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

2012 ◽  
Vol 5 (11) ◽  
pp. 2661-2673 ◽  
Author(s):  
M. Maahn ◽  
P. Kollias
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Low Cost ◽  
Spectral Width ◽  
Noise Removal ◽  
Radar System ◽  
Doppler Velocity ◽  
Full Potential ◽  
Post Processing ◽  
Rain Radar

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.

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

2012 ◽  
Vol 5 (4) ◽  
pp. 4771-4808 ◽  
Author(s):  
M. Maahn ◽  
P. Kollias
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Low Cost ◽  
Spectral Width ◽  
Noise Removal ◽  
Radar System ◽  
Doppler Velocity ◽  
Full Potential ◽  
Post Processing ◽  
Rain Radar

Abstract. The Micro Rain Radar (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 at 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.

scholarly journals ERUO: a spectral processing routine for the MRR-PRO

2021 ◽  
Author(s):  
Alfonso Ferrone ◽  
Anne-Claire Marie Billault-Roux ◽  
Alexis Berne
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Doppler Spectrum ◽  
Doppler Velocity ◽  
Spectral Processing ◽  
W Band ◽  
X Band ◽  
Radar Information ◽  
Rain Radar

Abstract. The Micro Rain Radar (MRR) PRO is a K-band Doppler weather radar, using frequency modulated continuous wave (FMCW) signals, developed by Metek Meteorologische Messtechnik GmbH (Metek) as successor to the MRR-2. Benefiting from four datasets collected during two field campaigns in Antarctica and Switzerland, we developed a processing library for snowfall measurements, named ERUO (Enhancement and Reconstruction of the spectrUm for the MRR-PRO), with a two-fold objective. Firstly, the proposed method addresses a series of issues plaguing the radar variables, which include interference lines, power drops at the extremes of the Doppler spectrum and abrupt cutoff of the transfer function. Secondly, the algorithm aims to improve the quality of the final variables, by lowering the minimum detectable equivalent attenuated reflectivity factor and extending the valid Doppler velocity range through antialiasing. The performance of the algorithm has been tested against the measurements of a co-located W-band Doppler radar. Information from a close-by X-Band Doppler dual-polarization radar has been used to exclude unsuitable radar volumes from the comparison. Particular attention has been dedicated to verify the estimation of the meteorological signal in the spectra covered by interferences.

Concept and realization of a low-cost multi-target simulator for CW and FMCW radar system calibration and testing

2018 ◽  
Vol 10 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Werner Scheiblhofer ◽  
Reinhard Feger ◽  
Andreas Haderer ◽  
Andreas Stelzer
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Dynamic Range ◽  
Low Cost ◽  
Intermediate Frequency ◽  
Radar System ◽  
Fmcw Radar ◽  
Radar Systems ◽  
Single Target ◽  
Wave Radar

AbstractWe present the realization of an frequency-modulated continuous-wave radar target simulator, based on a modulated-reflector radar system. The simulator, designed for the 24 GHz frequency band, uses low-cost modulated-reflector nodes and is capable to simultaneously generate multiple targets in a real-time environment. The realization is based on a modular approach and thus provides a high scalability of the whole system. It is demonstrated that the concept is able to simulate multiple artificial targets, located at user-selectable ranges and even velocities, utilized within a completely static setup. The characterization of the developed hardware shows that the proposed concept allows to dynamically and precisely adjust the radar cross-section of each single target within a dynamic range of 50 dB. Additionally, the provided range-proportional target frequency bandwidth makes the system perfectly suitable for fast and reliable intermediate frequency-chain calibration of multi-channel radar systems. Within this paper we demonstrate the application of the concept for a linear sweeped frequency-modulated continuous-wave radar. The presented approach is applicable to any microwave-based measurement system using frequency differences between transmit- and receive signals for range- and velocity evaluation, such as (non-)linear sweeped as well as pure Doppler radar systems.

scholarly journals Design of a Wearable, Low-Cost, Through-Wall Doppler Radar System

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Sam Agneessens ◽  
Patrick Van Torre ◽  
Frederick Declercq ◽  
Bart Spinnewyn ◽  
Gert-Jan Stockman ◽  
...  
Keyword(s):  
Moving Objects ◽  
Doppler Radar ◽  
Noise Figure ◽  
Low Cost ◽  
Axial Ratio ◽  
Low Complexity ◽  
Radar System ◽  
Indoor Environments ◽  
Textile Materials ◽  
Low Weight

