Differential Global Positioning System

A four-year study of site-specific weed control is presented in this paper. Weed seedling distribution was sampled and mapped prior to and after post-emergence herbicide application in four fields planted with maize, sugar beets, winter wheat and winter barley, rotating on one site. Herbicides and other weed control strategies were applied site-specifically according to the spatial variation of weed populations.

Research on adaptive cruise control (ACC) with Stop&Go maneuvers is presently one of the most important topics in the field of intelligent transportation systems. The main feature of such controllers is that there is adaptation to a user-preset speed and, if necessary, speed reduction to keep a safe distance from the vehicle ahead in the same lane of the road, whatever the speed. The extreme case is the stop and go operation in which the lead car stops and the vehicle at the rear must also do so. This paper presents the development of an ACC system and related experiments. The system input information is acquired by a real-time kinematic phase differential global positioning system (GPS) (i.e., centimetric GPS) and wireless local area network links. The outputs are the variables that control the pressure on the throttle and brake pedals, which is calculated by an onboard computer. In addition, the car control is based on fuzzy logic. The system has been installed in two mass-produced Citroën Berlingo electric vans, in which all the actuators have been automated to achieve humanlike driving. The results from real experiments show that the unmanned vehicles behave very similarly to human-driven cars and are very adaptive to any kind of situation at a broad range of speeds, thus raising the safety of the driving and allowing cooperation with manually driven cars.

This paper presents the chest worn pulse
oximeter with integrated universal software radio peripheral
(USRP) with the global positioning systems (GPS) disciplined
clock transceiver from the National Instruments. It
illustrates the respiratory cardio monitoring using the
flexible reflective pulse oximeter with ECG. The gathered
cardio respiratory data assessed by the microcontroller and
the output is sent through to the remote monitor display by
means of wireless system. The device also incorporates an
early warning feature to alert then both the user and also the
person being monitored. The GPS device is included for
tracking and to determine the present location of the client
in case of an emergency situation. The output is then
transmitted and also displayed to a web based server via
radio frequency (RF). A complete hardware prototype model
is designed, developed, tested, and implemented thus
validated the proposed scheme. The statistical assessment
method is then integrated where the parameters gathered
are evaluated.

This paper shows that multipath-mitigating C/A code tracking methods can induce meter-level PRN-dependent biases of C/A code measurements, which have adverse effect on positioning.

Namely, we found that some geodetic-grade receivers produce C/A pseudoranges with a bias of up to 1.65m for PRNs 7,8,15,17,21,22 and 24, when their multipath mitigation feature is enabled.  Analysis of this unexpected anomaly has revealed the reason for it: the affected PRNs have the peculiarity that their autocorrelation peaks exhibit slight deviations from the ideal triangle.  When multipath mitigation is enabled, this distortion is mistaken as multipath and induces the bias.

This anomaly adversely affects bias-sensitive applications, such as reference stations, or satellite C/A - P1 bias determination. It is shown by live examples that code-based DGPS or WAAS positioning may show meter-level deviations when multipath mitigation is active in the receiver. 

This paper will describe post-processing methods used to detect the anomaly, its mechanism, and countermeasures.

BACKGROUND: In the global program for the elimination of lymphatic filariasis (LF) longitudinal assessment of the prevalence of microfilaremia and antigenemia is recommended to monitor the effect of mass treatment on transmission. Additional monitoring tools such as entomologic and antibody methods may be useful in identifying residual foci of infection. In this study, we characterized serologic markers of infection and exposure spatially both before and after mass treatment, in an area of initial low Wuchereria bancrofti infection prevalence. METHODS: Consenting persons in the sentinel community were tested for circulating microfilaria and antigen (by immunochromatographic test) before and after the 1st annual mass drug administration of diethylcarbamazine and albendazole. A cohort of 161 persons provided serum specimens both years that were tested for antifilarial IgG (1 and 4) antibody. Every house was mapped using a differential Global Positioning System; this information was li...

GPS (Global Positioning System) has a variety of applications among which real-time tracking finds significance in day-today life. One of the technologies used to find locations by GPS (global positioning system). Service application based information location relies on the accuracy approximate position users. Unfortunately use this application not in real-time so cannot be identification development project a project by sending signals information on the competent also tracking this location many drained of energy batteries. The purpose of this research is to design systems that can monitor the work of the project to equitable regional development in real-time with the efficiency of the energy consumption of battery-based smartphone. By combining the methods of Location-based services (LBSs) and APIs methods that significantly reduce energy consumption up to 90% to the location tracking by applying power-saving algorithms with techniques of encapsulation to the fire without reducing the level of accuracy. I. INTRODUCTION GPS is a network of satellites that continuously emit radio signals at very low frequencies. GPS receivers passively receive these signals, provided that the view to the sky should not be obstructed, so usually this tool only works in open space. GPS satellites are working on a very thorough reference time and transmits data indicating the location and the current time. Operation of all existing GPS satellites are synchronized so that emit the same signal. GPS receiver will work if it receives a signal from at least four GPS satellites, so that its position in three dimensions can be calculated. At this time there are at least 24 operational GPS satellites at any time and is equipped with some reserve. The satellites operated by the US Department of Defense, in orbit for 12 hours (two orbits per day) at an altitude of about 11,500 mile and move at a speed of 2000 miles per hour.

