Pub Date : 2020-11-23DOI: 10.23919/ENC48637.2020.9317461
C. Liber, E. D. Donder, A. Calegaro, S. Chabanski, R. Vansintjan, J. O'Hara, A. Glover
ESA Space Weather Service Network supports end users in a wide range of affected sectors, in mitigating the effects of space weather on their systems, reducing costs and improving reliability. In this network, space weather products and tools are developed and federated in services, that are suitable for operational implementation to meet the end user needs. In the aim to establish a close relationship with the end users of space weather services, the SSA Space Weather Coordination Centre (SSCC) organizes user support campaigns to build tailored space weather bulletins. During the campaign, the SSCC works together with the user in order to compile dedicated space weather forecast notifications. We highlight here the SSCC user support campaign for a group of test users within the GNSS community.
{"title":"Space Weather Bulletins as part of a User Test Campaign for GNSS service users","authors":"C. Liber, E. D. Donder, A. Calegaro, S. Chabanski, R. Vansintjan, J. O'Hara, A. Glover","doi":"10.23919/ENC48637.2020.9317461","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317461","url":null,"abstract":"ESA Space Weather Service Network supports end users in a wide range of affected sectors, in mitigating the effects of space weather on their systems, reducing costs and improving reliability. In this network, space weather products and tools are developed and federated in services, that are suitable for operational implementation to meet the end user needs. In the aim to establish a close relationship with the end users of space weather services, the SSA Space Weather Coordination Centre (SSCC) organizes user support campaigns to build tailored space weather bulletins. During the campaign, the SSCC works together with the user in order to compile dedicated space weather forecast notifications. We highlight here the SSCC user support campaign for a group of test users within the GNSS community.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125891927","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317389
C. Schwalm, C. Enneking, S. Thoelert
We discuss robustness and accuracy of time of arrival (ToA) estimation using meta-signal combining (MSC). MSC is a receive strategy to process multiple navigation signals as a single wideband signal, even though they are transmitted on different carrier frequencies. This strategy was originally proposed due its potentially high ToA estimation accuracy in combination with good spectral efficiency and power efficiency. Furthermore, it offers the possibility to make optimal use of legacy signals and newly added signal components; in this work, we focus on the example of the E1 open serivce (OS) and the forthcoming E1-D signal. We discuss estimation robustness against noise on the basis of the Ziv-Zakai Lower Bound (ZZLB); our analytical results reveal that without large carrier-to-noise density ratio or long observation times, autocorrelation sidelobes make it impossible for an unbiased ToA estimator to attain the excellent performance promised by the simpler Cramér-Rao Lower Bound (CRLB). Furthermore, we demonstrate that a carefully configured bank of correlators should be used in order to avoid further performance losses.
{"title":"Ziv-Zakai Bound and Multicorrelator Compression for a Galileo E1 Meta-Signal","authors":"C. Schwalm, C. Enneking, S. Thoelert","doi":"10.23919/ENC48637.2020.9317389","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317389","url":null,"abstract":"We discuss robustness and accuracy of time of arrival (ToA) estimation using meta-signal combining (MSC). MSC is a receive strategy to process multiple navigation signals as a single wideband signal, even though they are transmitted on different carrier frequencies. This strategy was originally proposed due its potentially high ToA estimation accuracy in combination with good spectral efficiency and power efficiency. Furthermore, it offers the possibility to make optimal use of legacy signals and newly added signal components; in this work, we focus on the example of the E1 open serivce (OS) and the forthcoming E1-D signal. We discuss estimation robustness against noise on the basis of the Ziv-Zakai Lower Bound (ZZLB); our analytical results reveal that without large carrier-to-noise density ratio or long observation times, autocorrelation sidelobes make it impossible for an unbiased ToA estimator to attain the excellent performance promised by the simpler Cramér-Rao Lower Bound (CRLB). Furthermore, we demonstrate that a carefully configured bank of correlators should be used in order to avoid further performance losses.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122633098","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317528
T. Sakai
The QZSS, quasi-zenith satellite system, is a regional satellite navigation system constructed and operated by Japan. Currently, QZSS 4-satellite constellation has been operating since November 2018 and transmitting signals for several services including PNT as well as some augmentations. This paper explains the overview and future perspective of the QZSS. Over the next decade, GNSS signal authentication, QZSS-PPP service, and expansion of the service area will be accomplished with QZSS 7-satellite constellation for our safe and secure lives.