A novel, low-cost, low-weight, wearable Doppler radar system composed of textile materials and capable of detecting moving objects behind a barrier is presented. The system operates at 2.35 GHz and is integrable into garments, making it well-suited for usage in difficult to access terrain, such as disaster areas or burning buildings. Wearability is maximized by relying on flexible, low-weight, and breathable materials to manufacture the key parts of the system. The low-complexity Doppler radar system makes use of an array of four textile-transmit antennas to scan the surroundings. The beam emitted by this array is right-hand circularly polarized along all scanning angles and provides a measured gain of 9.2 dBi. At the receiving end, textile materials are used to develop an active wearable receive antenna, with 15.7 dBi gain, 1.1 dB noise figure, left-hand circular polarization, and a 3 dB axial ratio beamwidth larger than 50°. Several measurement setups demonstrate that the onbody system is capable of detecting multiple moving subjects in indoor environments, including through-wall scenarios.

scholarly journals EUREC<sup>4</sup>A's Maria S. Merian ship-based cloud and micro rain radar observations of clouds and precipitation

2021 ◽  
Author(s):  
Claudia Acquistapace ◽  
Richard Coulter ◽  
Susanne Crewell ◽  
Albert Garcia-Benadi ◽  
Rosa T. Gierens ◽  
...  
Keyword(s):  
Spectral Width ◽  
Trade Wind ◽  
Doppler Velocity ◽  
Ship Motions ◽  
High Temporal Resolution ◽  
Liquid Water Path ◽  
W Band ◽  
Online Book ◽  
The Impact ◽  
Rain Radar

Abstract. As part of the EUREC4A field campaign, the research vessel Maria S. Merian probed an oceanic region between 6° N and 13.8° N and 51° W to 60° W for approximately 32 days. Trade wind cumulus clouds were sampled in the trade-wind alley region east of Barbados as well as in the transition region between the trades and the intertropical convergence zone, where the ship crossed some mesoscale oceanic eddies. We collected continuous observations of cloud and precipitation profiles at unprecedented vertical resolution (7–10 m in the first 3000 m) and high temporal resolution (1–3 s) using a W-band radar and micro-rain radar (MRR-PRO), installed on an active stabilization platform to reduce the impact of ship motions on the observations. The paper describes the ship motion correction algorithm applied to the Doppler observations to extract corrected hydrometeors vertical velocities and the algorithm created to filter interference patterns in the MRR-PRO observations. Radar reflectivity, mean Doppler velocity, spectral width and skewness for W-band and attenuated reflectivity, mean Doppler velocity and rain rate for MRR-PRO are shown for a case study to demonstrate the potential of the high resolution adopted. As non-standard analysis, we also retrieved and provided liquid water path (LWP) from the 89 GHz passive channel available on the W-band radar system. All datasets and hourly and daily quicklooks are publically available. Data can be accessed and basic variables can be plotted online via the intake catalog of the online book "How to EUREC4A".

scholarly journals Detecting the Melting Layer with a Micro Rain Radar Using a Neural Network Approach

2019 ◽  
Author(s):  
Maren Brast ◽  
Piet Markmann
Keyword(s):  
Neural Network ◽  
Continuous Wave ◽  
Radiosonde Data ◽  
Doppler Velocity ◽  
Neural Network Approach ◽  
Layer Height ◽  
Melting Layer ◽  
The Neural Network ◽  
Wave Radar ◽  
Rain Radar

Abstract. A new method using the Micro Rain Radar (MRR) to determine the melting layer height is presented. The MRR is a small vertically pointing frequency modulated continuous wave radar which measures Doppler spectra of precipitation. From these Doppler spectra, various variables such as Doppler velocity or spectral width can be derived. The melting layer is visible through a higher reflectivity and an acceleration of the falling particles, among others. These characteristics are fed to a neural network to determine the melting layer height. For the training of the neural network, the melting layer height is determined manually. The neural network is trained and tested using data from two sites covering all seasons. For most cases, it is well able to detect the correct melting layer height. Sensitivity studies show that the neural network is able to handle different settings of the MRR. Comparisons to radiosonde data and cloud radar data show a good agreement in melting layer heights.

scholarly journals Educational Low-Cost C-Band FMCW Radar System Comprising Commercial Off-the-Shelf Components for Indoor Through-Wall Object Detection

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2758
Author(s):  
Hyunmin Jeong ◽  
Sangkil Kim
Keyword(s):  
Continuous Wave ◽  
Low Cost ◽  
Low Noise ◽  
Radar System ◽  
Indoor Environments ◽  
Voltage Controlled Oscillator ◽  
Band Frequency ◽  
Fmcw Radar ◽  
Sensing Applications ◽  
Commercial Off The Shelf

