Handheld Global Positioning System Receiver Research Articles

The Benefit and Importance of Mobile Satellite Signal in Northern Nigeria: GPS Approach

Lack of equipment to study mobile satellites signal propagation in colleges and universities prone this research work. A Handheld GPS receiver used as a tool for training college students to learn mobile satellite signal propagation using Global Positioning System (GPS) approach. These refer to the experimental setup of the equipment that is the connection done between the GPS receiver with a computer. The satellite propagation data received from the GPS machine can be recorded continuously with an updates rate of 2 seconds. The experiment was carried out in an open space environment at predetermine locations using simple setup, where a cheap, readily and available portable GPS receiver were connected to the computer to acquire propagation data. The computer was equipped with a self-developed package graphical user interface (GUI) monitoring the propagation information from the GPS satellites and saving the data. The developed system can be set up anywhere at any location. The sate-up will serve as a database for satellites view and analysis of mobile satellite data orbiting the sky of Northern part of Nigeria. Cost effective referring to a low-cost and readily available GPS receiver that can be easily set-up as compared to equipment designed specifically for an experimental purpose that is normally very expensive.

Coverage evaluation survey of the pentavalent vaccine using global positioning system technology and google earth in a rural area near Bangalore

Introduction: The government of Karnataka has introduced a new vaccine, i.e., pentavalent vaccine (PVV) in the Universal Immunization Programme (UIP) schedule from 1st April, 2013. There are no published studies on vaccination coverage of this new vaccine. Objectives: 1. To assess the coverage of PVV of infants in a rural area. 2. To find out the reasons for immunization failure. 3. To describe the use of Global Positioning System (GPS) technology and Google Earth as new tools for spatial mapping the vaccine coverage. Methodology: This exploratory study was conducted in September, 2014 by covering three rural Primary Health Centers near Bangalore by a team of field investigators. The population studied was children aged between 6 and 23 months at the time of the survey. WHO's standard EPI 30 cluster sampling technique was used for assessing the vaccine coverage. GarminGPS72H, a hand held GPS receiver, and Google Earth were used for spatial mapping the vaccination coverage. Results: A total of 210 children aged 6–23 months were included in the study. It was found that the completely immunized, partially immunized, and unimmunized children were 93.3%, 4.3%, and 2.4%, respectively. The most common cause for partial immunization and non-immunization was child being ill and the lack of information, respectively. Spatial mapping of vaccination coverage described the immunization coverage in the area and also gave insight into the probable reason for partial/non-immunized children. Conclusions: Coverage of PVV was very high and vaccine was well accepted by the community. GPS and Google Earth were useful in spatial mapping of the vaccination coverage.

Accuracy Evaluation of Digital Elevation Model Created Using Handheld Global Positioning System Receivers

This study aims to assess the accuracy of digital elevation model (DEM) created with utilization of handheld Global Positioning System (GPS) and comparing with Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), version 2. It is known that the quality of the DEM is affected by both of accuracy of elevation at each pixel (absolute accuracy) and accuracy of presented morphology (relative accuracy). The University of Baghdad, Al Jadriya campus was selected as a study area to create and analysis the resulting DEM. Additionally, Geographic Information System (GIS) was used to visualize, analyses and interpolate GPS track points (elevation data) of the study area. In this research, three additional DEMs were created using 60%, 30% and 15% of the all GPS track points to deduce the effect of the number of the included points on the accuracy of the resulting DEM. The study findings show a high resolution for the resulting DEM less than 5m when taking into consideration all GPS tracking points that observed in this research. Moreover, the resulting DEM has relative accuracy better than absolute accuracy and reaches to around 2m. By comparing with ground control points (reference points), the quality of handheld GPS DEM shows considerable improvement better than ASTER GDEM. Thus, this study indicates to improve the accuracy level of handheld GPS DEM by about 40% with increasing the observed number of GPS track points to twice.
 

The spatial distribution of Schistosoma mansoni infection in four regions of western Côte d'Ivoire.

