An advanced Receiver Autonomous Integrity Monitoring (ARAIM) approach is investigated when augmenting GPS satellites with the current regional BeiDou constellation. A procedure for integrity monitoring, including checking its availability, fault detection and exclusion, and integrity testing is presented. Fault modes and their probabilities using GPS and GPS+BeiDou are discussed. Testing of ARAIM for vertical guidance using real data in eight sites distributed globally (Australia, China, Netherlands, eastern Canada and Peru) show that the addition of the BeiDou constellation, despite the decreased preliminary confidence placed in its performance compared with GPS, results in a substantial improvement to ARAIM availability performance and a higher level of integrity, in particular at sites observing all of its current constellation (Australia and China). The improvement was less in sites that can only observe some or no GEO and IGSO satellites (Netherlands, Canada and Peru). However, the benefit of adding BeiDou to GPS at these sites is expected to substantially improve with full deployment of MEO satellites.
{"title":"ARAIM for vertical guidance using GPS and BeiDou","authors":"A. el-Mowafy","doi":"10.5081/JGPS.12.1.28","DOIUrl":"https://doi.org/10.5081/JGPS.12.1.28","url":null,"abstract":"An advanced Receiver Autonomous Integrity Monitoring (ARAIM) approach is investigated when augmenting GPS satellites with the current regional BeiDou constellation. A procedure for integrity monitoring, including checking its availability, fault detection and exclusion, and integrity testing is presented. Fault modes and their probabilities using GPS and GPS+BeiDou are discussed. Testing of ARAIM for vertical guidance using real data in eight sites distributed globally (Australia, China, Netherlands, eastern Canada and Peru) show that the addition of the BeiDou constellation, despite the decreased preliminary confidence placed in its performance compared with GPS, results in a substantial improvement to ARAIM availability performance and a higher level of integrity, in particular at sites observing all of its current constellation (Australia and China). The improvement was less in sites that can only observe some or no GEO and IGSO satellites (Netherlands, Canada and Peru). However, the benefit of adding BeiDou to GPS at these sites is expected to substantially improve with full deployment of MEO satellites.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129506469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Global Navigation Satellite System (GNSS) positioning, ranging signals are delayed when travelling through the ionosphere, the layer of the atmosphere ranging in altitude from about 50 to 1000 km consisting largely of ionized particles. This delay can vary from 1 meter to over 100 meters, and is still one of the most significant error sources in GNSS positioning. In precise GNSS positioning applications, ionospheric errors must be accounted for. One way to do so is to treat unknown ionosphere delay as stochastic parameter, which can account for the ionospheric errors in the GNSS measurements as well as keeping the full original information. The idea is adding ionospheric delay from external sources as pseudo-observables. In this paper, the performance of ionosphere-weighted model is evaluated using real data sets, and the correctness of priori ionosphere variance is also validated.
{"title":"Stochastic Ionosphere Models for Precise GNSS Positioning: Sensitivity Analysis","authors":"Peiyuan Zhou, Jinling Wang","doi":"10.5081/JGPS.12.1.53","DOIUrl":"https://doi.org/10.5081/JGPS.12.1.53","url":null,"abstract":"In Global Navigation Satellite System (GNSS) positioning, ranging signals are delayed when travelling through the ionosphere, the layer of the atmosphere ranging in altitude from about 50 to 1000 km consisting largely of ionized particles. This delay can vary from 1 meter to over 100 meters, and is still one of the most significant error sources in GNSS positioning. In precise GNSS positioning applications, ionospheric errors must be accounted for. One way to do so is to treat unknown ionosphere delay as stochastic parameter, which can account for the ionospheric errors in the GNSS measurements as well as keeping the full original information. The idea is adding ionospheric delay from external sources as pseudo-observables. In this paper, the performance of ionosphere-weighted model is evaluated using real data sets, and the correctness of priori ionosphere variance is also validated.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115533506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article provides an overview of the BeiDou navigation message contents and highlights its specific communalities and differences with respect to other GNSS constellations. Making use of data collected by multi-GNSS monitoring stations of the MGEX and CONGO networks, the quality of BeiDou broadcast ephemerides is assessed through the analysis of satellite laser ranging measurements, comparison with post-processed orbit and clock products as well as positioning tests. Specific attention is given to signal-specific group delays and their proper consideration in the positioning.