This paper presents an educational low-cost C-band frequency-modulated continuous wave (FMCW) radar system for use in indoor through-wall metal detection. Indoor remote-sensing applications, such as through-wall detection and positioning, are essential for the comprehensive realization of the internet of things or super-connected societies. The proposed system comprises a two-stage radio-frequency power amplifier, a voltage-controlled oscillator, circuits for frequency modulation and system synchronization, a mixer, a 3-dB power divider, a low-noise amplifier, and two cylindrical horn antennas (Tx/Rx antennas). The antenna yields gain values in the 6.8~7.8 range when operating in the 5.83~5.94 GHz frequency band. The backscattered Tx signal is sampled at 4.5 kHz using the Arduino UNO analog-to-digital converter. Thereafter, the sampled signal is transferred to the MATLAB platform and analyzed using a customized FMCW radar algorithm. The proposed system is built using commercial off-the-shelf components, and it can detect targets within a 56.3 m radius in indoor environments. In this study, the system could successfully detect targets through a 4 cm-thick ply board with a measurement accuracy of less than 10 cm.

scholarly journals EUREC<sup>4</sup>A's <i>Maria S. Merian</i> ship-based cloud and micro rain radar observations of clouds and precipitation

2022 ◽  
Vol 14 (1) ◽  
pp. 33-55
Author(s):  
Claudia Acquistapace ◽  
Richard Coulter ◽  
Susanne Crewell ◽  
Albert Garcia-Benadi ◽  
Rosa Gierens ◽  
...  
Keyword(s):  
Spectral Width ◽  
Data Availability ◽  
Trade Wind ◽  
Doppler Velocity ◽  
Ship Motions ◽  
High Temporal Resolution ◽  
Liquid Water Path ◽  
W Band ◽  
The Impact ◽  
Rain Radar

Abstract. As part of the EUREC4A field campaign, the research vessel Maria S. Merian probed an oceanic region between 6 to 13.8∘ N and 51 to 60∘ W for approximately 32 d. Trade wind cumulus clouds were sampled in the trade wind alley region east of Barbados as well as in the transition region between the trades and the intertropical convergence zone, where the ship crossed some mesoscale oceanic eddies. We collected continuous observations of cloud and precipitation profiles at unprecedented vertical resolution (7–10 m in the first 3000 m) and high temporal resolution (1–3 s) using a W-band radar and micro rain radar (MRR), installed on an active stabilization platform to reduce the impact of ship motions on the observations. The paper describes the ship motion correction algorithm applied to the Doppler observations to extract corrected hydrometeor vertical velocities and the algorithm created to filter interference patterns in the MRR observations. Radar reflectivity, mean Doppler velocity, spectral width and skewness for W-band and reflectivity, mean Doppler velocity, and rain rate for MRR are shown for a case study to demonstrate the potential of the high resolution adopted. As non-standard analysis, we also retrieved and provided liquid water path (LWP) from the 89 GHz passive channel available on the W-band radar system. All datasets and hourly and daily quicklooks are publically available, and DOIs can be found in the data availability section of this publication. Data can be accessed and basic variables can be plotted online via the intake catalog of the online book “How to EUREC4A”.

scholarly journals Detecting the melting layer with a micro rain radar using a neural network approach

2020 ◽  
Vol 13 (12) ◽  
pp. 6645-6656
Author(s):  
Maren Brast ◽  
Piet Markmann
Keyword(s):  
Neural Network ◽  
Continuous Wave ◽  
Radiosonde Data ◽  
Doppler Velocity ◽  
Neural Network Approach ◽  
Layer Height ◽  
Melting Layer ◽  
The Neural Network ◽  
Wave Radar ◽  
Rain Radar

Abstract. A new method to determine the melting layer height using a micro rain radar (MRR) is presented. The MRR is a small vertically pointing frequency-modulated continuous-wave radar that measures Doppler spectra of precipitation. From these Doppler spectra, various variables such as Doppler velocity or spectral width can be derived. The melting layer is visible due to higher reflectivity and an acceleration of the falling particles, among others. These characteristics are fed to a neural network to determine the melting layer height. To train the neural network, the melting layer height is determined manually. The neural network is trained and tested using data from two sites that cover all seasons. For most cases, the neural network is able to detect the correct melting layer height well. Sensitivity studies show that the neural network is able to handle different MRR settings. Comparisons to radiosonde data and cloud radar data show a good agreement with respect to the melting layer heights.

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