Articles | Volume 10, issue 1
https://doi.org/10.5194/amt-10-15-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/amt-10-15-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
03 Jan 2017
Research article |
| 03 Jan 2017
Open-loop GPS signal tracking at low elevation angles from a ground-based observation site
GFZ German Research Centre for Geosciences, Potsdam, Germany
Florian Zus
GFZ German Research Centre for Geosciences, Potsdam, Germany
Related authors
F. Zus, G. Beyerle, S. Heise, T. Schmidt, and J. Wickert
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amtd-7-12719-2014, https://doi.org/10.5194/amtd-7-12719-2014, 2014
Preprint withdrawn
Florian Zus, Kyriakos Balidakis, Ali Hasan Dogan, Rohith Thundathil, Galina Dick, and Jens Wickert
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2024-237, https://doi.org/10.5194/gmd-2024-237, 2025
Revised manuscript accepted for GMD
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Atmospheric signal propagation effects are one of the largest error sources in the analysis of space geodetic techniques. Inaccuracies in the modelling map into errors in positioning, navigation and timing. We describe the open source ray tracing tool DNS and show the two outstanding features of this tool compared to previous model developments: it can handle both the troposphere and the ionosphere and it does so efficiently. This makes the tool perfectly suited for geoscientific applications.
Rohith Thundathil, Florian Zus, Galina Dick, and Jens Wickert
EGUsphere, https://doi.org/10.5194/egusphere-2025-19, https://doi.org/10.5194/egusphere-2025-19, 2025
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Tropospheric gradients provide information on the moisture distribution, whereas ZTDs provide the absolute amount of moisture through integrated water vapor. When TGs are assimilated with ZTDs, it helps the model actuate the moisture fields, correcting its dynamics. In our research, we show evidence that in particular regions with very few GNSS stations, the assimilation of gradients on top of ZTDs can provide the same impact as the assimilation of only ZTDs with dense coverage of GNSS stations.
Rohith Thundathil, Florian Zus, Galina Dick, and Jens Wickert
Geosci. Model Dev., 17, 3599–3616, https://doi.org/10.5194/gmd-17-3599-2024, https://doi.org/10.5194/gmd-17-3599-2024, 2024
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Global Navigation Satellite Systems (GNSS) provides moisture observations through its densely distributed ground station network. In this research, we assimilate a new type of observation called tropospheric gradient observations, which has never been incorporated into a weather model. We develop a forward operator for gradient-based observations and conduct an assimilation impact study. The study shows significant improvements in the model's humidity fields.
Karina Wilgan, Galina Dick, Florian Zus, and Jens Wickert
Atmos. Meas. Tech., 15, 21–39, https://doi.org/10.5194/amt-15-21-2022, https://doi.org/10.5194/amt-15-21-2022, 2022
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The assimilation of GNSS data in weather models has a positive impact on the forecasts. The impact is still limited due to using only the GPS zenith direction parameters. We calculate and validate more advanced tropospheric products from three satellite systems: the US American GPS, Russian GLONASS and European Galileo. The quality of all the solutions is comparable; however, combining more GNSS systems enhances the observations' geometry and improves the quality of the weather forecasts.
Benjamin Männel, Florian Zus, Galina Dick, Susanne Glaser, Maximilian Semmling, Kyriakos Balidakis, Jens Wickert, Marion Maturilli, Sandro Dahlke, and Harald Schuh
Atmos. Meas. Tech., 14, 5127–5138, https://doi.org/10.5194/amt-14-5127-2021, https://doi.org/10.5194/amt-14-5127-2021, 2021
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Within the MOSAiC expedition, GNSS was used to monitor variations in atmospheric water vapor. Based on 15 months of continuously tracked data, coordinates and hourly zenith total delays (ZTDs) were determined using kinematic precise point positioning. The derived ZTD values agree within few millimeters with ERA5 and terrestrial GNSS and VLBI stations. The derived integrated water vapor corresponds to the frequently launched radiosondes (0.08 ± 0.04 kg m−2, rms of the differences of 1.47 kg m−2).
Michal Kačmařík, Jan Douša, Florian Zus, Pavel Václavovic, Kyriakos Balidakis, Galina Dick, and Jens Wickert
Ann. Geophys., 37, 429–446, https://doi.org/10.5194/angeo-37-429-2019, https://doi.org/10.5194/angeo-37-429-2019, 2019
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We provide an analysis of processing setting impacts on tropospheric gradients estimated from GNSS observation processing. These tropospheric gradients are related to water vapour distribution in the troposphere and therefore can be helpful in meteorological applications.
