Search results for "satellite"
showing 10 items of 1031 documents
Positioning Accuracy Comparison of GNSS Receivers Used for Mapping and Guidance of Agricultural Machines
2020
Global Navigation Satellite Systems (GNSS) allow the determination of the 3D position of a point on the Earth&rsquo
FPGA/LST-SW Encryption Module Implementation for Satellite Remote Sensing Secure Systems
2020
The need for security of data transmitted from satellites to the ground has increased. Therefore, the need for secure onboard systems is in great demand, particularly in satellite remote sensing missions. This paper describes an approach for a secure Field Programmable Gate Arrays (FPGA) implementation of the Land Surface Temperature Split Window (LST-SW) algorithm, with objective to meat real-time requirements, area optimization and achieved higher Throughput goals to be sufficient for a secure remote sensing satellite applications and missions. The system is designed using VHDL (VHSIC Hardware Description Language) in a Highlevel design method. The experimental results demonstrate that th…
Peer to Peer Equation Augmentation for an Altitude Aided GNSS Receiver
2010
This paper considers the possibility to integrate external altitude measurements with a Kalman based Global Navigation Satellite System (GNSS) receiver in a peer to peer scenario. The performance of such a system is investigated for different characteristics of the aiding measurement and for different degree of trust of the receiver upon the aiding measurement. The aiding measurement is obtained starting from the altitude measurements that the other peers in the network send to the aided user. The experiments highlight the need for a parameter that points out the effectiveness and the consistency of the computed aiding measurement. To this purpose, a reliability index is proposed, on the ba…
Utility of island populations in re-introduction programmes--relationships between Arabian gazelles (Gazella arabica) from the Farasan Archipelago an…
2014
Understanding local adaptation and population differentiation is vital to the success of re-introduction initiatives. As other mammals living on islands, Arabian gazelles (G. arabica) show reduced body size on the Farasan archipelago, which we corroborated in this study through morphometric analyses of skulls. In the light of the steep population decline on the Arabian Peninsula – but stable population development on the archipelago – we tested the potential suitability of Farasan gazelles as a source for re-introductions on the mainland. We therefore investigated genetic differentiation between Farasan and mainland populations using eleven nuclear microsatellite loci and detected a distinc…
Anthropogenic carbon stocks analysis in sparsely urbanized areas using remote sensing: a case study
2013
Anthropogenic carbon stocks in urbanized areas is a topic of growing importance at both local and regional scale nowadays, but its assessment is subjects to difficulties due to lack of data and spatial heterogeneity of the target. Remote sensing of urban areas has demonstrated its usefulness in assessing phenomena such as soil sealing and surface imperviousness, which are considered to be effective indicators of urbanization. This work presents a preliminary study of mid resolution satellite data capabilities in providing information about anthropogenic carbon stocks over the area of Emilia-Romagna region in Northern Italy. This has been done through a dual approach consisting of: (1) a dir…
In the realm of the Hubble tension—a review of solutions
2021
The $\Lambda$CDM model provides a good fit to a large span of cosmological data but harbors areas of phenomenology. With the improvement of the number and the accuracy of observations, discrepancies among key cosmological parameters of the model have emerged. The most statistically significant tension is the $4-6\sigma$ disagreement between predictions of the Hubble constant $H_0$ by early time probes with $\Lambda$CDM model, and a number of late time, model-independent determinations of $H_0$ from local measurements of distances and redshifts. The high precision and consistency of the data at both ends present strong challenges to the possible solution space and demand a hypothesis with en…
13C NMR spectroscopy of four tertiary methyl norbornenols and norbornanols
1975
Carbon chemical shifts and direct 13C1H coupling constants of 2-endo-methyl-5-norbornen-2-exo-ol, 2-exo-methyl-5-norbornen-2-endo-ol, 2-endo-methylnorbornan-2-exo-ol and 2-exo-methylnorbornan-2-endo-ol have been measured from single samples using a dual probe pulse Fourier transform method.
Complete Spectral Analysis of the1H NMR 16-Spin System of β-Pinene
1997
The complete analysis of the 1H NMR spectrum of β-pinene, (1S)-(-)-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane, which is of the ABCDEFGHIJX3Y3 type, is reported and earlier results are corrected. The vicinal coupling constants, 3J(H,H), are compared with the theoretical values calculated by using the Altona and co-workers’ equations for the structure derived by molecular modelling. The results were applied to the conformational analysis of β-pinene. © 1997 John Wiley & Sons, Ltd.
17O NMR and molecular mechanical studies of arylmethylenemalonaldehydes
1990
The 17O NMR spectra of six different arylmethylenemalonaldehydes were measured for various solvents and temperatures. The 17O NMR chemical shifts and line widths of the carbonyl oxygens of the malonaldehyde fragment show a clear variation in the series of monoaryl compounds studied. The differences between the 17O NMR chemical shifts of the formyl oxygens correlate well with two conformationally dependent 1H–1H and 1H–13C coupling constants for the same compounds. Molecular mechanical calculations were also performed in order to relate the present data with the conformational preferences of the malonaldehyde fragment of the arylmethylenemalonaldehydes.
EVASPA (EVapotranspiration Assessment from SPAce) tool: an overview
2013
International audience; Evapotranspiration (ET) is a fundamental variable of the hydrological cycle and its estimation is required for irrigation management, water resources planning and environmental studies. Remote sensing provides spatially distributed cost-effective information for ET maps production at regional scale. We have developed EVASPA too for mapping ET from remote sensing data at spatial and temporal scales relevant to hydrological or agronomica studies. EVASPA includes several algorithms for estimating evapotranspiration and various equations for estimating the required input information (net radiation, ground heat flux, evaporative fraction…), which provides a way to assess …