Space Engineering University

Analysis of Triple-Frequency PPP Ambiguity Resolution with Different Ambiguity Fixing Methods

Accurate ambiguity resolution (AR) is critical for precise point positioning (PPP). Triple-frequency observations enable longer wavelength combinations, improving AR performance. This study evaluates four AR algorithms, Integer Least Squares (ILS), Partial Ambiguity Resolution (P...

A 256-year daily rainfall record reveals multiscale rainy-season variability and emerging hydroclimatic hazard over northern East Asia

Monsoon rainy seasons shape water supply and flood hazard across northern East Asia, but their long-term variability remains poorly understood because few daily rainfall records extend beyond the instrumental era. Here, we reconstruct rainy-season onset, retreat, and duration fro...

Rotational-Stiffness Sensitivity of a Low-Frequency Aeroelastic Branch in a Wingtip-Connected Modular UAV

This study examines how the rotational stiffness of two wingtip interfaces changes the low-frequency aeroelastic response of a free–free, three-module unmanned aerial vehicle. A finite-element model coupled with doublet-lattice aerodynamics is analyzed using the p–k method. The r...

Fine-Grained Tree Species Classification in Urban Forests via Phenology–Structure Synergistic Fusion of Multi-Source Remote Sensing Data

Urban forest tree species composition and spatial distribution are essential for refined greenspace management, ecosystem-service assessment, and forest-health monitoring. High-resolution imagery captures crown texture and spatial boundaries, multi-temporal NDVI reflects phenolog...

Superradiant phonon laser with collective spin control

Hybrid systems consisting of phonon resonators and solid-state spin ensembles offer a unique opportunity for the study of emerging driven-dissipative quantum many-body physics. Our theoretical analysis shows that in such a phonon-matter hybrid system, the interplay of coherent an...

Key Node Identification in Spatial Information Networks via Soft Community Partition and Hypergraph Interweaving Degree

Due to the widespread deployment of large-scale satellite constellations, Spatial Information Networks (SINs) exhibit increasingly high-order node and service coupling characteristics, rendering them vulnerable to node removal and cascading failures. Traditional graph-theoretic m...

Deep Learning for Single-Frame Infrared Small and Dim Target Detection: A Paradigm-Oriented Review with Cross-Architecture Benchmarking

Single-frame infrared small and dim target detection underpins military early warning and space surveillance. However, existing review literature lacks a classification system based on architectural paradigms and standardized cross-architecture benchmarking. This paper systematic...

Label-Efficient and Lightweight Spectrum Prediction for UAV-Based Spectrum Sensing: A Critical Review

Radio-spectrum prediction can support proactive channel verification, sensing scheduling, and access decisions in unmanned aerial vehicle (UAV) systems. However, existing evidence remains fragmented across UAV-oriented prediction, label-efficient learning, and deployment-oriented...

Unraveling the dual interaction patterns of land use intensity on carbon balance: spatial heterogeneity and drivers in a transitional region of China

Abstract Under China’s “Dual Carbon” goals, accurate assessment of regional carbon balance is of critical importance. Land use acts as a core factor governing carbon balance. However, the differentiated effects of land use intensity (LUI)—a comprehensive indicator quantifying hum...

High-EfficiencyFiber Laser Generating up to 528th-OrderOrbital Angular Momentum Light

Abstract Structured light lasers carrying orbital angular momentum (OAM) have demonstrated considerable potential across diverse research fields and practical applications. Despite great progress in exploring this new degree of freedom of light, it remains challenging to achieve...

Rydberg-Atom-Based Angle-of-Arrival Estimation Method for Ku-Band Microwave Signals

The determination of the angle of arrival (AoA) of Ku-band microwave signals is of great significance in satellite communications, spectrum monitoring, and national defense security, which has created an urgent demand for high-precision and interference-resistant passive detectio...

Suppression of NF-κB signaling by Ganoderma-Rhodiola compound preparation alleviates immune dysregulation in a rat model of simulated microgravity

Background The extreme environment of spaceflight facilitates the increased pathogenicity of microorganisms while simultaneously compromising the immune systems of astronauts, thereby escalating the risk of infections and threatening mission safety. Effective countermeasures to b...

Global Optimization Design of Large-Scale Constellations for Maritime Target Detection Based on Circular Scanning Radar

Traditional Low Earth Orbit (LEO) satellite constellation design methods, primarily driven by geometric coverage, fail to satisfy the non-uniform and dynamic tracking requirements of moving targets. To address this, a multi-objective optimization framework for large-scale satelli...