Michal Kačmařík, Jan Douša, Galina Dick, Florian Zus, Hugues Brenot, Gregor Möller, Eric Pottiaux, Jan Kapłon, Paweł Hordyniec, Pavel Václavovic, and Laurent Morel
Atmos. Meas. Tech., 10, 2183–2208, https://doi.org/10.5194/amt-10-2183-2017, https://doi.org/10.5194/amt-10-2183-2017, 2017
Cuixian Lu, Florian Zus, Maorong Ge, Robert Heinkelmann, Galina Dick, Jens Wickert, and Harald Schuh
Atmos. Meas. Tech., 9, 5965–5973, https://doi.org/10.5194/amt-9-5965-2016, https://doi.org/10.5194/amt-9-5965-2016, 2016
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The recent dramatic development of multi-GNSS constellations brings great opportunities and potential for more enhanced precise positioning, navigation, timing, and other applications. In this contribution, we develop a numerical weather model (NWM) constrained PPP processing system to improve the multi-GNSS precise positioning. Compared to the standard PPP solution, significant improvements of both convergence time and positioning accuracy are achieved with the NWM-constrained PPP solution.
Jan Douša, Galina Dick, Michal Kačmařík, Radmila Brožková, Florian Zus, Hugues Brenot, Anastasia Stoycheva, Gregor Möller, and Jan Kaplon
Atmos. Meas. Tech., 9, 2989–3008, https://doi.org/10.5194/amt-9-2989-2016, https://doi.org/10.5194/amt-9-2989-2016, 2016
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GNSS products provide observations of atmospheric water vapour. Advanced tropospheric products focus on ultra-fast and high-resolution zenith total delays (ZTDs), horizontal gradients and slant delays, all suitable for rapid-cycle numerical weather prediction (NWP) and severe weather event monitoring. The GNSS4SWEC Benchmark provides a complex data set for developing and assessing these products, with initial focus on reference ZTDs and gradients derived from several NWP and dense GNSS networks.
F. Zus, G. Beyerle, S. Heise, T. Schmidt, and J. Wickert
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amtd-7-12719-2014, https://doi.org/10.5194/amtd-7-12719-2014, 2014
Preprint withdrawn
Related subject area
Subject: Others (Wind, Precipitation, Temperature, etc.) | Technique: Remote Sensing | Topic: Instruments and Platforms
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Francesco Manconi, Alessandro Battaglia, and Pavlos Kollias
Atmos. Meas. Tech., 18, 2295–2310, https://doi.org/10.5194/amt-18-2295-2025, https://doi.org/10.5194/amt-18-2295-2025, 2025
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Michael Vaughan, Kevin Ridley, Benjamin Witschas, Oliver Lux, Ines Nikolaus, and Oliver Reitebuch
Atmos. Meas. Tech., 18, 2149–2181, https://doi.org/10.5194/amt-18-2149-2025, https://doi.org/10.5194/amt-18-2149-2025, 2025
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Claire C. Trop, James LaBelle, Philip J. Erickson, Shun-Rong Zhang, David McGaw, and Terrence Kovacs
Atmos. Meas. Tech., 18, 1909–1925, https://doi.org/10.5194/amt-18-1909-2025, https://doi.org/10.5194/amt-18-1909-2025, 2025
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Traveling ionospheric disturbances (TIDs) are manifestations of atmospheric waves that are significant for the transfer of energy and momentum between atmospheric layers and regions. This work demonstrates that velocities and directions of TIDs can be measured by monitoring the tiny shift in frequency of AM radio signals when they reflect from a moving ionosphere and that this method can be scaled to use large numbers of radio receivers and transmitters to monitor TIDs on a continental scale.
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A new technique for the end-to-end calibration of weather radars is introduced. Highly precise artificial radar targets are generated with a radar target simulator and serve as a calibration reference for weather radar observables like reflectivity and Doppler velocity. The system allows to investigate and correct any biases associated with weather radar observations.
Peder Bagge Hansen, Martin Wienold, and Heinz-Wilhelm Hübers
EGUsphere, https://doi.org/10.5194/egusphere-2024-3648, https://doi.org/10.5194/egusphere-2024-3648, 2025
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In this numerical study, we assess the feasibility of a satellite-borne instrument for measuring the atomic oxygen concentration and temperature in the upper atmosphere by detecting its emission in the terahertz range. We simulate the measurement scenario considering technological feasibility and state-of-the-art atmosphere models. We find that both atomic oxygen and temperature could be accurately measured from an altitude of 100 km up to at least 200 km with such an instrument.
Zishun Qiao, Alan Z. Liu, Gunter Stober, Javier Fuentes, Fabio Vargas, Christian L. Adami, and Iain M. Reid
Atmos. Meas. Tech., 18, 1091–1104, https://doi.org/10.5194/amt-18-1091-2025, https://doi.org/10.5194/amt-18-1091-2025, 2025
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Atmos. Meas. Tech., 18, 909–919, https://doi.org/10.5194/amt-18-909-2025, https://doi.org/10.5194/amt-18-909-2025, 2025
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New low-cost, off-the-shelf Global Navigation Satellite System (GNSS) receivers enable the estimation of zonal ionospheric irregularity drifts using the scintillation spaced-receiver technique, previously tested only with commercial GNSS receivers. Despite their low C/No resolution (1 dB-Hz), we demonstrate that the recorded raw data can be used to estimate irregularity drifts. Further, our observations are consistent with the behavior of an empirical model of the thermospheric winds (HMW14).