{"title":"Japanese GNSS Future System Evolution in the 2020–2030 Perspective","authors":"T. Sakai","doi":"10.23919/ENC48637.2020.9317528","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317528","url":null,"abstract":"The QZSS, quasi-zenith satellite system, is a regional satellite navigation system constructed and operated by Japan. Currently, QZSS 4-satellite constellation has been operating since November 2018 and transmitting signals for several services including PNT as well as some augmentations. This paper explains the overview and future perspective of the QZSS. Over the next decade, GNSS signal authentication, QZSS-PPP service, and expansion of the service area will be accomplished with QZSS 7-satellite constellation for our safe and secure lives.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114480085","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317340
M. Caamano, Omar García Crespillo, Daniel Gerbeth, A. Grosch
Ground transportation systems demand accurate and robust localization functions. Satellite navigation is considered a key element in those systems, but its position determination can be highly corrupted in urban environments because of the presence of reflected signals (i.e. multipath). This paper deals with the detection of multipath in the code measurements of GNSS receivers for mobile users in urban scenarios. First, we discuss the different alternatives and limitations to properly isolate multipath autonomously at the receiver based on Code-Minus-Carrier (CMC) techniques in challenging GNSS applications. We then propose a practical methodology to design a suitable multipath detector based on the time difference of CMC. All the analysis and evaluations are supported with real measurements collected in Railway scenarios.
{"title":"Detection of GNSS Multipath with Time-Differenced Code-Minus-Carrier for Land-Based Applications","authors":"M. Caamano, Omar García Crespillo, Daniel Gerbeth, A. Grosch","doi":"10.23919/ENC48637.2020.9317340","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317340","url":null,"abstract":"Ground transportation systems demand accurate and robust localization functions. Satellite navigation is considered a key element in those systems, but its position determination can be highly corrupted in urban environments because of the presence of reflected signals (i.e. multipath). This paper deals with the detection of multipath in the code measurements of GNSS receivers for mobile users in urban scenarios. First, we discuss the different alternatives and limitations to properly isolate multipath autonomously at the receiver based on Code-Minus-Carrier (CMC) techniques in challenging GNSS applications. We then propose a practical methodology to design a suitable multipath detector based on the time difference of CMC. All the analysis and evaluations are supported with real measurements collected in Railway scenarios.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129147726","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317459
Rebekka Handirk, A. Piter, André Jensen, Vanessa Koppmann, Julia Mainz, Christopher Nagel, Yannick Breva, Lucy Icking, Johannes Kröger, S. Schön
Real Time Kinematic (RTK) GNSS is an important positioning technique not only for classic surveying tasks, but has become a part of everyday life as new fields of application such as autonomous driving arise. Especially for kinematic applications hardly any research about the performance of geodetic RTK systems has been carried out so far. In most cases only the manufacturers themselves have evaluated their own products. By testing two RTK systems under various signal reception conditions for static and kinematic applications we strive to investigate their accuracy and precision. Our experiments show that results obtained by static measurements under good signal reception conditions yield an accuracy better than 3 cm as can be expected for standard RTK measurements, whereas the tested systems perform significantly worse under unfavourable conditions. Cumulative histograms show the reduced accuracy obtained from kinematic measurements.