{"title":"The BeiDou Navigation Message","authors":"O. Montenbruck, P. Steigenberger","doi":"10.5081/JGPS.12.1.1","DOIUrl":"https://doi.org/10.5081/JGPS.12.1.1","url":null,"abstract":"The article provides an overview of the BeiDou navigation message contents and highlights its specific communalities and differences with respect to other GNSS constellations. Making use of data collected by multi-GNSS monitoring stations of the MGEX and CONGO networks, the quality of BeiDou broadcast ephemerides is assessed through the analysis of satellite laser ranging measurements, comparison with post-processed orbit and clock products as well as positioning tests. Specific attention is given to signal-specific group delays and their proper consideration in the positioning.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133950615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, an integrated inter-vehicles wireless communications and positioning system supporting alternate positioning techniques is proposed to meet the requirements of safety applications of Cooperative Intelligent Transportation Systems (C-ITS). Recent advances have repeatedly demonstrated that road safety problems can be to a large extent addressed via a range of technologies including wireless communications and positioning in vehicular environments. The novel communication stack utilizing a dedicated frequency spectrum (e.g. at 5.9 GHz band), known as Dedicated Short-Range Communications (DSRC), has been particularly designed for Wireless Access in Vehicular Environments (WAVE) to support safety applications in highly dynamic environments. Global Navigation Satellite Systems (GNSS) is another essential enabler to support safety on rail and roads. Although current vehicle navigation systems such as single frequency Global Positioning System (GPS) receivers can provide route guidance with 5-10 meters (road-level) position accuracy, positioning systems utilized in C-ITS must provide position solutions with lane-level and even inlane-level accuracies based on the requirements of safety applications. This article reviews the issues and technical approaches that are involved in designing a vehicular safety communications and positioning architecture; it also provides technological solutions to further improve vehicular safety by integrating the DSRC and GNSSbased positioning technologies.
{"title":"Design of an integration platform for V2X wireless communications and positioning supporting C-ITS safety applications","authors":"Keyvan Ansari, Yanming Feng","doi":"10.5081/JGPS.12.1.38","DOIUrl":"https://doi.org/10.5081/JGPS.12.1.38","url":null,"abstract":"In this paper, an integrated inter-vehicles wireless communications and positioning system supporting alternate positioning techniques is proposed to meet the requirements of safety applications of Cooperative Intelligent Transportation Systems (C-ITS). Recent advances have repeatedly demonstrated that road safety problems can be to a large extent addressed via a range of technologies including wireless communications and positioning in vehicular environments. The novel communication stack utilizing a dedicated frequency spectrum (e.g. at 5.9 GHz band), known as Dedicated Short-Range Communications (DSRC), has been particularly designed for Wireless Access in Vehicular Environments (WAVE) to support safety applications in highly dynamic environments. Global Navigation Satellite Systems (GNSS) is another essential enabler to support safety on rail and roads. Although current vehicle navigation systems such as single frequency Global Positioning System (GPS) receivers can provide route guidance with 5-10 meters (road-level) position accuracy, positioning systems utilized in C-ITS must provide position solutions with lane-level and even inlane-level accuracies based on the requirements of safety applications. This article reviews the issues and technical approaches that are involved in designing a vehicular safety communications and positioning architecture; it also provides technological solutions to further improve vehicular safety by integrating the DSRC and GNSSbased positioning technologies.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127174410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiwu Wang, Ruizhi Chen, Yuwei Chen, L. Pei, H. Hyyppä, J. Hyyppä, Lingli Zhu, K. Virrantaus
3D personal navigation is becoming a standard feature in smartphone platform, which develops in a fast speed nowadays. However, the hardware restrictions of smartphone may degrade the 3D rendering performance, and such real-time operation is not an energy-efficient procedure on smartphone, because heavy computation consumes a lot of power, which is crucial for a smartphone equipped with limited capacity battery. This paper presents a novel solution utilizing geocoded images instead of 3D models to mitigate these technical restrictions on the smartphone. To demonstrate the performance and the improvement of the proposed solution, evaluations are carried out in term of positioning accuracy, resource consumption, efficiency, visualization, and labour costs. The results show that the proposed solution has overwhelming advantages in all these comparisons. This solution also has the capability of achieving a higher frame rate and has a better visualization performance as well. In addition, the proposed solution provides an optional way to decrease the labour costs and hardware investment to build up a similar but quick application by utilizing photos instead of complex 3D model construction for a small-scale area personal navigation application.