Schistosomiasis poses a considerable public health burden in sub- Saharan Africa and a sound understanding of the spatial distribution facilitates to better target control interventions. The objectives of this study were i) to assess the prevalence of Schistosoma mansoni among school-aged children in four regions of western Côte d'Ivoire; ii) to determine demographic, climatic and environmental factors that influence the distribution of S. mansoni; and iii) to map and predict the distribution of S. mansoni in non-sampled locations. Parasitological surveys were carried out in 264 schools from June to December 2011. In each school, we aimed to examine 50 children for S. mansoni infection using duplicate Kato-Katz thick smears. Schools were georeferenced using a hand-held global positioning system receiver. Demographic data were obtained from readily available school lists, while climatic and environmental data were extracted from open-access remote sensing databases. Multivariable, binary non-spatial models and a Bayesian geostatistical logistic regression model were used to identify demographic, climatic and environmental risk factors for S. mansoni infection. Risk maps were developed based on observed S. mansoni prevalences and using Bayesian geostatistical models to predict prevalences at non-sampled locations. Overall, 12,462 children provided a sufficiently large stool sample to perform at least one Kato-Katz thick smear. The observed overall prevalence of S. mansoni infection was 39.9%, ranging from 0 to 100% at the unit of the school. Bayesian geostatistical analysis revealed that age, sex, altitude and difference between land surface temperature at day and night were significantly associated with S. mansoni infection. The S. mansoni risk map presented here is being been used by the national schistosomiasis control programme for spatial targeting of praziquantel and other interventions.

Global positioning system & Google Earth in the investigation of an outbreak of cholera in a village of Bengaluru Urban district, Karnataka.

Background & objectives:The global positioning system (GPS) technology along with Google Earth is used to measure (spatial map) the accurate distribution of morbidity, mortality and planning of interventions in the community. We used this technology to find out its role in the investigation of a cholera outbreak, and also to identify the cause of the outbreak.Methods:This study was conducted in a village near Bengaluru, Karnataka in June 2013 during a cholera outbreak. House-to-house survey was done to identify acute watery diarrhoea cases. A hand held GPS receiver was used to record north and east coordinates of the households of cases and these values were subsequently plotted on Google Earth map. Water samples were collected from suspected sources for microbiological analysis.Results:A total of 27 cases of acute watery diarrhoea were reported. Fifty per cent of cases were in the age group of 14-44 yr and one death was reported. GPS technology and Google Earth described the accurate location of household of cases and spot map generated showed clustering of cases around the suspected water sources. The attack rate was 6.92 per cent and case fatality rate was 3.7 per cent. Water samples collected from suspected sources showed the presence of Vibrio cholera O1 Ogawa.Interpretation & conclusions:GPS technology and Google Earth were easy to use, helpful to accurately pinpoint the location of household of cases, construction of spot map and follow up of cases. Outbreak was found to be due to contamination of drinking water sources.

Application of GIS in Solid Waste Management in Chanchaga Local Government Area of Niger State, Nigeria

This study aims at developing a decision support tool for solid waste management in Chanchaga Local Government Area of Niger State using Geo-information Technology. Waste management is a global environment issue, which constitutes a very significant problem in today's world. There is a considerable amount of waste disposal without proper segregation, which is leading to both economic and environmental problems. There is tremendous amount of loss in terms of environmental degradation and health hazards, due to direct disposal of waste. There has to be appropriate planning for good waste management by assessing the waste situation of the area. The method employed was to acquire attribute and spatial information using handheld Global Positioning System receiver (GPS) and satellite imagery. The image was geo-referenced and digitized showing the location of existing waste disposal unit and the final dumpsite. A database was created using ArcGIS 9.3 software. Queries and analysis of results were carried out. The results show primary, secondary disposal units and the condition of the disposal units.