实时动态GNSS (Real Time Kinematic GNSS, RTK)是一种重要的定位技术，不仅适用于经典的测量任务，而且随着自动驾驶等新应用领域的出现，它已成为日常生活的一部分。特别是在运动学应用方面，迄今为止很少有关于大地测量RTK系统性能的研究。在大多数情况下，只有制造商自己评估自己的产品。通过测试两种RTK系统在不同的静态和运动信号接收条件下的应用，我们努力研究它们的准确性和精度。我们的实验表明，在良好的信号接收条件下，通过静态测量获得的结果比标准RTK测量的精度高3厘米，而在不利的条件下，测试系统的表现明显更差。累积直方图显示了从运动学测量中获得的降低的精度。
{"title":"Performance Evaluation Of Geodetic Real Time Kinematic Units Under Various Signal Reception Conditions","authors":"Rebekka Handirk, A. Piter, André Jensen, Vanessa Koppmann, Julia Mainz, Christopher Nagel, Yannick Breva, Lucy Icking, Johannes Kröger, S. Schön","doi":"10.23919/ENC48637.2020.9317459","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317459","url":null,"abstract":"Real Time Kinematic (RTK) GNSS is an important positioning technique not only for classic surveying tasks, but has become a part of everyday life as new fields of application such as autonomous driving arise. Especially for kinematic applications hardly any research about the performance of geodetic RTK systems has been carried out so far. In most cases only the manufacturers themselves have evaluated their own products. By testing two RTK systems under various signal reception conditions for static and kinematic applications we strive to investigate their accuracy and precision. Our experiments show that results obtained by static measurements under good signal reception conditions yield an accuracy better than 3 cm as can be expected for standard RTK measurements, whereas the tested systems perform significantly worse under unfavourable conditions. Cumulative histograms show the reduced accuracy obtained from kinematic measurements.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125123948","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317508
R. Moradi, M. Hutchinson, Yuheng Zheng, Michael Roth
Railway infrastructure and vehicle maintenance costs are estimated at above 20,000M£ per year at European level. In this context, SIA (System for vehicle-infrastructure Interaction Assets health status monitoring) has the objective of developing new services to provide prognostic information about the health status of the railway's most demanding assets in terms of maintenance costs, at the points of the interaction between the vehicle and the infrastructure (wheelset, pantograph, rail and catenary). In SIA, events captured by a network of sensors are time-stamped and accurately positioned. The core positioning technique in SIA will be based on Global Navigation Satellite Systems (GNSS). Positioning using GNSS in the railway environment is very challenging due to events such as satellite masking, signal reflection problems (multipath) and the presence of interference. Hence, adaptation of a precise positioning algorithm tailored for the railway environment is essential in SIA. In such an algorithm, the availability and accuracy of the positioning can be improved by taking a multi-constellation approach (i.e. GPS plus GALILEO), using complementary sensors such as IMU and utilizing track map geometry characteristics. Such a positioning algorithm adopted for SIA and some preliminary results presented in this paper.
{"title":"Positioning Approach for Train-Infrastructure Interaction Assets Health Status Monitoring","authors":"R. Moradi, M. Hutchinson, Yuheng Zheng, Michael Roth","doi":"10.23919/ENC48637.2020.9317508","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317508","url":null,"abstract":"Railway infrastructure and vehicle maintenance costs are estimated at above 20,000M£ per year at European level. In this context, SIA (System for vehicle-infrastructure Interaction Assets health status monitoring) has the objective of developing new services to provide prognostic information about the health status of the railway's most demanding assets in terms of maintenance costs, at the points of the interaction between the vehicle and the infrastructure (wheelset, pantograph, rail and catenary). In SIA, events captured by a network of sensors are time-stamped and accurately positioned. The core positioning technique in SIA will be based on Global Navigation Satellite Systems (GNSS). Positioning using GNSS in the railway environment is very challenging due to events such as satellite masking, signal reflection problems (multipath) and the presence of interference. Hence, adaptation of a precise positioning algorithm tailored for the railway environment is essential in SIA. In such an algorithm, the availability and accuracy of the positioning can be improved by taking a multi-constellation approach (i.e. GPS plus GALILEO), using complementary sensors such as IMU and utilizing track map geometry characteristics. Such a positioning algorithm adopted for SIA and some preliminary results presented in this paper.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126801874","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317499
Y. Nakajima, Toru Yamamoto, R. Harada, Satoko Kawakami, Susumu Kumagai
This paper presents the latest GPS receiver developed by JAXA and NEC Space Technologies, Ltd. for satellites in geosynchronous orbit. This is the first attempt by a Japanese GPS receiver to use GPS signals above the GPS constellation of satellites. The expected signal strength is weaker at geosynchronous orbit than that observed at low Earth orbit. A new GPS receiver was developed to receive such signals and determine satellite position, by improving sensitivity and optimized software for GEO. In addition, signals received at GEO transfer phase has various doppler frequency and signal strength. This characteristic increase acquisition time of the receiver, thus the acquisition algorithm was modified to optimize during the transfer phase. This paper introduces the newly developed GPS receiver for geosynchronous satellites and its performance obtained by experiments using GNSS simulator. The results indicated that the GEO GPSR could determine its position within a few meters error at GEO. GEO GPS receiver could not be used whole transfer phase, but it could output its position at least once in every orbit around perigee. This result indicated that the GEO GPS receiver will help raising orbit.
