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The magnification effect provided by gravitational lensing overcomes the limitations of current observation instruments, allowing researchers to study faint objects at high redshift (z ≈ 4). Over the last decades, the sample of strong lenses has been mostly confined to optical bands. With the advent of (sub)millimeter wide field extragalactic surveys, about 200 strong lenses have been discovered in (sub)millimeter bands. Observations with high resolution and sensitivity from ALMA, NOEMA, and SMA, coupled with the flux boost from strong lensing, provide new windows to study galaxies at high redshift. Many works have investigated topics such as star formation, interstellar medium, and dynamic properties. The main objective of this paper is to review the current research status of galaxy-galaxy lensing in (sub)millimeter bands from the perspectives of observation samples, modeling methods, and scientific applications. [ABSTRACT FROM AUTHOR]

China plans to establish a lunar orbital VLBI (Very Long Baseline Interferometer) station around 2025, which will carry a space passive hydrogen maser as the time and frequency reference. Since it is the first time to use a space passive hydrogen maser for VLBI observation, its feasibility needs to be studied and verified. Therefore, we carried out VLBI observations using the space passive hydrogen maser as the frequency reference. In the experiment, the active hydrogen atomic clock and space passive hydrogen maser were used as the frequency standard, and the alternate VLBI observations of China's Mars probe TW1 (Tianwen 1) were carried out using the 25 m radio telescope at Sheshan, Shanghai, and other VLBI stations. The results of data processing and analysis show that the standard deviation of VLBI residual group delay based on both active hydrogen atomic clock and space passive hydrogen maser are within 0.5 ns, which indicates that the space passive hydrogen maser can meet the accuracy requirements of VLBI measurement for deep space exploration, and verify its feasibility as the frequency standard of lunar orbital VLBI stations. [ABSTRACT FROM AUTHOR]

The phase delay software is a key component of VLBI (Very Long Baseline Interferometry) orbit determination system in CE-4 mission, which is critical to deep space exploration. When processing X-band DOR (Differential One-way Ranging) signals of probes in the past, the group delay jumping occasionally occurred in the observed scan. This paper consists of two parts. First, according to the VLBI station signal reception and VLBI center data processing steps, we analyzed the frequency, phase, power, and self-correlation spectrum of the signal, and located the influencing factor at the abnormal analog signal of Kunming (KM) station. Second, the group delay jumping was revised by the post-correction method, which was based on the analysis of the abnormal unwrap phase. We used the corrected phase to get the new group delay, and used orbit determination software to verify the effectiveness of the post-correction method, which upgraded the phase delay processing software. [ABSTRACT FROM AUTHOR]