esa-sceva/satcom-chunk-collection huggingface dataset:
## 1 Introduction
### SMOS Calibration and Validation Activities  
SMOS is the outcome of a long process initiated in late 1970s. During recent years, many research activities have been performed to support this mission (see [18] for an extensive overview of recent research activities related to SMOS). Many of these activities focused on questions concerning calibration and validation issues for soil moisture and sea salinity retrieval. Others were dedicated to the detection of biomass, or to technical aspects of the sensor. Regarding soil moisture retrieval, many experimental and theoretical studies have been performed to explore the radiative properties of the basic land-cover types considered in the so-called 'L-band Microwave Emission of the Biosphere' (L-MEB) model [19] which is the Level-2 algorithm to produce soil-moisture data. This research has mostly been performed with ground-based L-band radiometers either mounted on towers or cranes. Thus, a considerable number of L-band radiometers with sometimes different characteristics have been built [20] and operated by the scientific community.  
Although our knowledge about the interaction between microwaves and land-surface features has increased dramatically in the course of these activities, further ground-based experiments during the SMOS commissioning and operative phases are essential. For this reason and to overcome the problem of different instrument performances affecting the L-band signatures, the construction of three identical L-band radiometers was recommended to ESA. These instruments have been built by a consortium consisting of an industrial partner (Metaplan, Adliswil, Switzerland) and two university partners (Institute of Applied Physics, Bern, Switzerland and Swiss Federal Research Institute WSL, Birmessdorf, Switzerland), headed by the company Gamma Remote Sensing AG (Gumligen, Switzerland), with a total budget of approximately 360 kEuro. The architecture of the three ELBARA II L-band radiometers is based on the ETH L-Band radiometer for soil-moisture research (ELBARA), [21] designed and built by the Institute of Applied Physics, University of Berne. This instrument has been successfully deployed in a series of field experiments [22, 23, 24, 25, 26, 27]. However, major improvements of the microwave electronics, the mechanics, and the user interface have been made to the successor, ELBARA II. In particular the development of an Active Cold Source as an instrument internal calibration noise source has improved the absolute accuracy significantly.
# A Target Detection Method of Distributed Passive Radar without Direct-Path Signal
## 5 Conclusions  
This paper focuses on a distributed target detection method in the without-direct-path signals system. In the case of without-direct-path signals, the target detection is realized by the GLRT. The relationship between the target detection performance, SNR, and signal length is verified. The higher the SNR, the longer the signal length and the better the target detection performance. The experimental results show that in the case of without-direct-path signals, the accuracy of target detection by GLRT is improved, and the delay detection algorithm in this paper is insensitive to the change of SNR, so the accuracy can reach 100% at \(-40\) dB.  
Figure 8: Performance comparison of different algorithms.  
Figure 9: The result of TDOA estimation.  
**Author Contributions:** Conceptualization, C.W. and H.Z.; methodology, C.W. and H.Z.; software, C.W. and L.W.; validation, H.Z., C.W. and L.W.; formal analysis, C.W.; investigation, L.W.; resources, C.W. and H.Z.; data curation, H.Z.; writing--original draft preparation, L.W.; writing--review and editing, C.W. and H.Z.; visualization, L.W.; supervision, C.W.; project administration, H.Z.; funding acquisition, H.Z. and C.W. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded in part by the China Postdoctoral Science Foundation, grant nos. 2020M673346, 2017M613076, and 2016M602775; in part by the National Natural Science Foundation of China, grant nos. 61801344, 61801347, 61631019, 61201418, and 62001350; in part by the Fundamental Research Funds for the Central Universities, grant nos. XJS200212, XJS200210, XJS200204, XJS210210, and JB210202; in part by the Aeronautical Science Foundation of China, grant no. 20181081003; and by the Postdoctoral Science Research Projects of Shaanxi Province, grant no. 2018 BSHEDZZ39.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
## 4 Analysis
### Final Considerations  
As mentioned at the beginning of the section, nowadays the computational power has strongly accelerated the possibility to use almost all methods to solve an inverse problem, ranging from a simple homogeneous medium to a 3D tomography. The DE can be easily overcome by MC, RTE, PN solutions.  
TD-DOS aims at the determination of the optical properties of homogeneous or layered tissues (e.g., brain tissue, muscle, breast, etc.) in a wide range of wavelengths. From this, by using the Beer-Lambert law and a semi-empirical scattering power law [29; 111; 112], it is possible to retrieve the chromophore concentrations and structural information (see Section 5.2).  
To make the analysis more robust, spectrally-constrained approaches were proposed, in which all the DTOFs collected from tissue at different wavelengths were analyzed as a whole with the constrain given by the optical properties of the expected constituents (e.g., water, lipid, collagen, hemoglobin) [113; 114].  