{"title":"Evaluations on 3D Personal Navigation based on Geocoded Images in Smartphones","authors":"Yiwu Wang, Ruizhi Chen, Yuwei Chen, L. Pei, H. Hyyppä, J. Hyyppä, Lingli Zhu, K. Virrantaus","doi":"10.5081/JGPS.11.2.116","DOIUrl":"https://doi.org/10.5081/JGPS.11.2.116","url":null,"abstract":"3D personal navigation is becoming a standard feature in smartphone platform, which develops in a fast speed nowadays. However, the hardware restrictions of smartphone may degrade the 3D rendering performance, and such real-time operation is not an energy-efficient procedure on smartphone, because heavy computation consumes a lot of power, which is crucial for a smartphone equipped with limited capacity battery. This paper presents a novel solution utilizing geocoded images instead of 3D models to mitigate these technical restrictions on the smartphone. To demonstrate the performance and the improvement of the proposed solution, evaluations are carried out in term of positioning accuracy, resource consumption, efficiency, visualization, and labour costs. The results show that the proposed solution has overwhelming advantages in all these comparisons. This solution also has the capability of achieving a higher frame rate and has a better visualization performance as well. In addition, the proposed solution provides an optional way to decrease the labour costs and hardware investment to build up a similar but quick application by utilizing photos instead of complex 3D model construction for a small-scale area personal navigation application.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126377216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Global Navigation Satellite System (GNSS) Continuously Operating Reference Station (CORS) networks are being built and expanded around the world, contributing to the definition and realisation of geodetic reference frames as well as providing reliable and accurate positioning infrastructure for a wide range of applications. Depending on the purpose of the GNSS station, CORS antenna monuments typically vary from concrete pillars anchored to bedrock to masts attached to buildings. An antenna mount is used to connect the GNSS antenna to the monument. In all cases it is desired that the CORS antenna is oriented to True North in order to gain maximum benefit from GNSS antenna modelling. Other requirements generally include the unambiguous definition of the survey mark and Antenna Reference Point (ARP), and a zero or minimal antenna height. This paper introduces the CORSnet-NSW Adjustable Antenna Mount (CAAM), developed by NSW Land and Property Information (LPI) for CORSnet-NSW, LPI’s rapidly growing GNSS CORS network covering the state of New South Wales, Australia. The CAAM was purposely designed to be incorporated into (rather than simply attached to) antenna masts located on buildings or free-standing pole monuments but can also be used for pillar monuments. Being free of removable parts, it is adjustable in order to orient the antenna to True North without introducing an antenna height, thereby allowing clear definition and maximum traceability of the survey mark and the ARP. LPI encourages adoption of the CAAM for use in other GNSS CORS networks.
