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The quick and precise location of the burning zones of coal fires, which are continuously burning in abandoned coal mines worldwide, has long been a technical problem. The unmanned aerial vehicle (UAV) can reduce field work intensity, improve data collection efficiency, and ensure high accuracy at low cost. In order to visualize the distribution of burning points of coal fires, the UAV-based thermal infrared oblique photography is adopted. A 4-step 3D thermal imaging method is proposed in which the processing of thermal images is the most crucial. Furthermore, a software program is developed to improve the contrast and quality of batches of thermal images in one-click as well as to unify the temperature level and scale in each thermal image. This methodology is implemented in the Maoergou coal fires in China to reconstruct the surface thermal field in genuine 3D. The high-temperature zones are illustrated clearly in the 3D thermal model. The results indicate that this methodology can be used as a tool for the delineation of coal fires and other types of thermal anomaly scenario. [ABSTRACT FROM AUTHOR]

Winter fallow farmland is increasing dramatically in some regions in China. Our goal was three-fold: (1) to develop a consistent procedure to identify winter fallow farmland from satellite images; (2) to examine the driving factors of winter fallow farmland; and (3) to identify additional determinants affecting the spatial distribution of winter fallow farmland. We applied geographically weighted regression to examine the spatial interactions of these driving factors. High percentages of winter fallow farmland in the north-eastern region were largely attributed to elevation, income, farmland area, and slope. Geography had a strong impact on the occurrence of fallow farmland. [ABSTRACT FROM AUTHOR]

Fractional-order derivative is attracting more and more attention of researchers in image processing because of its better property in restoring more texture than the total variation. To improve the performance of fractional-order variation model in image restoration, a truncated fractional-order variation model was proposed in Chan and Liang [Truncated fractional-order variation model for image restoration, J. Oper. Res. Soc. China]. In this paper, we propose a dual approach to solve this truncated fractional-order variation model on noise removal. The proposed algorithm is based on the dual approach proposed by Chambolle [An algorithm for total variation minimisation and applications, J. Math Imaging Vis. 20 (2004), pp. 89–97]. Conversely, the Chambolle's dual approach can be treated as a special case of the proposed algorithm with fractional order α = 1. The work of this paper modifies the result in Zhang et al. [Adaptive fractional-order multi-scale method for image denoising, J. Math. Imaging Vis. 43(1) (2012), pp. 39–49. Springer Netherlands 0924–9907, Computer Science, pp. 1–11, 2011], where the convergence is not analysed. Based on the truncation, the convergence of the proposed dual method can be analysed and the convergence criteria can be provided. In addition, the accuracy of the reconstruction is improved after the truncation is taken. [ABSTRACT FROM AUTHOR]

Many users are now showing strong interest in UAV RS (Unmanned Aerial Vehicle Remote Sensing) due to its easy accessibility. UAVs have become popular platforms for remote sensing data acquisition. In a number of practical and time constrained circumstances, UAV RS data have been widely used as a substitute for traditional satellite remote sensing data. However, airspace-related regulations are far behind the rapid growth in the number of UAVs and their wide applications. Much effort of the network-based UAV RS have been made by the UAV RS group of the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (IGSNRR, CAS), which proposed the concept of UAV RS data carrier. UAV RS data carrier refers to UAV RS data platform with task planning, data storage, image processing, product generation and output products for various UAVs. An ongoing effort to create a nationwide UAV RS network in addition to an existing ground observational network is being carried out in China. [ABSTRACT FROM AUTHOR]

Gifted programs are an indispensable component of gifted education, and have drawn much academic attention in the recent years. However, the public images of such programs are still under-examined. In this study, we employed semantic network analysis and content analysis to uncover the public images of gifted programs in China and their change over time. Based on 1,486 Chinese news reports between 1978-2015 on gifted education, our analysis revealed four different images of gifted programs and their participants in China: "successful graduates", "early ripe, early rot", "superb intelligence", and "all-around development". The co-existence of two common stereotypes, "the chosen ones" and "Mad genius", can be concluded from the emerging process of these four images and the correlations between them. In addition, the rise and fall of different images show how the public opinions of gifted programs change over time, influenced by both institutional interventions and culture shifts. The change over time is indicative of the social-constructive nature of public opinions towards gifted education. [ABSTRACT FROM AUTHOR]