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Junho Ho, Zhe Li, and Guifu Zhang
Atmos. Meas. Tech., 18, 619–638, https://doi.org/10.5194/amt-18-619-2025, https://doi.org/10.5194/amt-18-619-2025, 2025
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This paper presents a design of a UV wind lidar, made with a UV fiber laser and a Quadri Mach-Zehnder interferometer as a spectral analyzer, used to measure the wind in front of future low-consumption aircraft. The article details the optimization of the different elements of the instrument with simulations. This paper also presents a method to optimize laser angles for determining wind direction and strength and shows a 50 % improvement over the current angles used.
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Atmos. Meas. Tech., 17, 6213–6222, https://doi.org/10.5194/amt-17-6213-2024, https://doi.org/10.5194/amt-17-6213-2024, 2024
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Soon the MetOp Second Generation (Metop-SG) series of polar orbiting meteorological satellites will be launched. On these satellites, the GRAS-2 instrument will be mounted. It will provide GNSS radio occultation measurements with unsurpassed accuracy. The occultation measurements are used routinely for numerical weather prognosis, i.e. predicting the weather. In this paper, we describe the design of this new instrument and the novel methods developed to process the data.
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EGUsphere, https://doi.org/10.5194/egusphere-2024-2789, https://doi.org/10.5194/egusphere-2024-2789, 2024
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This work studies powerful bursts of radiation, called Terrestrial Gamma Ray Flashes, which happen during thunderstorms. It explores the use of planes and weather balloons as platforms for radiation detectors to gather data about this phenomenon. Using computer simulations, it was found that balloons might work better for high-altitude storms, while planes could be useful for lower ones. Moreover, the influence of the Terrestrial Gamma Ray Flash strength and its altitude of origin was revealed.
Jens Fiedler and Gerd Baumgarten
Atmos. Meas. Tech., 17, 5841–5859, https://doi.org/10.5194/amt-17-5841-2024, https://doi.org/10.5194/amt-17-5841-2024, 2024
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This article describes the current status of a lidar installed at ALOMAR in northern Norway. It has investigated the Arctic middle atmosphere on a climatological basis for 30 years. We discuss major upgrades of the system implemented during recent years, including methods for reliable remote operation of this complex lidar. We also show examples that illustrate the performance of the lidar during measurements at different altitude ranges and timescales.
Jonathan E. Murray, Laura Warwick, Helen Brindley, Alan Last, Patrick Quigley, Andy Rochester, Alexander Dewar, and Daniel Cummins
Atmos. Meas. Tech., 17, 4757–4775, https://doi.org/10.5194/amt-17-4757-2024, https://doi.org/10.5194/amt-17-4757-2024, 2024
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The Far INfrarEd Spectrometer for Surface Emissivity, FINESSE, is designed to measure the ability of natural surfaces to emit infrared radiation. FINESSE combines a commercial instrument with custom-built optics to view a surface from different angles with complementary views of the sky. Its choice of internal components means it can cover a wide range of wavelengths, extending into the far-infrared. We characterize FINESSE’s uncertainty budget and provide examples of its measurement capability.
Cornelius Hald, Maximilian Schaper, Annette Böhm, Michael Frech, Jan Petersen, Bertram Lange, and Benjamin Rohrdantz
Atmos. Meas. Tech., 17, 4695–4707, https://doi.org/10.5194/amt-17-4695-2024, https://doi.org/10.5194/amt-17-4695-2024, 2024
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Weather radars should use lightning protection to be safe from damage, but the rods can reduce the quality of the radar measurements. This study presents three new solutions for lightning protection for weather radars and evaluates their influence on data quality. The results are compared to the current system. All tested ones have very little effect on data, and a new lightning protection system with four rods is recommended for the German Meteorological Service.
Samuel K. Kristoffersen, William E. Ward, and Chris E. Meek
Atmos. Meas. Tech., 17, 3995–4014, https://doi.org/10.5194/amt-17-3995-2024, https://doi.org/10.5194/amt-17-3995-2024, 2024
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In this paper, the relationship between observations from two instruments, a meteor radar and a field-widened Michelson interferometer (ERWIN) which provide complementary information on this region, is investigated. On average the ratio of ERWIN winds to meteor radar winds is ∼ 0.7. Differences between the wind observations may be caused by variations in the airglow brightness associated with dissipating gravity waves.
