Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851433
Y. Tsai, K. Low
In past decade, the GPS plays an important role in many navigation applications. In some cases, the GPS is the only device providing navigation service. For safety-of-life user, GPS alone cannot provide the stringent performance in accuracy, integrity and availability. As a result, several SBAS (Satellite Based Augmentation System) systems have been developed to provide corrections and assistances to GPS users. The notably SBAS systems are U.S. WAAS (Wide Area Augmentation System), Europe EGNOS (European Geostationary Navigation Overlay Service) and Japanese MSAS (Multi-functional Satellite Augmentation System), In addition, India and Russia have engaged in the deployment and development of SBAS system, named GAGAN (GPS Aided Geo Augmented Navigation) and SDCM (System of Differential Correction and Monitoring). Also, other regions in the world currently proceed feasibility studies on SBAS. For instance, SACCSA (The Augmentation Solution for the Caribbean, Central America and South America) project in Latin-America, ASAS (African Satellite Augmentation System) in Africa and Malaysian SBAS. SBAS broadcast the correction for ionosphere delay and satellite clock. By using these corrections, the user position accuracy can improve to several meters or better. In Singapore, Changi airport is one of busiest airport in the world, and it handled more than fifty million passengers in 2012. Additionally, Singapore is located in the equatorial region so that the ionosphere activities are dramatic. Currently, there is no SBAS service in the Singapore region. The objective of this paper is to propose a fusion scheme to exploit the correction and integrity monitoring messages from nearby two SBAS systems, GAGAN and MSAS and then provide a reliable correction for GPS users. Singapore is not located in the service volume of either GAGAN or MSAS. Because of the lack of SBAS monitoring stations, the navigation quality in Singapore region cannot be assured through either GAGAN or MSAS. The messages from both SBAS systems can be still received. Therefore, it is desired to investigate how messages from GAGAN and MSAS can be utilized to enhance the performance for GPS user. Then, its goal is to ensure a smooth transition and assured navigation performance in this region. In the paper, both GAGAN and MSAS messages are firstly received and analyzed for the assessment of the signal quality. And then, a comparison with the requirements at different phases of flight is made. A synergistic integration of the messages from by GAGAN and MSAS in Singapore is developed to pave a way for the future regional augmentation system implementation. An extrapolation scheme is proposed to expand the coverage of ionospheric delay correction messages from GAGAN and MSAS. All proposed fusion and extrapolation schemes are assessed by using real data to evaluate performance. The result shows that our approach has reliable performance compared to a surveying-grade receiver.
{"title":"Performance assessment on expanding SBAS service areas of GAGAN and MSAS to Singapore region","authors":"Y. Tsai, K. Low","doi":"10.1109/PLANS.2014.6851433","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851433","url":null,"abstract":"In past decade, the GPS plays an important role in many navigation applications. In some cases, the GPS is the only device providing navigation service. For safety-of-life user, GPS alone cannot provide the stringent performance in accuracy, integrity and availability. As a result, several SBAS (Satellite Based Augmentation System) systems have been developed to provide corrections and assistances to GPS users. The notably SBAS systems are U.S. WAAS (Wide Area Augmentation System), Europe EGNOS (European Geostationary Navigation Overlay Service) and Japanese MSAS (Multi-functional Satellite Augmentation System), In addition, India and Russia have engaged in the deployment and development of SBAS system, named GAGAN (GPS Aided Geo Augmented Navigation) and SDCM (System of Differential Correction and Monitoring). Also, other regions in the world currently proceed feasibility studies on SBAS. For instance, SACCSA (The Augmentation Solution