To determine the relationships between rootless cone emplacement mechanisms, morphology, and spatial distribution, we mapped the Hnúta and Hrossatungur groups of the 1783–1784 Laki lava flow in Iceland. We based our facies maps on Differential Global Positioning System (DGPS) measurements, photogeological interpretations, and supporting field observations. The study area covers 2.77 km2 and includes 2216 explosion sites. To establish the timing of rootless cone formation we incorporated tephrochronological constraints from eighty-eight stratigraphic sections and determined that the Hnúta and Hrossatungur groups are composite structures formed by the emplacement of six geographically and chronologically discrete domains. Rootless eruptions initiated in domain 1 on the first day of the Laki eruption (June 8, 1783) and lasted 1–2 days. The second episode of rootless activity began in domain 2 on June 11 and lasted 1–3 days. The four domains of the Hrossatungur group dominantly formed after June 14 and exhibit a complex emplacement sequence that reflects interactions between the Laki lava, contemporaneously emplaced rootless cones, and an existing topographic ridge. In the study area, we identify three distinct rootless cone archetypes (i.e., recurring morphological forms) that are related to tube-, channel-, and broad sheet lobe-fed eruptions. We assert that emplacement of lava above compressible substrates (e.g., unconsolidated sediments) may trigger rootless eruptions by causing subsidence-induced flexure and failure of the basal crust, thereby allowing molten lava (fuel) to come into direct contact with groundwater (coolant) and initiating analogs to explosive molten fuel–coolant interactions (MFCIs).

Carbonate rocks are extremely vulnerable to biochemical weathering and, consequently carbonate shores are morphologically complex. Living organisms on hard substrates develop specialized strategies to construct its domicile, to dislodge and to compete by space and food with other species. Those strategies include mechanical and chemical processes, among them, substrate boring, etching, cementation and dissolution (e.g.,Trudgill, 1988; Andrews and Williams, 2000; Bromley and Heinberg, 2006). Shore platforms represent available areas to be biocolonized and, the role of biochemical processes have been emphasizes as important mechanisms on platform genesis (e.g., Stephenson and Kirk, 2000). The current work aims to quantify the role of biological activity in carbonate rocky coast evolution at the centre Algarve (south Portugal). In this area, cliffs expose Miocene carbonate rocks composed by calcarenites and carbonate siltstones. Two coastal sectors with different exposure to waves were monitored: (i) Galé, a well exposed sector to dominant waves from SW and, (ii) Olhos de Água in a sheltered position exposing softer rocks than in Galé. Shore platforms survey and cross-shore topography profiles were done by using a Differential Global Position System (DGPS). Macroalgae and macrozoobenthos colonizing shore platform in both sites (Galé and Olhos de Água) were sampled and identified and, density and species richness was quantified. Three stations in Galé and two more in Olhos de Água where chosen to downwearing measurements. Each station was divided in two half portions: (i) control area, (ii) area to be monitored. In the later one, rock was maintained bared by monthly adding H2O2 to kill organisms. Downwearing rates on bare rock were measured by using a Transverse Microerosion Meter (TMEM) along sixteen months. The control area was measured at the begin of the experience and after sixteen months during which was naturally biocolonized. In addition, density of holes produced by borers as well its volume inside the TMEM stations were estimated either by photo-interpretation and direct measurements. The rocks Schmidt hardness and uniaxial compressive strength were quantified. The measured downwearing rates correlate positively with borer and etching activities and negatively with the percentage of macroalgae coverage and substrate hardness. Despite we consider the lower value of downwearing rate it is enough to justify a height decrease of 26.13cm during the last 5 kyr when mean sea level was similar to the current one. Acknowledgments The present work is supported by the Portuguese Foundation for Science and Technology-FCT, Research Project PTDC/CTE-GEX/70448/2006 (BISHOP) References Andrews, C., Williams, R.B.G., 2000. Limpet erosion of chalk shore platforms in southeast England. Earth Surface Processes and Landforms, 25, 1371-1381. Bromley, R.G., Heinberg, C., 2006. Attachments strategies of organisms on hard substrates: A palaeoontological view. Palaegeography, Palaeoclimatology, Palaeoecology, 232, 429-453. Trudgill, S., 1988. Integrated geomorphological and ecological studies on rocky shores in Southern Britain. Field Studies, 7, 239-279. Stephenson, W.J., Kirk, R.M., 2000. Development of shore platforms on Kaikoura Peninsula, South Island, New Zealand:II. The role of subaerial weathering. Geomorphology 32, 43-56.

RUGGIERO, P.; KAMINSKY, G.M.; GELFENBAUM, G., and VOIGT, B., 2005. Seasonal to interannual morphodyn- amics along a high-energy dissipative littoral cell. Journal of Coastal Research, 21(3), 553-578. West Palm Beach (Florida), ISSN 0749-0208. A beach morphology monitoring program was initiated during summer 1997 along the Columbia River littoral cell (CRLC) on the coasts of northwest Oregon and southwest Washington, USA.

Although the Navigation Satellite Timing and Ranging (NAVSTAR) Global Positioning System (GPS) is, de facto, the standard positioning system used in outdoor navigation, it does not provide, per se, all the features required to perform many outdoor navigational tasks. The accuracy of the GPS measurements is the most critical issue. The quest for higher position readings accuracy led to the development, in the late nineties, of the Differential Global Positioning System (DGPS). The differential GPS method detects ...