{"title":"Improving GNSS CORS design: The CORSnet-NSW Adjustable Antenna Mount (CAAM)","authors":"R. Commins","doi":"10.5081/JGPS.11.2.109","DOIUrl":"https://doi.org/10.5081/JGPS.11.2.109","url":null,"abstract":"Global Navigation Satellite System (GNSS) Continuously Operating Reference Station (CORS) networks are being built and expanded around the world, contributing to the definition and realisation of geodetic reference frames as well as providing reliable and accurate positioning infrastructure for a wide range of applications. Depending on the purpose of the GNSS station, CORS antenna monuments typically vary from concrete pillars anchored to bedrock to masts attached to buildings. An antenna mount is used to connect the GNSS antenna to the monument. In all cases it is desired that the CORS antenna is oriented to True North in order to gain maximum benefit from GNSS antenna modelling. Other requirements generally include the unambiguous definition of the survey mark and Antenna Reference Point (ARP), and a zero or minimal antenna height. This paper introduces the CORSnet-NSW Adjustable Antenna Mount (CAAM), developed by NSW Land and Property Information (LPI) for CORSnet-NSW, LPI’s rapidly growing GNSS CORS network covering the state of New South Wales, Australia. The CAAM was purposely designed to be incorporated into (rather than simply attached to) antenna masts located on buildings or free-standing pole monuments but can also be used for pillar monuments. Being free of removable parts, it is adjustable in order to orient the antenna to True North without introducing an antenna height, thereby allowing clear definition and maximum traceability of the survey mark and the ARP. LPI encourages adoption of the CAAM for use in other GNSS CORS networks.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"295 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116222935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The modernization of Global Positioning Systems (GPS) and the availability of more complex signals and modulation schemes boost the development of civil and military applications while the accuracy and coverage of receivers continually improve. Recently, software defined receiver solutions gained attention for flexible multimode operations. For them, developers address algorithmic and hardware accelerators or their hybrids for fast prototyping and testing high performance receivers for various conditions. This paper presents a new fast prototyping concept exploiting digital signal processor (DSP) peripherals and the benefits of the host environment using the National Instruments (NI) LabVIEW platform. With a reasonable distribution of tasks between the host hardware and reconfigurable peripherals, a higher performance is achieved. As a case study, in this paper the Texas Instruments (TI) TMS320C6713 DSP is used along with a Real Time Data Exchange (RTDX) communication link to compare with similar Simulink-based solutions. The proposed testbed GPS signal is created using the NI PXI signal generator and the NI GPS Simulation Toolkit.
{"title":"A LabVIEW-Based GPS Receiver Development and Testing Platform with DSP Peripherals: Case study with C6713 DSK","authors":"A. Soghoyan, D. Akopian","doi":"10.5081/JGPS.11.2.127","DOIUrl":"https://doi.org/10.5081/JGPS.11.2.127","url":null,"abstract":"The modernization of Global Positioning Systems (GPS) and the availability of more complex signals and modulation schemes boost the development of civil and military applications while the accuracy and coverage of receivers continually improve. Recently, software defined receiver solutions gained attention for flexible multimode operations. For them, developers address algorithmic and hardware accelerators or their hybrids for fast prototyping and testing high performance receivers for various conditions. This paper presents a new fast prototyping concept exploiting digital signal processor (DSP) peripherals and the benefits of the host environment using the National Instruments (NI) LabVIEW platform. With a reasonable distribution of tasks between the host hardware and reconfigurable peripherals, a higher performance is achieved. As a case study, in this paper the Texas Instruments (TI) TMS320C6713 DSP is used along with a Real Time Data Exchange (RTDX) communication link to compare with similar Simulink-based solutions. The proposed testbed GPS signal is created using the NI PXI signal generator and the NI GPS Simulation Toolkit.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"44 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131264247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monitoring and mapping variations in shoreline location is an activity that can be undertaken using several different techniques of data collection, e.g., photogrammetric restitution, satellite images, LiDAR (Light Detection and Ranging) or classical topographical surveys to support coastal environmental protection such as identifying flood risk areas. The global navigation satellite system (GNSS) has been employed by the Federal University of Parana (UFPR) as part of their research into the application of geodetic survey methods for shoreline mapping in coastal environments since 1996. The advantages of using GNSS are accuracy and productivity, given that a great number of points can be determined within a short period of time at decimeterlevel accuracy. In this work, GNSS relative kinematic positioning approach was applied to monitor Matinhos coastal district of Brazil. Other important data, such as the highand low-tide marks, all obtained using GNSS, and thematic maps have also been incorporated. Through the reanalysis of historical surveys, it is possible to make some conclusions about the shoreline dynamics and to use this information as material in support of the planning and management of the coastal environment, for example, when planning engineering works that set out to minimize coastal erosion and for urban planning. The results achieved in this work include defining the position of the shoreline for 2008, developing the thematic map of the shoreline, the quantification of the advance and retreat of the shoreline between 2001 and 2008, and a map showing those critical areas where the shoreline position is equal to the high-tide water line. GNSS-based method offers quicker, all-weather, highly accurate and continuously updatable shoreline positional time series relevant for monitoring, thus enabling quicker management decisions to be undertaken, which may be of benefit to coastal engineering applications.