for the Caribbean, Central America and South America) project in Latin-America, ASAS (African Satellite Augmentation System) in Africa and Malaysian SBAS. SBAS broadcast the correction for ionosphere delay and satellite clock. By using these corrections, the user position accuracy can improve to several meters or better. In Singapore, Changi airport is one of busiest airport in the world, and it handled more than fifty million passengers in 2012. Additionally, Singapore is located in the equatorial region so that the ionosphere activities are dramatic. Currently, there is no SBAS service in the Singapore region. The objective of this paper is to propose a fusion scheme to exploit the correction and integrity monitoring messages from nearby two SBAS systems, GAGAN and MSAS and then provide a reliable correction for GPS users. Singapore is not located in the service volume of either GAGAN or MSAS. Because of the lack of SBAS monitoring stations, the navigation quality in Singapore region cannot be assured through either GAGAN or MSAS. The messages from both SBAS systems can be still received. Therefore, it is desired to investigate how messages from GAGAN and MSAS can be utilized to enhance the performance for GPS user. Then, its goal is to ensure a smooth transition and assured navigation performance in this region. In the paper, both GAGAN and MSAS messages are firstly received and analyzed for the assessment of the signal quality. And then, a comparison with the requirements at different phases of flight is made. A synergistic integration of the messages from by GAGAN and MSAS in Singapore is developed to pave a way for the future regional augmentation system implementation. An extrapolation scheme is proposed to expand the coverage of ionospheric delay correction messages from GAGAN and MSAS. All proposed fusion and extrapolation schemes are assessed by using real data to evaluate performance. The result shows that our approach has reliable performance compared to a surveying-grade receiver.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122276820","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851455
R. H. Wu, S. A. Davidson
An Alternative Positioning Navigation and Timing concept, called Diverse Ranging (DivR) is proposed for sustaining NextGen Performance Based Navigation and Automatic Dependent Surveillance - Broadcast during Global Navigation Satellite System outages. The system consists of a network of ground stations providing navigation signaling services to aircraft. The service is provided by using ground stations to selectively reply to the spontaneous broadcast messages of a small subset of aircraft. These new messages allow avionics to calculate positions in two modes - the Direct-Reply (DR) mode and Non-Reply (NR) mode. The DR mode is used by aircraft receiving addressed replies from the ground stations and is based on observed round-trip range measurements. The NR mode is used by aircraft receiving ground station replies that are addressed to other aircraft, and the processing is based on pseudorange and echoed pseudorange measurements. Timing signal broadcasts are also sent by the ground stations, which are synchronized using aircrafts' position broadcasts. The following analyses were conducted in order to characterize the performance of DivR: (1) nominal error overbounding and a preliminary Fault Modes and Effects Analysis, (2) initial integrity and continuity risk allocations based on Targeted Level of Safety Fault Tree Analysis, (3) theoretical derivations of the Navigation System Error (NSE) and Horizontal Protection Level (HPL) performance bounds, and (4) a terminal case study based on Washington Dulles International Airport for which the NSE, nominal-condition HPL, and spectrum impact were analyzed. The results show that DivR meets the required navigation accuracy and integrity requirements under nominal conditions for terminal operations in both low and high interference environments, with 99% availability and a 1-sec update interval. Further analyses are required to evaluate the performance under faulted conditions and evaluate time to alert and continuity performance. Timing service synchronization accuracy is expected to be sub-microsecond.
