Pub Date : 2008-05-05DOI: 10.1109/PLANS.2008.4570075
U. Iqbal, A. F. Okou, A. Noureldin
This paper demonstrates a low cost navigation solution that can efficiently work, in real-time, in denied GPS environment. It explores a reduced inertial sensor system (RISS) involving single-axis gyroscope and two-axis accelerometers together with a speed sensor to provide full navigation solution in denied GPS environments. With the assumption that the vehicle mostly stay in the horizontal plane, the vehicle speed obtained from the speed sensor are used together with the heading information obtained from the gyroscope to determine the velocities along the East and North directions. Consequently, the vehiclespsila longitude and latitude are determined. The position and velocity errors are estimated by Kalman filter (KF) relying on RISS dynamic error model and GPS position and velocity updates. The two accelerometers pointing towards the forward and transverse directions are used together with a reliable gravity model to determine the pitch and roll angles. This paper analyzes and discusses the merits and limitations of the proposed RISS system and its integration with GPS. The performance of the proposed method is examined by conducting road test experiment in a land vehicle.
{"title":"An integrated reduced inertial sensor system — RISS / GPS for land vehicle","authors":"U. Iqbal, A. F. Okou, A. Noureldin","doi":"10.1109/PLANS.2008.4570075","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570075","url":null,"abstract":"This paper demonstrates a low cost navigation solution that can efficiently work, in real-time, in denied GPS environment. It explores a reduced inertial sensor system (RISS) involving single-axis gyroscope and two-axis accelerometers together with a speed sensor to provide full navigation solution in denied GPS environments. With the assumption that the vehicle mostly stay in the horizontal plane, the vehicle speed obtained from the speed sensor are used together with the heading information obtained from the gyroscope to determine the velocities along the East and North directions. Consequently, the vehiclespsila longitude and latitude are determined. The position and velocity errors are estimated by Kalman filter (KF) relying on RISS dynamic error model and GPS position and velocity updates. The two accelerometers pointing towards the forward and transverse directions are used together with a reliable gravity model to determine the pitch and roll angles. This paper analyzes and discusses the merits and limitations of the proposed RISS system and its integration with GPS. The performance of the proposed method is examined by conducting road test experiment in a land vehicle.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114984193","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570093
N. Viandier, D. Nahimana, J. Marais, E. Duflos
Today, GNSS (Global Navigation Satellite System) systems made their entrance in the transport field through applications such as monitoring of containers or fleet management. These applications do not necessarily request a high availability, integrity and accuracy of the positioning system. For safety applications (for instance management of level crossing), the performances require to be more stringent. Moreover all these transport applications are used in dense urban or sub-urban areas, resulting in signal propagation variations. This increases difficulty of getting the best reception conditions for each available satellite signal. The consequences of environmental obstructions are unavailability of the service and multipath reception that degrades in particular the accuracy of the positioning. Our works consist in two main tasks. The first one concerns the pseudo-range error model. Indeed, the model differs in relation of the satellite state of reception. When the state of reception is direct, as described in literature, the associated pseudo-range error model is a Gaussian distribution. However, when the state of reception is NLOS (Non Line Of Sight), this assumption is no more valid. We have shown that the associated model can be approximated by a Gaussian mixture. The Second contribution concerns the reception state evolution. We have modeled the propagation channel with a Markov chain. From the state of reception of each satellite, we deduce the appropriated error model. This model is then used in a filtering process to estimate the position. The approach is based on filtering methodology and on the application of a Jump Markov System algorithm.
