Improved sensitivity for space domain awareness observations with the murchison widefield array

Prabu, S.; Hancock, P. J.; Zhang, Xiang; Tingay, Steven; Hodgson, Torrance; Crosse, B.; Johnston‐Hollitt, M.

doi:10.1016/j.asr.2022.05.013

Cited by 9 publications

(10 citation statements)

References 23 publications

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“…The details about reflector trajectories, details about the signal properties that are known a priori by the transmitting parties, and an atmospheric model could be combined to produce an accurate physical model of a received RFI signal. For example, Prabu et al (2022) demonstrated that RFI detection can be greatly enhanced by two different methods that incorporate more specific prior information about the RFI. The first method, called "shift-stacking," coherently averages in image space over a region expected to be occupied by a known reflector.…”

Section: Discussionmentioning

confidence: 99%

Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array

Wilensky,

Morales,

Hazelton

et al. 2023

ApJ

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We present deep upper limits from the 2014 Murchison Widefield Array Phase I observing season, with a particular emphasis on identifying the spectral fingerprints of extremely faint radio frequency interference (RFI) contamination in the 21 cm power spectra (PS). After meticulous RFI excision involving a combination of the SSINS RFI flagger and a series of PS-based jackknife tests, our lowest upper limit on the Epoch of Reionization (EoR) 21 cm PS signal is Δ2 ≤ 1.61 × 104 mK2 at k = 0.258h Mpc−1 at a redshift of 7.1 using 14.7 hr of data. By leveraging our understanding of how even fainter RFI is likely to contaminate the EoR PS, we are able to identify ultrafaint RFI signals in the cylindrical PS. Surprisingly this signature is most obvious in PS formed with less than 1 hr of data, but is potentially subdominant to other systematics in multiple-hour integrations. Since the total RFI budget in a PS detection is quite strict, this nontrivial integration behavior suggests a need to more realistically model coherently integrated ultrafaint RFI in PS measurements so that its potential contribution to a future detection can be diagnosed.

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Section: Discussionmentioning

confidence: 99%

Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array

Wilensky,

Morales,

Hazelton

et al. 2023

ApJ

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“…Te second phase was completed in 2017 and ofcially put into use in 2018; the construction of the second phase doubled the number of antennas [42]. Te MWA is an international efort by different countries and its data are publicly available [43]. MWA's primary scientifc goals consist of four key scientifc themes: searching for the redshift of 21 cm radiation in the reionization era of the early universe, galactic and extragalactic sky surveys, time-domain astrophysics, as well as the study of scientifc problems and space weather in the sun, heliosphere, and ionosphere [44].…”

Section: Five Hundred-meter Aperture Spherical Radio Telescope (Fast)mentioning

confidence: 99%

Progress and Challenges in Electromechanical Coupling of Radio Telescopes

Yan

Xue

et al. 2022

International Journal of Antennas and Propagation

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Radio astronomy is a discipline of dynamics and wonders. The vast universe has many secrets to unravel. As one of the important facilities in this discipline, radio telescopes play a key role in collecting astronomical data and unraveling mysteries. With the demand of radio astronomy for a higher frequency, wider bandwidth, higher gain, and higher pointing accuracy, the aperture of the radio telescope is gradually increasing, and its electrical performance and structure have become tightly coupled. Therefore, how to ensure the stable and efficient operation of the telescope for the long-term operation has become the urgent demand for large aperture high-performance radio telescopes. Therefore, this paper firstly makes a comparison of the overall condition of large radio telescopes in nearly a decade that are both constructed and operated, including the progress of radio telescopes that are being constructed and the planning for construction. Then, systematically summarized the latest research progress of electromechanical coupling technology from 3 aspects of connotation and application of electromechanical coupling, and performance guarantee under slowly varying load and performance guarantee under rapidly varying load from the perspectives of design, manufacturing, and observation operating. Lastly, the future research direction of electromechanical coupling technology is pointed out according to the development trend of radio astronomy.

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“…Space domain awareness (SDA) is the basis of space activities and an important support for space information acquisition [1][2][3]. Geosynchronous orbit (GEO) has attracted much attention because of its special geographical location [4].…”

Section: Introductionmentioning

confidence: 99%

Prediction model of GEO spacecraft position after maneuver based on causal Bayesian network

Long

Yang

Chen

2023

J. Phys.: Conf. Ser.

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Predicting the position of Geosynchronous (GEO) spacecraft under maneuver is a crucial work for space domain awareness (SDA) as it can help to improve the flexibility and operational efficiency of space surveillance network (SSN). The longitude is a unique freely assigned parameter for GEO spacecraft, in this paper, a predictive model of GEO spacecraft longitude based on causal Bayesian network is proposed. Firstly, the causal parameters of longitude is found by Gaussian perturbation equation. Secondly, the Markov order of the causal parameters is obtained by transfer entropy. Finally, the linear expressions for Gaussian functions is proved and a causal Bayesian network (CBN) prediction model for longitude is constructed. After experimental analysis, the mean absolute error (MAE) and mean square error (MSE) of the proposed method are decreased by 71.88% and 72.18%, respectively compared with the traditional Long short-term memory (LSTM) method.

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Improved sensitivity for space domain awareness observations with the murchison widefield array

Cited by 9 publications

References 23 publications

Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array

Evidence of Ultrafaint Radio Frequency Interference in Deep 21 cm Epoch of Reionization Power Spectra with the Murchison Wide-field Array

Progress and Challenges in Electromechanical Coupling of Radio Telescopes

Prediction model of GEO spacecraft position after maneuver based on causal Bayesian network

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