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.2014.6851352
E. Tatar, T. Mukherjee, G. Fedder
This paper presents a system level MEMS gyroscope simulation technique analyzing the effect of stress on MEMS gyroscope zero rate output (ZRO) and scale factor (SF). A circuit simulation environment that includes the parameterized behavioral models of the MEMS devices is used for predicting the stress effects on gyroscope output. The simulations show that typical packaging stress values (2MPa) create on the order of °/hr bias shifts that can limit the gyroscope performance. Drive comb gap mismatches as a result of different stator and rotor displacements due to stress are responsible for the ZRO, and they create a Coriolis in-phase force that cannot be distinguished from the rotational rate signal.
{"title":"Simulation of stress effects on mode-matched MEMS gyroscope bias and scale factor","authors":"E. Tatar, T. Mukherjee, G. Fedder","doi":"10.1109/PLANS.2014.6851352","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851352","url":null,"abstract":"This paper presents a system level MEMS gyroscope simulation technique analyzing the effect of stress on MEMS gyroscope zero rate output (ZRO) and scale factor (SF). A circuit simulation environment that includes the parameterized behavioral models of the MEMS devices is used for predicting the stress effects on gyroscope output. The simulations show that typical packaging stress values (2MPa) create on the order of °/hr bias shifts that can limit the gyroscope performance. Drive comb gap mismatches as a result of different stator and rotor displacements due to stress are responsible for the ZRO, and they create a Coriolis in-phase force that cannot be distinguished from the rotational rate signal.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"71 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":"123174026","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.2014.6851504
R. Bauernfeind, B. Eissfeller
The road transportation sector is the most dynamic and growing field of GNSS applications, far beyond vehicle navigation. Distance based road user charging systems and location based services generate important revenue streams. GNSS based advanced driver assistance systems increase the traffic efficiency and help to reduce the number of accidents. As GNSS is the primary sensor for position determination, it is important to be aware of performance degradations and have means to mitigate upcoming threats. An recent emerging threat originates from GNSS jammers, so called Personal Privacy Devices (PPDs), which are used either to hide someone's whereabouts in order to protect privacy or for criminal actions like attempting fraud on GNSS based charging systems or to disable GNSS based theft protection systems. In order to give local authorities the means to estimate the extent of the threat, a jammer detector is presented which can be easily deployed and operated at any point of interest. Results from an initial measurement campaign are presented where the detector has been deployed over several weeks at two highway gantries in the area of Munich.
{"title":"Software-defined radio based roadside jammer detector: Architecture and results","authors":"R. Bauernfeind, B. Eissfeller","doi":"10.1109/PLANS.2014.6851504","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851504","url":null,"abstract":"The road transportation sector is the most dynamic and growing field of GNSS applications, far beyond vehicle navigation. Distance based road user charging systems and location based services generate important revenue streams. GNSS based advanced driver assistance systems increase the traffic efficiency and help to reduce the number of accidents. As GNSS is the primary sensor for position determination, it is important to be aware of performance degradations and have means to mitigate upcoming threats. An recent emerging threat originates from GNSS jammers, so called Personal Privacy Devices (PPDs), which are used either to hide someone's whereabouts in order to protect privacy or for criminal actions like attempting fraud on GNSS based charging systems or to disable GNSS based theft protection systems. In order to give local authorities the means to estimate the extent of the threat, a jammer detector is presented which can be easily deployed and operated at any point of interest. Results from an initial measurement campaign are presented where the detector has been deployed over several weeks at two highway gantries in the area of Munich.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"1 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":"125887436","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.2014.6851496
F. O. Silva, E. M. Hemerly, Waldemar C. L. Filho
In this paper, a new approach for the coarse self-alignment of strapdown inertial navigation systems (SINS) is presented. This approach, here called indirect approach, consists on estimating the initial Euler angles of the SINS for a given rotation sequence, directly from the inertial sensors raw readings, to then proceed with the calculation of the corresponding direct cosine matrix (DCM), which represents the SINS initial orientation. It is demonstrated in this paper that the utilization of the proposed approach with rotation sequences 321, or 312, allows the SINS initial orientation to be accurately determined in terms of its DCM, even if the actual position of the SINS on the Earth's surface is unknown. This approach is, therefore, particularly useful in situations where the SINS position is unknown, or for safety reasons, must not be informed.
