Search results for "Remote Sensing"

Exploring single polarization X-band weather radar potentials for local meteorological and hydrological applications

2015

Summary The aim of this study is to evaluate the potential use of a low-cost single polarization X-band weather radar, verified by a disdrometer and a dense rain gauge network, installed as a supporting tool for hydrological applications and for monitoring the urban area of Palermo (Italy). Moreover, this study focuses on studying the temporal variability of the Z–R relation for Mediterranean areas. The radar device is provided with an automatic operational ground-clutter filter developed by the producer. Attention has been paid to the development of blending procedures between radar measurements and other auxiliary instruments and to their suitability for both meteorological and hydrologic…

Derivation of a Distributed Unit Hydrograph Integrating GIS and Remote Sensing

2007

The paper describes the results of a study based on the integration of remote sensing and geographical information system techniques to evaluate a distributed unit hydrograph model linked to an excess rainfall model for estimating the streamflow response at the outlet of a watershed. Travel time computation, based on the definition of a distributed unit hydrograph, has been performed, implementing a procedure using (1) a cell-to-cell flow path through the landscape determined from a digital elevation model (DEM); and (2) roughness parameters obtained from remote sensing data. This procedure allows the taking into account of the differences, in terms of velocity, between the hillslopes and t…

Timing and patterns of the ENSO signal in Africa over the last 30 years: insights from normalized difference vegetation index data.

2014

Abstract A more complete picture of the timing and patterns of the ENSO signal during the seasonal cycle for the whole of Africa over the three last decades is provided using the normalized difference vegetation index (NDVI). Indeed, NDVI has a higher spatial resolution and is more frequently updated than in situ climate databases, and highlights the impact of ENSO on vegetation dynamics as a combined result of ENSO on rainfall, solar radiation, and temperature. The month-by-month NDVI–Niño-3.4 correlation patterns evolve as follows. From July to September, negative correlations are observed over the Sahel, the Gulf of Guinea coast, and regions from the northern Democratic Republic of Congo…

2003

Rocks from the depths of the Earth can be found on its surface. They provide information on the thickness of continents and permit conclusions to be drawn regarding orogenic processes

Assessment of Classifiers and Remote Sensing Features of Hyperspectral Imagery and Stereo-Photogrammetric Point Clouds for Recognition of Tree Specie…

2018

Recognition of tree species and geospatial information on tree species composition is essential for forest management. In this study, tree species recognition was examined using hyperspectral imagery from visible to near-infrared (VNIR) and short-wave infrared (SWIR) camera sensors in combination with a 3D photogrammetric canopy surface model based on RGB camera stereo-imagery. An arboretum with a diverse selection of 26 tree species from 14 genera was used as a test area. Aerial hyperspectral imagery and high spatial resolution photogrammetric color imagery were acquired from the test area using unmanned aerial vehicle (UAV) borne sensors. Hyperspectral imagery was processed to calibrated …

An automatic filtering algorithm for SURF-based registration of remote sensing images

2017

International audience; The registration of remote sensing images has been often a necessary step for further analyses of images taken at different times, different viewing geometry or with different sensors. For this task there exists many approaches. This paper focuses on the feature-based category of image registration methods. Particularly, we propose an improvement of the SURF algorithm on the point matching step. Indeed, in order to achieve a correct registration, a good matching of feature point is required. However The presence of outliers lead to a fail in the registration. Therefore, in this paper, we introduce an efficient method devoted to the detection and removal of such outli…

A kernel regression approach to cloud and shadow detection in multitemporal images

2013

Earth observation satellites will provide in the next years time series with enough revisit time allowing a better surface monitoring. In this work, we propose a cloud screening and a cloud shadow detection method based on detecting abrupt changes in the temporal domain. It is considered that the time series follows smooth variations and abrupt changes in certain spectral features will be mainly due to the presence of clouds or cloud shadows. The method is based on linear and nonlinear regression analysis; in particular we focus on the regularized least squares and kernel regression methods. Experiments are carried out using Landsat 5 TM time series acquired over Albacete (Spain), and compa…

Una aproximación volumétrica a la desagregación espacial de la población combinando cartografía temática y datos LIDAR

2016

[EN] Availability of high resolution population distribution data, independent of the administrative units in which demographic statistics are collected, is a real necessity in many fields: risk evaluation due to earthquakes, flooding or fires, to name just a few, integration between socio-demographic and environmental or geographical information collected in different formats, policy design for the provision public services, such as health, education or public transport, or mobility studies in urban areas or metropolitan regions. Because of this, the literature has explored various methods of population downscaling, collected at communality or census tract level, into smaller areas; typica…

Remote Sensing for Agriculture, Ecosystems, and Hydrology XX

2018

This proceedings volume contains papers presented during the Remote Sensing for Agriculture, Ecosystems, and Hydrology Conference. The Conference was part of the International Symposium on Remote Sensing sponsored by SPIE—The International Society for Optics and Photonics. The Symposium was held at the ESTREL Congress Centre, Berlin, Germany, from 10th to 13th of September 2018. Approximately 40+ oral and 20 poster papers were presented during this year’s conference, covering a broad range of topics in the field of remote sensing applications for environmental science.

Digital orthophotos at a scale of 1:5000 from high resolution satellite images

2004

This paper describes the first results of a study, carried out within the national research program “Cofin2001”, on the potential use of high resolution satellite images for making digital orthophotos at a scale of 1:5000 and 1:10,000. Particularly, images from IKONOS II and QuickBird of four different types of areas were employed: the first area is the city of Palermo, a greatly urbanized area; the second area is the extra-urban territory near the town of Contessa Entellina in south-western Sicily; the third area is the famous tourist resort of Scopello, in the western Sicily; the last area is the Caselle Airport, a flat zone near Torino. The first three images were orthorectified by using…