Monitoring of Soil Loss from Erosion Using Geoinformatics and Geotechnical Engineering Methods

In this study, the position of all major rill and gully erosion sites were located using hand held GPS (Global Positioning System) receiver during reconnaissance surveys. Based on severity rating and geopolitical considerations, six of the erosion gully sites were selected for monitoring. Control points were established around each of the gully sites using three Leica 500 dual frequency GPS receivers by method of DGPS (differential GPS) surveys. Detailed topographical survey of the gully sites was carried out using total stations. With the aid of SPOT satellite imageries in combination with total station data and GIS (geographic information system) location maps, contoured maps along with DEM (digital elevation model) were generated using ARCGIS 9.2 software. The morphological parameters of the gullies including depth, width, length and area of the gullies were determined. Volumetric estimate of the amount of soil loss from gully erosion was also carried out. Soil samples were recovered from the gully sites to determine their erodibility and other parameters to be used for soil loss modeling. The result of the studies was used as an indicator for determining the gully initiation point. Slope-area relationship and threshold of gully initiation was established. The minimum volume of soil loss occurred in gully No. 2 (Queen Ede). The minimum AS 2 value was 345 while the maximum was 3,267.

Evaluation of the Effect of Radio Frequency Interference on Global Positioning System (GPS) Accuracy via GPS Simulation

In this study, Global positioning system (GPS) simulation is employed to study the effect of radio frequency interference (RFI) on the accuracy of two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both GPS receivers employ the GPS L1 coarse acquisition (C/A) signal. It was found that with increasing interference signal power level, probable error values of the GPS receivers increase due to decreasing carrier-to-noise density (C/N0) levels for GPS satellites tracked by the receivers. Varying probable error patterns are observed for readings taken at different locations and times. This was due to the GPS satellite constellation being dynamic, causing varying GPS satellite geometry over location and time, resulting in GPS accuracy being location/time dependent. In general, the highest probable error values were observed for readings with the highest position dilution of precision (PDOP) values, and vice versa. Defence Science Journal, 2012, 62(5), pp.338-347 , DOI:http://dx.doi.org/10.14429/dsj.62.1606

Preliminary Evaluation of Baseline Relative Accuracies Using L1 Frequency Observations of Navigation-Grade GARMIN Receivers

Handheld navigation global positioning system (GPS) receivers are significantly cheaper and their position determination accuracy is less than their geodetic-grade counterparts. Although the main observable in most low-cost handheld GPS receivers is the coarse acquisition (C/A) code, some receive L1 frequency observations and utilize them to smooth the code measurements. In this technical paper, we examined the use of the C/A code and L1 phase observations captured by two GARMIN eTrex receivers in a postprocessing mode. We used software applications that send low level commands to download and save the receiver data stream and convert the observations into standard RINEX file format. Nineteen baselines with different lengths were observed using the eTrex receivers and dual frequency geodetic-grade receivers. The baseline lengths were derived from the eTrex observations and compared to corresponding ones derived from the higher accuracy geodetic-grade receiver observations. Several tests were conducted to analyze the effect of potential error sources on the achieved accuracy. The results showed that low satellite angles and existing cycle slips contributed to the errors in the processed eTrex data. The implementation of a cycle slip detection algorithm and their subsequent deletion significantly enhanced the obtained baseline relative accuracy to a finally limited range of 1.8–13.4 cm/km.

Mapping Natural Phenomena: Boreal Forest Fires with Non-discrete Boundaries

Forest fires are spatially and temporally frequent in the boreal forest biome and continue to alter the spatial mosaic of its forest cover. Some of these fires occur in remote locations where direct socio-economic impacts are negligible, and are therefore not suppressed. However, these natural fires have many ecological consequences, and their monitoring and mapping therefore pose both an important and a challenging task. The current state of the art for fire-event mapping in remote northern Ontario is conducted at variable cartographic scales and generally relies on recording the approximate perimeters of the burned area from fixed-wing aircraft or helicopters with a handheld global positioning system receiver. All such techniques treat forest-fire boundaries, regardless of their detection and mapping resolutions or of the irregularity and gradient-like characteristics of their burned/not-burned interface, as crisp lines. Here we describe a procedure for standardizing the mapping of forest fires by an approach using high-spatial-resolution IKONOS satellite imagery that considers the actuality of gradual boundaries by assessing the fire-membership strength of each pixel prior to developing a footprint describing an individual fire event. Our case study is from northern Ontario, Canada, where the remote boreal forest fires are not regularly suppressed or monitored/mapped using traditional means. Furthermore, our analysis explores the sensitivity of this mapping effort to spatial resolution when describing measures of fire-footprint spatial geometry. We compare our mapping results with fire boundaries obtained by other means, using a series of overlap statistics to assess their spatial coincidence.

