Search results for "Remote sensing"
showing 10 items of 1262 documents
Object-based image analysis technique for gully mapping using topographic data at very high resolution (VHR)
2018
An accurate mapping of gullies is important since they are still major contributors of sediment to streams. Mapping gullies can be difficult because of the presence of dense canopy, which precludes the identification through aerial photogrammetry and other traditional remote sensing methods. Moreover, the wide spatial extent of some gullies makes their identification and characterization through field surveys a very large and expensive proposition. One cheaper and more expeditious way to detect gullies can be achieved in terms of morphological characteristics by the Digital Elevation Models (DEMs). The recent widespread availability of very high resolution (VHR) imagery, such as LIDAR data,…
Thermal-Infrared Spectral and Angular Characterization of Crude Oil and Seawater Emissivities for Oil Slick Identification
2014
Previous work has shown that the emissivity of crude oil is lower than that of the seawater in the thermal-infrared (TIR) spectrum. Thus, oil slicks cause an emissivity decrease relative to the seawater in that region. The aim of this paper was to carry out experimental measurements to characterize the spectral and angular variations of crude oil and seawater emissivities. The results showed that the crude oil emissivity is lower than the seawater emissivity and that it is essentially flat in the atmospheric window of 8-13 μm. The crude oil emissivity has a marked emissivity decrease with the angle (from 0.956 ± 0.005 at 15 ° to 0.873 ± 0.007 at 65 °), which is even higher than that of the …
Assessment of vine development according to available water resources by using remote sensing in La Mancha, Spain
1999
Abstract The relevance of growing vines under semiarid conditions is universally accepted because of its impacts on social, economic and environmental aspects. Improving the knowledge of the soil–plant–atmosphere system related to the expression of vine growth allows the study of vine cover in wide areas. Several aspects of vine growing under semiarid conditions, related to weather, soil, and plant cover are analysed in this paper. Once the ground truth is achieved, multitemporal studies by remote sensing are especially useful for vine growth monitoring. The purpose of this work is focussed on determining changes of vine cover development according to available water resources in relation t…
Global Navigation Satellite Systems And Services
2008
This chapter introduces the concept of Satellite Navigation in the context of space infrastructures and technologies that can contribute for improvement of life on Earth. It includes a review of the motivations for developing a satellite navigation system, and the applications and services these systems have in daily life. Furthermore, currently existing Global Navigation Satellite Systems (GPS and GLONASS) and other GNSS systems under development (GALILEO) are described from different perspectives: from the technical and architectural aspects to the ways chosen to finance their development and operations. To round up this chapter, an analysis of the expected trends in GNSS systems is prese…
LST retrieval algorithm adapted to the Amazon evergreen forests using MODIS data
2018
Abstract Amazonian tropical forests play a significant role in global water, carbon and energy cycles. Considering the importance of this biome and climate change projections, the monitoring of vegetation status of these rainforests becomes of significant importance. In this context vegetation temperature is presented as a key variable linked with plant physiology. In particular some studies showed the relationship between this variable and the CO2 absorption capacity and biomass loss of these tropical forests proving the potential use of vegetation temperature in the monitoring of the vegetation status. Nevertheless, the use of thermal remote sensing data over tropical forests still has so…
UVolc: A software platform for measuring volcanic SO2 fluxes
2012
We present here a novel stand-alone software platform, UVolc, for remotely sensed measurement of volcanic SO"2 emission rates. Such data are important diagnostics of activity conditions, with utility in forecasting measures. This code is made user friendly to enable volcanologists, who are not experts in the underlying physics of spectroscopy, to perform their own measurements. The program provides considerable reduction in errors and far greater operating flexibility than existing analogous code, which, unlike UVolc, can only interface with hardware no longer in manufacture. UVolc will be described here, including a presentation of data collected with this program in the field.
The bridge volcanic LIdar-BILLI: A review of data collection and processing techniques in the Italian most hazardous volcanic areas
2020
Volcanologists have demonstrated that carbon dioxide (CO2) fluxes are precursors of volcanic eruptions. Controlling volcanic gases and, in particular, the CO2 flux, is technically challenging, but we can retrieve useful information from magmatic/geological process studies for the mitigation of volcanic hazards including air traffic security. Existing techniques used to probe volcanic gas fluxes have severe limitations such as the requirement of near-vent in situ measurements, which is unsafe for operators and deleterious for equipment. In order to overcome these limitations, a novel range-resolved DIAL-Lidar (Differential Absorption Light Detection and Ranging) has been developed as part of…
Hot-spot detection and characterization of strombolian activity from MODIS infrared data
2014
Identifying and characterizing strombolian activity from space is a challenging task for satellite-based infrared systems. Stromboli volcano is a natural laboratory that offers a unique opportunity for refining thermal remote-sensing applications that involve transient phenomena and small to moderate hot-spots. A new simple and fast algorithm gave us the opportunity to revisit the MODIS-derived thermal output at Stromboli volcano over the last 13 years. The new algorithm includes both night-time and daytime data and shows high performance with the detection of small-amplitude thermal anomalies ( 1000 MW). The ...
Pixel-oriented land use classification in energy balance modelling
2012
Mass and energy transfer between soil, vegetation and atmosphere is the process that allows to maintain an adequate energy and water balance in the earth–atmosphere system. However, the evaluation of the energy balance components, such as the net radiation and the sensible and latent heat fluxes, is characterized by significant uncertainties related to both the dynamic nature of heat transfer processes and surfaces heterogeneity. Therefore, a detailed land use classification and an accurate evaluation of vegetation spatial distribution are required for an accurate estimation of these variables. For this purpose, in the present article, a pixel-oriented supervised classification was applied …
Assessing impacts of soil management measures on ecosystem services
2018
Only a few studies have quantified and measured ecosystem services (ES) specifically related to soil. To address this gap, we have developed and applied a methodology to assess changes in ecosystem services, based on measured or estimated soil property changes that were stimulated by soil management measures (e.g., mulching, terracing, no-till). We applied the ES assessment methodology in 16 case study sites across Europe representing a high diversity of soil threats and land use systems. Various prevention and remediation measures were trialled, and the changes in manageable soil and other natural capital properties were measured and quantified. An Excel tool facilitated data collection, c…