The aim of this paper is to remark possibilities to use WorldView-2 imagery for coastline extraction. Applications are conducted on a Phlegrean area in the Campania Region (Italy): the considered range of coastline is particularly interesting because it shows two typologies of shoreline including reefs interspersed with segments of sandy beach. Two indices are used: Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI).To enhance geometric resolution of the results pan-sharpening is applied so as to obtain maps with the same pixel dimensions of the panchromatic data. To solve the problem of thresholds determination that typically affects the classification, Maximum Likelihood method based on training sites is adopted to distinguish bare soil and sea water. Best results are given by NDWI and, comparing the resultant coastline with that obtained with visual interpretation of images, shifts of less than 1 m outcome from pan-sharpened data

High Resolution Satellite Images to Reconstruct Recent Evolution of Domitian Coastline

Very High Resolution Optical Satellites: An Overview of the Most Commonly used

Italian coasts are subjected to morphological modifications that in the last decades have, in many cases, been the cause of considerable...

The integration of thematic layers and DTM (Digital Terrain Model) becomes possible to achieve 3D models that can contextually display the variability of both the morphology and territorial and / or environmental components. WorldView-2 high resolution images, presenting a reduced size of the pixels on the ground (0.5 m in panchromatic and 2 m in multispectral) and a high spectral resolution (with 8 bands in the portion of the electromagnetic spectrum between wavelengths 400 nm and 1040 nm) allow the creation of very detailed maps of land cover. The simultaneous availability of DTM with appropriate cell size transforms these thematic layers in digital 3D models with high resolution.\ud This paper is aimed to test positional and thematic accuracies that can be achieved in the construction of 3D models of land cover using WorldView-2 images. Phlegraean area (in Campania region, Italy), characterized by particular morphological configuration, mainly due to the presence of craters and volcanic cones, is considered. The dataset is firstly orthorectified, using rational polynomial functions, and then processed using supervised classification (Maximum Likelihood method) to identify several homogenous classes. The indices derived by confusion matrix (Producer Accuracy, User Accuracy, Overall Accuracy, Cohen Index) permit to check the thematic accuracy. DTM is derived from technical maps (at 1:5.000 scale) and used as the basis for 3D models of land cover

GeoEye-1 panchromatic images (geometric resolution: 0.5 m) can be rectified using Rational Polynomial Functions (RPFs) without knowledge of the full sensor information: rectification is conducted using DEM (Digital Elevation Model) of the area as well as Ground Control Points (GCPs) of which both elevation and X,Y positioning must be known. Check Points with the same characteristics of GCPs (but not coincident with them) are used to verify the accuracy of the product. For both GCPs and CPs coordinates can be not only obtained with survey, but also derived from detailed maps or orthophotos (scale 1:5,000 or greater). In this paper methods to rectify GeoEye-1 images using orthophotos (scale 1:2,000) for GCPs and CPs detection are considered, with particular attention to achieved positional accuracy. The research is performed on one GeoEye-1 panchromatic image of an area in Campania region around the mouth of Volturno river and Domitian coast: differences between the coordinates of GCPs (as well as of the Check Points) on the ortophotos and the corresponding values on the rectified image are calculated and analyzed to define quality of resulting product. The variability of results in relation to the number of GCPs is analyzed and considerations about their positional accuracy so to define scale use of the corresponding rectified image are supplied