The aim of this work is to develop a model for orthogonal transformation, called Tasselled Cap, to Sentinel-2 images. The essence of the Tasselled Cap Transformation (TCT) model is the unitary matrix ...for orthogonal transformation. In this paper is generated unitary matrix for ortogonalisation of the images from MSI (MultiSpectral Instrument) sensor Sentinel-2. Brightness, Greenness, and Wetness Tasselled Cap indices were derived for the MSI Sentinel-2 sensor. Eight images of sensor Sentinel-2 from July 2016 were used. Two images are from Northwestern Bulgaria, two are from the central part of Northern Bulgaria, two from Northeast Bulgaria, and the remaining two--from the central and eastern part of Southern Bulgaria. Test areas are used to choose respective homogenous clusters for determining the base vector of Orthogonal Transformation, Brightness and the two other components, Greenness, and Wetness. Based on the obtained unitary matrix a model for automatic preprocessing of Sentinel-2 images was developed aimed at obtaining Brightness, Greenness, and Wetness Tasselled Cap indices.Part of the obtained results from applying the orthogonalisation model are presented for four test areas of MSI sensor Sentinel-2 images.Key words: Sentinel-2, satelite images, orthogonal transformation, unitary matrix, Tasselled Cap, Brightness, Greenness, Wetness
La complejidad en la determinación inicial del parámetro hidrológico de impermeabilidad, comúnmente abreviado como (% imp.), se debe, entre otras razones, a la alta variabilidad espacial que ...caracteriza el medio urbano, en el cual se presentan varias coberturas de suelo en pequeñas porciones de terreno, que en ocasiones llegan a ser menores de una hectárea. Con este artículo se busca hacer una contribución metodológica para la estimación indirecta de tal parámetro, a partir de la cantidad de habitantes por unidad de área y de la relación domicilios por área, tomando como caso de estudio dos subcuencas localizadas dentro del sector oeste de la ciudad de Coro, Venezuela. Primero se realizaron pruebas de sensibilidad del parámetro y después se probó la técnica de interpretación digital automática de imágenes de satélite con clasificadores tradicionales para determinar su cuantificación, revelando incoherencias predominantes en las zonas de transición con usos mezclados. Se optó por la extracción manual de zonas impermeables y se construyeron curvas regionalizadas. Desde el punto de vista metodológico, el procedimiento resulta eficaz, ya que las curvas regionalizadas permiten ahorrar tiempo importante en la estimación inicial de este parámetro.
Studying of solar radiation is essential to estimate its amount at ground level. In practice, there are two sources of solar data; the first consists of the measured ground data available in ...meteorological networks and radiometric solar stations. And, the other consists of extracting solar data from digital satellite images. However, only a few stations measured irregularly the amount solar radiation. Hence, in this paper, we will present a description and classification of some solar radiation estimation models based on ground measurements. Moreover, satellite image processing models are also discussed, an improvement of these models using fuzzy logic is also viewed. The validity of these models will be judged by comparing the obtained results by actually measured values of the available ground stations.
Many of technologies which are nowadays useful for the mankind were developed for the military purpose. One of these technologies is Remote Sensing, which has been aimed to obtain information from ...the hostile territory. Investments to the development of Remote Sensing technologies are now coming back because these systems output data are increasingly used for the monitoring and data analysis in various fields of our life.
This study was undertaken to analyze the quantitative impact of a municipal wastewater treatment operation on the long-term water quality changes in a tributary of the Han-river, Korea from 1994 to ...1999. Changes of land use pattern in the study watershed are quantitatively analyzed on the basis of land use maps that were created by classifying Landsat TM images acquired in April 1994 and March 1999. During this period, the average increase of land use area in terms of residence, cultivation, and barren was 5.89, 0.13, and 0.12%, respectively, and the corresponding decrease in water and forest area was 0.21 and 0.16%. The annual average reductions of BOD, T-N, and T-P by the municipal wastewater treatment operation were about 89, 11 and 27%, respectively. Spatial analysis of the pollution discharge from watershed was undertaken using a geographic information system (GIS) based model. A clear reciprocal relationship was found between the basin-wide self-purification coefficient and the watershed form ratio excepting a catchment area with water drain facilities. Due to land use changes over the five year study period, water quality change in terms of BOD, T-N, and T-P were (+)1.04 mg l(-1) (corresponding to a 13.7% increase of pollution), (+)0.58 mgl(-1) (10.0% increase), and (-)0.01 mg l(-1) (1.6% decrease). On the other hand, the effect of water quality restoration assessed by outward appearance during the same period was about 67.6, 39, and 36.5%, respectively. Consequently, it is understood that total stream water quality recovery in terms of BOD, T-N, and T-P were 81.3, 49.0, and 38.1% respectively, and that this included a negative contribution resulting from increased land use and a positive contribution due to the wastewater treatment operation at Inchon.
Process of object recognition in satellite images of high resolution is a complex task associated with a time consumption and complexity of the operator's work. This paper describes an innovative ...approach for solving this problem. Based on monochromatic high-resolution satellite images (in the process of using data from the QuickBird satellite with a maximum resolution of 0.6 meters per pixel) geodata bitmap and vectorized output are received (shape files). The principle of object recognition in a satellite image is based on the allocation of edges in the gradient transition using a threshold filter. Obtained data is then transformed to a vector output using straight line detection and connected components analysis. The proposed method allows to process satellite images of large size with high performance. The performance of the proposed method can be improved by using GPU-based computations.
