vertical and Horizontal Polarization Observations of Slowly Varying Solar Emissions from Operational Swiss Weather Radars, Atmosphere, 6, 50-59, 2014.
    • Gorgucci, E., Scarchilli, G., and Chandrasekar, V.: Calibration of radars using polarimetric techniques, IEEE T. Geosci. Remote, 30, 853-858, 1992.
    • Gorgucci, E., Scarchilli, G., Chandrasekar, V., and Bringi, V.: Rainfall estimation from polarimetric radar measurements: Composite algorithms immune to variability in raindrop shape-size relation, J. Atmos. Ocean. Tech., 18, 1773-1786, 2001.
    • Holleman, I. and Beekhuis, H.: Weather radar monitoring using the sun, Tech. rep., KNMI Koninklijk Nederlands Meteorologisch Instituut, De Bilt, technical report: TR-272, KNMIAUT2004, ISBN: 9036922615 ISSN: 01691708, 2004.
    • Holleman, I., Huuskonen, I., A., Kurri, M., and Beekhuis, H.: Operational Monitoring of Weather Radar Receiving Chain Using the Sun, J. Atmos. Ocean. Tech., 27, 159-166, 2010a.
    • Holleman, I., Huuskonen, A., Gill, R., and Tabary, P.: Operational monitoring of radar differential reflectivity using the sun, J. Atmos. Ocean. Tech., 27, 881-887, 2010b.
    • Huuskonen, A. and Holleman, I.: Determining weather radar antenna pointing using signals detected from the sun at low antenna elevations, J. Atmos. Ocean. Tech., 24, 476-483, 2007.
    • Huuskonen, A., Kurri, M., Hohti, H., Beekhuis, H., Leijnse, H., and Holleman, I.: Radar performance monitoring using the angular width of the solar image, J. Atmos. Ocean. Tech., 31, 1704-1712, 2014.
    • Joss, J. and Waldvogel, A.: A method to improve the accuracy of radar measured amounts of precipitation, in: 14th Conference on radar meteorology (preprints), 237-238, 1970.
    • Météo France and Emilia Romagna: Evaluation of New Radar Technologies, http://www.eumetnet.eu/opera (last access: 1 November 2016), 2012.
    • OPERA 3-WP1.4b: Project E-NradTech “Evaluation of New Radar Technologies” Subproject 1: Operational monitoring and use of polarimetric C and S-band radars, http://www.eumetnet.eu/sites/default/files/OPERA_2012_ 03_Operational_polarimetry_in_C_and_S_bands.pdf, 2012.
    • Ribaud, J.-F., Bousquet, O., Coquillat, S., Al-Sakka, H., Lambert, D., Ducrocq, V., and Fontaine, E.: Evaluation and application of hydrometeor classification algorithm outputs inferred from multi-frequency dual-polarimetric radar observations collected during HyMeX, Q. J. Roy. Meteor. Soc., 142, 95-107, doi:10.1002/qj.2589, 2015.
    • Rinehart, R. E.: Radar for Meteorologists, Rinehart Publications, 4 edn., 2004.
    • Ryzhkov, A. V., Giangrande, S. E., Melnikov, V. M., and Schuur, T. J.: Calibration issues of dual-polarization radar measurements, J. Atmos. Ocean. Tech., 22, 1138-1155, 2005.
    • Scarchilli, G., Gorgucci, E., Chandrasekar, V., and Dobaie, A.: Selfconsistency of polarization diversity measurement of rainfall, IEEE T. Geosci. Remote Sens., 34, 22-26, 1996.
    • Silberstein, D., Wolff, D., Marks, D., Atlas, D., and Pippit, J.: Ground Clutter as a Monitor of Radar Stability at Kwajalein, RMI, J. Atmos. Ocean. Tech., 25, 2037-2045, 2008.
    • Tapping, K.: Antenna calibration using the 10.7 cm solar flux, in: Workshop on Radar Calibration, Albuquerque, NM, 2001a.
    • Tapping, K.: Antenna Calibration Using the 10.7cm Solar Flux, in: Workshop on Radar Calibration, Abuquerque, AMS, 2001b.
    • Testud, J., Bouar, E. L., Obligis, E., and Ali-Mehenni, M.: The rain profiling algorithm applied to polarimetric weather radar, J. Atmos. Ocean. Tech., 17, 332-356, 2000.
    • Ulbrich, C. W.: Natural variations in the analytical form of the raindrop size distribution, J. Clim. Appl. Meteorol., 22, 1764-1775, 1983.
    • Vukovic, Z., Young, J. M., and Donaldson, N.: Inter-radar comparison accounting for partially overlapping volumes, ERAD, 2014.
    • Wang, Y. and Chandrasekar, V.: Algorithm for estimation of the specific differential phase, J. Atmos. Ocean. Technol., 26, 2565- 2578, 2009.
    • Whiton, R. C., Smith, P. L., and Harbuck, A. C.: Calibration of weather radar systems using the sun as a radio source, in: 17th Conference on Radar Meteorology, 60-65, 1976.
    • Wolff, D. B., Marks, D. A., and Petersen, W. A.: General Application of the Relative Calibration Adjustment (RCA) Technique for Monitoring and Correcting Radar Reflectivity Calibration, J. Atmos. Ocean. Tech., 32, 496-506, 2015.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article