Qingchen Xu, Iain Murray Reid, Bing Cai, Christian Adami, Zengmao Zhang, Mingliang Zhao, and Wen Li
Atmos. Meas. Tech., 17, 2957–2975, https://doi.org/10.5194/amt-17-2957-2024, https://doi.org/10.5194/amt-17-2957-2024, 2024
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To have better understanding of the dynamics of the lower and middle atmosphere, we installed a newly designed dual-frequency radar system that uses 53.8 MHz for near-ground to 20 km wind measurements and 35.0 MHz for 70 to 100 km wind measurements. The initial results show its good performance, along with the analysis of typical winter gravity wave activities.
Michael Gerding, Robin Wing, Eframir Franco-Diaz, Gerd Baumgarten, Jens Fiedler, Torsten Köpnick, and Reik Ostermann
Atmos. Meas. Tech., 17, 2789–2809, https://doi.org/10.5194/amt-17-2789-2024, https://doi.org/10.5194/amt-17-2789-2024, 2024
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This paper describes a new lidar system developed in Germany intended to study wind and temperature at night in the middle atmosphere. The paper explains how we have set up the system to work automatically and gives technical details for anyone who wants to build a similar system. We present a case study showing temperatures and winds at different altitudes. In a future article, we will present how we process the data and deal with uncertainties.
Jinhong Xian, Chao Lu, Xiaoling Lin, Honglong Yang, Ning Zhang, and Li Zhang
Atmos. Meas. Tech., 17, 1837–1850, https://doi.org/10.5194/amt-17-1837-2024, https://doi.org/10.5194/amt-17-1837-2024, 2024
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Improving the monitoring capability of atmospheric turbulence can help unravel the mystery of turbulence. Based on some assumptions, scientists have proposed various detection methods. However, these assumptions limit their applicability. We abandoned these assumptions and proposed a more accurate method, revealing some new results. Our method can provide more accurate three-dimensional features of turbulence, which will have a huge driving effect on the development of turbulence.
Thorben H. Mense, Josef Höffner, Gerd Baumgarten, Ronald Eixmann, Jan Froh, Alsu Mauer, Alexander Munk, Robin Wing, and Franz-Josef Lübken
Atmos. Meas. Tech., 17, 1665–1677, https://doi.org/10.5194/amt-17-1665-2024, https://doi.org/10.5194/amt-17-1665-2024, 2024
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A novel lidar system with five beams measured horizontal and vertical winds together, reaching altitudes up to 25 km. Developed in Germany, it revealed accurate horizontal wind data compared to forecasts, but vertical wind estimates differed. The lidar's capability to detect small-scale wind patterns was highlighted, advancing atmospheric research.
Peter Dalin, Urban Brändström, Johan Kero, Peter Voelger, Takanori Nishiyama, Trond Trondsen, Devin Wyatt, Craig Unick, Vladimir Perminov, Nikolay Pertsev, and Jonas Hedin
Atmos. Meas. Tech., 17, 1561–1576, https://doi.org/10.5194/amt-17-1561-2024, https://doi.org/10.5194/amt-17-1561-2024, 2024
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A novel infrared imaging instrument (OH imager) was put into operation in November 2022 at the Swedish Institute of Space Physics in Kiruna (Sweden). The OH imager is dedicated to the study of nightglow emissions coming from the hydroxyl (OH) and molecular oxygen (O2) layers in the mesopause (80–100 km). Based on a brightness ratio of two OH emission lines, the neutral temperature is estimated at around 87 km. The average daily winter temperature for the period January–April 2023 is 203±10 K.
Thomas Wagner and Jānis Puķīte
Atmos. Meas. Tech., 17, 277–297, https://doi.org/10.5194/amt-17-277-2024, https://doi.org/10.5194/amt-17-277-2024, 2024
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We present a radiance calibration method based on the comparison of measurements and radiative transfer simulations of the zenith-scattered sun radiance during twilight. Cloud-free conditions are required. The method can be applied to measurements in the filed, and no laboratory measurements are required. The accuracy is estimated to range from about 4 % at 340 nm to about 10 % at 700 nm.
Tobias Böck, Bernhard Pospichal, and Ulrich Löhnert
Atmos. Meas. Tech., 17, 219–233, https://doi.org/10.5194/amt-17-219-2024, https://doi.org/10.5194/amt-17-219-2024, 2024
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In this study, measurement uncertainties from microwave radiometers and their impact on temperature profiling are analyzed. These measurement uncertainties include horizontal inhomogeneities of the atmosphere, pointing errors or tilts of the instrument, physical obstacles which are in the line of sight of the radiometer, and radio frequency interferences. Impacts on temperature profiles from these uncertainties are usually small in real-life scenarios and when obstacles are far enough away.
Philipp Gasch, James Kasic, Oliver Maas, and Zhien Wang
Atmos. Meas. Tech., 16, 5495–5523, https://doi.org/10.5194/amt-16-5495-2023, https://doi.org/10.5194/amt-16-5495-2023, 2023
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This paper rethinks airborne wind measurements and investigates a new design for airborne Doppler lidar systems. Recent advances in lidar technology allow the use of multiple lidar systems with fixed viewing directions instead of a single lidar attached to a scanner. Our simulation results show that the proposed new design offers great potential for both higher accuracy and higher-resolution airborne wind measurements.