{"title":"An Alternative Positioning Navigation and Timing concept based on Diverse Ranging","authors":"R. H. Wu, S. A. Davidson","doi":"10.1109/PLANS.2014.6851455","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851455","url":null,"abstract":"An Alternative Positioning Navigation and Timing concept, called Diverse Ranging (DivR) is proposed for sustaining NextGen Performance Based Navigation and Automatic Dependent Surveillance - Broadcast during Global Navigation Satellite System outages. The system consists of a network of ground stations providing navigation signaling services to aircraft. The service is provided by using ground stations to selectively reply to the spontaneous broadcast messages of a small subset of aircraft. These new messages allow avionics to calculate positions in two modes - the Direct-Reply (DR) mode and Non-Reply (NR) mode. The DR mode is used by aircraft receiving addressed replies from the ground stations and is based on observed round-trip range measurements. The NR mode is used by aircraft receiving ground station replies that are addressed to other aircraft, and the processing is based on pseudorange and echoed pseudorange measurements. Timing signal broadcasts are also sent by the ground stations, which are synchronized using aircrafts' position broadcasts. The following analyses were conducted in order to characterize the performance of DivR: (1) nominal error overbounding and a preliminary Fault Modes and Effects Analysis, (2) initial integrity and continuity risk allocations based on Targeted Level of Safety Fault Tree Analysis, (3) theoretical derivations of the Navigation System Error (NSE) and Horizontal Protection Level (HPL) performance bounds, and (4) a terminal case study based on Washington Dulles International Airport for which the NSE, nominal-condition HPL, and spectrum impact were analyzed. The results show that DivR meets the required navigation accuracy and integrity requirements under nominal conditions for terminal operations in both low and high interference environments, with 99% availability and a 1-sec update interval. Further analyses are required to evaluate the performance under faulted conditions and evaluate time to alert and continuity performance. Timing service synchronization accuracy is expected to be sub-microsecond.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132756986","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851364
Yuwei Chen, Jingbin Liu, Antonni Jaakkola, J. Hyyppa, Liang Chen, H. Hyyppa, Tang Jian, Ruizhi Chen
In this paper, an environment knowledge-based multiple sensors indoor positioning system is designed and tested. The system integrates a LiDAR sensor, an odometer and a light sensor onto a low-cost robot platform. While, a LiDAR point-cloud-based pattern match algorithm - Iterative Closed Point (ICP) is used to estimate the relative change in heading and displacement of the platform. Based on the knowledge of the construction's structure, outdoor weather, and lighting situation, the light sensor offers an efficient parameter to improve indoor position accuracy with a light intensity fingerprint matching algorithm on low computational cost. The estimated heading and position change from LiDAR are eventually fused by Extended Kalman Filter (EKF) with those calculated from the light sensor measurement. The results prove that the spatial structure and the ambient light information in indoor environment as knowledge base can be utilized to estimate and mitigate the accumulated errors and inherent drifts of ICP algorithm. These improvements lead to longer sustainable sub meter-level indoor positioning for UGVs.
{"title":"Knowledge-based indoor positioning based on LiDAR aided multiple sensors system for UGVs","authors":"Yuwei Chen, Jingbin Liu, Antonni Jaakkola, J. Hyyppa, Liang Chen, H. Hyyppa, Tang Jian, Ruizhi Chen","doi":"10.1109/PLANS.2014.6851364","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851364","url":null,"abstract":"In this paper, an environment knowledge-based multiple sensors indoor positioning system is designed and tested. The system integrates a LiDAR sensor, an odometer and a light sensor onto a low-cost robot platform. While, a LiDAR point-cloud-based pattern match algorithm - Iterative Closed Point (ICP) is used to estimate the relative change in heading and displacement of the platform. Based on the knowledge of the construction's structure, outdoor weather, and lighting situation, the light sensor offers an efficient parameter to improve indoor position accuracy with a light intensity fingerprint matching algorithm on low computational cost. The estimated heading and position change from LiDAR are eventually fused by Extended Kalman Filter (EKF) with those calculated from the light sensor measurement. The results prove that the spatial structure and the ambient light information in indoor environment as knowledge base can be utilized to estimate and mitigate the accumulated errors and inherent drifts of ICP algorithm. These improvements lead to longer sustainable sub meter-level indoor positioning for UGVs.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130505814","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851404