{"title":"A Spaceborne GPS Receiver for Electric Propulsion Driven Geosynchronous Satellites","authors":"Y. Nakajima, Toru Yamamoto, R. Harada, Satoko Kawakami, Susumu Kumagai","doi":"10.23919/ENC48637.2020.9317499","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317499","url":null,"abstract":"This paper presents the latest GPS receiver developed by JAXA and NEC Space Technologies, Ltd. for satellites in geosynchronous orbit. This is the first attempt by a Japanese GPS receiver to use GPS signals above the GPS constellation of satellites. The expected signal strength is weaker at geosynchronous orbit than that observed at low Earth orbit. A new GPS receiver was developed to receive such signals and determine satellite position, by improving sensitivity and optimized software for GEO. In addition, signals received at GEO transfer phase has various doppler frequency and signal strength. This characteristic increase acquisition time of the receiver, thus the acquisition algorithm was modified to optimize during the transfer phase. This paper introduces the newly developed GPS receiver for geosynchronous satellites and its performance obtained by experiments using GNSS simulator. The results indicated that the GEO GPSR could determine its position within a few meters error at GEO. GEO GPS receiver could not be used whole transfer phase, but it could output its position at least once in every orbit around perigee. This result indicated that the GEO GPS receiver will help raising orbit.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128145078","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317323
Grischa Gottschalg, M. Becker, S. Leinen
For automated driving high-integrity localization information is essential. Often sensor fusion algorithms are used to fulfill this task. In this work three implementations of integrity concepts for such algorithms used in automated driving are compared. Therefore, requirements for sensor fusion algorithms used for automated driving functions of a prototype vehicle in a German research project are derived. Known integrity concepts are reviewed. A selection of three concepts that include the computation of protection levels is implemented. They are evaluated using a set of measurement data obtained for our loosely coupled GNSS/INS/Odometry fusion algorithm. With the chosen set of tuning parameters, all implemented protection levels bound the horizontal position error in the given measurements according to the specified integrity risk.
{"title":"Integrity Concept for Sensor Fusion Algorithms used in a Prototype Vehicle for Automated Driving","authors":"Grischa Gottschalg, M. Becker, S. Leinen","doi":"10.23919/ENC48637.2020.9317323","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317323","url":null,"abstract":"For automated driving high-integrity localization information is essential. Often sensor fusion algorithms are used to fulfill this task. In this work three implementations of integrity concepts for such algorithms used in automated driving are compared. Therefore, requirements for sensor fusion algorithms used for automated driving functions of a prototype vehicle in a German research project are derived. Known integrity concepts are reviewed. A selection of three concepts that include the computation of protection levels is implemented. They are evaluated using a set of measurement data obtained for our loosely coupled GNSS/INS/Odometry fusion algorithm. With the chosen set of tuning parameters, all implemented protection levels bound the horizontal position error in the given measurements according to the specified integrity risk.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125752403","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317434
D. Miralles, D. Akos, Dong-Kyeong Lee, A. Konovaltsev, L. Kurz, S. Lo
Reliable radio satellite navigation is of extreme importance globally. Currently modern societies rely on GNSS-related technologies for a range of applications including agricultural, financial, transportation, and military applications. As such, providing navigation, specifically within the Android environment, with the tools to combat the threat presented by malicious spoofing or jamming attacks is critical to keep its dependence on GNSS functional. This proposal aims to introduce GNSSalarm, a set of algorithms based on resources already within Android OS, and develops an effective anti-spoofing, anti-jamming solution that will allow proper functionality when in the presence of these malicious attacks. GNSSAlarm will detect spoofing or jamming attacks by monitoring alarm triggers set by a combination of measurements, including but not limited to (1) network location metrics, (2) combined AGC and C/N0 readings, (3) external aiding information data, and (4) pseudorange residual metrics. After spoofing or jamming is detected, GNSSalarm will alert the user of the situation and will attempt to continue to provide its position solution by using any of the remaining constellations measurements offered in the new raw GNSS engine supported by Android.