Christiane Duscha, Juraj Pálenik, Thomas Spengler, and Joachim Reuder
Atmos. Meas. Tech., 16, 5103–5123, https://doi.org/10.5194/amt-16-5103-2023, https://doi.org/10.5194/amt-16-5103-2023, 2023
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We combine observations from two scanning Doppler lidars to obtain new and unique insights into the dynamic processes inherent to atmospheric convection. The approach complements and enhances conventional methods to probe convection and has the potential to substantially deepen our understanding of this complex process, which is crucial to improving our weather and climate models.
Anna Špačková, Martin Fencl, and Vojtěch Bareš
Atmos. Meas. Tech., 16, 3865–3879, https://doi.org/10.5194/amt-16-3865-2023, https://doi.org/10.5194/amt-16-3865-2023, 2023
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Commercial microwave links as rainfall sensors have been investigated and evaluated in numerous studies with gauge-adjusted radar used for reference for rainfall observations. We evaluate collocated commercial microwave links, which are thus exposed to identical atmospheric conditions. This set-up enables the exploration of inconsistencies in observations of independent sensors using data from a real telecommunication network. The sensors are in agreement and are homogeneous in their behaviour.
Alessandro Battaglia, Filippo Emilio Scarsi, Kamil Mroz, and Anthony Illingworth
Atmos. Meas. Tech., 16, 3283–3297, https://doi.org/10.5194/amt-16-3283-2023, https://doi.org/10.5194/amt-16-3283-2023, 2023
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Some of the new generation of cloud and precipitation spaceborne radars will adopt conical scanning. This will make some of the standard calibration techniques impractical. This work presents a methodology to cross-calibrate radars in orbits by matching the reflectivity probability density function of ice clouds observed by the to-be-calibrated and by the reference radar in quasi-coincident locations. Results show that cross-calibration within 1 dB (26 %) is feasible.
Claudio Belotti, Flavio Barbara, Marco Barucci, Giovanni Bianchini, Francesco D'Amato, Samuele Del Bianco, Gianluca Di Natale, Marco Gai, Alessio Montori, Filippo Pratesi, Markus Rettinger, Christian Rolf, Ralf Sussmann, Thomas Trickl, Silvia Viciani, Hannes Vogelmann, and Luca Palchetti
Atmos. Meas. Tech., 16, 2511–2529, https://doi.org/10.5194/amt-16-2511-2023, https://doi.org/10.5194/amt-16-2511-2023, 2023
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FIRMOS (Far-Infrared Radiation Mobile Observation System) is a spectroradiometer measuring in the far-infrared, developed to support the preparation of the FORUM (Far-infrared Outgoing Radiation Understanding and Monitoring) satellite mission. In this paper, we describe the instrument, its data products, and the results of the comparison with a suite of observations made from a high-altitude site during a field campaign, in winter 2018–2019.
Christopher R. Williams, Joshua Barrio, Paul E. Johnston, Paytsar Muradyan, and Scott E. Giangrande
Atmos. Meas. Tech., 16, 2381–2398, https://doi.org/10.5194/amt-16-2381-2023, https://doi.org/10.5194/amt-16-2381-2023, 2023
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This study uses surface disdrometer observations to calibrate 8 years of 915 MHz radar wind profiler deployed in the central United States in northern Oklahoma. This study had two key findings. First, the radar wind profiler sensitivity decreased approximately 3 to 4 dB/year as the hardware aged. Second, this drift was slow enough that calibration can be performed using 3-month intervals. Calibrated radar wind profiler observations and Python processing code are available on public repositories.
Xin Fang, Feng Li, Lei-lei Sun, and Tao Li
Atmos. Meas. Tech., 16, 2263–2272, https://doi.org/10.5194/amt-16-2263-2023, https://doi.org/10.5194/amt-16-2263-2023, 2023
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We successfully developed the first pseudorandom modulation continuous-wave narrowband sodium lidar (PMCW-NSL) system for simultaneous measurements of the mesopause region's temperature and wind. Based on the innovative decoded technique and algorithm for CW lidar, both the main and residual lights modulated by M-code are used and directed to the atmosphere in the vertical and eastward directions, tilted 20° from the zenith. The PMCW-NSL system can applied to airborne and space-borne purposes.
Dana L. McGuffin, Philip J. Cameron-Smith, Matthew A. Horsley, Brian J. Bauman, Wim De Vries, Denis Healy, Alex Pertica, Chris Shaffer, and Lance M. Simms
Atmos. Meas. Tech., 16, 2129–2144, https://doi.org/10.5194/amt-16-2129-2023, https://doi.org/10.5194/amt-16-2129-2023, 2023
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This work demonstrates the viability of a remote sensing technique using nanosatellites to measure stratospheric temperature. This measurement technique can probe the stratosphere and mesosphere at a fine vertical scale around the globe unlike other high-altitude measurement techniques, which would provide an opportunity to observe atmospheric gravity waves and turbulence. We analyze observations from two satellite platforms to provide a proof of concept and characterize measurement uncertainty.