When the shape of the sample is complex or the accuracy of MC is needed, it is possible to generate a look-up table (LUT) of simulations and apply the inverse problem by searching and/or interpolating results in the LUT [115; 116]. This avoids the repetitive computation of MC, which, however, nowadays efficient, could not reach the computation speed of an analytical formula.  
Finally, an advanced fitting method was proposed to be used when there is an a priori knowledge of the probability distribution of the unknowns (typically absorption and scattering) or uncertainties in the experimental measurement (e.g., uncertainty on the temporal calibration). It is possible to include these uncertainties in the analysis process using a Bayesian approach and thus improve the estimation of the optical properties [117; 118].
# Siberia: A Self-Sovereign Identity and Multi-Factor Authentication Framework for Industrial Access
## 1 Introduction
### Practical Relevance and Application Scenarios  
SIBERIA offers a secure and privacy-oriented identity management solution applicable across a wide range of sensitive sectors. Below are several representative scenarios where its implementation would be particularly beneficial:  
* Critical Infrastructure Management: In sectors such as energy, water treatment, and transportation, SIBERIA could restrict access to control rooms strictly to authorized personnel through the use of decentralized credentials and biometric verification (voice or behavioral), ensuring operational traceability and system integrity.
* Healthcare: SIBERIA would enable secure access to medical records and hospital systems without directly storing user credentials. Furthermore, CA via behavioral biometrics would ensure that the medical professional accessing a patient's data remains verified throughout the session, preventing unauthorized use of shared terminals. Patients could also grant temporary, verifiable access to other specialists while maintaining full control over their data, in compliance with the GDPR.
* Financial and Corporate Services: In corporate environments, SIBERIA could safeguard access to sensitive financial data or intellectual property. Additionally, in high-value or high-risk transactions, initial voice-based authentication combined with continuous behavioral monitoring would ensure that the individual performing the operation remains consistently verified, significantly reducing the risk of internal or external fraud.
* Public Services: SIBERIA could provide citizens with a self-managed digital identity to securely access public services such as transportation, social programs, or electronic voting. Using VCs, users could disclose only the attributes strictly necessary, in accordance with data minimization and SSI principles.
## 4 Algorithm Test and AGV Quantity Analysis
### Single AGV Path Planning Simulation  
In order to verify the effectiveness of the improved A* algorithm, the algorithm was used to randomly produce raster maps and simulate the start and endpoints. The size of the grid was 30 \(\times\) 30; the proportion of barrier cells was 20% and 30%. The grid side length was 1, m = 10. The traditional A* algorithm and the improved A* algorithm were each used to conduct 50 simulations. After removing the abnormal data, the AGV driving distance and number of turns were recorded. The results are shown in Table 1.  
According to Table 1, total turn times with 20% were down 36.6%, and total turn times with 30% were down 27.7%. In the process of single AGV path planning, the improved A* algorithm can reduce the number of AGV turns and improve the AGV transportation efficiency.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Total Path Length** & **Total Turns Times** & **Total Path Length** & **Total Turns Times** \\
**with 20\%** & **with 20\%** & **with 30\%** & **with 30\%** \\ \hline A* algorithm & 1412 & 449 & 1458 & 574 \\ Improved A* algorithm & 1412 & 285 & 1458 & 396 \\ \hline \end{tabular}
\end{table}
Table 1: Comparison table of single-AGV path planning.  
Figure 7: Multi-AGV path planning flowchart.
# Quality Assessment of HDR/WCG Images Using HDR Uniform Color Spaces
## 2 From State-of-the-Art SDR Quality Assessment Metrics to HDR/WCG Quality Assessment Metrics  
In this section we first present the perceptually uniform color spaces able to encode the HDR/WCG content. Then in a second part, we elaborate on the color difference metrics associated with these color space. In a third part, we describe a selection of SDR quality metrics. Finally, we present how we tailor SDR quality metrics to HDR/WCG content.
# Overview of the Research Status of Intelligent Water Conservancy Technology System
## 3 Status Quo of Key Technologies of Smart Water Conservancy
### Cloud Network Convergence Architecture Based on Digital Twin  
The cloud network convergence architecture is the virtualization and integration technology framework of the network and cloud computing basic resource layer, which is regarded as the key link between the network, cloud services and computing power infrastructure, laying the foundation for the new information infrastructure. The cloud network fusion architecture ensures the timeliness of data update and synchronization with the physical basin [47]. The advantage of the cloud network integration technology of digital twins is that it considers the integration of cloud, edge and end, migrates resource-intensive tasks to the edge and end of IoT devices, and relies on the cloud native platform to realize resource sharing and network resource management and scheduling. The infrastructure needs to meet the requirements of high bandwidth, low latency and accurate simulation to support the efficient operation of digital twins [48]. The cloud computing platform can integrate network information perception, communication and intelligent computing functions to improve network intelligence, and operation and maintenance [49]. Cloud computing promotes the evolution of digital twin services into a cloud model to achieve high-precision simulation computing requirements and improve resource utilization [50]. Figure 3 shows the triangular model of the water conservancy twin \"cloud-edge-end\".  
