Search results for "Computers in Earth Science"
showing 10 items of 323 documents
Radial cracks around inclusions: A program to calculate P-T paths with respect to elastic properties of minerals
1994
Abstract Radial cracking around inclusions in a matrix originated by their differential elastic behavior allows the development of a new method for reconstructing the evolution of P-T paths during metamorphism. The appearance of radial cracking is a function of the variation of the elastic parameters between the matrix and inclusion, the initial P-T conditions of inclusion entrapment and the component of isothermal decompression characteristic for a retrograde path. The program RADCRA is written in FORTRAN 77 and presents a general form to calculate the different P-T evolutions for a matrix and an inclusion during metamorphism. Necessary input data are the elastic properties of each mineral…
A satellite stand-alone procedure for deriving net radiation by using SEVIRI and MODIS products
2018
Abstract In this study, a new stand-alone satellite approach for the estimation of net surface radiation (Rn) has been implemented and validated for the Italian territory. The method uses the MODIS and MSG-SEVIRI time series products and it is independent of the use of ancillary data (i.e. ground measurements). A database of daily measurements of Rn, provided by 9 stations of the FLUXNET network, was used to validate the method in different ecological scenarios in the period 2010-12. The Rn modelled by the proposed approach and the corresponding FLUXNET measurements were in good agreement, with RMSE and R2 of 19.8 Wm−2 and 0.87, respectively, at 8-days scale, and 23.3 Wm−2 and 0.92, respect…
A GIS-Based Methodology for Evaluating the Increase in Multimodal Transport between Bicycle and Rail Transport Systems. A Case Study in Palermo
2021
Background: In a world where every municipality is pursuing the goals of more sustainable mobility, bicycles play a fundamental role in getting rid of private cars and travelling by an eco-friendly mode of transport. Additionally, private and shared bikes can be used as a feeder transit system, solving the problem of the first- and last-mile trips. Thanks to GIS (Geographic Information System) software, it is possible to evaluate the effectiveness of such a sustainable means of transport in future users’ modal choice. Methods: Running an accessibility analysis of cycling and rail transport services, the potential mobility demand attracted by these services and the possible multimodality bet…
The SMAP and Copernicus Sentinel 1A/B microwave active-passive high resolution surface soil moisture product
2019
Abstract Soil Moisture Active Passive (SMAP) mission of NASA was launched in January 2015. Currently, SMAP has an L-band radiometer and a defunct L-band radar with a rotating 6-m mesh reflector antenna. On July 7th, 2015, the SMAP radar malfunctioned and became inoperable. Consequently, the production of high-resolution active-passive soil moisture product got hampered, and only ~2.5 months (April 15th, 2015 to July 7th, 2015) of data remain available. Therefore, during the SMAP post-radar phase, many ways were examined to restart the high-resolution soil moisture product generation of the SMAP mission. One of the feasible approaches was to substitute the SMAP radar with other available SAR…
The SMAP mission combined active-passive soil moisture product at 9 km and 3 km spatial resolutions
2018
Abstract The NASA Soil Moisture Active Passive (SMAP) mission was launched on January 31st, 2015. The spacecraft was to provide high-resolution (3 km and 9 km) global soil moisture estimates at regular intervals by combining for the first time L-band radiometer and radar observations. On July 7th, 2015, a component of the SMAP radar failed and the radar ceased operation. However, before this occurred the mission was able to collect and process ~2.5 months of the SMAP high-resolution active-passive soil moisture data (L2SMAP) that coincided with the Northern Hemisphere's vegetation green-up and crop growth season. In this study, we evaluate the SMAP high-resolution soil moisture product deri…
Land surface temperature derived from airborne hyperspectral scanner thermal infrared data
2006
Abstract The AHS (airborne hyperspectral scanner) instrument has 80 spectral bands covering the visible and near infrared (VNIR), short wave infrared (SWIR), mid-infrared (MIR), and thermal infrared (TIR) spectral range. The instrument is operated by Instituto Nacional de Tecnica Aerospacial (INTA) and it has been involved in several field campaigns since 2004. The main goal of this paper is to analyze the feasibility of retrieving land surface temperature from the 10 AHS thermal infrared bands, from 71 to 80, located in the region between 8 and 13 μm. For this purpose, three different methods have been considered: (i) the single-channel method, which uses only one thermal band; (ii) the sp…
The effects of cors network geometry and differential nrtk corrections on gnss solutions
2021
The widespread availability of Continuosly Operating Reference Station (CORS) all over the world, allows to improve more scientific and technical studies on the use of satellite positioning techniques. The aim of this paper is to understand the effects of a GNSS CORS network geometry and differential corrections on the solutions. The analysis is carried out using ten different network configurations, with different inter-distances between the stations within GNSMART Geo++ software. The coordinates of one control point placed on the top of the Department of Engineering (University of Palermo, Italy) have been used to perform several static positioning mode test within fourthy hours. Differen…
Evaluation of the AVHRR surface reflectance long term data record between 1984 and 2011
2021
Abstract The long-term data record (LTDR) from the Advanced Very High-Resolution Radiometer (AVHRR) provides daily surface reflectance with global coverage from the 1980s to present day, making it a unique source of information for the study of land surface properties and their long-term dynamics. Surface reflectance is a critical input for the generation of products such as vegetation indices, albedo, and land cover. Therefore, it is of utmost importance to quantify its uncertainties to better understand how they might propagate into downstream products. Due to the prolonged length of the surface reflectance LTDR and previous unavailability of a well calibrated reference, no comprehensive …
Analysis of technical criticalities for GIS modelling an Urban noise map
2017
This paper analyzes criticalities and strengthens of a procedure used to model the acoustic map of the vehicular traffic of an urban agglomeration. The research is based on a pilot project for the acoustic mapping of a portion of the city of Palermo (Italy). Simulations indicate that the acoustic climate was in line with expectations and with typical of large Italian cities. The most remarkable result was obtained by an increase in the number of reflections (from two to five), while the influence of the height of the building (from 9 to 18 meters) was negligible – on the order of a few points per thousand. Regarding the analysis conducted with the ‘Gden Method’, acoustic values do not diver…
A combinatorial algorithm for the optimization of refraction seismics data inversion
1993
Abstract The problem of data inversion in refraction seismics can be split in two parts: data first must be preprocessed in order to determine the travel-time curve; this essentially is a geometrical problem, complicated, however, by its pattern recognition aspects. Once the geometrical problem is solved, the second part, the inversion proper, is straightforward, as the soil layering model can be calculated according to well-known algorithms. The more difficult part of the problem is the former, which implies a type of pattern recognition; because of this type of difficulty, the geometrical part of the problem usually is committed to the skill of a human operator. This paper describes an al…