Search results for "Positioning system"
showing 10 items of 107 documents
Automatic Generation of Custom Tourist Routes
2019
In this paper we present a new tool for the automatic generation of custom tourist routes. Starting from the user preferences (place to visit, starting and ending points, available time, favourite types of attractions) our system is able to extract information from the Web and to suggest a custom route to the user. Our system is based only onto online information, which is dynamically extracted at the query time, so that it can work for every location in the world, with no restrictions. Furthermore, our method does not require any user intervention, unless the input parameters. Our system is also able to give to the users supplementary information about the route stops, as a photo slideshow…
A Multichannel Information System to Build and Deliver Rich User-Experiences in Exhibits and Museums
2011
In this article a multichannel information system to build and deliver rich user experiences in exhibits and museums is presented. The system was designed to use information about a particular exhibit or museum while delivering a wide user experience based on different distribution channels. The overall information is used to build different solutions that can be delivered simultaneously on different media from touch-screen installations to portable devices like smart phones. Moreover, all the devices signed in the environment are able to communicate to each others to increase the level of the usability of the system. A case study and analysis of experimental results are also provided.
Monitoring displacements of an earthen dam using GNSS and remote sensing
2014
This paper shows the results of a scientific research in which a GNSS continuous monitoring system for earth-dam deformations has been developed, then, deformations have been related with reservoir water surface and level. The experiment was conducted near Bivona (Sicily, Italy), on the Castello dam (Magazzolo Lake). On the top of the dam three control points were placed and three GNSS permanent stations were installed. The three stations continuously transmitted data to the control centre of the University of Palermo. The former has been determined using freely available satellite data (specifically Landsat 7 SLC-Off) collected during the whole study period (DOYs 101 to 348 2011). Issues r…
Physics-aware Gaussian processes in remote sensing
2018
Abstract Earth observation from satellite sensory data poses challenging problems, where machine learning is currently a key player. In recent years, Gaussian Process (GP) regression has excelled in biophysical parameter estimation tasks from airborne and satellite observations. GP regression is based on solid Bayesian statistics, and generally yields efficient and accurate parameter estimates. However, GPs are typically used for inverse modeling based on concurrent observations and in situ measurements only. Very often a forward model encoding the well-understood physical relations between the state vector and the radiance observations is available though and could be useful to improve pre…
Deep Gaussian processes for biogeophysical parameter retrieval and model inversion
2020
Parameter retrieval and model inversion are key problems in remote sensing and Earth observation. Currently, different approximations exist: a direct, yet costly, inversion of radiative transfer models (RTMs); the statistical inversion with in situ data that often results in problems with extrapolation outside the study area; and the most widely adopted hybrid modeling by which statistical models, mostly nonlinear and non-parametric machine learning algorithms, are applied to invert RTM simulations. We will focus on the latter. Among the different existing algorithms, in the last decade kernel based methods, and Gaussian Processes (GPs) in particular, have provided useful and informative so…
State Estimation of a Nonlinear Unmanned Aerial Vehicle Model using an Extended Kalman Filter
2008
An Extended Kalman Filter is designed in order to estimate both state variables and wind velocity vector at the same time for a non conventional unmanned aircraft. The proposed observer uses few measurements, obtained by means of either conventional simple air data sensors or a low cost GPS. To cope with the low rate of the GPS with respect to the other sensors, the EKF algorithm has been modified to allow for a dual rate measurement model. State propagation is obtained by means of an accurate six degrees of freedom nonlinear model of the aircraft dynamics. To obtain joint estimation of state and disturbance, wind velocity components are included in the set of the state variables. Both stoc…
Inhomogeneous spatio-temporal point processes on linear networks for visitors’ stops data
2022
We analyse the spatio-temporal distribution of visitors' stops by touristic attractions in Palermo (Italy) using theory of stochastic point processes living on linear networks. We first propose an inhomogeneous Poisson point process model, with a separable parametric spatio-temporal first-order intensity. We account for the spatial interaction among points on the given network, fitting a Gibbs point process model with mixed effects for the purely spatial component. This allows us to study first-order and second-order properties of the point pattern, accounting both for the spatio-temporal clustering and interaction and for the spatio-temporal scale at which they operate. Due to the strong d…
Deep Gaussian Processes for Geophysical Parameter Retrieval
2018
This paper introduces deep Gaussian processes (DGPs) for geophysical parameter retrieval. Unlike the standard full GP model, the DGP accounts for complicated (modular, hierarchical) processes, provides an efficient solution that scales well to large datasets, and improves prediction accuracy over standard full and sparse GP models. We give empirical evidence of performance for estimation of surface dew point temperature from infrared sounding data.
Precipitable water vapour content from ESR/SKYNET sun-sky radiometers: validation against GNSS/GPS and AERONET over three different sites in Europe
2018
The estimation of the precipitable water vapour content (W) with high temporal and spatial resolution is of great interest to both meteorological and climatological studies. Several methodologies based on remote sensing techniques have been recently developed in order to obtain accurate and frequent measurements of this atmospheric parameter. Among them, the relative low cost and easy deployment of sun–sky radiometers, or sun photometers, operating in several international networks, allowed the development of automatic estimations of W from these instruments with high temporal resolution. However, the great problem of this methodology is the estimation of the sun-photometric calibration par…
A survival approach for the analysis of cruise passengers’ behavior at the destination
2016
The present work aims at proposing an analysis of cruise passengers’ behavior at the destination through a survival analysis approach. Data collected through GPS devices on cruise passengers’ behavior in the port of Palermo and Dubrovnik are analyzed in order to show similarities and differences among behaviors at the destination, according to socio-demographic characteristics. Results are of interest from both a methodological perspective, related with the processing and the analysis of GPS data, and from the destination management perspective.