Mass-Market Receiver for Static Positioning: Tests and Statistical Analyses

Nowadays, there are several low cost GPS receivers able to provide both pseudorange and carrier phase measurements in the L1band, that allow to have good realtime performances in outdoor condition. The present paper describes a set of dedicated tests in order to evaluate the positioning accuracy in static conditions. The quality of the pseudorange and the carrier phase measurements let hope for interesting results. The use of such kind of receiver could be extended to a large number of professional applications, like engineering fields: survey, georeferencing, monitoring, cadastral mapping and cadastral road. In this work, the receivers performance is verified considering a single frequency solution trying to fix the phase ambiguity, when possible. Different solutions are defined: code, float and fix solutions. In order to solve the phase ambiguities different methods are considered. Each test performed is statistically analyzed, highlighting the effects of different factors on precision and accurac

89Y NMR Probe of Zn Induced Local Magnetism in YBa2(Cu(1-y)Zn(y))3O(6+x)

We present detailed data and analysis of the effects of Zn substitution on the planar Cu site in YBa$_2$Cu$_3$O$_{6+x}$ (YBCO$_{6+x}$) as evidenced from our $^{89}$Y NMR measurements on oriented powders. For $x<<1$ we find additional NMR lines which are associated with the Zn substitution. From our data on the intensities and temperature dependence of the shift, width, and spin-lattice relaxation rate of these resonances, we conclude that the spinless Zn 3$d$$^{10}$ state induces local moments on the near-neighbour ($$) Cu atoms. Additionally, we conjecture that the local moments actually extend to the farther Cu atoms with the magnetization alternating in sign at subsequent $nn$ sites. We show that this analysis is compatible with ESR data taken on dilute Gd doped (on the Y site) and on neutron scattering data reported recently on Zn substituted YBCO$_{6 + x}$. For optimally doped compounds $^{89}$Y $nn$ resonances are not detected, but a large $T$% -dependent contribution to the $^{89}$Y NMR linewidth is evidenced and is also attributed to the occurence of a weak induced local moment near the Zn. These results are compatible with macroscopic magnetic measurements performed on YBCO$_{6 + x}$ samples prepared specifically in order to minimize the content of impurity phases. We find significant differences between the present results on the underdoped YBCO$_{6 + x}$ samples and $$Al NMR data taken on Al$^{3+}$ substituted on the Cu site in optimally doped La$_2$CuO$_4$. Further experimental work is needed to clarify the detailed evolution of the impurity induced magnetism with hole content in the cuprates.Comment: To be published in EPJB 15 pages of text and figures in eps forma

Pesticide application horticultural and floricultural farms of Liguria Region: Current situation and results of one year of sprayer inspections

contribution to session 2 Member States may apply different timetables and inspection intervals with exceptions following a risk assessment and exempt handheld pesticide application equipment or knapsack sprayers (according article 8/3

The evaluation of sprayers inspection procedure in Italy

contribution to session 6 Defining criteria for rejecting pesticide application equipment, authorization and monitoring of worksho

A Comparative Sensitivity Analysis of GPS Receivers

GNSS technologies are progressively becoming one of the key elements in most of innovative wireless applications. Most location-based services and systems are in fact employing standalone GPS, GPS+EGNOS (or WAAS), Assisted-GPS and Differential GPS as core technologies and therefore more and more companies have been integrating GNSS receivers into their consumer products. By considering the large number of available GPS receivers on the market and the lack of standard specifications on the performance, a general evaluation of low cost GPS chipset is very interesting. The present paper describes the performance tests of a set of GPS receivers by different manufacturers in different environmental conditions (outdoor, light indoor, temporary blockage of the signal). The results of the tests are compared with the claimed performance reported on the data sheets. The comparative study on the performance is performed according to different figures of merit: acquisition sensitivity, Time To First Fix (TTFF) and the accuracy. Performance of the different receivers were tested by means of a hardware platform and a software tool called Sat-Surf and Sat-Surfer respectively

Doppler measurement integration for kinematic real-time GPS positioning

The present paper discusses the advantages of the use of Doppler shift measurements in a Kalman filter estimator in order to improve the kinematic stand-alone global positioning system positioning performance. Tests conducted in an urban environment using a single-frequency receiver demonstrate the real advantages of the proposed real- time computation technique

Normal State Magnetic Properties of Ni and Zn Substituted in YBa_{2}Cu_{3} O_{6+x}: Hole-Doping Dependence

We present SQUID susceptibility data on Zn and Ni substituted YBa_{2}Cu_{3}O_{6+x}. Cross-checks with NMR yield an unprecedented accuracy in the estimate of the magnetic susceptibility associated with the substituants, from the underdoped to the lightly overdoped case. This allows us to determine the Weiss temperature \theta for YBCO: its value is very small for all hole dopings n_h. Since in conventional metals, the Kondo temperature, $T_{K}<\theta$, magnetic screening effects would not be expected for $T\gg \theta$; in contrast, increasing n_h produces a reduction of the small moment induced by Zn^{2+} and a nearly constant effective moment for Ni^{2+} corresponding to a spin 1/2 rather than to a spin 1.Comment: 4 pages, 5 figures, to be published in Europhysics Letter

Cu NMR evidence for enhanced antiferromagnetic correlations around Zn impurities in YBa2Cu3O6.7

Doping the high-Tc superconductor YBa2Cu3O6.7 with 1.5 % of non-magnetic Zn impurities in CuO2 planes is shown to produce a considerable broadening of 63Cu NMR spectra, as well as an increase of low-energy magnetic fluctuations detected in 63Cu spin-lattice relaxation measurements. A model-independent analysis demonstrates that these effects are due to the development of staggered magnetic moments on many Cu sites around each Zn and that the Zn-induced moment in the bulk susceptibility might be explained by this staggered magnetization. Several implications of these enhanced antiferromagnetic correlations are discussed.Comment: 4 pages including 2 figure

The necessity of a harmonized procedure for sprayers inspectors training: the Italian activity

European Directive on Sustainable Use of Pesticides requires that the people making inspections of sprayers in use have an official license, recognized at national level, released by the competent Authority. In Italy, Authorities responsible of training and upgrading of sprayers inspectors are Regional and Provincial administrations. They make this job in collaboration with research institutes that provide qualified teachers.With the aim to homogenize in the whole country the activity of training and licensing of sprayers inspectors the rules for training courses and the criteria for releasing licenses have been defined by ENAMA. Training courses shall have a duration of at least 40 hours subdivided between theory (60% of total time) and practical (40% of total time).Topics treated during courses are: criteria to apply pesticides, main sprayer types used in agriculture and relative components, test methods and equipment used to carry out the inspections of sprayers in use and to adjust them. The exam to get the inspector license shall consist in: a) filling of a questionnaire with multiple answers (at least 80% of answers have to be correct); the questions are selected among a database approved by ENAMA Working Group; b) oral test; c) practical exam consisting in the complete inspection of one sprayer.In order to guarantee the same quality level of sprayers inspections in the different European countries and to guarantee the mutual recognition of inspections made it is considered necessary to reach in short terms an agreement to harmonize the activity of training, licensing and upgrading of sprayers inspectors across Europe