Junfu Fan

Shandong University of Technology · School of Civil Engineering and Geomatics

With the rapid development of remote sensing technologies, the frequency of observations of the same location is increasing, and many satellites and sensors produced a large amount of time series images. These images make long-term change detection and dynamic characteristic estimation of ground features possible. However, conventional remote sensi...

Composited nighttime light (NTL) data are widely used to evaluate the intensity of human activities and estimate urban dynamics. However, due to the effects of stray light, Visible Infrared Imaging Radiometer Suite (VIIRS) monthly composited data are vastly missing in middle-high latitude areas in summer, resulting in obvious application limitation...

Vector polygon overlay is a complex type of geo-spatial analysis algorithm used in GIS, which requires increasingly higher computational efficiency given the rapid growth of spatial datasets. Parallel computing has provided an effective approach to improve the computational efficiency and expand the processing scales of polygon overlay algorithms....

China has been undergoing a remarkably rapid urbanization process in the last several decades. Urbanization is a complicated phenomenon involving imbalanced transformation processes, such as population migrations, economic advancements and human activity dynamics. It is important to evaluate the imbalances between transformation processes to suppor...

Urbanization process involving increased population size, spatially extended land cover and intensified economic activity plays a substantial role in anthropogenic environment changes. Remotely sensed nighttime lights datasets derived from the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS) provide a consistent mea...

Building change detection is an important task in the remote sensing field, and the powerful feature extraction ability of the deep neural network model shows strong advantages in this task. However, the datasets used for this study are mostly three-band high-resolution remote sensing images from a single data source, and few spectral features limi...

Nighttime light data and land use data derived from remote sensing satellites are commonly used to monitor human activities on the Earth. A thorough understanding of the spatiotemporal interactions between these data enables better characterization and reconstruction of urbanization processes. In this work, a pixelwise fusion analysis using nightti...

Road crack segmentation based on high-resolution images is an important task in road service maintenance. The undamaged road surface area is much larger than the damaged area on a highway. This imbalanced situation yields poor road crack segmentation performance for convolu-tional neural networks. In this paper, we first evaluate the mainstream con...

There are significant differences in the dominant driving factors of rocky desertification evolution in different historical periods in southwest karst mountainous areas. However, previous studies were mostly conducted in specific periods. In this study, taking Bijie City as an example, the spatial and temporal evolution pattern of rocky desertific...

Building change detection is a primary task in the application of remote sensing images, especially in city land resource management and urbanization process assesment. Due to the rich textural features of remote sensing images and the multiscale characteristics of buildings, it is still a huge challenge to effectively filter out irrelevant change...

Based on DMSP/OLS nighttime light data and statistical yearbook data from 1992 to 2013, this paper extracts the urban built-up areas of China and India by using the reference comparison method and empirical threshold method. Nine landscape pattern indicators such as the patch number and total patch area were selected. Extracting the characteristics...

Polygon shape is an important factor affecting the efficiency of vector polygon overlay analysis. Aiming at the problems that polygon shape is difficult to accurately measure and different algorithms have different sensitivities to the same polygon in vector polygon overlay analysis, 27 shape variables are selected from literature to establish the...

There were dramatic changes in the ecological vulnerability (EV) of the China-Pakistan Economic Corridor (CPEC) region due to the effects of climate change and human activity. Obtaining field observation and statistical data for the evaluation of the EV of the CPEC region is difficult due to its transnational status. This study proposes a novel rem...

The differences between the imaging environments of sensors lead to great differences in remote sensing images of the same area in different seasons. Relative radiation correction has high practical value as the main method to reduce such differences. However, the differences in vegetation radiation caused by seasonal changes are difficult to corre...

Freeze–thaw erosion can lead to accelerated soil loss, which is an important factor related to soil erosion in cold regions. Tibet is a typical region that is seriously affected by freeze–thaw erosion. Traditionally, the analytic hierarchy process (AHP) method is used to calculate the weight of the factors in evaluations of freeze–thaw erosion, but...

Intelligence method to detect changes in remote sensing images is a difficult but important issue and it is of great significance for natural resources, environmental and social-economy monitoring. In this paper, we presented a novel deep learning model named PSPNet-CONC which combined multi-scale feature deep learning model PSPNet and features ext...

Under the context of global climate change, vegetation on the Tibetan Plateau (TP) has experienced significant changes during the past three decades. In this study, the spatiotemporal changes of growing season vegetation index (GSVI) on the TP were analyzed using various methods from pixel level to ecoregion level. In addition, a relative importanc...

Due to the harsh natural environment on the Tibetan Plateau (TP), its vegetation is sensitive to climate change. Therefore, it is essential to characterize long-term vegetation shifts for understanding of land surface processes across the TP. Gradual greening or browning growth in vegetation greenness is detectable while the alternating process bet...

While extracting roads from high-resolution remote sensing imagery, shadow shielding is a main factor causing roads missing or defects, which could lead to difficulties for automatic road extraction. Therefore, developing methods for shaded road extraction with strong applicability has a great significance in map data production and research of geo...