Benjamin Witschas, Sonja Gisinger, Stephan Rahm, Andreas Dörnbrack, David C. Fritts, and Markus Rapp
Atmos. Meas. Tech., 16, 1087–1101, https://doi.org/10.5194/amt-16-1087-2023, https://doi.org/10.5194/amt-16-1087-2023, 2023
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In this paper, a novel scan technique is applied to an airborne coherent Doppler wind lidar, enabling us to measure the vertical wind speed and the horizontal wind speed along flight direction simultaneously with a horizontal resolution of about 800 m and a vertical resolution of 100 m. The performed observations are valuable for gravity wave characterization as they allow us to calculate the leg-averaged momentum flux profile and, with that, the propagation direction of excited gravity waves.
Kevin J. Nelson, Feiqin Xie, Bryan C. Chan, Ashish Goel, Jonathan Kosh, Tyler G. R. Reid, Corey R. Snyder, and Paul M. Tarantino
Atmos. Meas. Tech., 16, 941–954, https://doi.org/10.5194/amt-16-941-2023, https://doi.org/10.5194/amt-16-941-2023, 2023
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Global Navigation Satellite System (GNSS) radio occultation (RO) remote sensing is effective for atmospheric profiling. The capability of a low-cost and scalable commercial off-the-shelf (COTS) GNSS receiver on board high-altitude balloons is tested in two campaigns. Preliminary results demonstrate high-quality refractivity observations from the COTS RO receiver, which is worth further improvement for dense atmospheric observations over a targeted region.
Jenna Ritvanen, Ewan O'Connor, Dmitri Moisseev, Raisa Lehtinen, Jani Tyynelä, and Ludovic Thobois
Atmos. Meas. Tech., 15, 6507–6519, https://doi.org/10.5194/amt-15-6507-2022, https://doi.org/10.5194/amt-15-6507-2022, 2022
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Doppler lidars and weather radars provide accurate wind measurements, with Doppler lidar usually performing better in dry weather conditions and weather radar performing better when there is precipitation. Operating both instruments together should therefore improve the overall performance. We investigate how well a co-located Doppler lidar and X-band radar perform with respect to various weather conditions, including changes in horizontal visibility, cloud altitude, and precipitation.
Bhupal Shrestha, Jerald A. Brotzge, and Junhong Wang
Atmos. Meas. Tech., 15, 6011–6033, https://doi.org/10.5194/amt-15-6011-2022, https://doi.org/10.5194/amt-15-6011-2022, 2022
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The NYS Mesonet Profiler Network is comprised of 17 profiler sites, each equipped with a Doppler lidar, microwave radiometer, and sun photometer. This study presents a multi-year, multi-station evaluation based on well-defined reference measurements. Results demonstrate robust technologies that can aid real-time weather operations and a network test bed that can be used for further expansion, evaluation, and integration of such technologies at a large scale.
Felix Kelberlau and Jakob Mann
Atmos. Meas. Tech., 15, 5323–5341, https://doi.org/10.5194/amt-15-5323-2022, https://doi.org/10.5194/amt-15-5323-2022, 2022
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Floating lidar systems are used for measuring wind speeds offshore, and their motion influences the measurements. This study describes the motion-induced bias on mean wind speed estimates by simulating the lidar sampling pattern of a moving lidar. An analytic model is used to validate the simulations. The bias is low and depends on amplitude and frequency of motion as well as on wind shear. It has been estimated for the example of the Fugro SEAWATCH wind lidar buoy carrying a ZX 300M lidar.
Alessandro Battaglia, Paolo Martire, Eric Caubet, Laurent Phalippou, Fabrizio Stesina, Pavlos Kollias, and Anthony Illingworth
Atmos. Meas. Tech., 15, 3011–3030, https://doi.org/10.5194/amt-15-3011-2022, https://doi.org/10.5194/amt-15-3011-2022, 2022
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We present an instrument simulator for a new sensor, WIVERN (WInd VElocity Radar Nephoscope), a conically scanning radar payload with Doppler capabilities, recently down-selected as one of the four candidates for the European Space Agency Earth Explorer 11 program. The mission aims at measuring horizontal winds in cloudy areas. The simulator is instrumental in the definition and consolidation of the mission requirements and the evaluation of mission performances.
