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The design, analysis, and test of the integrated device for the launch adapter and the resettable orbital deployer are presented in this paper. This integrated device contains both functions of the single-use launch adapter and the resettable orbital deployer. Two types of release mechanisms are combined. The four-bar linkage mechanism is applied in the single-use adapter function. This release mechanism provides sufficient strength of connection in the launch stage and is released when entering the orbit. The electromagnetic hook mechanism is applied in the resettable orbital deployer. The deployer can be reloaded by the manipulator on the mother satellite with picosatellites taken out from the cargo to deploy multiple times. Dynamics simulation, finite element simulation, as well as the prototype test verify the preliminary feasibility of this design.

It has long been established that plastic flow in the asthenosphere interacts constantly with the overlying lithosphere and plays a pivotal role in controlling the occurrence of geohazards such as earthquakes and volcanic eruptions. Unfortunately, accurately characterizing the direction and lateral extents of the mantle flow field is notoriously difficult, especially in oceanic areas where deployment of ocean bottom seismometers (OBSs) is expensive and thus rare. In this study, by applying shear wave splitting analyses to a dataset recorded by an OBS array that we deployed between mid-2019 and mid-2020 in the South China Sea (SCS), we show that the dominant mantle flow field has a NNW–SSE orientation, which can be attributed to mantle flow extruded from the Tibetan Plateau by the ongoing Indian–Eurasian collision. In addition, the results suggest that E–W oriented flow fields observed in South China and the Indochina Peninsula do not extend to the central SCS.New geophysical measurements, obtained from ocean-bottom seismometers, suggest that the continental collision occurring along the Himalayas exerts a significant influence on the mantle flow field beneath the South China Sea.

Abstract: In this paper, we address the problem of interference cancellation in global positioning system (GPS) receiver using an adaptive reduced-rank space-time adaptive processing (STAP) interference suppression method based on multistage nested Wiener filter (MSNWF). This improved adaptive reduced-rank method is based on the improved Gerschgorin radii algorithm. First, the cross-correlations between the desired signals of the adjacent stages of MSNWF are directly used to calculate the Gerschgorin radii instead of employing the eigenvalue decomposition of the covariance matrix. Then, a heuristic decision rule based on Gerschgorin disk estimator (GDE) is employed to estimate the rank of interference subspace. Thus optimal rank can be adaptively selected without increasing the computation. Analysis and results of the experiment show that the proposed method further reduces the computation of STAP and enhances its real-time property with the interference suppression performance unaffected.