Calibration and testing of the MEXART antenna using solar transits

González-Esparza, A.; Carrillo, A.; Andrade, E.; Sierra, P.; Vazquez, S.; Rodríguez, Carmen Dolores Arbelo; Pérez-Enríquez, R.; Kurtz, S.; Blanco‐Cano, X.

doi:10.1016/j.asr.2005.09.032

Cited by 8 publications

(4 citation statements)

References 3 publications

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“…The other version of the heliospheric tomography uses the observation of white light Thomson scattering brightness from the Solar Mass Ejection Imager [e.g., Eyles et al ., ; Jackson et al ., ], available for years 2003–2010. We choose the CCMC tomography version using IPS data for this validation because IPS arrays are still in operation, and there are several IPS arrays around the globe, some of which are upgraded or newly built [e.g., Swarup et al ., ; González‐Esparza et al ., ; van Haarlem et al ., ].…”

Section: Introductionmentioning

confidence: 99%

Validation for solar wind prediction at Earth: Comparison of coronal and heliospheric models installed at the CCMC

et al. 2015

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Multiple coronal and heliospheric models have been recently upgraded at the Community Coordinated Modeling Center (CCMC), including the Wang-Sheeley-Arge (WSA)-Enlil model, MHD-Around-a-Sphere (MAS)-Enlil model, Space Weather Modeling Framework (SWMF), and heliospheric tomography using interplanetary scintillation data. To investigate the effects of photospheric magnetograms from different sources, different coronal models, and different model versions on the model performance, we run these models in 10 combinations. Choosing seven Carrington rotations in 2007 as the time window, we compare the modeling results with the Operating Mission as Nodes on the Internet data for near-Earth space environment during the late declining phase of solar cycle 23. Visual comparison is proved to be a necessary addition to the quantitative assessment of the models' capabilities in reproducing the time series and statistics of solar wind parameters. The MAS-Enlil model captures the time patterns of solar wind parameters better, while the WSA-Enlil model matches with the time series of normalized solar wind parameters better. Models generally overestimate slow wind temperature and underestimate fast wind temperature and magnetic field. Using improved algorithms, we have identified magnetic field sector boundaries (SBs) and slow-to-fast stream interaction regions (SIRs) as focused structures. The success rate of capturing them and the time offset vary largely with models. For this quiet period, the new version of MAS-Enlil model works best for SBs, while heliospheric tomography works best for SIRs. The new version of SWMF with more physics added needs more development. General strengths and weaknesses for each model are diagnosed to provide an unbiased reference to model developers and users. MotivationWe are motivated to validate the coronal and heliospheric models for the quasi-steady solar wind from the following three respects. First, a stream interaction region (SIR) forms when fast wind overtakes and interacts with the proceeding slow wind. It is in nature the same as the commonly known corotating interaction region [e.g., Smith and Wolfe, 1976;Gosling and Pizzo, 1999]. However, we use SIRs to emphasize that when the solar background changes within one Carrington rotation (CR), the resultant SIRs are short lived and do not corotate with the Sun to recur. In fact, Jian et al. [2006, 2011a] find 51% of SIRs near solar maximum and 10% at solar minimum do not recur at Earth. Large-amplitude Alfvén waves [Belcher and Davis, 1971] in SIRs and the following fast wind can drive a series of particle injections and affect the evolution of outer radiation belt (centered at about 4 R E ), as demonstrated in Miyoshi and Kataoka [2005]. Additionally, in geomagnetic storms, a large amount of energy is transferred from the solar wind into the magnetosphere and eventually dissipated in the thermosphere (about 90-600 km aboveground) and ionosphere (about 60-1000 km aboveground) by Joule heating and auroral precipitation [e.g., Gonzal...

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Section: Introductionmentioning

confidence: 99%

Validation for solar wind prediction at Earth: Comparison of coronal and heliospheric models installed at the CCMC

et al. 2015

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“…In 2004 -2005 we initiated the calibration testings of the antenna radiation pattern using E -W rows in a full power configuration to observe transits of the Sun and strong cosmic radio sources (González-Esparza et al, 2005, 2006 characteristics. In this work, we report observations using 16 E -W rows (1/4 of the antenna, covering a physical area of about 2400 m 2 ) and a BM of 16 × 16 ports.…”

Section: Description Of the Arraymentioning

confidence: 99%

Observations of Interplanetary Scintillation (IPS) Using the Mexican Array Radio Telescope (MEXART)

et al. 2010

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The Mexican Array Radio Telescope (MEXART) consists of a 64 × 64 (4096) full-wavelength dipole antenna array, operating at 140 MHz, with a bandwidth of 2 MHz, occupying about 9660 square meters (69 m × 140 m) (http://www.mexart.unam.mx). This is a dedicated radio array for Interplanetary Scintillation (IPS) observations located at latitude 19°48 N, longitude 101°41 W. We characterize the performance of the system. We report the first IPS observations with the instrument, employing a Butler Matrix (BM) of 16 × 16 ports, fed by 16 east -west lines of 64 dipoles (1/4 of the total array). The BM displays a radiation pattern of 16 beams at different declinations (from −48, to +88 degrees). We present a list of 19 strong IPS radio sources (having at least 3σ in power gain) detected by the instrument. We report the power spectral analysis procedure of the intensity fluctuations. The operation of MEXART will allow us a better coverage of solar wind disturbances, complementing the data provided by the other, previously built, instruments.

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“…DIVISION II / COMMISSION 49 (E-W 70 m × N-S 170 m) (Gonzalez-Esparza et al 2006). This array supports a multiplebeam system (<www.mexart.unam.mx/>).…”

Section: The Termination Shock and Heliospheric Boundarymentioning

confidence: 99%