如今，GNSS(全球导航卫星系统)系统通过集装箱监控或车队管理等应用进入运输领域。这些应用并不一定要求定位系统的高可用性、完整性和准确性。对于安全应用(例如平交道口管理)，性能要求更为严格。此外，所有这些运输应用都是在人口密集的城市或郊区使用，导致信号传播变化。这增加了获得每个可用卫星信号的最佳接收条件的难度。环境障碍的后果是服务不可用和多路径接收，特别是降低了定位的准确性。我们的工作主要包括两项任务。第一个是伪距离误差模型。实际上，模型在卫星接收状态的关系上有所不同。当接收状态为直接时，如文献所述，相关的伪距离误差模型为高斯分布。然而，当接收状态为NLOS (Non Line of Sight)时，这种假设就不成立了。我们已经证明，相关模型可以用高斯混合近似。第二个贡献是关于接收状态的演变。我们用马尔可夫链对传播通道进行了建模。根据各卫星的接收状态，推导出相应的误差模型。然后在滤波过程中使用该模型来估计位置。该方法基于滤波方法和跳跃马尔可夫系统算法的应用。
{"title":"Gnss performance enhancement in urban environment based on pseudo-range error model","authors":"N. Viandier, D. Nahimana, J. Marais, E. Duflos","doi":"10.1109/PLANS.2008.4570093","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570093","url":null,"abstract":"Today, GNSS (Global Navigation Satellite System) systems made their entrance in the transport field through applications such as monitoring of containers or fleet management. These applications do not necessarily request a high availability, integrity and accuracy of the positioning system. For safety applications (for instance management of level crossing), the performances require to be more stringent. Moreover all these transport applications are used in dense urban or sub-urban areas, resulting in signal propagation variations. This increases difficulty of getting the best reception conditions for each available satellite signal. The consequences of environmental obstructions are unavailability of the service and multipath reception that degrades in particular the accuracy of the positioning. Our works consist in two main tasks. The first one concerns the pseudo-range error model. Indeed, the model differs in relation of the satellite state of reception. When the state of reception is direct, as described in literature, the associated pseudo-range error model is a Gaussian distribution. However, when the state of reception is NLOS (Non Line Of Sight), this assumption is no more valid. We have shown that the associated model can be approximated by a Gaussian mixture. The Second contribution concerns the reception state evolution. We have modeled the propagation channel with a Markov chain. From the state of reception of each satellite, we deduce the appropriated error model. This model is then used in a filtering process to estimate the position. The approach is based on filtering methodology and on the application of a Jump Markov System algorithm.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124895146","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570072
P. Aggarwal, Z. Syed, N. El-Sheimy
Integration of complementary systems like inertial navigation system (INS) and Global Positioning System (GPS), improves navigation parameters accuracy. Currently, integrated navigation systems are commonly implemented using extended Kalman filter (EKF) and unscented Kalman filter (UKF). The EKF assumes linear process and measurement models while UKF generates sigma points using the real mean and standard deviation of data. However, both EKF and UKF assume the noise to be Gaussian, which is unrealistic for highly nonlinear systems. To overcome these limitations, particle filter (PF) was proposed lately which is a non-parametric filter and hence can easily deal with non-linearity and non-Gaussian noises. In this paper, hybrid extended particle filter (HEPF) is developed as an alternative to the EKF to achieve better navigation accuracy for low-cost micro electro mechanical systems (MEMS) sensors. Experimental GPS/INS datasets consisting of GPS carrier phase data and inertial measurements from low-cost MEMS-grade inertial measurement unit (IMU) is used to evaluate the proposed HEPF. The HEPF performance is compared to that of other estimation techniques such as the EKF. The results show that both HEPF and EKF provide comparable navigation results during periods without GPS outages. However in cases when GPS outages are simulated, HEPF performs much better than the EKF, especially when simulated outages are located during periods with high vehicle dynamics.
{"title":"Hybrid Extended Particle Filter (HEPF) for integrated civilian navigation system","authors":"P. Aggarwal, Z. Syed, N. El-Sheimy","doi":"10.1109/PLANS.2008.4570072","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570072","url":null,"abstract":"Integration of complementary systems like inertial navigation system (INS) and Global Positioning System (GPS), improves navigation parameters accuracy. Currently, integrated navigation systems are commonly implemented using extended Kalman filter (EKF) and unscented Kalman filter (UKF). The EKF assumes linear process and measurement models while UKF generates sigma points using the real mean and standard deviation of data. However, both EKF and UKF assume the noise to be Gaussian, which is unrealistic for highly nonlinear systems. To overcome these limitations, particle filter (PF) was proposed lately which is a non-parametric filter and hence can easily deal with non-linearity and non-Gaussian noises. In this paper, hybrid extended particle filter (HEPF) is developed as an alternative to the EKF to achieve better navigation accuracy for low-cost micro electro mechanical systems (MEMS) sensors. Experimental GPS/INS datasets consisting of GPS carrier phase data and inertial measurements from low-cost MEMS-grade inertial measurement unit (IMU) is used to evaluate the proposed HEPF. The HEPF performance is compared to that of other estimation techniques such as the EKF. The results show that both HEPF and EKF provide comparable navigation results during periods without GPS outages. However in cases when GPS outages are simulated, HEPF performs much better than the EKF, especially when simulated outages are located during periods with high vehicle dynamics.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125290424","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570084
I. Miller, B. Schimpf, M. Campbell, J. Leyssens
This paper analyzes the design decisions made in building the tightly-coupled position, velocity, and attitude estimator used as a position feedback signal for autonomous navigation in Cornell University's 2007 DARPA urban challenge robot, 'Skynet.' A statistical sensitivity analysis is conducted on Skynet's estimator by examining the changes in its output as critical design decisions are reversed. The effects of five design decisions are considered: map aiding via computer vision algorithms, inclusion of differential corrections, filter integrity monitoring, WAAS augmentation, and inclusion of carrier phases. The effects of extensive signal blackouts are also considered. All estimator variants are scrutinized both in a statistical sense and in a practical sense, by comparing each variant's performance on logged data recorded at the 2007 DARPA urban challenge.