D. Salmon, D. Bevly
This paper discusses an exploratory analyses of the benefits of using Vehicle Odometry/Steer Angle and an accurate vehicle model (VM) to replace/assist a low-cost Inertial Measurement Unit (IMU) for blended ground vehicle navigation. In this research, multiple variations of the tightly coupled Extended Kalman Filter (EKF) algorithm are performed using multiple sensor sets to find the optimal solution, factoring in sensor cost and pose accuracy. Many automotive precision navigation solutions have been developed based on sensor fusion in recent years; however, as autonomous navigation technology becomes more prevalent on consumer vehicles, the need for a high-accuracy, low-cost pose solution is increasing. One widely used solution to this problem is the combination of a Micro-Electro-Mechanical (MEMS) IMU with Global Positioning System (GPS); however, this may not be the optimal solution due to the high noise characteristics of lower cost IMU's. Measurements from GPS, IMU/Inertial Navigation System (INS), and VM are used in this research. The different algorithm setups being investigated include: GPS/VM sensor fusion with accurate vehicle model constraints, GPS/INS with low-cost commercially available IMU, and GPS/INS/VM with the IMU. The determination of the level of IMU necessary for GPS/INS fusion to exceed the pose solution accuracy achievable using GPS/VM sensor fusion with accurate vehicle model constraints is a priority for this research. Another goal of this research is the quantitative and qualitative analysis of the benefits of using VM to assist normal GPS/INS EKF and whether the inclusion of VM in either the time update or the measurement update results in a more accurate pose solution. Direct experimental comparison of tightly coupled EKF Fault Detection and Exclusion (FDE) algorithms based on vehicle wheel speed and steering angle versus the IMU measurements to determine if either sensor set yields a distinct advantage over the other is also investigated. All analysis will be based on real world experimental data.
{"title":"An exploration of low-cost sensor and vehicle model Solutions for ground vehicle navigation","authors":"D. Salmon, D. Bevly","doi":"10.1109/PLANS.2014.6851404","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851404","url":null,"abstract":"This paper discusses an exploratory analyses of the benefits of using Vehicle Odometry/Steer Angle and an accurate vehicle model (VM) to replace/assist a low-cost Inertial Measurement Unit (IMU) for blended ground vehicle navigation. In this research, multiple variations of the tightly coupled Extended Kalman Filter (EKF) algorithm are performed using multiple sensor sets to find the optimal solution, factoring in sensor cost and pose accuracy. Many automotive precision navigation solutions have been developed based on sensor fusion in recent years; however, as autonomous navigation technology becomes more prevalent on consumer vehicles, the need for a high-accuracy, low-cost pose solution is increasing. One widely used solution to this problem is the combination of a Micro-Electro-Mechanical (MEMS) IMU with Global Positioning System (GPS); however, this may not be the optimal solution due to the high noise characteristics of lower cost IMU's. Measurements from GPS, IMU/Inertial Navigation System (INS), and VM are used in this research. The different algorithm setups being investigated include: GPS/VM sensor fusion with accurate vehicle model constraints, GPS/INS with low-cost commercially available IMU, and GPS/INS/VM with the IMU. The determination of the level of IMU necessary for GPS/INS fusion to exceed the pose solution accuracy achievable using GPS/VM sensor fusion with accurate vehicle model constraints is a priority for this research. Another goal of this research is the quantitative and qualitative analysis of the benefits of using VM to assist normal GPS/INS EKF and whether the inclusion of VM in either the time update or the measurement update results in a more accurate pose solution. Direct experimental comparison of tightly coupled EKF Fault Detection and Exclusion (FDE) algorithms based on vehicle wheel speed and steering angle versus the IMU measurements to determine if either sensor set yields a distinct advantage over the other is also investigated. All analysis will be based on real world experimental data.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130715546","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851449
B. Schipper
This paper describes a method to observe the likely presence of multipath errors and mitigate them from the computation of the GNSS position solution.
