scholarly journals Validation of the radiation pattern of the Middle Atmosphere Alomar Radar System (MAARSY)

2012 ◽  
Vol 10 ◽  
pp. 245-253 ◽  
Author(s):  
T. Renkwitz ◽  
W. Singer ◽  
R. Latteck ◽  
G. Stober ◽  
M. Rapp
Keyword(s):  
Radiation Pattern ◽  
Middle Atmosphere ◽  
Beam Steering ◽  
Lower Thermosphere ◽  
Radar System ◽  
The Arctic ◽  
Current Status ◽  
Beam Forming ◽  
Noise Power ◽  
Phased Array Antenna

Abstract. In 2009/2010 the Leibniz-Institute of Atmospheric Physics (IAP) installed a new powerful VHF radar on the island Andøya in Northern Norway (69.30° N, 16.04° E). The Middle Atmosphere Alomar Radar System (MAARSY) allows studies with high spatial and temporal resolution in the troposphere/lower stratosphere and in the mesosphere/lower thermosphere of the Arctic atmosphere. The monostatic radar is operated at 53.5 MHz with an active phased array antenna consisting of 433 Yagi antennas. Each individual antenna is connected to its own transceiver with independent phase control and a scalable power output of up to 2 kW, which implies high flexibility of beam forming and beam steering. During the design phase of MAARSY several model studies have been carried out in order to estimate the radiation pattern for various combinations of beam forming and steering. However, parameters like mutual coupling, active impedance and ground parameters have an impact on the radiation pattern, but can hardly be measured. Hence, experiments need to be designed to verify the model results. For this purpose, the radar has occasionally been used in passive mode, monitoring the noise power received from both distinct cosmic noise sources like e.g. Cassiopeia A and Cygnus A, and the diffuse cosmic background noise. The analysis of the collected dataset enables us to verify beam forming and steering attempts. These results document the current status of the radar during its development and provide valuable information for further improvement.

scholarly journals Horizontally resolved structures of radar backscatter from polar mesospheric layers

2012 ◽  
Vol 10 ◽  
pp. 285-290 ◽  
Author(s):  
R. Latteck ◽  
W. Singer ◽  
M. Rapp ◽  
T. Renkwitz ◽  
G. Stober
Keyword(s):  
Middle Atmosphere ◽  
Beam Steering ◽  
Lower Thermosphere ◽  
The Arctic ◽  
Phased Array Antenna ◽  
Vhf Radar ◽  
The North ◽  
Expansion Stage ◽  
Arctic Atmosphere ◽  
High Flexibility

Abstract. The Leibniz-Institute of Atmospheric Physics in Kühlungsborn, Germany (IAP) installed a new powerful VHF radar on the North-Norwegian island Andøya (69.30° N, 16.04° E) from 2009 to 2011. The new Middle Atmosphere Alomar Radar System (MAARSY) replaces the existing ALWIN radar which has been in continuous operation on Andøya for more than 10 yr. MAARSY is a monostatic radar operated at 53.5 MHz with an active phased array antenna consisting of 433 Yagi antennas each connected to its own transceiver with independent control of frequency, phase and power of the transmitted signal. This arrangement provides a very high flexibility of beam forming and beam steering. It allows classical beam swinging operation as well as experiments with simultaneous multiple beams and the use of modern interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatial-temporal resolution. The installation of the antenna was completed in August 2009. An initial expansion stage of 196 transceiver modules was installed in spring 2010, upgraded to 343 transceiver modules in December 2010 and the installation of the radar was completed in spring 2011. Beside standard observations of tropospheric winds and Polar Mesosphere Summer Echoes, multi-beam experiments using up to 91 beams quasi-simultaneously in the mesosphere have been carried out using the different expansion stages of the system during campaigns in 2010 and 2011. These results provided a first insight into the horizontal variability of Polar Mesosphere Summer and Winter Echoes in an area of about 80 km by 80 km with time resolutions between 3 and 9 min.

scholarly journals MAARSY – the new MST radar on Andøya/Norway

2010 ◽  
Vol 8 ◽  
pp. 219-224 ◽  
Author(s):  
R. Latteck ◽  
W. Singer ◽  
M. Rapp ◽  
T. Renkwitz
Keyword(s):  
Middle Atmosphere ◽  
Beam Steering ◽  
Lower Thermosphere ◽  
The Arctic ◽  
Circular Aperture ◽  
Phased Array Antenna ◽  
Spatiotemporal Resolution ◽  
Vhf Radar ◽  
High Flexibility ◽  
New System