{"title":"GNSS-based monitoring and mapping of shoreline position in support of planning and management of Matinhos/PR (Brazil)","authors":"R. M. Gonçalves, J. Awange, C. P. Krueger","doi":"10.5081/JGPS.11.2.156","DOIUrl":"https://doi.org/10.5081/JGPS.11.2.156","url":null,"abstract":"Monitoring and mapping variations in shoreline location is an activity that can be undertaken using several different techniques of data collection, e.g., photogrammetric restitution, satellite images, LiDAR (Light Detection and Ranging) or classical topographical surveys to support coastal environmental protection such as identifying flood risk areas. The global navigation satellite system (GNSS) has been employed by the Federal University of Parana (UFPR) as part of their research into the application of geodetic survey methods for shoreline mapping in coastal environments since 1996. The advantages of using GNSS are accuracy and productivity, given that a great number of points can be determined within a short period of time at decimeterlevel accuracy. In this work, GNSS relative kinematic positioning approach was applied to monitor Matinhos coastal district of Brazil. Other important data, such as the highand low-tide marks, all obtained using GNSS, and thematic maps have also been incorporated. Through the reanalysis of historical surveys, it is possible to make some conclusions about the shoreline dynamics and to use this information as material in support of the planning and management of the coastal environment, for example, when planning engineering works that set out to minimize coastal erosion and for urban planning. The results achieved in this work include defining the position of the shoreline for 2008, developing the thematic map of the shoreline, the quantification of the advance and retreat of the shoreline between 2001 and 2008, and a map showing those critical areas where the shoreline position is equal to the high-tide water line. GNSS-based method offers quicker, all-weather, highly accurate and continuously updatable shoreline positional time series relevant for monitoring, thus enabling quicker management decisions to be undertaken, which may be of benefit to coastal engineering applications.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"19 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123541438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Global Satellite Navigation Systems (GNSS) have been widely used for positioning, navigation and timing (PNT). Therefore, the integrity of the satellite based navigation systems has been a major concern for many liability critical applications, such as civil aviation, and location-based services (LBS). Over the past two decades, GNSS Receiver Autonomous Integrity Monitoring (RAIM) procedures have been developed, but the efficiency of such procedures is highly dependent on measurement redundancy and geometric strength within the GNSS positioning solutions. Reliability of a PNT system can be measured by, not only the wellknown Minimal Detectable Biases (MDBs), but also the recently derived Minimal Separable Biases (MSBs) for the measurements. While the previous research has shown that the MSBs are directly related to the correlations between the faulty measurement detection statistics, a comprehensive analysis for such correlations between fault (or outlier) detection statistics is still lacking, even for commonly used GNSS/INS integration scenarios. In this research, we have demonstrated that with the aid of inertial sensors, even with low-cost MEMS sensors, the MDBs and correlation coefficients between the measurement fault detection statistics can be significantly reduced, thus improving the separability of faults in GNSS measurements.
