A novel multi-source data fusion method based on Bayesian inference for accurate estimation of chlorophyll-a concentration over eutrophic lakes

2021 ◽  
pp. 105057
Author(s):  
Cheng Chen ◽  
Qiuwen Chen ◽  
Gang Li ◽  
Mengnan He ◽  
Jianwei Dong ◽  
...  
Keyword(s):  
Bayesian Inference ◽  
Data Fusion ◽  
Chlorophyll A ◽  
Accurate Estimation ◽  
Fusion Method ◽  
Eutrophic Lakes ◽  
Chlorophyll A Concentration ◽  
Source Data

scholarly journals Multi-source data fusion method for structural safety assessment of water diversion structures

2021 ◽  
Author(s):  
Sherong Zhang ◽  
Ting Liu ◽  
Chao Wang
Keyword(s):  
Data Fusion ◽  
Safety Assessment ◽  
Evidence Theory ◽  
Weighted Average ◽  
Water Diversion ◽  
Sensor Data ◽  
Structural Safety ◽  
Fusion Method ◽  
Bhattacharyya Distance ◽  
Source Data

Abstract Building safety assessment based on single sensor data has the problems of low reliability and high uncertainty. Therefore, this paper proposes a novel multi-source sensor data fusion method based on Improved Dempster–Shafer (D-S) evidence theory and Back Propagation Neural Network (BPNN). Before data fusion, the improved self-support function is adopted to preprocess the original data. The process of data fusion is divided into three steps: Firstly, the feature of the same kind of sensor data is extracted by the adaptive weighted average method as the input source of BPNN. Then, BPNN is trained and its output is used as the basic probability assignment (BPA) of D-S evidence theory. Finally, Bhattacharyya Distance (BD) is introduced to improve D-S evidence theory from two aspects of evidence distance and conflict factors, and multi-source data fusion is realized by D-S synthesis rules. In practical application, a three-level information fusion framework of the data level, the feature level, and the decision level is proposed, and the safety status of buildings is evaluated by using multi-source sensor data. The results show that compared with the fusion result of the traditional D-S evidence theory, the algorithm improves the accuracy of the overall safety state assessment of the building and reduces the MSE from 0.18 to 0.01%.

scholarly journals Chlorophyll-a concentration retrieval in eutrophic lakes in Lithuania from Sentinel-2 data

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Dalia Grendaitė ◽  
Edvinas Stonevičius ◽  
Jūratė Karosienė ◽  
Ksenija Savadova ◽  
Jūratė Kasperovičienė
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Remote Sensing Data ◽  
Empirical Equations ◽  
Active Constituent ◽  
Eutrophic Lakes ◽  
Band Ratio ◽  
Local Conditions ◽  
Chlorophyll A Concentration ◽  
Sentinel 2

Inland waters are an important habitat for flora and fauna and are also used for aesthetic, recreational, and industrial needs; therefore, monitoring the current state of freshwaters and applying measures to improve water quality are of high importance. To have an efficient monitoring system that could cover large areas, the use of remote sensing data is crucial. In this study the suitability of the Sentinel-2 Multispectral Imager data is tested for observing cyanobacteria bloom events in the eutrophic lakes and retrieving the chlorophyll-a concentration – an indicator of phytoplankton biomass. The analysis is carried out using data from four lakes in Lithuania – two eutrophic blooming lakes and two oligo-mesotrophic non-blooming lakes. The results showed that reflectances are higher in the eutrophic lakes than in the oligo-mesotrophic lakes due to the presence of an optically active constituent, namely, chlorophyll-a pigment. We tested empirical equations for chlorophyll-a concentration retrieval in eutrophic lakes derived in other studies to check whether they could be used without adaptation to local conditions. Most of the equations performed well (R2 = 0.5–0.8); however, they had high RMSEs = 17–53 μg L–1. The equation used with the bottom of atmosphere data CHL8_L2A (R2 = 0.76) had the lowest RMSE = 9 μg L–1. In addition, we derived empirical equations for eutrophic lakes in Lithuania. The equations that were based on the Sentinel-2 band ratio B5/B4 and the three band (B4, B5, and B8A) expression performed the best (R2 = 0.77–0.79) and had lower RMSE = 7 μg L–1 than empirical equations from other studies. A larger in situ dataset could improve the algorithm performance in retrieving the chlorophyll-a concentration. The first attempts to map water quality parameters in eutrophic lakes in Lithuania using the data received from the Sentinel-2 MSI sensor show good results, as the changes in reflectance, caused by the changes in chlorophyll-a concentration, can be seen from satellite images.

