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X.B. Zhao W.Z. Shao L.B. Zhao Y. Gao Y.Y. Hu X.Z. Yuan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(10):3072-3086
The main objective of our work was to investigate the impact of rain on wave observations from C-band (~5.3 GHz) synthetic aperture radar (SAR) in tropical cyclones. In this study, 10 Sentinel-1 SAR images were available from the Satellite Hurricane Observation Campaign, which were taken under cyclonic conditions during the 2016 hurricane season. The third-generation wave model, known as Simulating WAves Nearshore (SWAN) (version 41.31), was used to simulate the wave fields corresponding to these Sentinel-1 SAR images. In addition, rainfall data from the Tropical Rainfall Measuring Mission satellite passing over the spatial coverage of the Sentinel-1 SAR images were collected. The simulated results were validated against significant wave heights (SWHs) from the Jason-2 altimeter and European Centre for Medium-Range Weather Forecasts data, revealing a root mean square error (RMSE) of ~0.5 m with a 0.25 scatter index. Winds retrieved from the VH-polarized Sentinel-1 SAR images using the Sentinel-1 Extra Wide-swath Mode Wind Speed Retrieval Model after Noise Removal were taken as prior information for wave retrieval. It was discovered that rain did indeed affect the SAR wave retrieval, as evidenced by the 3.21-m RMSE of SWHs between the SAR images and the SWAN model, which was obtained for the ~1000 match-ups with raindrops. The raindrops dampened the wave retrieval when the rain rate was < ~5 mm/hr; however, they enhanced wave retrieval for higher rain rates. It was also found that the portion of the rain-induced ring wave with a wave number > 0.05 rad/m (~125 m wavelength) was clearly observed in the SAR-derived wave spectra. 相似文献
3.
The water content of magma oceans is widely accepted as a key factor that determines whether a terrestrial planet is habitable. Water ocean mass is determined as a result not only of water delivery and loss, but also of water partitioning among several reservoirs. Here we review our current understanding of water partitioning among the atmosphere, magma ocean, and solid mantle of accreting planetary embryos and protoplanets just after giant collisions. Magma oceans are readily formed in planetary embryos and protoplanets in their accretion phase. Significant amounts of water are partitioned into magma oceans, provided the planetary building blocks are water-rich enough. Particularly important but still quite uncertain issues are how much water the planetary building blocks contain initially and how water goes out of the solidifying mantle and is finally degassed to the atmosphere. Constraints from both solar-system explorations and exoplanet observations and also from laboratory experiments are needed to resolve these issues. 相似文献
4.
A. V. Bogatyi R. V. El’nikov I. P. Nazarenko G. A. Popov S. A. Semenikhin 《Russian Aeronautics (Iz VUZ)》2018,61(3):445-451
The paper presents the research results of the effect of a capacitor energy storage device configuration on the specific characteristics of advanced modern propulsion systems based on the ablative pulsed plasma thrusters (APPT). These thrusters are designed to perform specific tasks within the small spacecrafts with the onboard power capacity up to 200 W. 相似文献
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E. R. Muslimov E. Hugot M. Ferrari T. Behaghel N. K. Pavlycheva 《Russian Aeronautics (Iz VUZ)》2018,61(1):1-7
The possibility of constructing an optical scheme of a telescope for a small satellite based on mirrors with freeform surfaces and a curved photodetector is considered. It is shown that the use of a new element base allows the effective area of the main mirror to be maximized and the field of view up to 9.4 times to be increased in comparison with the classical scheme of the Ritchey–Chretien scheme in ensuring the high image quality. 相似文献
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T. K. Sirazetdinov 《Russian Aeronautics (Iz VUZ)》2007,50(1):30-36
A brief review of studies on simulation and control of a porous cooling process taking into account material transpiration is given. An approximated solution for an equation of the one-dimensional problem of fast ablation is also presented. 相似文献
8.
The results of the experimental studies of damping characteristics of a composite torsion bar in the helicopter main rotor
hingeless hub are presented. A variant of their improvement is considered. 相似文献
9.
We present an algorithm for calculating the shells of revolution with the branching meridian using the triangular finite elements, the rigidity matrices of which are formed based on the vector method of displacement interpolation [1]. The correct kinematic and static conditions of shell conjugation on the line of their coupling have been developed. The shell structure consisting of a cylinder and adjacent shells is calculated under various conditions of support. 相似文献
10.
I. S. Akhmed’yanov 《Russian Aeronautics (Iz VUZ)》2009,52(4):383-389
The application of the quadrature method [1] to analyzing the shells of revolution under symmetrical loading relative to the
zero meridian is considered. The method can be treated as a generalization of the method presented in [2] to solve the Volterra
integral equation of the second kind. 相似文献