Traditionally, studies on freeze–thaw erosion have used the analytic hierarchy process (AHP) to calculate the weight of evaluation factors, however, this method cannot accurately depict the fuzziness and randomness of the problem. To overcome this disadvantage, the present study has proposed an improved AHP method based on the cloud model to evalua...

Nighttime light data from the Defense Meteorological Satellite Program’s Operational Linescan System are widely used for monitoring urbanization development. Brazil, Russia, India, China and South Africa (BRICS) countries have global economic and cultural influence in the new era. It was the first time for the researches about BRICS countries adopt...

To address the difficulty involved when using existing commercial Geographic Information System platforms to integrate multi-source image data fusion, this research proposes the loading of multi-source local tile data based on CesiumJS and examines the tile data organization mechanisms and spatial reference differences of the CesiumJS platform, as...

China’s cities have been undergoing rapid and intense urbanization processes in the past few decades. Shandong is a coastal province which is located in East China with big economy and population scales, and which also plays an important role in the rapid process of China’s modernization. The DMSP/OLS dataset has been widely used for the urban deve...

Projecting the distribution of malaria vectors under climate change is essential for planning integrated vector control activities for sustaining elimination and preventing reintroduction of malaria. In China, however, little knowledge exists on the possible effects of climate change on malaria vectors. Here we assess the potential impact of climat...

Computational efficiencies of traditional vector computing-based polygon clipping algorithms will decrease rapidly when handling polygons contain large amount of vertices. The computing flows of traditional polygon clipping algorithms are tightly coupled with special data structures, which difficult to be optimized in the underlying of them. Under...

The double-sided parallel line method and the geometry rasterization-based dilation method have been extensively used for buffer generation in spatial analysis. The former involves a series of complex numerical operations and may not be suitable for parallelized computation; the latter inevitably introduces precision problems and computation comple...

On buffer zone construction, the rasterization-based dilation method inevitably introduces errors, and the double-sided parallel line method involves a series of complex operations. In this paper, we proposed a parallel buffer algorithm based on area merging and MPI (Message Passing Interface) to improve the performances of buffer analyses on proce...

A dual-way seeds indexing (DWSI) method based on R-tree and the Open Geospatial Consortium (OGC) simple feature model was proposed to solve the polygon intersection-spreading problem. The parallel polygon union algorithm based on the improved DWSI and the OpenMP parallel programming model was developed to validate the usability of the data partitio...

矢量叠加分析是地理信息系统软件空间分析算法中的基础分析方法，是构建高级空间分析模型和复杂空间分析应用的基础算法，其中多边形叠加分析是矢量叠加分析中最为困难和棘手的核心操作。分治法采用分解-解决-合并的问题处理模式，应用于多边形合并算法中能够在平均水平上有效地降低合并结果的结点累积效应，与经典的“滚雪球”处理模式相比能有效提升多边形合并算法的整体计算效率。本文以多边形合并算法为例，首先通过分析基于Vatti算法实现的多边形合并算子的效率相对于多边形点数的变化特征，指出合并过程中的结点累积效应是“滚雪球”多边形合并模式的潜在性能瓶颈和隐患，进而提出基于分治法的多边形“树状”合并处理模式，在此基础上实现了面向要素集合或者要素层的多边形快速合并算法，最后给出了面向多边形合并的算法效率提升评价模型，依...

Remotely sensed measurements of anthropogenic nocturnal lighting have been extensively used for studying human settlements and socioeconomic dynamics. Considerable efforts have been devoted to build the connections between nightlight signals and demographic and economic variables at local to global scales in order to obtain observationally based es...

The photoelectric amplification characteristics of Operational Linescan System(OLS) sensors on board of the Defense Meteorological Satellite Program's(DMSP) satellites make the instruments sensitive to low visible lights in the night which can distinguish the differences of light signals between urban and rural areas.Remotely sensed nighttime light...

In this study, we proposed a new method for extracting urban built-up area from satellite-based nighttime light data. Our methods are based on locally thresholding correction of nighttime lights in association with economic statistical data (termed TC-ESD). We grouped China's cities into a series of categories according to gross domestic product an...

A visual circle based image registration algorithm for optical and SAR imagery is proposed in this paper. The visual circles with robustness to angle differences and flexible resolution build a bridge between the reference and sensed images with different resolutions and angles, and combine the spatial features and correlation measures together for...

Researchers agree that there are two main causes to sea-level rise: melting of land-ice and thermal expansion of ocean water due to global climate warming. However there exist several secondary causes that can result in sea level rise, which used to be ignored. In this study we firstly qualitatively analyzed several secondary reasons that can also...

Errors or outliers are prone to be made on account of various accidental factors or system errors in the observation process of ground object spectrums. To find out and remove the data records with outliers from the field spectroscopy data of several typical crops in Yanzhou mining area, we proposed a field spectroscopy data quality controlling the...