{"title":"Tightly-coupled GPS / INS system design for autonomous urban navigation","authors":"I. Miller, B. Schimpf, M. Campbell, J. Leyssens","doi":"10.1109/PLANS.2008.4570084","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570084","url":null,"abstract":"This paper analyzes the design decisions made in building the tightly-coupled position, velocity, and attitude estimator used as a position feedback signal for autonomous navigation in Cornell University's 2007 DARPA urban challenge robot, 'Skynet.' A statistical sensitivity analysis is conducted on Skynet's estimator by examining the changes in its output as critical design decisions are reversed. The effects of five design decisions are considered: map aiding via computer vision algorithms, inclusion of differential corrections, filter integrity monitoring, WAAS augmentation, and inclusion of carrier phases. The effects of extensive signal blackouts are also considered. All estimator variants are scrutinized both in a statistical sense and in a practical sense, by comparing each variant's performance on logged data recorded at the 2007 DARPA urban challenge.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125300612","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570068
T. Hektor, H. Karlsson, P. Nordlund
Accurate and reliable navigation systems will become increasingly important in future aircraft applications, in particular within unmanned aerial vehicle systems. This paper describes a particle filter approach of integrating an Inertial navigation system (INS) with a terrain-aided positioning system (TAP) to achieve such a system. The integrated system is realized applying a marginalized particle filter (MPF) where the highly nonlinear TAP is designed tightly with the INS using one and the same filter. In order to better estimate the multi-modal errors in the altitude measurements, a first order Generalized Pseudo-Bayesian (GPB1) filter is used for this purpose. This will also reduce the number of particles in the MPF and therefore also reduce the computational workload. The performance of the algorithm has been evaluated using recorded flight data from the Saab Gripen fighter aircraft. Compared to an existing INS/TAP system based on a suboptimal integration of a point mass filter representing TAP and a single extended Kalman filter estimating the INS errors, the MPF approach is similar in performance but shows better results on convergence times when recovering after loss of data.
{"title":"A Marginalized Particle Filter approach to an integrated INS/TAP system","authors":"T. Hektor, H. Karlsson, P. Nordlund","doi":"10.1109/PLANS.2008.4570068","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570068","url":null,"abstract":"Accurate and reliable navigation systems will become increasingly important in future aircraft applications, in particular within unmanned aerial vehicle systems. This paper describes a particle filter approach of integrating an Inertial navigation system (INS) with a terrain-aided positioning system (TAP) to achieve such a system. The integrated system is realized applying a marginalized particle filter (MPF) where the highly nonlinear TAP is designed tightly with the INS using one and the same filter. In order to better estimate the multi-modal errors in the altitude measurements, a first order Generalized Pseudo-Bayesian (GPB1) filter is used for this purpose. This will also reduce the number of particles in the MPF and therefore also reduce the computational workload. The performance of the algorithm has been evaluated using recorded flight data from the Saab Gripen fighter aircraft. Compared to an existing INS/TAP system based on a suboptimal integration of a point mass filter representing TAP and a single extended Kalman filter estimating the INS errors, the MPF approach is similar in performance but shows better results on convergence times when recovering after loss of data.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114960923","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570027
Li Qiao, Jianye Liu, Guanglou Zheng, Zhi Xiong
In recent years, X-ray navigation (XNAV) has become of great interest for spacecraft autonomous navigation. The XNAV system can be used as an augmentation to the current navigation capability or as a backup to the Global Position System (GPS) and the deep space network (DSN). In this paper, the XNAV system is used to augment the ultraviolet (UV) sensor based satellite navigation system. In order to simplify the structure of the XNAV system, only one X-ray detector is used. The federated filtering technique is used to process the data from the X-ray detector and the UV sensor. It is analyzed that the XNAV system using one X-ray detector is not completely observable, but the satellite integrated navigation system using these two sensors has a good navigation performance. It is demonstrated on the GPS satellite orbit and the geosynchronous satellite orbit that, the navigation performance of the satellite integrated navigation system is improved a lot with respect to that of the UV sensor-based satellite navigation system.