The cloud network convergence technology system based on digital twins mainly includes three key technologies: (1) river basin ubiquitous connection and collaboration technology, which realizes network ubiquitous connection and collaboration by integrating computing power nodes through hierarchical connection architecture [51]; (2) cloud access and inter-cloud interconnection technology, using SD-WAN and SRv6 technologies to achieve network expansion and collaboration, ensuring performance and reliability [52; 53]; and (3) cloud network resource supply and differentiated service technology to provide resource pool and differentiated bearer services to ensure the differentiated service capability of the network [54]. At present, the research on cloud network integration in the field of water conservancy immatization is in the application and exploration stage, and it is necessary to deepen the research on cloud native technology in the cloud network integration scenario, so as to improve the capability of the digital twin basin information infrastructure [55].
# Lightweight Physical Layer Aided Key Agreement and Authentication for the Internet of Things +
## 4 Performance Analysis
### Effect of Intercarrier Dependency  
Another constraint that arises in measuring test statistics is intercarrier dependency. Figure 6 describes two different channels: simulated Rayleigh independent fading channel, and measured channel from the experiment. In this situation, (a) can extract useful information as the number of subcarrier increases, but (b) provides no additional information, even if it exploits the entire CRS subcarrier to encapsulate the secret key. This result implies that however a number of subcarriers are used, there is no significant reliability increase, but it improves the secrecy ability with the extension of the key length. From the point of view of reliability and computational efficiency, the selective subcarrier benefits from the signaling overhead, but it has to sacrifice its secrecy ability.
# Converging Telco-Grade Solutions 5G and beyond to Support Production in Industry 4.0
## 4 5G Functions and Features to Support the Information Flow within Industry 4.0
### Communication Requirements in MES and ERP Systems
As the ongoing improvement cycles of several lean initiatives focus on cost control and improvement in product quality, uncertainty in global markets needs greater resilience and responsiveness without sacrificing cost and quality [89, 90]. Today's businesses work in a lively and volatile market environment; therefore, to solve this scenario, businesses seek to understand horizontal and vertical integration of companies and engineering processes leading to real-time enterprise [72, 91, 92]. The integration of barcode identification and sensing technology [94] with 5G technology contains more information. It increases the efficiency of the ERP system by fast and automatic material processing operation.
# Spinning Reserve Capacity Optimization of a Power System When Considering Wind Speed Correlation
###### Abstract  
Usually, the optimal spinning reserve is studied by considering the balance between the economy and reliability of a power system. However, the uncertainties from the errors of load and wind power output forecasting have seldom been considered. In this paper, the optimal spinning reserve capacity of a power grid considering the wind speed correlation is investigated by Nataf transformation. According to the cost-benefit analysis method, the objective function for describing the optimal spinning reserve capacity is established, which considers the power cost, reserve cost, and expected cost of power outages. The model was solved by the quantum-behaved particle swarm optimization (QPSO) algorithm, based on stochastic simulation. Furthermore, the impact of the related factors on the optimal spinning reserve capacity is analyzed by a test system. From the simulation results, the model and algorithm are proved to be feasible. The method provided in this paper offers a useful tool for the dispatcher when increasing wind energy is integrated into power systems.  
spinning reserve; wind speed correlation; Nataf transformation; cost-benefit analysis; QPSO
## 1 Introduction
Thus, channel coding with a stronger ability is required to correct both key errors and transmitted error bits, which leads to a lower secure transmission rate. This continues to be a significant problem for the existing NRK-SC scheme. Aiming at this problem, this paper conducts a comprehensive and theoretical study on non-reconciled key generation and secure transmission. Furthermore, the potential merit of channel correlation between key generation and secure transmission is analyzed. Motivated by this advantage, we present a non-reconciled physical-layer keys-assisted secure communication scheme based on channel correlation. The main contributions are as follows:  
* We design a signal frame to adjust the pilot and data signals transmission process, which contributes to utilizing channel correlation between non-reconciled key generation and secure transmission. * Based on the channel correlation, the non-reconciled keys generated from the wireless channel are used to encrypt transmitted data. Before encryption, we propose an adaptive coding algorithm based on the equivalent channel to encode data bits according to different signal-to-noise ratios (SNRs). * Theoretical analysis and simulation results demonstrate that compared with the NRK-SC scheme, the proposed scheme has significant effects in reducing BER and improving the secure transmission rate. The rest of this paper is organized as follows. Section 2 deals with the system model and introduces the problem statement with respect to the prior scheme. The non-reconciled physical-layer keys-assisted secure communication scheme based on channel correlation is proposed in Section 3. The security and reliability of the proposed scheme are evaluated in Section 4 through mathematical analysis. Section 5 presents the simulation results, and Section 6 concludes the paper.
