Improved Micro Rain Radar snow measurements using Doppler spectra post-processing

Abstract

Abstract. The Micro Rain Radar 2 (MRR) is a compact Frequency Modulated Continuous Wave (FMCW) system that operates at 24 GHz. The MRR is a low-cost, portable radar system that requires minimum supervision in the field. As such, the MRR is a frequently used radar system for conducting precipitation research. Current MRR drawbacks are the lack of a sophisticated post-processing algorithm to improve its sensitivity (currently at +3 dBz), spurious artefacts concerning radar receiver noise and the lack of high quality Doppler radar moments. Here we propose an improved processing method which is especially suited for snow observations and provides reliable values of effective reflectivity, Doppler velocity and spectral width. The proposed method is freely available on the web and features a noise removal based on recognition of the most significant peak. A dynamic dealiasing routine allows observations even if the Nyquist velocity range is exceeded. Collocated observations over 115 days of a MRR and a pulsed 35.2 GHz MIRA35 cloud radar show a very high agreement for the proposed method for snow, if reflectivities are larger than −5 dBz. The overall sensitivity is increased to −14 and −8 dBz, depending on range. The proposed method exploits the full potential of MRR's hardware and substantially enhances the use of Micro Rain Radar for studies of solid precipitation.

Blowing snow detection from ground-based ceilometers: application to East Antarctica

“…The raw Doppler spectra is post-processed following Maahn and Kollias (2012) to calculate radar reflectivity profiles which are then linked to snowfall rates using the newly developed ZeSr relation for PE by Souverijns et al (2017). A full description of MRRs can be found in Klugmann et al (1996) and the radar set up at PE is described in Gorodetskaya et al (2015).…”

Measurements of precipitation in Dumont d'Urville, Adélie Land, East Antarctica

“…4 (whose standard deviation of the residuals is 1.9 dB). It is worth mentioning that Z K is originally obtained with the method of Maahn and Kollias (2012), who proposed an improved and innovative processing chain for MRR data collected in snow. Once mapped to X-band, reflectivity can be converted to snowfall rate S rate by means of Z-S power laws available in the literature.…”

“…The simplicity of its deployment and operation makes it an attractive tool for long-term measurements in places with complex logistics and with limited possibility of support, in the case of instrumental failures. The raw K-band reflectivity measurements collected by the MRR were first processed with the method proposed by Maahn and Kollias (2012), then converted to X-band reflectivities and in a third step to snowfall intensities. Additional information about the processing of the MRR data is provided in Sect.…”

Orientations and aspect ratios of falling snow

“…Data quality and sensitivity were improved using the methods of Maahn and Kollias [2012]. The minimum detectable echo of the MRR is approximately −5 dBZ.…”