{"title":"Correlation Analysis for Fault Detection Statistics in Integrated GNSS/INS Systems","authors":"Jinling Wang, A. Almagbile, Youlong Wu, T. Tsujii","doi":"10.5081/JGPS.11.2.89","DOIUrl":"https://doi.org/10.5081/JGPS.11.2.89","url":null,"abstract":"Global Satellite Navigation Systems (GNSS) have been widely used for positioning, navigation and timing (PNT). Therefore, the integrity of the satellite based navigation systems has been a major concern for many liability critical applications, such as civil aviation, and location-based services (LBS). Over the past two decades, GNSS Receiver Autonomous Integrity Monitoring (RAIM) procedures have been developed, but the efficiency of such procedures is highly dependent on measurement redundancy and geometric strength within the GNSS positioning solutions. Reliability of a PNT system can be measured by, not only the wellknown Minimal Detectable Biases (MDBs), but also the recently derived Minimal Separable Biases (MSBs) for the measurements. While the previous research has shown that the MSBs are directly related to the correlations between the faulty measurement detection statistics, a comprehensive analysis for such correlations between fault (or outlier) detection statistics is still lacking, even for commonly used GNSS/INS integration scenarios. In this research, we have demonstrated that with the aid of inertial sensors, even with low-cost MEMS sensors, the MDBs and correlation coefficients between the measurement fault detection statistics can be significantly reduced, thus improving the separability of faults in GNSS measurements.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127527048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Location Based Systems (LBS) market has emerged exponentially since early 2000 in the wake of growing need for Emergency Relief Applications. The argument of course outstanding is which device outperforms all other in diverse scenarios without failure. While many purpose built LBS are in use, SPOT satellite messenger gained attention for its reliability. This paper summates the system architecture and experimental tests results with those of competing Assisted and Global Navigation Satellite Systems (A/GNSS). Our test bed comprised of 26 test points with pre-established database of GNSS difficulty levels in diverse environments in UNSW. Parameters of interest are availability, accuracy and Time to First Fix (TTFF). Relative benchmarking proves SPOT’s higher TTFF and higher failure rate in general. While High Sensitivity GNSS and Assisted GNSS (MSBased and MS-Assisted) had higher availability, higher accuracy and lower TTFF. Altogether fewer failure scenarios, trustworthy coverage with cost effectiveness were observed for MS-Based AGNSS which is vital for LBS applications. However reliance on wired or wireless IP network potentially limits the performance in nonexistent underlying infrastructure in remote applications. SPOT demonstrated higher TTFF and failure rates in test scenario. On the contrary Assisted GNSS (MS-Based or MS-Assisted) can provide a reliable, cost effective and open source alternative to SPOT satellite messenger with better TTFF, availability and accuracy for consumer and research applications.
{"title":"SPOT GNSS in Emergency and Location Based Services","authors":"Ali Sarwar, Binghao Li","doi":"10.5081/JGPS.11.2.100","DOIUrl":"https://doi.org/10.5081/JGPS.11.2.100","url":null,"abstract":"Location Based Systems (LBS) market has emerged exponentially since early 2000 in the wake of growing need for Emergency Relief Applications. The argument of course outstanding is which device outperforms all other in diverse scenarios without failure. While many purpose built LBS are in use, SPOT satellite messenger gained attention for its reliability. This paper summates the system architecture and experimental tests results with those of competing Assisted and Global Navigation Satellite Systems (A/GNSS). Our test bed comprised of 26 test points with pre-established database of GNSS difficulty levels in diverse environments in UNSW. Parameters of interest are availability, accuracy and Time to First Fix (TTFF). Relative benchmarking proves SPOT’s higher TTFF and higher failure rate in general. While High Sensitivity GNSS and Assisted GNSS (MSBased and MS-Assisted) had higher availability, higher accuracy and lower TTFF. Altogether fewer failure scenarios, trustworthy coverage with cost effectiveness were observed for MS-Based AGNSS which is vital for LBS applications. However reliance on wired or wireless IP network potentially limits the performance in nonexistent underlying infrastructure in remote applications. SPOT demonstrated higher TTFF and failure rates in test scenario. On the contrary Assisted GNSS (MS-Based or MS-Assisted) can provide a reliable, cost effective and open source alternative to SPOT satellite messenger with better TTFF, availability and accuracy for consumer and research applications.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130106837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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