1,721,201 research outputs found
Classification of TiungSAT-1 MSEIS Data for Land Cover Mapping with Hyperspectral Analysis Approach
Full text linkThe low to medium spatial resolution satellite data can still be utilized to meet the requirement for a certain level of land cover mapping. However, the land cover classifications of assigning pixel-by-pixel basic to specific land cover classes have been known to be a problematic phenomenon that limits the accuracy of classification. This paper examines the result of utilizing the hyperspectral approach as a recent alternative solution to the above problem to investigate whether or not the sensitivity allowed in the latter can increase the classification accuracy. Using TiungSAT-1 MSEIS data as input, comparative analysis were also performed with classical Maximum Likelihood classification. The results of this study clearly indicate that hyperspectral analysis can improve classification accuracy of multi-spectral data, especially when the mixed pixels are of great concern
The Potential of Agent-Based Modelling for Verification of People Trajectories Based on Smartphone Sensor Data
No full textIn this paper the potential of smartphone sensor data for verification of people trajectories derived from airborne remote sensing data are investigated and discussed based on simulated test recordings in the city of Osnabrueck, Germany. For this purpose, the airborne imagery is simulated by images taken from a high building with a typical single lens reflex camera. The smartphone data required for the analysis of the potential is simultaneously recorded by test persons on the ground. In a second step, the quality of the smartphone sensor data is evaluated regarding the integration into simulation and modelling approaches. In this context we studied the potential of the agent-based modelling technique concerning the verification of people trajectories
Very high resolution optical satellites for DEM generation: a review
Full text linkThe advent of very high resolution (VHR) optical satellites capable of producing stereo images led to a new era in extracting digital elevation model which commenced with the launch of IKONOS. The special specifications of VHR optical satellites besides, the significant economic profit stimulated other countries and companies to have their constellations such as EROS-A1 and EROS-B1 as the cooperation between Israel and ImageSat. QuickBird, WorldView-1 and WorldVew-2 were launched by DigitalGlobe. ALOS and GeoEye-1 were offered by Japan and GeoEye Respectively. In addition to aforementioned satellites, Indian and South Korea initiated their own constellation by launching CartoSat-1 and KOPOSAT-2 respectively.The availability of all so-called satellites make a huge market of stereo images for extracting of digital elevation model and other correspondent applications such as, producing orthorectifcatin images and updating maps. Therefore, there is a need for a comprehensive comparison for scientific and commercial clients to choose appropriate satellite images and methods of generating digital elevation model to obtain optimum results. This paper will thus give a review about the specifications of VHR optical satellites. Then it will discuss the automatic elaborating of digital elevation model. Finally an overview of studies and corresponding results is reported
Utilization of TiungSAT-1 Data for Coastal Current Studies
Full text linkThis study proposes a method for utilizing TiungSAT-1 data for coastal current studies. The Hopfield neural network has been used to model surface current movements. The study shows that the surface currents vectors range from 0.7 m/s to 1.4 m/s. It can be concluded that TiungSAT-1 data could be used for the detection of surface currents based on the intensity gradient variations that can be detected from the energy equation motion of neuron
Assessment of the Capability of TiungSAT-1 Satellite Data for Mapping Chlorophyll Distribution
Full text linkThe capability of TiungSAT-1 Multispectral Earth Imaging System (MSEIS) satellite data for mapping chlorophyll distribution was assessed for the coastal areas of Muar, Johor by using the green band 3 (0.50 – 0.59µm), acquired on 29 July 2001. Sea viewing Wide Field of view Sensor (SeaWiFS) data using the SeaWiFS default chlorophyll-a algorithm (OC4V4) was used to derive chlorophyll-a in the study area. The bands used are band 2 (443nm), band 3 (490nm), band 4 (510nm) and band 5 (555nm). The digital numbers (DN) of TiungSAT-1 data were converted to reflectance values by using internal average relative reflectance (IARR). A plot of SeaWiFS chlorophyll-a versus reflectance values from TiungSAT-1 data was made. The plots show that there is no correlation between reflectance values from TiungSAT-1 data and chlorophyll-a values from SeaWiFS data. This is due to the unavailability of the blue band and the stripping effects in the TiungSAT-1 data. This indicates that the TiungSAT-1 satellite data is not useful in ocean colour studies to derive chlorophyll data
Generation of Tasseled Cap Transformation Coefficients for the Use of TiungSAT-1 Multi Spectral Earth Imaging System (MSEIS) Data
Full text linkThe so-called “Tasseled Cap†transformation developed by Kauth and Thomas in 1976 is a means for highlighting the most important (spectrally-observable) phenomena of crop development in a way that allows discrimination of specific crops. For Landsat Multispectral Scanner (MSS) data, the Tasseled cap transform perform an orthogonal transformation of the original data into new four-dimensional space consisting of the soil brightness index (SBI), the green vegetation index (GVI), the yellow stuff/vegetation index (YVI) and non-such index (NSI) associated with atmospheric effects. For LandSAT Thematic Mapper (TM) data, the Tasseled Cap vegetation index consists of three factors, “Brightnessâ€, “Greennessâ€, and “Thirdâ€. The Brightness and Greenness are equivalent to the MSS tasseled cap SBI and GVI, and the third component is related to soil features, including moisture status. In this project, an effort has been made to generate Tasseled Cap coefficient for TiungSAT-1 Multi Spectral Earth Imaging System (MSEIS) data which has no such coefficient yet. This is a recent effort since TiungSAT-1 is a Malaysian micro satellite which was recently launched in September 2000. These generated coefficients were then used to generate TC layers to derive vegetation and soil information from TiungSAT-1 data. Besides TiungSAT-1 data, LandSAT TM data were also used to compare the results obtained from TiungSAT-1. Both TiungSAT-1 and TM images were processed for TTC and supervised classification. The results show that the generated TTC coefficients are sufficient to separate vegetation information from TiungSTA-1 data
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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