Human Factors Considerations in Global Positioning System (GPS) Receiver Technology: Contrasting Military Technical Requirements with User Expectations

This paper presents only the opinions of the authors for a forum of other Human Factors professionals. No representation of The Aerospace Corporation, GPS Wing, US Air Force, US Army, or US Department of Defense (DoD) policy is implied or intended. The need for human factors considerations in the development of handheld GPS receiver technology becomes increasingly apparent as society becomes increasingly dependant on precision navigation and timing information. GPS receivers provide ubiquitous situational awareness, during the daily mundane commute or in theater amidst the fog of war. Both military and commercial receivers are only as useful as their ability to convey navigation information to the user in a timely and reliable manner. Warfighters have become familiar with the ease and convenience of commercial receivers, mapping functionality, and integrated technology. However, there is great variance between the requirement set for military operations and civilian applications. The US Army and Air Force GPS Wing face future expectation management issues with military GPS user equipment. Potential areas for risk mitigation include careful human factors considerations early in the requirements development process, platform and application tailoring, incorporating “best practices” from industry and commercial end-user experience, and education and training.

Space Weather and the Global Positioning System

Space Weather and the Global Positioning System

Susceptibility of Civilian GPS Receivers to Electromagnetic Radiation

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Civilian handheld global positioning system receivers were tested for their susceptibility against radiated electromagnetic disturbances of different characteristics and field levels. This susceptibility data were compared to the existing electromagnetic compatibility (EMC) immunity requirements for electronic devices. Some of the receivers were disrupted by continues waves at in- as well as out-of-band frequencies, at field levels far below the existing EMC requirements. The possible reason for this is discussed. In general, due to the ever-growing use of commercial-off-the-shelf equipment even for critical functions, certificates of conformity to current EMC requirements may be inadequate. </para>

Microfabricated atomic frequency references

Using microfabrication processes, we have been able to construct physics packages for vapour cell atomic frequency references 100× smaller than previously existing versions, with a corresponding reduction in power consumption. In addition, the devices offer the potential for wafer-level fabrication and assembly, which would substantially reduce manufacturing costs. It is anticipated that a complete frequency reference could be constructed based on these physics packages with a total volume below 1 cm3, a power dissipation near 30 mW and a fractional frequency instability below 10−11 over time periods from hours to days. Such a device would enable the use of atomically precise timing in applications that require battery operation and portability, such as hand-held global positioning system receivers and wireless communication systems.

Improving the accuracy of low-cost GPS measurements for remote sensing applications

Field work in remote sensing often requires that the absolute position of a point on the Earth's surface can be determined with an accuracy of better than 100 m, for example to locate a Ground Control Point or to identify the land cover at a point corresponding to a particular pixel in an image. This paper assesses the extent to which low-cost, hand-held GPS (Global Positioning System) receivers can be used for this purpose. The nominal accuracy of GPS is 100 m, meaning that a single position measurement should yield a result within 100 m of the true position at least 95% of the time. Here, we investigate the extent to which this performance can be improved upon. Two approaches are studied: averaging several measurements, and correcting the measurement at one receiver using the known error at another. The first approach involves an investigation of the temporal correlation properties of the errors in a measured position. The correlation time is shown to be about 4 min for the horizontal coordinates and about 11 min for the vertical coordinate. Simple models are derived to allow the accuracy of an average measurement to be estimated, and it is shown that accuracies of typically 15 m (horizontally) and 30 m (vertically) can be achieved from 30 min of observation. The second approach involves an investigation of the spatial correlation properties of the errors. It is shown that these are inadequate to provide any improvement in accuracy.