{"title":"Robust Satellite Navigation in the Android Operating System using the Android Raw GNSS Measurements Engine and Location Providers","authors":"D. Miralles, D. Akos, Dong-Kyeong Lee, A. Konovaltsev, L. Kurz, S. Lo","doi":"10.23919/ENC48637.2020.9317434","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317434","url":null,"abstract":"Reliable radio satellite navigation is of extreme importance globally. Currently modern societies rely on GNSS-related technologies for a range of applications including agricultural, financial, transportation, and military applications. As such, providing navigation, specifically within the Android environment, with the tools to combat the threat presented by malicious spoofing or jamming attacks is critical to keep its dependence on GNSS functional. This proposal aims to introduce GNSSalarm, a set of algorithms based on resources already within Android OS, and develops an effective anti-spoofing, anti-jamming solution that will allow proper functionality when in the presence of these malicious attacks. GNSSAlarm will detect spoofing or jamming attacks by monitoring alarm triggers set by a combination of measurements, including but not limited to (1) network location metrics, (2) combined AGC and C/N0 readings, (3) external aiding information data, and (4) pseudorange residual metrics. After spoofing or jamming is detected, GNSSalarm will alert the user of the situation and will attempt to continue to provide its position solution by using any of the remaining constellations measurements offered in the new raw GNSS engine supported by Android.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130276171","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 : 2020-11-23DOI: 10.23919/ENC48637.2020.9317475
P. Henkel
Precise Point Positioning (PPP) provides accurate absolute position information without the direct need of measurements from a reference station at the user. The current challenge of GPS L1/L2-based PPP is its long convergence time of more than 20 minutes being caused by the need to estimate atmospheric parameters, and the relatively large code noise and multipath errors. There are two options to reduce the convergence time of PPP: First, the Galileo wideband signals on E5 and E6 have a much lower code noise than current GPS L1 and L2 pseudoranges. Second, the satellite positions and satellite-related biases can be determined much faster and more accurately with optical inter-satellite links supporting ranging, time-transfer and intra-system communication. In this paper, we consider both options. A joint estimation of the receiver position, receiver clock offset, tropospheric zenith delay, ionospheric slant delays and carrier phase ambiguities is performed with a Kalman filter. Orbital errors and pseudo range multipath are also taken into account. The float carrier phase ambiguity estimates are mapped to integers using the famous Least-Squares Ambiguity Decorrelation Adjustment (LAMBDA) method. The simulation results show that an ambiguity fixing and, thereby, a highly-accurate PPP solution, can be achieved consistently within a few epochs. This is a quite substantial benefit and could make PPP attractive for numerous applications.
{"title":"Precise Point Positioning for Next-Generation GNSS","authors":"P. Henkel","doi":"10.23919/ENC48637.2020.9317475","DOIUrl":"https://doi.org/10.23919/ENC48637.2020.9317475","url":null,"abstract":"Precise Point Positioning (PPP) provides accurate absolute position information without the direct need of measurements from a reference station at the user. The current challenge of GPS L1/L2-based PPP is its long convergence time of more than 20 minutes being caused by the need to estimate atmospheric parameters, and the relatively large code noise and multipath errors. There are two options to reduce the convergence time of PPP: First, the Galileo wideband signals on E5 and E6 have a much lower code noise than current GPS L1 and L2 pseudoranges. Second, the satellite positions and satellite-related biases can be determined much faster and more accurately with optical inter-satellite links supporting ranging, time-transfer and intra-system communication. In this paper, we consider both options. A joint estimation of the receiver position, receiver clock offset, tropospheric zenith delay, ionospheric slant delays and carrier phase ambiguities is performed with a Kalman filter. Orbital errors and pseudo range multipath are also taken into account. The float carrier phase ambiguity estimates are mapped to integers using the famous Least-Squares Ambiguity Decorrelation Adjustment (LAMBDA) method. The simulation results show that an ambiguity fixing and, thereby, a highly-accurate PPP solution, can be achieved consistently within a few epochs. This is a quite substantial benefit and could make PPP attractive for numerous applications.","PeriodicalId":157951,"journal":{"name":"2020 European Navigation Conference (ENC)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134125720","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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