{"title":"Integration of ultraviolet sensor and X-ray detector for navigation satellite orbit estimation","authors":"Li Qiao, Jianye Liu, Guanglou Zheng, Zhi Xiong","doi":"10.1109/PLANS.2008.4570027","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570027","url":null,"abstract":"In recent years, X-ray navigation (XNAV) has become of great interest for spacecraft autonomous navigation. The XNAV system can be used as an augmentation to the current navigation capability or as a backup to the Global Position System (GPS) and the deep space network (DSN). In this paper, the XNAV system is used to augment the ultraviolet (UV) sensor based satellite navigation system. In order to simplify the structure of the XNAV system, only one X-ray detector is used. The federated filtering technique is used to process the data from the X-ray detector and the UV sensor. It is analyzed that the XNAV system using one X-ray detector is not completely observable, but the satellite integrated navigation system using these two sensors has a good navigation performance. It is demonstrated on the GPS satellite orbit and the geosynchronous satellite orbit that, the navigation performance of the satellite integrated navigation system is improved a lot with respect to that of the UV sensor-based satellite navigation system.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122949110","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570117
R. B. Harris, E. Lightsey
The introduction of M-Code to the GPS signal structure can redefine the accuracy of the broadcast ephemeris. Existing ephemeris generation systems use dual frequency observations, obtained through the tracking of existing precise codes on the LI and L2 frequencies. These codes are modulated using Binary Phase Shift Key (BPSK) modulation. The modernization signal M-Code is modulated using Binary Offset Carrier (BOC) modulation. In this study pseudorange observables derived from the tracking of M-Code are proven to have greater accuracy than those from existing precise codes, given equivalent receiver designs and operating conditions. In addition, the error due to specular multipath is derived. These general models of noise and multipath can be applied to any BOC modulated signals, including Galileo and QZSS. When applied to M-Code, the models predict that the maximum multipath error in the pseudorange is reduced in magnitude by 50% compared to the existing precise codes. However the range of multipath delays for which M-Code observables exhibit multipath is approximately twice that associated with existing precise BPSK codes. Much like other precise applications of GPS, some ephemeris generation processes use the ionosphere free combination and carrier phase smoothing of the pseudorange to form smoothed pseudoranges. The smoothed pseudoranges are then input as measurements to an ephemeris filter. The analytic models of multipath error in the pseudorange and carrier phase observables are applied to predict errors in the smoothed pseudorange. Multipath error, amplified by ionosphere free combination, causes a bias in the smoothed pseudorange when parameterized as a function of multipath delay. There are conditions under which the bias is zero mean, and in those conditions multipath is suppressed. The solution of carrier phase multipath for BOC modulated signals contains a feature not seen in the BPSK solution. There are multipath delays for which the carrier phase multipath is identically zero regardless of the multipath phase. The zero carrier phase multipath condition may be the most promising feature associated with observables derived from BOC modulated codes.
{"title":"Precise observation of BOC modulated signals in the presence of noise and specular multipath","authors":"R. B. Harris, E. Lightsey","doi":"10.1109/PLANS.2008.4570117","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570117","url":null,"abstract":"The introduction of M-Code to the GPS signal structure can redefine the accuracy of the broadcast ephemeris. Existing ephemeris generation systems use dual frequency observations, obtained through the tracking of existing precise codes on the LI and L2 frequencies. These codes are modulated using Binary Phase Shift Key (BPSK) modulation. The modernization signal M-Code is modulated using Binary Offset Carrier (BOC) modulation. In this study pseudorange observables derived from the tracking of M-Code are proven to have greater accuracy than those from existing precise codes, given equivalent receiver designs and operating conditions. In addition, the error due to specular multipath is derived. These general models of noise and multipath can be applied to any BOC modulated signals, including Galileo and QZSS. When applied to M-Code, the models predict that the maximum multipath error in the pseudorange is reduced in magnitude by 50% compared to the existing precise codes. However the range of multipath delays for which M-Code observables exhibit multipath is approximately twice that associated with existing precise BPSK codes. Much like other precise applications of GPS, some ephemeris generation processes use the ionosphere free combination and carrier phase smoothing of the pseudorange to form smoothed pseudoranges. The smoothed pseudoranges are then input as measurements to an ephemeris filter. The analytic models of multipath error in the pseudorange and carrier phase observables are applied to predict errors in the smoothed pseudorange. Multipath error, amplified by ionosphere free combination, causes a bias in the smoothed pseudorange when parameterized as a function of multipath delay. There are conditions under which the bias is zero mean, and in those conditions multipath is suppressed. The solution of carrier phase multipath for BOC modulated signals contains a feature not seen in the BPSK solution. There are multipath delays for which the carrier phase multipath is identically zero regardless of the multipath phase. The zero carrier phase multipath condition may be the most promising feature associated with observables derived from BOC modulated codes.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114508436","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570058
M. Jabbour, P. Bonnifait
This paper studies the use of lidar for the egolocalization of car-like vehicles in conjunction with GPS. We consider a laser scanner installed at the front of a vehicle that detects both sides of the road. We present a method that fuses the lidar information to improve the localization process by providing additional exteroceptive information and by rejecting bad GPS fixes. The strategy is inspired by a SLAM paradigm and is efficient if the vehicle navigates often in the same area. We present the different main stages of such a strategy: lidar data processing, map data representation, and augmented Kalman filtering scheme. Finally, experimental results are reported to illustrate the performance of this approach.