本文描述了一种从GNSS位置解的计算中观察可能存在的多径误差并减轻它们的方法。
{"title":"Multipath detection and mitigation leveraging the growing GNSS constellation","authors":"B. Schipper","doi":"10.1109/PLANS.2014.6851449","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851449","url":null,"abstract":"This paper describes a method to observe the likely presence of multipath errors and mitigate them from the computation of the GNSS position solution.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131541431","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851511
Qian Li, Yueyang Ben, F. Sun, Liang Huo
Common mechanizations are not applicable for a marine strapdown Inertial Navigation System (INS) in Polar Region. Aiming at this problem, transversal strapdown INS mechanization and corresponding damping technology are proposed in this paper to replace common strapdown INS mechanizations. The transversal coordinate system is constructed for the mechanization of transversal strapdown INS, and then an error analysis for transversal strapdown INS is performed. The error analysis for transversal strapdown INS reveals the fact that the system also includes three kinds of periodic oscillating errors as common strapdown INS. To restrain the periodic oscillating errors, damping equalizers applicable to transversal strapdown INS are designed with reference velocity compensating the effect of ship motion. Finally simulation test is carried out to demonstrate the performance of transversal strapdown INS and damping technology in Polar Region.
{"title":"Transversal strapdown INS and damping technology for marine in polar region","authors":"Qian Li, Yueyang Ben, F. Sun, Liang Huo","doi":"10.1109/PLANS.2014.6851511","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851511","url":null,"abstract":"Common mechanizations are not applicable for a marine strapdown Inertial Navigation System (INS) in Polar Region. Aiming at this problem, transversal strapdown INS mechanization and corresponding damping technology are proposed in this paper to replace common strapdown INS mechanizations. The transversal coordinate system is constructed for the mechanization of transversal strapdown INS, and then an error analysis for transversal strapdown INS is performed. The error analysis for transversal strapdown INS reveals the fact that the system also includes three kinds of periodic oscillating errors as common strapdown INS. To restrain the periodic oscillating errors, damping equalizers applicable to transversal strapdown INS are designed with reference velocity compensating the effect of ship motion. Finally simulation test is carried out to demonstrate the performance of transversal strapdown INS and damping technology in Polar Region.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"212 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132369070","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851375
J. Pinchin, Michael A. Brown, Jesse M. Blum, D. Shaw, J. Blakey
Focus groups, interviews and anecdotal evidence suggest that senior clinicians are better than their juniors at managing their task load when working `out of hours' in hospitals. For example experience allows them to prioritise cases which are likely to degrade and to organise their time to account for personal needs such as rest and refreshment. Quantifying this behaviour, and the variations between staff groups, is a complex task. Traditional direct observation and self-report methods are very intrusive, expensive and lack both scalability and validity. In this work we propose the use of positioning technology to augment or replace these traditional methods. We integrate contextual information from a digital task management system with location information to obtain a temporally ordered list of completed tasks with associated timings. The positioning system described in this work is based upon observations of visible WiFi access points. As the clinician moves between wards the set of visible access points changes and can be used to infer location. We propose a method by which access points can be associated with a discrete set of locations. This method removes the need for an expensive, intrusive `ground survey' and is mindful of user privacy by only providing location within the pre-defined set. This paper describes the structure of the problem and a method for the integration of contextual and WiFi visibility data. Exemplar results are given from a limited scale trial performed in a large UK teaching hospital. The novel application of positioning technology to the study of clinical workplace behaviour offers opportunities to drive efficiencies, enhance staff training and hence improve patient safety.