Abstract. The Leibniz-Institute of Atmospheric Physics in Kühlungsborn, Germany (IAP) is installing a new powerful VHF radar on the North-Norwegian island Andøya (69.30° N, 16.04° E) in 2009/2010. The new Middle Atmosphere Alomar Radar System (MAARSY) replaces the existing ALWIN radar which has been operated continuously on Andøya for more than 10 years. The new system is a monostatic radar operated at 53.5 MHz with an active phased array antenna consisting of 433 Yagi antennas. The 3-element Yagi antennas are arranged in an equilateral triangle grid forming a circular aperture of approximately 6300 m2. Each individual antenna is connected to its own transceiver with independent phase control and a scalable output up to 2 kW. This arrangement allows very high flexibility of beam forming and beam steering with a symmetric radar beam of a minimum half power beam width of 3.6°, a maximum directive gain of 33.5 dB and a total transmitted peak power of approximately 800 kW. The IF signals of each 7 transceivers connected to each 7 antennas arranged in a hexagon are combined to 61 receiving channels. Selected channels or combinations of IF signals are sent to a 16-channel data acquisition system with 25 m sampling resolution and 16-bit digitization specified which will be upgraded to 64 channels in the final stage. The high flexibility of the new system allows classical Doppler beam swinging as well as experiments with simultaneously formed multiple beams and the use of modern interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatiotemporal resolution.

scholarly journals New experiments to validate the radiation pattern of the Middle Atmosphere Alomar Radar System (MAARSY)

2013 ◽  
Vol 11 ◽  
pp. 283-289 ◽  
Author(s):  
T. Renkwitz ◽  
G. Stober ◽  
R. Latteck ◽  
W. Singer ◽  
M. Rapp
Keyword(s):  
Radiation Pattern ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Radar System ◽  
Flexible Beam ◽  
Cosmic Radio ◽  
Phased Array Antenna ◽  
Sky Temperature ◽  
Temperature Maps ◽  
Actual Radiation

Abstract. The Middle Atmosphere Alomar Radar System (MAARSY) is a monostatic radar with an active phased array antenna designed for studies of phenomena in the mesosphere and lower thermosphere. Its design in particular the flexible beam forming and steering capability makes it to a powerful instrument to perform observations with high angular and temporal resolution. The knowledge of the actual radiation pattern is crucial to configure and analyze experiments carried out with the radar. The simulated radiation pattern is evaluated by the observation of cosmic radio emissions which are compared to a Global Sky temperature Maps model consisting of the most recent, thorough and accurate radio astronomy surveys. Additionally to these passive receive-only experiments active two-way experiments are presented, which corroborate the findings of the passive experiments.

scholarly journals Validation of the radiation pattern of the VHF MST radar MAARSY by scattering off a sounding rocket's payload

2015 ◽  
Vol 13 ◽  
pp. 41-48 ◽  
Author(s):  
T. Renkwitz ◽  
C. Schult ◽  
R. Latteck ◽  
G. Stober
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Middle Atmosphere ◽  
Phase Distribution ◽  
Lower Thermosphere ◽  
Beam Width ◽  
Sounding Rocket ◽  
Flexible Beam ◽  
Phased Array Antenna ◽  
Pointing Accuracy

Abstract. The Middle Atmosphere Alomar Radar System (MAARSY) is a monostatic radar with an active phased array antenna designed for studies of phenomena in the mesosphere and lower thermosphere. Its design, in particular the flexible beam forming and steering capability, makes it a powerful instrument to perform observations with high angular and temporal resolution. For the configuration and analysis of experiments carried out with the radar it is essential to have knowledge of the actual radiation pattern. Therefore, during the time since the radar was put into operation various active and passive experiments have been performed to gain knowledge of the radiation pattern. With these experiments the beam pointing accuracy, the beam width and phase distribution of the antenna array were investigated. Here, the use of a sounding rocket and its payload as a radar target is described which was launched in the proximity of the radar. The analysis of these observations allows the detailed investigation of the two-way radiation pattern for different antenna array sizes and beam pointing positions.

scholarly journals VHF antenna pattern characterization by the observation of meteor head echoes

2016 ◽  
Author(s):  
Toralf Renkwitz ◽  
Carsten Schult ◽  
Ralph Latteck
Keyword(s):  
Radiation Pattern ◽  
Middle Atmosphere ◽  
Radar Data ◽  
Lower Atmosphere ◽  
Beam Forming ◽  
Flexible Beam ◽  
Phased Array Antenna ◽  
Active Experiments ◽  
Head Echo ◽  
Actual Radiation

Abstract. The Middle Atmosphere Alomar Radar SYstem (MAARSY) with its active phased array antenna is designed and used for studies of phenomena in the mesosphere and lower atmosphere. The flexible beam forming and steering combined with a large aperture array allows observations with high temporal and angular resolution. For both, the analysis of the radar data and the configuration of experiments, the actual radiation pattern needs to be known. For that purpose various simulations as well as passive and active experiments have been conducted. Here, results of meteor head echo observations are presented, which allow derivation of detailed information of the actual radiation pattern for different beam pointing positions and the current health status of the entire radar. For MAARSY, the described method offers robust beam pointing and width estimations for a minimum of a few days of observations.

scholarly journals VHF antenna pattern characterization by the observation of meteor head echoes

2017 ◽  
Vol 10 (2) ◽  
pp. 527-535 ◽  
Author(s):  
Toralf Renkwitz ◽  
Carsten Schult ◽  
Ralph Latteck
Keyword(s):  
Radiation Pattern ◽  
Middle Atmosphere ◽  
Radar Data ◽  
Lower Atmosphere ◽  
Beam Forming ◽  
Flexible Beam ◽  
Phased Array Antenna ◽  
Active Experiments ◽  
Head Echo ◽  
Actual Radiation