James B. Duncan Jr., Laura Bianco, Bianca Adler, Tyler Bell, Irina V. Djalalova, Laura Riihimaki, Joseph Sedlar, Elizabeth N. Smith, David D. Turner, Timothy J. Wagner, and James M. Wilczak
Atmos. Meas. Tech., 15, 2479–2502, https://doi.org/10.5194/amt-15-2479-2022, https://doi.org/10.5194/amt-15-2479-2022, 2022
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In this study, several ground-based remote sensing instruments are used to estimate the height of the convective planetary boundary layer, and their performance is compared against independent boundary layer depth estimates obtained from radiosondes launched as part of the CHEESEHEAD19 field campaign. The impact of clouds (particularly boundary layer clouds) on the estimation of the boundary layer depth is also investigated.
Vicki Kelsey, Spencer Riley, and Kenneth Minschwaner
Atmos. Meas. Tech., 15, 1563–1576, https://doi.org/10.5194/amt-15-1563-2022, https://doi.org/10.5194/amt-15-1563-2022, 2022
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In the interior western USA there are distances of hundreds of kilometers between weather balloon launch sites for weather forecasting. Satellite coverage can also be sparse or with poor resolution. Using infrared thermometers, clear-sky temperatures were collected and compared with data from weather balloons. A correlation between clear-sky temperatures and precipitable water measurements from weather balloons was found. This means that citizen scientists can collect data.
Benjamin Witschas, Christian Lemmerz, Oliver Lux, Uwe Marksteiner, Oliver Reitebuch, Fabian Weiler, Frederic Fabre, Alain Dabas, Thomas Flament, Dorit Huber, and Michael Vaughan
Atmos. Meas. Tech., 15, 1465–1489, https://doi.org/10.5194/amt-15-1465-2022, https://doi.org/10.5194/amt-15-1465-2022, 2022
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In August 2018, the ESA launched the first Doppler wind lidar into space. In order to calibrate the instrument and to monitor the overall instrument conditions, instrument spectral registration measurements have been performed with Aeolus on a weekly basis. Based on these measurements, the alignment drift of the Aeolus satellite instrument is estimated by applying tools and mathematical model functions to analyze the spectrometer transmission curves.
Joseph J. Michalsky and Peter W. Kiedron
Atmos. Meas. Tech., 15, 353–364, https://doi.org/10.5194/amt-15-353-2022, https://doi.org/10.5194/amt-15-353-2022, 2022
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This paper describes an instrument that measures spectrally from 360 nm (ultraviolet) to 1070 nm (near-infrared) at 1002 separate wavelengths. The measurements were made every minute from the late summer of 2009 to the winter of 2014 at a site in northern Oklahoma (USA; 36.605° N, 97.486° W). Methods are described that enable the normalized transmission across the spectrum to be measured and, subsequently, used to calculate the aerosol optical depth and spectra irradiance.
Julien Totems, Patrick Chazette, and Alexandre Baron
Atmos. Meas. Tech., 14, 7525–7544, https://doi.org/10.5194/amt-14-7525-2021, https://doi.org/10.5194/amt-14-7525-2021, 2021
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We describe in detail the design and calibration of the new Raman channels for the WALI system, going over the important sources of bias and uncertainty on retrieved temperature profiles. For the first time, their impact is investigated using horizontal shots in a homogenous atmosphere: the magnitude of the highlighted biases can be much larger than the targeted absolute accuracy of 1° C. Actual measurement errors are quantified using radiosoundings launched close to the lidar site.
René Sedlak, Patrick Hannawald, Carsten Schmidt, Sabine Wüst, Michael Bittner, and Samo Stanič
Atmos. Meas. Tech., 14, 6821–6833, https://doi.org/10.5194/amt-14-6821-2021, https://doi.org/10.5194/amt-14-6821-2021, 2021
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High-resolution images of the OH* airglow layer (ca. 87 km height) acquired at Otlica Observatory, Slovenia, have been analysed. A statistical analysis of small-scale wave structures with horizontal wavelengths up to 4.5 km suggests strong presence of instability features in the upper mesosphere or lower thermosphere. The dissipated energy of breaking gravity waves is derived from observations of turbulent vortices. It is concluded that dynamical heating plays a vital role in the atmosphere.
Oliver Lux, Christian Lemmerz, Fabian Weiler, Thomas Kanitz, Denny Wernham, Gonçalo Rodrigues, Andrew Hyslop, Olivier Lecrenier, Phil McGoldrick, Frédéric Fabre, Paolo Bravetti, Tommaso Parrinello, and Oliver Reitebuch
Atmos. Meas. Tech., 14, 6305–6333, https://doi.org/10.5194/amt-14-6305-2021, https://doi.org/10.5194/amt-14-6305-2021, 2021
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The work assesses the frequency stability of the laser transmitters on board Aeolus and discusses its influence on the quality of the global wind data. Excellent frequency stability of the space lasers is evident, although enhanced frequency noise occurs at certain locations along the orbit due to micro-vibrations that are introduced by the satellite’s reaction wheels. The study elaborates on this finding and investigates the extent to which the enhanced frequency noise increases the wind error.