{"title":"Integrating WiFi based positioning with a job management system to study task management behaviour","authors":"J. Pinchin, Michael A. Brown, Jesse M. Blum, D. Shaw, J. Blakey","doi":"10.1109/PLANS.2014.6851375","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851375","url":null,"abstract":"Focus groups, interviews and anecdotal evidence suggest that senior clinicians are better than their juniors at managing their task load when working `out of hours' in hospitals. For example experience allows them to prioritise cases which are likely to degrade and to organise their time to account for personal needs such as rest and refreshment. Quantifying this behaviour, and the variations between staff groups, is a complex task. Traditional direct observation and self-report methods are very intrusive, expensive and lack both scalability and validity. In this work we propose the use of positioning technology to augment or replace these traditional methods. We integrate contextual information from a digital task management system with location information to obtain a temporally ordered list of completed tasks with associated timings. The positioning system described in this work is based upon observations of visible WiFi access points. As the clinician moves between wards the set of visible access points changes and can be used to infer location. We propose a method by which access points can be associated with a discrete set of locations. This method removes the need for an expensive, intrusive `ground survey' and is mindful of user privacy by only providing location within the pre-defined set. This paper describes the structure of the problem and a method for the integration of contextual and WiFi visibility data. Exemplar results are given from a limited scale trial performed in a large UK teaching hospital. The novel application of positioning technology to the study of clinical workplace behaviour offers opportunities to drive efficiencies, enhance staff training and hence improve patient safety.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128106083","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851444
C. Hackman, S. Byram, V. Slabinski, J. Tracey
The GPS Analysis Division, Earth Orientation Department, US Naval Observatory processes data from hundreds of carrier-phase GNSS receivers daily, computing 16 product sets/day using measurements from the GPS and/or (Russian) GLONASS satellite systems. Product sets include high-precision satellite orbits and clock corrections, receiver clock corrections, earth-orientation parameters (EOPs), a UT1-UTC extrapolator, and IGS Final Troposphere values for 300+ IGS receiver locations worldwide. The division has maintained a 98-100% on-time rate for all of its products since 2007. Both post-processed (3-16 hour latency) and predicted clocks/orbits/EOPs are produced. Post-processed GPS satellite orbits/clocks have approximately 17 mm/150 ps precision, with predicted GPS satellite orbits/clocks in the 40 mm/2 ns range. Post-processed/predicted GLONASS orbits have 5 and 12 cm precision, respectively. The clock/orbit predictions may be useful for real-time applications. This article consists of two parts. In the first, we summarize the precision and availability of GPS Analysis Division positioning/navigation/timing (PNT) and meteorology products. In the second, we present the results of a test in which we estimate PNT values using the precise-point positioning technique with GPS, GLONASS, and combined GPS and GLONASS measurements.
{"title":"USNO GPS/GLONASS PNT products: Overview, and GPS+GLONASS vs GLONASS only PPP accuracy","authors":"C. Hackman, S. Byram, V. Slabinski, J. Tracey","doi":"10.1109/PLANS.2014.6851444","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851444","url":null,"abstract":"The GPS Analysis Division, Earth Orientation Department, US Naval Observatory processes data from hundreds of carrier-phase GNSS receivers daily, computing 16 product sets/day using measurements from the GPS and/or (Russian) GLONASS satellite systems. Product sets include high-precision satellite orbits and clock corrections, receiver clock corrections, earth-orientation parameters (EOPs), a UT1-UTC extrapolator, and IGS Final Troposphere values for 300+ IGS receiver locations worldwide. The division has maintained a 98-100% on-time rate for all of its products since 2007. Both post-processed (3-16 hour latency) and predicted clocks/orbits/EOPs are produced. Post-processed GPS satellite orbits/clocks have approximately 17 mm/150 ps precision, with predicted GPS satellite orbits/clocks in the 40 mm/2 ns range. Post-processed/predicted GLONASS orbits have 5 and 12 cm precision, respectively. The clock/orbit predictions may be useful for real-time applications. This article consists of two parts. In the first, we summarize the precision and availability of GPS Analysis Division positioning/navigation/timing (PNT) and meteorology products. In the second, we present the results of a test in which we estimate PNT values using the precise-point positioning technique with GPS, GLONASS, and combined GPS and GLONASS measurements.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128137369","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851490
E. Brewer, Gavin Haentjens, V. Gavrilets, G. McGraw
Several aerial platforms rely on decimeter-level relative position accuracy for various applications including automatic takeoff and landing, precision targeting, and airborne refueling. For such applications, a Real Time Kinematic (RTK) GPS system provides a relatively low cost, robust, and reliable solution. Current commercial RTK products are inherently susceptible to jamming and spoofing. The Selective Availability Anti-Spoof Module (SAASM) implementations to date typically relied on relatively large and complicated architectures which would be difficult to port into a small (Groups 1-3) Unmanned Aircraft System (UAS) due to Size, Weight, and Power (SWaP) constraints. This paper describes the architecture, algorithms, and testing approach from Rockwell Collins high integrity relative navigation system including a SAASM-based RTK implementation for small UAS. A variant of the system was implemented for the Navy's Small Tactical Unmanned Aircraft System (STUAS) program. The STUAS system performed its first successful ship-based launch and recoveries on the U.S.S. Mesa Verde using Rockwell Collins high integrity relative navigation system in February of 2013.