The global positioning system

A hand-held global positioning system receiver displays the operator's latitude, longitude and velocity. Knowledge of GCSE-level physics will allow the basic principles of the system to be understood; knowledge of A-level physics will allow many important aspects of their implementation to be comprehended. A discussion of the system provides many simple numerical calculations relevant to school and first-year undergraduate syllabuses.

Experimental Application of Global Positioning system To Locate Motor Vehicle Crashes: Impact on Time and Accuracy

Motor vehicle crash countermeasures often are selected after an extensive data analysis of the crash history of a roadway segment. The value of this analysis depends on the accuracy or precision with which the crash itself is located. yet this crash location only is as accurate as the estimate of the police officer. Global Positioning System (GPS) technology may have the potential to increase data accuracy and decrease the time spent to record crash locations. Over 10 months, 32 motor vehicle crash locations were determined by using both conventional methods and hand-held GPS receivers, and the timeliness and precision of the methods were compared. Local crash data analysts were asked how the improved precision affected their consideration of potential crash countermeasures with regard to five crashes selected from the sample. On average, measuring a crash location by using GPS receivers added up to 10 extra minutes, depending on the definition of the crash location, the technology employed, and how that technology was applied. The average difference between conventional methods of measuring the crash location and either GPS or a wheel ranged from 5 m (16 ft) to 39 m (130 ft), depending on how one defined the crash location. Although there are instances in which improved precision will affect the evaluation of crash countermeasures, survey respondents and the literature suggest that problems with conventional crash location methods often arise from human error, not a lack of precision inherent in the technology employed.

The use of remote sensing and geographic information systems in UNICEF's dracunculiasis (Guinea worm) eradication effort

Dracunculiasis (Guinea worm disease) is a parasitic disease which is endemic in 18 African and two Asian countries. It has a marked potential for eradication by a combination of water supply management, health education and controlled medical intervention. While data on the disease are, in many cases, both in short supply and unreliable, increasingly the tools of remote sensing and geographic information systems (GIS) are becoming important components of the eradication effort. In particular, remotely sensed data from LANDSAT have allowed the identification and location of remote and small settlements in dracunculiasis-endemic areas. When coupled with additional information available in remotely sensed data from LANDSAT, and when used in conjunction with a GIS containing digitized maps and field data collected from hand-held global positioning system receivers, the eradication effort has developed an epidemiological tool of potential power. While at first this system is finding uses in managing existing data in a unified inventory, the system shows potential for use as an effective management decision-making tool as the control effort moves from disease reduction to disease eradication. This paper will use a single province within one country, the Zou Province of Benin, to demonstrate the varied data sources involved in the system, the software and hardware components of the system, and to discuss the specific problems involved in using the system in the field. Of particular consideration, and of potential use to other similar programs, is a consideration of the management and implementation of the system. The paper concludes that a combination of remote sensing and GIS technologies offers the epidemiologist a new and important means by which to effectively implement solutions to public health management problems.

Next generation digital GPS receiver

The architecture and technology features of the next-generation (NGR) digital GPS (Global Positioning System) receiver manufactured by Collin are described. The project's objective was to develop an advanced GPS receiver chipset with high antijam capabilities. The program, initiated in 1985, has provided the technology for miniature receiver products for both unmanned and manned vehicle applications. A two-channel version of the receiver is in full-scale development for tactical missile applications. A five-channel version is being tested and evaluated as a drop-in replacement for RCVR-3A, the US Department of Defense standard high dynamic receiver. The NGR design started with the digital signal processing architecture developed for the Defense Advanced Research Project Agency (DARPA) hand-held GPS receiver. Enhancements were made to improve the antijam and signal acquisition performance. Producible, qualifiable and cost-effective silicon monolithic microwave integrated circuits and semicustom digital technologies were used to develop the core GPS chipset. A system design approach was established to permit reuse of mature and validated GPS software.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>