{"title":"Influence of latitude in coarse self-alignment of strapdown inertial navigation systems","authors":"F. O. Silva, E. M. Hemerly, Waldemar C. L. Filho","doi":"10.1109/PLANS.2014.6851496","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851496","url":null,"abstract":"In this paper, a new approach for the coarse self-alignment of strapdown inertial navigation systems (SINS) is presented. This approach, here called indirect approach, consists on estimating the initial Euler angles of the SINS for a given rotation sequence, directly from the inertial sensors raw readings, to then proceed with the calculation of the corresponding direct cosine matrix (DCM), which represents the SINS initial orientation. It is demonstrated in this paper that the utilization of the proposed approach with rotation sequences 321, or 312, allows the SINS initial orientation to be accurately determined in terms of its DCM, even if the actual position of the SINS on the Earth's surface is unknown. This approach is, therefore, particularly useful in situations where the SINS position is unknown, or for safety reasons, must not be informed.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"9 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":"127668689","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.2014.6851373
K. Frank, Estefania Munoz Diaz, P. Robertson, Francisco Javier Fuentes Sanchez
Activity recognition has been a hot topic in research throughout the last years. Walking, standing, sitting or lying have been detected with more or less confidence, in more or less suitable system designs. None of these systems however has entered daily life, neither in mass market, nor in professional environments. What is required is an unobtrusive system, requiring few resources and - most important - recognizing all important activities with high confidence. To this end, our research has focused on the professional market for safety related applications: first responders or also military use. Next to the classical motion related activities, our system supports motions in three dimensions that are necessary for all kinds of movements indoors as well as outdoors. These include falling, wriggling, crawling, climbing stairs up and down and using an elevator. We have proven this approach to run in real-time with only a single wireless sensor attached to the body while achieving robust and reliable recognition with a delay lower than two seconds.
{"title":"Bayesian recognition of safety relevant motion activities with inertial sensors and barometer","authors":"K. Frank, Estefania Munoz Diaz, P. Robertson, Francisco Javier Fuentes Sanchez","doi":"10.1109/PLANS.2014.6851373","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851373","url":null,"abstract":"Activity recognition has been a hot topic in research throughout the last years. Walking, standing, sitting or lying have been detected with more or less confidence, in more or less suitable system designs. None of these systems however has entered daily life, neither in mass market, nor in professional environments. What is required is an unobtrusive system, requiring few resources and - most important - recognizing all important activities with high confidence. To this end, our research has focused on the professional market for safety related applications: first responders or also military use. Next to the classical motion related activities, our system supports motions in three dimensions that are necessary for all kinds of movements indoors as well as outdoors. These include falling, wriggling, crawling, climbing stairs up and down and using an elevator. We have proven this approach to run in real-time with only a single wireless sensor attached to the body while achieving robust and reliable recognition with a delay lower than two seconds.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"33 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":"126967530","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.2014.6851370
Mostafa Elhoushi, J. Georgy, M. Korenberg, A. Noureldin
Portable navigation has become increasingly prevalent in daily activities. The need for accurate user positioning information, including a person's location and velocity, when using a portable device (such as a cell phone, tablet, or even a smart watch) is growing in various fields. Knowing the user's mode of motion or conveyance allows appropriate algorithms or constraints, related to each mode, to be used to estimate a more accurate position and velocity. The modes covered in this paper are walking, running, cycling, and land-based vessels (including vehicles, truck, buses, and trains which include light rail trains and subways). The work discussed in this paper involves the use of sensors - with and without Global Navigation Satellite Systems (GNSS) signal availability - in portable devices to help recognize the mode of motion for an arbitrary user, an arbitrary use case - whether the device is held in the hand, in the pocket, or at the ear, etc. - and an arbitrary orientation of the device.
{"title":"Robust motion mode recognition for portable navigation independent on device usage","authors":"Mostafa Elhoushi, J. Georgy, M. Korenberg, A. Noureldin","doi":"10.1109/PLANS.2014.6851370","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851370","url":null,"abstract":"Portable navigation has become increasingly prevalent in daily activities. The need for accurate user positioning information, including a person's location and velocity, when using a portable device (such as a cell phone, tablet, or even a smart watch) is growing in various fields. Knowing the user's mode of motion or conveyance allows appropriate algorithms or constraints, related to each mode, to be used to estimate a more accurate position and velocity. The modes covered in this paper are walking, running, cycling, and land-based vessels (including vehicles, truck, buses, and trains which include light rail trains and subways). The work discussed in this paper involves the use of sensors - with and without Global Navigation Satellite Systems (GNSS) signal availability - in portable devices to help recognize the mode of motion for an arbitrary user, an arbitrary use case - whether the device is held in the hand, in the pocket, or at the ear, etc. - and an arbitrary orientation of the device.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"85 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":"126239589","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.2014.6851467
Shifei Liu, M. Atia, Tashfeen B. Karamat, S. Givigi, A. Noureldin
The demand for a reliable and accurate navigation system that can replace Global Positioning System (GPS) in GPS-denied environment has become increasingly imperative. For indoor environment where GPS is almost unavailable or unreliable, the utilization of other sensors such as inertial sensors becomes necessary. However, inertial sensors alone cannot sustain reliable long-term accuracy due to errors accumulation without external periodic corrections. Thus this paper proposes the utilization of Light Detection and Ranging (LiDAR) as an alternative system to provide periodic corrections. In this paper, a tightly-coupled integrated navigation system that integrates LiDAR, a single-axis gyroscope and wheel encoder is introduced. Straight lines detection and extraction algorithm is utilized to estimate the changes in orientation and range from LiDAR to the extracted line. LiDAR-estimated orientation change and range change to the extracted line feature between two consecutive LiDAR scans are first filtered out through a high rate extended Kalman Filter (EKF) to remove the effect of short-term noise associated with LiDAR scans. Then the smoothed orientation and range changes are fused by a low rate EKF with those predicted by gyroscope and wheel encoder. The proposed system is verified through real experiment on a wirelessly controlled Unmanned Ground Vehicle (UGV). Experimental results indicate that navigation accuracy has been improved to sub-meter and gyroscope bias is precisely estimated.