## 4 Numerical Simulation
### Analysis of Simulation Results
#### 4.3.2 Deformation Patterns of Tunnel Lining Structures  
To further investigate the deformation characteristics of the tunnel lining under water-rich conditions, deformations at various measurement points across different water levels were analyzed through numerical simulation, as depicted in Figure 13.  
Figure 13 shows that the deformation patterns of the tunnel lining across the four sections are generally similar. As the water table rises, all sections of the lining deform more. The inverted arch experiences the most significant deformation, which is followed by the arch foot and the vault. The least deformation occurs at the arch waist and spandrel.  
Due to their proximity to the fault fracture zone, the four sections experience enhanced fissure development in the surrounding rock, leading to groundwater accumulation at the inverted arch. This results in significant lining deformation from increased water and rock pressure with a notable deformation of 25.5 mm at the inverted arch (N8) in section \(\text{LK51}+640\) at a 129 m water level. The inverted arch in sections \(\text{LK51}+640\) and \(\text{RK51}+590\) exhibits greater deformation due to higher water pressures compared to sections \(\text{LK51}+610\) and \(\text{RK51}+620\). Additionally, the tunnel vault, bearing the load from the overlying soil, experiences significant deformation due to high vertical and tensile stresses. The arch foot, a stress concentration point, undergoes substantial plastic deformation under water-rich conditions, slightly exceeding the deformation at the vault.  
As the water table rises, the deformation of the inverted arch, arch foot, and vault intensifies. The appearance of macro-cracks in these critical areas allows groundwater behind the lining to seep into the tunnel, severely disrupting its normal operation. With the onset of the rainy season and rising groundwater levels, reinforcing the inverted arch, arch foot, and vault becomes essential to mitigate the risk of water seepage.  
Figure 13: Deformation of lining structure at different water level heights. (**a**) \(\text{LK51}+610\). (**b**) \(\text{LK51}+640\). (**c**) \(\text{RK51}+590\). (**d**) \(\text{RK51}+620\).
# Satellite Quantum Communications When Man-in-the-Middle Attacks Are Excluded
## 3 Discussion
### Single Photon Source (SPS)  
The SPS was assumed to be a perfect device that produces single photons on demand and never multi-photon pulses. For QKD this means it can perform the BB84 [24] protocol without any requirement for decoy states. For PKD it can even be encoded in wavelength giving a broad scope for multiplexing. In both cases the SPS has the highest rates. It should be noted that compared to the other technologies SPS devices are currently at low 'technology readiness levels' [25] or only work at cryogenic temperatures which means they are not a practical choice for deployment in space.
# A MODIS-Based Robust Satellite Technique (RST) for Timely Detection of Oil Spilled Areas
## 3 Results and Discussion
### Confutation Analysis  
To assess RST performances in the case of normal seawater conditions (i.e., unperturbed by the presence of an oil spill), a falsification analysis was carried out to verify that, in such conditions, no \"false positive\" values were detected. To this aim, we first looked for the information available in the main oil spill catalogues available online (e.g., EMSA and the Centre of Documentation, Research and Experimentation on Accidental Water Pollution (CEDRE) web sites [54; 55]), finding that no other event affected the investigated area during June 2007. Then we applied the indices of Equation (1) to the approximately 30 MODIS-Aqua images available for this period. In Figure 8, an example of the obtained results is reported for two representative MODIS-Aqua images, one acquired before and the other after the event, respectively, on 03 June 2007 at 11:33 a.m. GMT (Figure 8a,b) and 22 June 2007 at 10:25 a.m. GMT (Figure 8c,d). For both images and channels, no \(\otimes_{\text{chx}}\) values higher than three were found. Similar results were found for the whole dataset of June 2007, indicating the ability and the robustness of the RST approach to detect only pixels affected by the anomalous presence of the oil spill.  
Figure 8: As Figure 7 for MODIS-Aqua image of 03 June 2007 at 11:33 a.m. GMT (**a**) channel 1; (**b**) channel 2 and 22 June 2007 at 10:25 a.m. GMT (**c**) = channel 1; (**d**) channel 2. No anomalous pixel was detected. In the background, the corresponding R\({}_{\text{rc}}\) images are depicted in grey tones on the basis of the values indicated in the color bars. Land is masked in black.  
Such a result encourages the implementation of operational RST-based products that might furnish an estimation of the amount of oil spilled in a specific area, which could be crucial information for those regions affected by heavy oil-tanker traffic.