Abstract. The Middle Atmosphere Alomar Radar System (MAARSY) with its active phased array antenna is designed and used for studies of phenomena in the mesosphere and lower atmosphere. The flexible beam forming and steering combined with a large aperture array allows for observations with a high temporal and angular resolution. For both the analysis of the radar data and the configuration of experiments, the actual radiation pattern needs to be known. For that purpose, various simulations as well as passive and active experiments have been conducted. Here, results of meteor head echo observations are presented, which allow us to derive detailed information of the actual radiation pattern for different beam-pointing positions and the current health status of the entire radar. For MAARSY, the described method offers robust beam pointing and width estimations for a minimum of a few days of observations.

scholarly journals Unusually strong nitric oxide descent in the Arctic middle atmosphere in early 2013 as observed by Odin/SMR

2014 ◽  
Vol 14 (3) ◽  
pp. 3563-3581
Author(s):  
K. Pérot ◽  
J. Urban ◽  
D. P. Murtagh
Keyword(s):  
Nitric Oxide ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Polar Vortex ◽  
Meteorological Conditions ◽  
Atmospheric Composition ◽  
The Arctic ◽  
The Reformation ◽  
Polar Stratosphere ◽  
Energetic Particle Precipitation

Abstract. The middle atmosphere has been affected by an exceptionally strong midwinter stratospheric sudden warming (SSW) during the Arctic winter 2012/2013. These unusual meteorological conditions led to a breakdown of the polar vortex, followed by the reformation of a strong upper stratospheric vortex associated with particularly efficient descent of air. Measurements by the Sub-Millimetre Radiometer (SMR), on board the Odin satellite, show that very large amounts of nitric oxide (NO), produced by Energetic Particle Precipitation (EPP) in the mesosphere/lower thermosphere (MLT), could thus enter the polar stratosphere in early 2013. The mechanism referring to the downward transport of EPP generated-NOx during winter is generally called the EPP indirect effect. SMR observed up to 20 times more NO in the upper stratosphere than the average NO measured at the same latitude, pressure and time during three previous winters where no mixing between mesospheric and stratospheric air was noticeable. This event turned out to be an unprecedently strong case of this effect. Our study is based on a comparison with the Arctic winter 2008/2009, when a similar situation was observed and which was so far considered as a record-breaking winter for this kind of events. This outstanding situation is the result of the combination between a relatively high geomagnetic activity and an unusually high dynamical activity, which makes this case a prime example to study the EPP impacts on the atmospheric composition.

Vertical Atmospheric Coupling during the September 2019 Antarctic Sudden Stratospheric Warming

2020 ◽  
Author(s):  
Yosuke Yamazaki ◽  
Vivien Matthias ◽  
Yasunobu Miyoshi ◽  
Claudia Stolle ◽  
Tarique Siddiqui ◽  
...  
Keyword(s):  
Large Scale ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Upper Atmosphere ◽  
The Arctic ◽  
Electron Content ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Total Electron ◽  
Zonal Wavenumber

<p>A sudden stratospheric warming (SSW) is an extreme wintertime meteorological phenomenon occurring mostly over the Arctic region. Studies have shown that an Arctic SSW can influence the whole atmosphere including the ionosphere. In September 2019, a rare SSW event occurred in the Antarctic region, following strong wave-1 planetary wave activity. The event provides an opportunity to investigate its broader impact on the upper atmosphere, which has been largely unexplored in previous studies. Ionospheric data from ESA's Swarm satellite constellation mission show prominent 6-day variations in the dayside low-latitude region during the SSW, including 20-70% variations in the equatorial zonal electric field, 20-40% variations in the electron density, and 5-10% variations in the top-side total electron content. These ionospheric variations have characteristics of a westward-propagating wave with zonal wavenumber 1, and can be attributed to forcing from the middle atmosphere by the Rossby normal mode “quasi-6-day wave” (Q6DW). Geopotential height measurements by the Microwave Limb Sounder aboard NASA's Aura satellite reveal a burst of global Q6DW activity in the mesosphere and lower thermosphere at this time, which is one of the strongest in the record. These results suggest that an Antarctic SSW can lead to ionospheric variability by altering middle atmosphere dynamics and propagation characteristics of large-scale waves from the middle atmosphere to the upper atmosphere.</p>

scholarly journals Analysis of the influence of radiators basing errors in the monopulse phased array antenna aperture on its characteristics

2019 ◽  
Vol 30 ◽  
pp. 05019
Author(s):  
Yury Rusov
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Phased Array ◽  
Array Antenna ◽  
Beam Forming ◽  
Phased Array Antenna ◽  
Antenna Aperture ◽  
Forming Accuracy ◽  
The Difference

The influence of radiators basing errors in the flat monopulse phased array antenna with spatial excitation on the beam forming accuracy is researched. The results of calculations of the deviation of the position of the difference radiation pattern minimum depending on the displacement of the antenna array radiators for antenna arrays with diameters from 10 to 100 wavelengths are presented.

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