{"title":"A dual-rate multi-filter algorithm for LiDAR-aided indoor navigation systems","authors":"Shifei Liu, M. Atia, Tashfeen B. Karamat, S. Givigi, A. Noureldin","doi":"10.1109/PLANS.2014.6851467","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851467","url":null,"abstract":"The demand for a reliable and accurate navigation system that can replace Global Positioning System (GPS) in GPS-denied environment has become increasingly imperative. For indoor environment where GPS is almost unavailable or unreliable, the utilization of other sensors such as inertial sensors becomes necessary. However, inertial sensors alone cannot sustain reliable long-term accuracy due to errors accumulation without external periodic corrections. Thus this paper proposes the utilization of Light Detection and Ranging (LiDAR) as an alternative system to provide periodic corrections. In this paper, a tightly-coupled integrated navigation system that integrates LiDAR, a single-axis gyroscope and wheel encoder is introduced. Straight lines detection and extraction algorithm is utilized to estimate the changes in orientation and range from LiDAR to the extracted line. LiDAR-estimated orientation change and range change to the extracted line feature between two consecutive LiDAR scans are first filtered out through a high rate extended Kalman Filter (EKF) to remove the effect of short-term noise associated with LiDAR scans. Then the smoothed orientation and range changes are fused by a low rate EKF with those predicted by gyroscope and wheel encoder. The proposed system is verified through real experiment on a wirelessly controlled Unmanned Ground Vehicle (UGV). Experimental results indicate that navigation accuracy has been improved to sub-meter and gyroscope bias is precisely estimated.","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":"121112609","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.2014.6851389
V. Kropp, B. Eissfeller, G. Berz
This paper describes and further develops two algorithms which are currently being considered by a bilateral EU-U.S. working group on Advanced Receiver Autonomous Integrity Monitoring (ARAIM) called Working Group C (WG-C); the baseline ARAIM MHSS algorithm and an expansion of this approach termed Q*-MHSS. The availability performance, given either an equal or an optimized allocation of integrity and continuity budgets to all failure modes, is assessed. The paper furthermore proposes an improvement to the protection level calculations by introducing a geometry check to exclude weak geometries and corresponding fault modes leading to excessive protection levels. This is relevant in particular when considering constellation-wide consistent faults under relatively high constellation fault probabilities, such as may be necessary when initially starting ARAIM service with constellations that have a limited service history.
{"title":"Optimized MHSS ARAIM user algorithms: Assumptions, protection level calculation and availability analysis","authors":"V. Kropp, B. Eissfeller, G. Berz","doi":"10.1109/PLANS.2014.6851389","DOIUrl":"https://doi.org/10.1109/PLANS.2014.6851389","url":null,"abstract":"This paper describes and further develops two algorithms which are currently being considered by a bilateral EU-U.S. working group on Advanced Receiver Autonomous Integrity Monitoring (ARAIM) called Working Group C (WG-C); the baseline ARAIM MHSS algorithm and an expansion of this approach termed Q*-MHSS. The availability performance, given either an equal or an optimized allocation of integrity and continuity budgets to all failure modes, is assessed. The paper furthermore proposes an improvement to the protection level calculations by introducing a geometry check to exclude weak geometries and corresponding fault modes leading to excessive protection levels. This is relevant in particular when considering constellation-wide consistent faults under relatively high constellation fault probabilities, such as may be necessary when initially starting ARAIM service with constellations that have a limited service history.","PeriodicalId":371808,"journal":{"name":"2014 IEEE/ION Position, Location and Navigation Symposium - PLANS 2014","volume":"30 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":"130196041","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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