IPS observations at 140 MHz to study solar wind speeds and density fluctuations by MEXART

Chang, O.; González-Esparza, A.; Mejia‐Ambriz, J. C.

doi:10.1016/j.asr.2015.12.023

Cited by 10 publications

(7 citation statements)

References 21 publications

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“…Once the observed power spectrum of the 3C48 radio source has been obtained, we perform the speed calculation using the single-station analysis methodology (Manoharan & Ananthakrishnan, 1990). We followed the methodology used in a previous analysis (Chang et al, 2016(Chang et al, , 2019Mejia-Ambriz et al, 2015). Figure 10 shows the fit of the theoretical spectrum with the observed one.…”

Section: Ips Observationsmentioning

confidence: 99%

“…MEXART was originally operating with a 16 × 16 Butler matrix, which produced 16 fixed latitudinal beams (Gonzalez-Esparza et al, 2004). Using 1/4 of the antenna (16 E-W lines), MEXART undertook operations and reported the first measurements of IPS sources (Mejia-Ambriz et al, 2010), the detection of solar wind transient events (Romero-Hernandez et al, 2015), and the systematic observations of a few IPS sources to infer the yearly variation of their scintillation indexes (Chang et al, 2016). To improve the single-station fitting analysis, Aguilar-Rodriguez et al (2014) presented a new technique based on the wavelet transform for analyzing MEXART IPS data.…”

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confidence: 99%

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First Observations of the New MEXART's Digital System

et al. 2022

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The Mexican Array Radio Telescope (MEXART) is a transit instrument mainly dedicated to performing interplanetary scintillation (IPS) observations with a central operating frequency of 139.65 MHz. The main scientific objective is to perform studies of solar wind properties and space weather effects. MEXART initially operated with an analog beam former (16 × 16 Butler matrix), which produced 16 fixed latitudinal beams. MEXART began operations and reported the first measurements of IPS sources. MEXART's beam forming system had several problems, however. The North‐South beams had poor directivity, with large side lobes, and the instrument did not achieve the expected performance. Therefore, we commissioned the design and construction of a digital back‐end. The digital system solved the problems with the beam forming, increases the bandwidth, and significantly improves the instrument's sensitivity. In this paper, we present the first light of MEXART's digital system. We describe the new technical capabilities of the instrument, and we show some preliminary results: an estimation of the radio telescope's sensitivity (ΔSmin = 2.28 ± 0.23 Jy), the transit of the Galaxy at 140 MHz with the simultaneous tracking of 62 latitudinal beams, and an example of an IPS observation and the single‐station methodology for calculating the solar wind speed. The new technical capabilities of the radio telescope will provide the potential for participating in several scientific studies. These include solar wind properties, space weather forecasting, ionospheric perturbations, and astrophysical aims such as the monitoring of repeating fast radio bursts and pulsars' observations.

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Section: Ips Observationsmentioning

confidence: 99%

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confidence: 99%

First Observations of the New MEXART's Digital System

et al. 2022

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“…To calculate the velocity from a single-site system alone (where only a single observing frequency is used), it is necessary to fit a theoretical model to the power spectrum (e.g., Chang et al, 2016;Manoharan & Ananthakrishnan, 1990). The generalized equation for the theoretical model of a single-station IPS power spectrum, P(f), is given by equation (1); this work is based on the adaptation of Mejia-Ambriz et al (2015) for use with different instruments and with different observing frequencies.…”

Section: Ssamentioning

confidence: 99%

Single‐Site IPS Power Spectra Analysis for Space Weather Products Using Cross‐Correlation Function Results From EISCAT and MERLIN IPS Data

et al. 2019

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Interplanetary scintillation (IPS) manifests itself as a variation in the radio signal received from a distant, compact radio source on the sky. The intensity fluctuations of the radio waves are caused by density inhomogeneities in the outflowing solar plasma across the heliosphere. IPS allows us to infer solar wind speed and density variations along the line of sight. There are two types of techniques in the literature to infer solar wind speed using IPS data sets: single‐site analysis (SSA), where the power spectra from single time series are analyzed to obtain solar wind parameters, and multisite analysis, where the cross‐correlation function of data from two or more widely separated sites is used. The selection of the analysis technique depends on the number of sites available to each IPS system. In order to combine and complement solar wind speed determinations from different instruments, it is important to validate results and methodologies of the two techniques. In this paper, we analyzed previously well‐studied European Incoherent SCATter (EISCAT) and Multi‐Element Radio‐Linked Interferometer Network (MERLIN) observations of IPS with well‐known results from the cross‐correlation function methodology. We applied the SSA technique to each of the individual EISCAT and MERLIN IPS power spectra. This work shows the capabilities of the SSA to describe complex events and seeks to obtain improved parameter fits using the SSA methodology.

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“…This transit radio telescope has an extension of 140 m along the east‐west direction and 70 m along the north‐south direction, covering a physical area of about 9600 m 2 [ Gonzalez‐Esparza et al , ; Mejia‐Ambriz et al , ]. The main scientific objective for space weather purposes is to track large‐scale solar wind perturbations (such as coronal mass ejections and stream interaction regions) in their course from the Sun to the Earth using Interplanetary Scintillation (IPS) observations [ Romero‐Hernandez et al , ; Chang et al , ]. The IPS is detected with radio telescope measurements of extragalactic radio sources with a signal that is affected by solar wind electron density variations [ Hewish et al , ].…”

Section: Ground‐based Instrumental Networkmentioning

confidence: 99%

Mexican Space Weather Service (SCiESMEX)

et al. 2017

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Legislative modifications of the General Civil Protection Law in Mexico in 2014 included specific references to space hazards and space weather phenomena. The legislation is consistent with United Nations promotion of international engagement and cooperation on space weather awareness, studies, and monitoring. These internal and external conditions motivated the creation of a space weather service in Mexico. The Mexican Space Weather Service (SCiESMEX in Spanish) (www.sciesmex.unam.mx) was initiated in October 2014 and is operated by the Institute of Geophysics at the Universidad Nacional Autonoma de Mexico (UNAM). SCiESMEX became a Regional Warning Center of the International Space Environment Services (ISES) in June 2015. We present the characteristics of the service, some products, and the initial actions for developing a space weather strategy in Mexico. The service operates a computing infrastructure including a web application, data repository, and a high‐performance computing server to run numerical models. SCiESMEX uses data of the ground‐based instrumental network of the National Space Weather Laboratory (LANCE), covering solar radio burst emissions, solar wind and interplanetary disturbances (by interplanetary scintillation observations), geomagnetic measurements, and analysis of the total electron content (TEC) of the ionosphere (by employing data from local networks of GPS receiver stations).

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IPS observations at 140 MHz to study solar wind speeds and density fluctuations by MEXART

Cited by 10 publications

References 21 publications

First Observations of the New MEXART's Digital System

First Observations of the New MEXART's Digital System

Single‐Site IPS Power Spectra Analysis for Space Weather Products Using Cross‐Correlation Function Results From EISCAT and MERLIN IPS Data

Mexican Space Weather Service (SCiESMEX)

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