{"title":"A low SWaP implementation of high integrity relative navigation for small UAS","authors":"E. Brewer, Gavin Haentjens, V. Gavrilets, G. McGraw","doi":"10.1109/PLANS.2014.6851490","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851490","url":null,"abstract":"Several aerial platforms rely on decimeter-level relative position accuracy for various applications including automatic takeoff and landing, precision targeting, and airborne refueling. For such applications, a Real Time Kinematic (RTK) GPS system provides a relatively low cost, robust, and reliable solution. Current commercial RTK products are inherently susceptible to jamming and spoofing. The Selective Availability Anti-Spoof Module (SAASM) implementations to date typically relied on relatively large and complicated architectures which would be difficult to port into a small (Groups 1-3) Unmanned Aircraft System (UAS) due to Size, Weight, and Power (SWaP) constraints. This paper describes the architecture, algorithms, and testing approach from Rockwell Collins high integrity relative navigation system including a SAASM-based RTK implementation for small UAS. A variant of the system was implemented for the Navy's Small Tactical Unmanned Aircraft System (STUAS) program. The STUAS system performed its first successful ship-based launch and recoveries on the U.S.S. Mesa Verde using Rockwell Collins high integrity relative navigation system in February of 2013.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132149705","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}
Pub Date : 2014-05-05DOI: 10.1109/PLANS.2014.6851517
Wei Gao, Yanting Che, Fei Yu, Yalong Liu
In this paper, a improved inertial frame alignment algorithm is proposed, which significantly improves the accuracy and time cost of the traditional inertial frame coarse alignment algorithm. Firstly, a dimensionality reduction Gauss-Hermite filter algorithm is employed in the horizontal fine alignment phase. Secondly, according to the feature of the gravity, that the horizontal components of the gravity projected in horizontal reference frame is zero, the projection of the gravity in body inertial coordinate frame could be calculated easily after the horizontal fine alignment. Thirdly, a weighted smoothing algorithm is used to adjust the gravity which obtained after the horizontal fine alignment phase, and then the initial alignment algorithm is accomplished. The simulation results show that the alignment time can be greatly reduced. And the fast initial alignment algorithm can achieve the medium accuracy within 6 minutes. That meets the accuracy requirement of the medium accuracy marine SINS.
{"title":"A fast inertial frame alignment algorithm based on horizontal alignment information for marine SINS","authors":"Wei Gao, Yanting Che, Fei Yu, Yalong Liu","doi":"10.1109/PLANS.2014.6851517","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851517","url":null,"abstract":"In this paper, a improved inertial frame alignment algorithm is proposed, which significantly improves the accuracy and time cost of the traditional inertial frame coarse alignment algorithm. Firstly, a dimensionality reduction Gauss-Hermite filter algorithm is employed in the horizontal fine alignment phase. Secondly, according to the feature of the gravity, that the horizontal components of the gravity projected in horizontal reference frame is zero, the projection of the gravity in body inertial coordinate frame could be calculated easily after the horizontal fine alignment. Thirdly, a weighted smoothing algorithm is used to adjust the gravity which obtained after the horizontal fine alignment phase, and then the initial alignment algorithm is accomplished. The simulation results show that the alignment time can be greatly reduced. And the fast initial alignment algorithm can achieve the medium accuracy within 6 minutes. That meets the accuracy requirement of the medium accuracy marine SINS.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131809783","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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