scholarly journals Geographical Scene Reconstruction and Application of Ancient Site with Fused Multi-source Data

2019 ◽  
Vol 1 ◽  
pp. 1-2
Author(s):  
Lin Yang ◽  
Jiangwei Shen ◽  
Fangzihao Zheng
Keyword(s):  
Data Fusion ◽  
Archaeological Site ◽  
Temporal Analysis ◽  
Fusion Method ◽  
Time Data ◽  
Seamless Integration ◽  
Human Environment ◽  
Source Data ◽  
Spatio Temporal ◽  
Functional Areas

<p><strong>Abstract.</strong> As important places and cultural relics retained by the ancients in production and activities, ancient sites have internal geographical feature and differentiation laws under the interaction of long-term human-environment relationship. Thereof, aiming to the current relative research shortage of geographical background and space-time frame, the research goal of multi-level geographical parsing for archaeological site was proposed in this paper. By summarizing the characteristics of multi-source spatio-temporal data, we studied on the data fusion method and building the whole archaeological site considering total scene factors and knowledge rules, as well as the related application research. The Lingjiatan Site was adopted as the study area in this paper, and we reconstructed its 3D geographical scene with the surveying and excavation data in the past 30 years. Furthermore, we attempted to study the spatial morphology, patterns and arrangement on different levels and scales about the site.</p><p>Methodology: the data fusion method proposed in this paper was as Figure1. The multi-source data included UAV images, LiDAR data, archaeological drilling and excavation data, basic geographical data and so on. On basis of the completed spatio-temporal elements information, aiming at the characteristic of these data, we put forward the methods of data pre-processing and data fusion, which involved registration, space interpolation, raster calculation, Boolean operation, 3D modelling and so on. The key research focused on the seamless integration and uniform data maintenance of these multi dimensions and multi-time data. Ultimately, we constructed the holographic geographical scene of the historical site, which provided a spatio-time platform for the subsequent geographical analysis and primary application.</p><p>Analysis and primary application: the geographical scene of Lingjiatan Site was as figure 2. Combining with the archaeological data, we could carry out some primary spatio-temporal analysis: (1) the distribution of the functional areas (three kinds of relics: sacrificial area, living areas and trenches) and the relationship with the natural environment; (2) the spatio-temporal relationship among the functional areas; (3) by simulating the optimal paths of several typical relics (the details were as following figure 3 showed ), reasoning for the ancients’ behaviour patterns, and providing the forecasting and verification for field archaeology.</p>

scholarly journals An Improved Multi-Source Data Fusion Method Based on the Belief Entropy and Divergence Measure

Entropy ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 611 ◽  
Author(s):  
Zhe Wang ◽  
Fuyuan Xiao
Keyword(s):  
Data Fusion ◽  
Evidence Theory ◽  
Weighted Average ◽  
Weights Of Evidence ◽  
Experimental Result ◽  
Fusion Method ◽  
Combination Rule ◽  
Combination Rules ◽  
Source Data ◽  
Belief Entropy

Dempster–Shafer (DS) evidence theory is widely applied in multi-source data fusion technology. However, classical DS combination rule fails to deal with the situation when evidence is highly in conflict. To address this problem, a novel multi-source data fusion method is proposed in this paper. The main steps of the proposed method are presented as follows. Firstly, the credibility weight of each piece of evidence is obtained after transforming the belief Jenson–Shannon divergence into belief similarities. Next, the belief entropy of each piece of evidence is calculated and the information volume weights of evidence are generated. Then, both credibility weights and information volume weights of evidence are unified to generate the final weight of each piece of evidence before the weighted average evidence is calculated. Then, the classical DS combination rule is used multiple times on the modified evidence to generate the fusing results. A numerical example compares the fusing result of the proposed method with that of other existing combination rules. Further, a practical application of fault diagnosis is presented to illustrate the plausibility and efficiency of the proposed method. The experimental result shows that the targeted type of fault is recognized most accurately by the proposed method in comparing with other combination rules.

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