{"title":"Backing up GPS in urban areas using a scanning laser","authors":"M. Jabbour, P. Bonnifait","doi":"10.1109/PLANS.2008.4570058","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570058","url":null,"abstract":"This paper studies the use of lidar for the egolocalization of car-like vehicles in conjunction with GPS. We consider a laser scanner installed at the front of a vehicle that detects both sides of the road. We present a method that fuses the lidar information to improve the localization process by providing additional exteroceptive information and by rejecting bad GPS fixes. The strategy is inspired by a SLAM paradigm and is efficient if the vehicle navigates often in the same area. We present the different main stages of such a strategy: lidar data processing, map data representation, and augmented Kalman filtering scheme. Finally, experimental results are reported to illustrate the performance of this approach.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122004200","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570115
T. Fan, V. Lin, G.H. Wang, P. Dafesh
The number of GPS ranging signals has increased steadily from GPS IIR to IIR-M and IIF. This trend will continue for the future GPS system-GPS III. Besides the increase in number of ranging signals, the future GPS system is also envisioned to implement a flexible navigation payload. This payload will have the ability to modify the number, the configuration and the power of ranging signals while the satellite is in orbit. In designing this flexible navigation payload, one of the tasks is to find the right signal combing methodology to be implemented for combining multiple signals together. This paper will study two well-known signal combining methodologies, coherent adaptive subcarrier modulation (CASM) and majority-vote. In addition, a new methodology, inter-vote, will also be studied. The assessment of those three combining methodologies will be focused on their power efficiency performance, which is closely related to the efficient usage of satellite power. The impact of inter-modulation signal, which is generated when the above three combining methodologies are used, will be briefly discussed at the end.
{"title":"Study of signal combining methodologies for future GPS flexible navigation payload (Part II)","authors":"T. Fan, V. Lin, G.H. Wang, P. Dafesh","doi":"10.1109/PLANS.2008.4570115","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570115","url":null,"abstract":"The number of GPS ranging signals has increased steadily from GPS IIR to IIR-M and IIF. This trend will continue for the future GPS system-GPS III. Besides the increase in number of ranging signals, the future GPS system is also envisioned to implement a flexible navigation payload. This payload will have the ability to modify the number, the configuration and the power of ranging signals while the satellite is in orbit. In designing this flexible navigation payload, one of the tasks is to find the right signal combing methodology to be implemented for combining multiple signals together. This paper will study two well-known signal combining methodologies, coherent adaptive subcarrier modulation (CASM) and majority-vote. In addition, a new methodology, inter-vote, will also be studied. The assessment of those three combining methodologies will be focused on their power efficiency performance, which is closely related to the efficient usage of satellite power. The impact of inter-modulation signal, which is generated when the above three combining methodologies are used, will be briefly discussed at the end.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117074545","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 : 2008-05-05DOI: 10.1109/PLANS.2008.4570035
H. Rice, V. Benischek
Atom Interferometry is a next generation navigation technology based on Nobel Prize winning research into atom laser cooling and coherent atom waves. The technology is applicable to inertial navigation sensors: gyroscopes, accelerometers, gravity gradiometers and precision time. This paper discusses the theory of free fall atom interferometry, and its application as the inertial navigator for future submarine platforms.
{"title":"Submarine navigation applications of atom interferometry","authors":"H. Rice, V. Benischek","doi":"10.1109/PLANS.2008.4570035","DOIUrl":"https://doi.org/10.1109/PLANS.2008.4570035","url":null,"abstract":"Atom Interferometry is a next generation navigation technology based on Nobel Prize winning research into atom laser cooling and coherent atom waves. The technology is applicable to inertial navigation sensors: gyroscopes, accelerometers, gravity gradiometers and precision time. This paper discusses the theory of free fall atom interferometry, and its application as the inertial navigator for future submarine platforms.","PeriodicalId":446381,"journal":{"name":"2008 IEEE/ION Position, Location and Navigation Symposium","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129573459","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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