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Modern studies of solar radio emission are complicated by continuous power amplification and multifrequency external interference, which often completely overlap important frequency ranges. Many topical problems in solar radio astronomy require large effective areas of radio telescopes, high frequency and time resolutions, accurate spatial measurements, and a large dynamic range. It becomes relevant to change the concept of receiving recording equipment. This paper deals with topical problems of the physics of the solar corona in combination with optimal methods of observation with large instruments. The features and difficulties of combining high parameters—dynamic, spatial, temporal, and frequency resolutions—are considered. The proposed solutions of the new-generation observation complex implement the possibilities of intelligent selection of registration conditions in a multioctave mode with multichannel over 8000 channels/GHz with temporary permission up to 8 ms/spectrum. A multiobject observation mode becomes available from powerful flaring objects to faint structures of various nature. High-speed data processing makes it possible to implement an online mode of interference elimination, which is based on a fast statistical analysis of the spectrum with the selection of non-Gaussian (interference) structures. Methods for high-speed analysis of large-volume data (the principal component analysis method) and their presentation to the user are proposed. Examples of the operation of the complex in the range of 1–3 GHz are given. The prospects of a new approach for multiobject radio astronomy observations in the implementation of the RATAN-600 tracking mode are considered: from recombination lines to wide-range spectra, from low-contrast fluctuations to fast changes in flares, etc. [ABSTRACT FROM AUTHOR]

The rapidly increasing number of satellites in Earth's orbit motivates the development of Space Domain Awareness (SDA) capabilities using wide field-of-view sensor systems that can perform simultaneous detections. This work demonstrates preliminary orbit determination capability for Low Earth Orbit objects using the 36 ° × 36 ° field-of-view of the Murchison Widefield Array (MWA) at commercial Frequency Modulated (FM) frequencies (transmitters in 88 - 108 MHz range). Non-coherent passive radar techniques with the MWA produce spatially smeared detections, due to time averaging in the MWA's standard signal processing chain. The work develops methods to extract time-stamped measurements of a satellite's angular coordinates from these data. The developed method was tested on observations of 32 satellite passes and the extracted measurements were used to perform orbit determination for the targets using a least-squares fitting approach. The target satellites span a range in altitude and Radar Cross Section, providing examples of both high and low signal-to-noise detections. The estimated orbital elements for the satellites are validated against the publicly available Two Line Element (TLE) updates provided by the Space Surveillance Network (SSN) and the preliminary estimates are found to be in close agreement. The work also tests for re-acquisition for one target using the orbital elements and finds the trajectory predicted by the method to coincide within 0.2 ° cross-track and 0.3 ° in-track for a subsequent pass, reduced to approximately 0.1 ° cross-track (less than one kilometre) if two passes are used to predict the subsequent pass (using simple two-body propagation). The median uncertainty in the angular position for objects in LEO (range less than 1000 km) is found to be 860 m in the cross-track direction and 780 m in the in-track direction, which are comparable to the typical uncertainty of ∼ 1000 m in the publicly available TLE information. The techniques, therefore, demonstrate the MWA to be capable of being a valuable contributor to the global SDA community. Based on the understanding of the MWA SDA system, this paper also briefly describes methods to mitigate the impact of FM-reflecting LEO satellites on radio astronomy observations, and how maintaining a catalog of FM-reflecting LEO objects is in the best interests of both SDA and radio astronomy. [ABSTRACT FROM AUTHOR]

We propose a parity-baseline segmented planar imaging method with more frequency components by changing different baseline selection to achieve better imaging in the rotational process. A theoretical model of the parity-baseline segmented planar imaging system with rotational operation is built to analyze the imaging effect. The simulation results show that the imaging quality of the parity-baseline segmented planar imaging system has an approximately 20% increase by rotation compared with the conventional system. In addition, the CLEAN algorithm in radio astronomy imaging is also applied to the parity-baseline segmented planar imaging system, and the image quality is further improved by 55%. Such a new imaging method holds great potential toward astronomical observation and detection. [ABSTRACT FROM AUTHOR]

Understanding how material accretes onto the rotationally supported disk from the surrounding envelope of gas and dust in the youngest protostellar systems is important for describing how disks are formed. Magnetohydrodynamic simulations of magnetized, turbulent disk formation usually show spiral-like streams of material (accretion flows) connecting the envelope to the disk. However, accretion flows in these early stages of protostellar formation still remain poorly characterized, due to their low intensity, and possibly some extended structures are disregarded as being part of the outflow cavity. We use ALMA archival data of a young Class 0 protostar, Lupus 3-MMS, to uncover four extended accretion flowâ€"like structures in C18O that follow the edges of the outflows. We make various types of positionâ€"velocity cuts to compare with the outflows and find the extended structures are not consistent with the outflow emission, but rather more consistent with a simple infall model. We then use a dendrogram algorithm to isolate five substructures in positionâ€"positionâ€"velocity space. Four out of the five substructures fit well (>95%) with our simple infall model, with specific angular momenta between 2.7â€"6.9 Ă— 10âˆ'4 km sâˆ'1 pc and mass-infall rates of 0.5â€"1.1 Ă— 10âˆ'6 M ⊙ yrâˆ'1. Better characterization of the physical structure in the supposed “outflow cavities” is important to disentangle the true outflow cavities and accretion flows. [ABSTRACT FROM AUTHOR]