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

Renkwitz, Toralf; Singer, W.; Latteck, R.; Stober, Gunter; Rapp, Markus

doi:10.5194/ars-10-245-2012

Cited by 9 publications

(14 citation statements)

References 20 publications

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“…The radar system is located at Andøya, Norway (69.03 • N, 16.04 • E) and designed for studying polar atmosphere, i.e. the UTLS (the upper troposphere and lower stratosphere) and MLT (the mesosphere and lower thermosphere) regions covering the ionospheric E region altitudes in polar regions Renkwitz et al, 2012Renkwitz et al, , 2013Stober et al, 2012Stober et al, , 2013Chau et al, 2014;Latteck and Strelnikova, 2015). The basic parameters of the radar system are summarized in Table 1 for convenience.…”

Section: Observationsmentioning

confidence: 99%

Derivation of turbulent energy dissipation rate with the Middle Atmosphere Alomar Radar System (MAARSY) and radiosondes at Andøya, Norway

Rapp

Schrön

et al. 2016

Ann. Geophys.

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Abstract. We present the derivation of turbulent energy dissipation rate ε from a total of 522 days of observations with the Middle Atmosphere Alomar Radar SYstem (MAARSY) mesosphere-stratosphere-troposphere (MST) radar running tropospheric experiments during the period of 2010-2013 as well as with balloon-borne radiosondes based on a campaign in the summer 2013. Spectral widths are converted to ε after the removal of the broadening effects due to the finite beam width of the radar. With the simultaneous in situ measurements of ε with balloon-borne radiosondes at the MAARSY radar site, we compare the ε values derived from both techniques and reach an encouraging agreement between them. Using all the radar data available, we present a preliminary climatology of atmospheric turbulence in the UTLS (upper troposphere and lower stratosphere) region above the MAARSY site showing a variability of more than 5 orders of magnitude inherent in turbulent energy dissipation rates. The derived ε values reveal a log-normal distribution with a negative skewness, and the ε profiles show an increase with height which is also the case for each individual month. Atmospheric turbulence based on our radar measurements reveals a seasonal variation but no clear diurnal variation in the UTLS region. Comparison of ε with the gradient Richardson number Ri shows that only 1.7 % of all the data with turbulence occur under the condition of Ri < 1 and that the values of ε under the condition of Ri < 1 are significantly larger than those under Ri > 1. Further, there is a roughly negative correlation between ε and Ri that is independent of the scale dependence of Ri. Turbulence under active dynamical conditions (velocity of horizontal wind U > 10 m s −1 ) is significantly stronger than under quiet conditions (U < 10 m s −1 ). Last but not least, the derived ε values are compared with the corresponding vertical shears of background wind velocity showing a linear relation with a corresponding correlation coefficient r = 58 % well above the 99.9 % significance level. This implies that wind shears play an important role in the turbulence generation in the troposphere and lower stratosphere (through the Kelvin-Helmholtz instability).

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Section: Observationsmentioning

confidence: 99%

Derivation of turbulent energy dissipation rate with the Middle Atmosphere Alomar Radar System (MAARSY) and radiosondes at Andøya, Norway

Rapp

Schrön

et al. 2016

Ann. Geophys.

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“…The antenna gain is calculated with a numerical electromagnetic code (NEC) which revealed good experimental results in a passive scan mode (Renkwitz et al, 2012(Renkwitz et al, , 2013. P R is the received power which is calculated from the SNR, the Boltzmann constant k B , the bandwidth f B and the noise temperature T n The noise temperature is strongly radar and direction dependent.…”

Section: Interferometric Analysismentioning

confidence: 99%

“…P R is the received power which is calculated from the SNR, the Boltzmann constant k B , the bandwidth f B and the noise temperature T n The noise temperature is strongly radar and direction dependent. To get the absolute sky noise temperature at different times, a convolution of the MAARSY antenna gain pattern with a cosmic sky model is used (de Oliveira-Costa et al, 2008;Stober et al, 2011b;Renkwitz et al, 2012). Figure 6 shows the SNR, the antenna gain and the RCS of the meteorhead echo at different time steps.…”

Section: Interferometric Analysismentioning

confidence: 99%

Determination of meteor-head echo trajectories using the interferometric capabilities of MAARSY

et al. 2013

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Abstract. During the flight of a meteoroid through the neutral atmosphere, the high kinetic energy is sufficient to ionize the meteoric constituents. Radar echoes coming from plasma irregularities surrounding the meteoroids are called meteor-head echoes, and can be detected by HPLA radar systems. Measurements of these echoes were conducted with MAARSY (Middle Atmosphere Alomar Radar System) in December 2010. The interferometric capabilities of the radar system permit the determination of the meteor trajectories within the radar beam with high accuracy. The received data are used to gain information about entry velocities, source radiants, observation heights and other meteoroid parameters. Our preliminary results indicate that the majority of meteors have masses between 10 −10 and 10 −3 kg and the mean masses of the sporadic meteors and Gemenids meteors are ∼ 10 −8 kg.

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“…Additionally, active experiments were conducted in which the Earth's moon and large artificial satellites were used as radar targets, as described in Renkwitz et al (2013), as well as scattering off a sounding rocket's payload (Renkwitz et al, 2015) more recently. In general, these experiments have shown a good agreement with the simulated radiation pattern, though some discrepancies have been found in the estimated beam widths and negligible inaccuracy of the beam pointing.…”

Section: Introductionmentioning

confidence: 99%

VHF antenna pattern characterization by the observation of meteor head echoes

Renkwitz¹,

Schult²,

Latteck³

2017

Atmos. Meas. Tech.

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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.

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

Cited by 9 publications

References 20 publications

Derivation of turbulent energy dissipation rate with the Middle Atmosphere Alomar Radar System (MAARSY) and radiosondes at Andøya, Norway

Derivation of turbulent energy dissipation rate with the Middle Atmosphere Alomar Radar System (MAARSY) and radiosondes at Andøya, Norway

Determination of meteor-head echo trajectories using the interferometric capabilities of MAARSY

VHF antenna pattern characterization by the observation of meteor head echoes

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