Tingyu Yan, Jeffery A. Langille, William E. Ward, William A. Gault, Alan Scott, Andrew Bell, Driss Touahiri, Sheng-Hai Zheng, and Chunmin Zhang
Atmos. Meas. Tech., 14, 6213–6232, https://doi.org/10.5194/amt-14-6213-2021, https://doi.org/10.5194/amt-14-6213-2021, 2021
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High-resolution interferometers are routinely used to measure upper atmospheric motions by measuring small Doppler shifts in spectrally isolated airglow emissions. The birefringent interferometer presented in this paper has similar capabilities as several existing state-of-the-art instruments but is smaller and less complex to construct and operate. This paper presents the measurement technique and characterization of a lab prototype and examines the performance of the instrument.
Etienne Cheynet, Martin Flügge, Joachim Reuder, Jasna B. Jakobsen, Yngve Heggelund, Benny Svardal, Pablo Saavedra Garfias, Charlotte Obhrai, Nicolò Daniotti, Jarle Berge, Christiane Duscha, Norman Wildmann, Ingrid H. Onarheim, and Marte Godvik
Atmos. Meas. Tech., 14, 6137–6157, https://doi.org/10.5194/amt-14-6137-2021, https://doi.org/10.5194/amt-14-6137-2021, 2021
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The COTUR campaign explored the structure of wind turbulence above the ocean to improve the design of future multi-megawatt offshore wind turbines. Deploying scientific instruments offshore is both a financial and technological challenge. Therefore, lidar technology was used to remotely measure the wind above the ocean from instruments located on the seaside. The experimental setup is tailored to the study of the spatial correlation of wind gusts, which governs the wind loading on structures.
Fabian Weiler, Thomas Kanitz, Denny Wernham, Michael Rennie, Dorit Huber, Marc Schillinger, Olivier Saint-Pe, Ray Bell, Tommaso Parrinello, and Oliver Reitebuch
Atmos. Meas. Tech., 14, 5153–5177, https://doi.org/10.5194/amt-14-5153-2021, https://doi.org/10.5194/amt-14-5153-2021, 2021
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This paper reports on dark current signal anomalies of the detectors used on board the ESA's Earth Explorer satellite Aeolus during the first 1.5 years in orbit. After introducing sophisticated algorithms to classify dark current anomalies according to their characteristics, the impact of the different kinds of anomalies on wind measurements is discussed. In addition, mitigation approaches for the wind retrieval are presented and potential root causes are discussed.
Chuanliang Zhang, Xuejin Sun, Wen Lu, Yingni Shi, Naiying Dou, and Shaohui Li
Atmos. Meas. Tech., 14, 4787–4803, https://doi.org/10.5194/amt-14-4787-2021, https://doi.org/10.5194/amt-14-4787-2021, 2021
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The first spaceborne doppler wind lidar (DWL) Aeolus operates on sun-synchronous dawn–dusk orbit to lower the impact of solar background radiation (SBR) on wind observation accuracy. Increased SBR leads to an increment of averaged wind observation uncertainties from 0.19 to 0.27 m s-1 comparing Aeolus and two added spaceborne DWLs operating on orbits with local ascending times of 15:00 and 12:00 LT. A quantitative design of laser pulse energy according to accuracy requirements is also proposed.
Didier Bruneau and Jacques Pelon
Atmos. Meas. Tech., 14, 4375–4402, https://doi.org/10.5194/amt-14-4375-2021, https://doi.org/10.5194/amt-14-4375-2021, 2021
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Taking advantage of Aeolus success and of our airborne lidar system expertise, we present a new spaceborne wind lidar design for operational Aeolus follow-on missions, keeping most of the initial lidar system but relying on a single Mach–Zehnder interferometer to relax operational constraints and reduce measurement bias. System parameters are optimized. Random and systematic errors are shown to be compliant with the initial mission requirements. In addition, the system allows unbiased retrieval.
Franz-Josef Lübken and Josef Höffner
Atmos. Meas. Tech., 14, 3815–3836, https://doi.org/10.5194/amt-14-3815-2021, https://doi.org/10.5194/amt-14-3815-2021, 2021
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We present a new concept for a cluster of lidars that allows us to measure time-resolved profiles of temperatures, winds, and aerosols in the entire middle atmosphere for the first time, also covering regional horizontal scales (
four-dimensional coverage). Measurements are performed during day and night. The essential component is a newly developed laser with unprecedented performance. We present the first measurements. New observational capabilities in atmospheric physics are established.
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Short summary
Ground-based observations of GPS satellites disappearing below the local horizon are analysed. Starting at +2 degree elevation angle the GPS signals are recorded in open-loop tracking mode down to −1.5 degrees. The open-loop Doppler model has negligible influence on the derived data products for strong signal-to-noise ratios; at lower signal levels, however, a notable bias is uncovered. These results may have implications for the design of future space-based GPS radio occultation missions.
Ground-based observations of GPS satellites disappearing below the local horizon are analysed....