Land-surface water is an important factor influencing the regional environment and climate and is a key factor in the Tibetan Plateau, which is one of the most sensitive regions to global changes. Because of the high elevation, complex topography, and erratic weather of the Tibetan Plateau, direct measurement of the area of every lake is largely unfeasible. Moreover, complex natural geographic conditions increase the difficulty of image processing and information extraction with remote sensing because they enhance the uncertainty of quantitative data retrieved with satellites. Methods based on spectral features do not generate the expected results of lake area over the Tibetan Plateau due to a lack of distinction between water and other land objects, especially snow, vegetation, and low cloud cover. Therefore, a new method to extract lake area from satellite images in the Tibetan Plateau is needed. In this article, an automatic method was proposed to evaluate lake area during the wet season (from 1 September to 31 October) on the Tibetan Plateau with multi-day Advanced Very High Resolution Radiometer (AVHRR) remote-sensing images on board the Meteorological Operational satellite-A (MetOp-A) satellite. The method considers both spectral and textural features of lakes and does not need a cloud mask as an input. In addition, the Mixture Tuned Matched Filtering (MTMF) algorithm was applied to decompose the mixed pixels to better identify lakes and estimate the lake area. Based on daily lake identifications, the wet season’s lake data were composited with the maximum value composition (MVC) method to determine the lake area. A comparison of our work with the manually interpreted results from Landsat Thematic Mapper (TM) images and observational reports demonstrates the accuracy and reliability of our approach. However, certain factors, i.e. the sensor zenith angle of the polar-orbit satellite and the topography, can affect the lake area extracted from the remote-sensing images. [ABSTRACT FROM AUTHOR]

This article uses principal component analysis (PCA) to determine the spatial pattern of total electron content (TEC) anomalies in the ionosphere corresponding to China's Wenchuan Earthquake of 12 May 2008 UTC (Mw = 7.9). PCA is applied to global ionospheric maps (GIMs) with transforms conducted for the time period from 08:00 to 10:00 UT on 9 May 2008. The GIMs are subdivided into 100 smaller maps (36° longitude and 18° latitude). The smaller maps (71 × 71 pixels) form the transform matrices of corresponding dimensions (2 × 1) through image processing. The transform allows for extreme principal eigenvalues to be assigned to the seismo-ionospheric signature described by Zhao et al. [2008, Is an unusual large enhancement of ionospheric electron density linked with the 2008 great Wenchuan earthquake? Journal of Geophysical Research, 113, A11304, doi: 10.1029/2008JA013613.]. Results show that the range of the TEC anomaly declines with height; however, the anomaly becomes more localized and intense at higher altitudes (250–300 km), giving the anomaly the spatial pattern of a downward-facing trumpet. [ABSTRACT FROM AUTHOR]

A multivalued wavelet transform (MWT) is proposed to fuse multisensor images in feature space. First, feature space is constructed using image-derived features, and then the MWT is introduced. The multisensor images are then fused in the MWT domain using a voting and electing fuser based on the cross-feature scale guideline and the posterior probability of the MWT coefficient. The performance of the MWT is estimated using metric measures regarding various aspects of image quality. A fusion experiment using Thematic Mapper (TM) multispectral and SPOT panchromatic images of south China demonstrates that MWT outperforms smoothing filter-based intensity modulation (SFM) in terms of the fidelity to spectral properties and the injection of salient information. The experimental results confirm that the MWT is a superior fusion method for enhancing spatial quality of multispectral images with their spectral properties reliably preserved. [ABSTRACT FROM AUTHOR]