Pub Date : 2010-12-03DOI: 10.1109/UPINLBS.2010.5653681
W. Storms, Jeremiah A. Shockley, J. Raquet
This paper describes a method that has been developed to aid an inertial navigation system when GNSS signals are not available, by taking advantage of the uniqueness of magnetic field variations. Most indoor environments have many different features (ferrous structural materials or contents, electrical currents, etc.) which perturb the Earths natural magnetic field. The variations in the magnetic field in indoor environments can be used as a way to identify a users position, and possibly orientation, because the 3-dimensional magnetic field varies significantly as a function of position. Using relatively inexpensive 3-axis magnetic field sensors, it is possible to estimate a users location in an indoor environment.
{"title":"Magnetic field navigation in an indoor environment","authors":"W. Storms, Jeremiah A. Shockley, J. Raquet","doi":"10.1109/UPINLBS.2010.5653681","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5653681","url":null,"abstract":"This paper describes a method that has been developed to aid an inertial navigation system when GNSS signals are not available, by taking advantage of the uniqueness of magnetic field variations. Most indoor environments have many different features (ferrous structural materials or contents, electrical currents, etc.) which perturb the Earths natural magnetic field. The variations in the magnetic field in indoor environments can be used as a way to identify a users position, and possibly orientation, because the 3-dimensional magnetic field varies significantly as a function of position. Using relatively inexpensive 3-axis magnetic field sensors, it is possible to estimate a users location in an indoor environment.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"29 17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114727248","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5654005
B. A. Siddiqui, Jie Zhang, M. Z. H. Bhuiyan, E. Lohan
Global Navigation Satellite Systems (GNSSs), such as the modernized Global Positioning System (GPS) and the ongoing European satellite navigation system Galileo, incorporate the new composite GNSS signals (e.g., Galileo E1 Open Service (OS) signal), which consist of two different components, the data and pilot channels. The existence of dual channel allows one to adopt special techniques to acquire and track these new signals. In this paper, the authors analyze the performance of three different implementation strategies, namely, i. Data-only, ii. Pilot-only, and iii. Joint Data-Pilot, for two different receiver modes: one with Sine Binary Offset Carrier (1,1) (SinBOC(1,1)) reference receiver, and the other one with Composite BOC (CBOC) reference receiver. All the simulations have been carried out in TUT Galileo E1 open source signal simulator, based on the most recent Galileo Signal-In-Space Interface Control Document (SIS-ICD). The simulation results show that acquisition with individual channel is not the best approach to acquire the signal as intuitively expected. Joint Data-Pilot channel combines all the significant power from data and pilot channels non-coherently that ultimately improves the signal detection around 2.8 dB, which has been verified via simulations in the context of the paper. Joint Data-Pilot channel also provides around 3 dB improvement over any individual channel in terms of tracking error variance. It will also be shown in the paper that the performance deterioration caused by using Sine BOC(1,1) reference receiver instead of CBOC reference receiver is negligible. Most of the findings based on data-pilot combination are as intuitively expected. However, the main novelty of the paper stays in presenting a realistic and detailed Simulink-based simulator for Galileo E1 signal that takes into account two receiver modes, and has already been made open access for research purpose.
全球导航卫星系统(GNSS)，例如现代化的全球定位系统(GPS)和正在进行的欧洲伽利略卫星导航系统，合并了新的复合GNSS信号(例如伽利略E1开放服务(OS)信号)，它由两个不同的组件组成，数据和导频信道。双通道的存在使得人们可以采用特殊的技术来获取和跟踪这些新的信号。在本文中，作者分析了三种不同的实现策略的性能，即i. Data-only, ii. Data-only。仅限飞行员，iii。联合数据导航仪，用于两种不同的接收器模式:一种是正弦二进制偏移载波(1,1)(SinBOC(1,1))参考接收器，另一种是复合BOC(CBOC)参考接收器。所有的仿真都是在TUT伽利略E1开源信号模拟器中进行的，基于最新的伽利略空间信号接口控制文件(SIS-ICD)。仿真结果表明，单通道采集并非直观预期的最佳信号采集方式。联合数据导频信道将来自数据和导频信道的所有重要功率非相干地结合在一起，最终将信号检测提高到2.8 dB左右，这一点已在本文的背景下通过仿真得到验证。联合数据导频信道在跟踪误差方差方面也比任何单独信道提供了大约3db的改进。本文还将表明，使用正弦BOC(1,1)参考接收器而不是CBOC参考接收器所引起的性能下降可以忽略不计。大多数基于数据-试验组合的结果与直觉预期一致。然而，本文的主要新颖之处在于提出了一个现实而详细的基于simulink的伽利略E1信号模拟器，该模拟器考虑了两种接收器模式，并且已经开放获取用于研究目的。
{"title":"Joint Data-Pilot acquisition and tracking of Galileo E1 Open Service signal","authors":"B. A. Siddiqui, Jie Zhang, M. Z. H. Bhuiyan, E. Lohan","doi":"10.1109/UPINLBS.2010.5654005","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5654005","url":null,"abstract":"Global Navigation Satellite Systems (GNSSs), such as the modernized Global Positioning System (GPS) and the ongoing European satellite navigation system Galileo, incorporate the new composite GNSS signals (e.g., Galileo E1 Open Service (OS) signal), which consist of two different components, the data and pilot channels. The existence of dual channel allows one to adopt special techniques to acquire and track these new signals. In this paper, the authors analyze the performance of three different implementation strategies, namely, i. Data-only, ii. Pilot-only, and iii. Joint Data-Pilot, for two different receiver modes: one with Sine Binary Offset Carrier (1,1) (SinBOC(1,1)) reference receiver, and the other one with Composite BOC (CBOC) reference receiver. All the simulations have been carried out in TUT Galileo E1 open source signal simulator, based on the most recent Galileo Signal-In-Space Interface Control Document (SIS-ICD). The simulation results show that acquisition with individual channel is not the best approach to acquire the signal as intuitively expected. Joint Data-Pilot channel combines all the significant power from data and pilot channels non-coherently that ultimately improves the signal detection around 2.8 dB, which has been verified via simulations in the context of the paper. Joint Data-Pilot channel also provides around 3 dB improvement over any individual channel in terms of tracking error variance. It will also be shown in the paper that the performance deterioration caused by using Sine BOC(1,1) reference receiver instead of CBOC reference receiver is negligible. Most of the findings based on data-pilot combination are as intuitively expected. However, the main novelty of the paper stays in presenting a realistic and detailed Simulink-based simulator for Galileo E1 signal that takes into account two receiver modes, and has already been made open access for research purpose.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128954269","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5654353
F. D. Rosa, H. Hurskainen, M. Detratti, Ernesto Pérez-Serna, J. Nurmi
In this paper we describe the prototype concept of multi-constellation GNSS receivers investigated in the Galileo Ready Advanced Mass Marker Receiver (GRAMMAR) EU FP7 project [1]. The purpose of our work is to provide technology solutions with their implementations for multi-system GNSS mass market receivers by motivating the need for both hardware and software research and present the functional blocks for a multi-constellation GNSS receiver.
{"title":"GRAMMAR: Challenges and solutions for multi-constellation Mass Market user Receivers","authors":"F. D. Rosa, H. Hurskainen, M. Detratti, Ernesto Pérez-Serna, J. Nurmi","doi":"10.1109/UPINLBS.2010.5654353","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5654353","url":null,"abstract":"In this paper we describe the prototype concept of multi-constellation GNSS receivers investigated in the Galileo Ready Advanced Mass Marker Receiver (GRAMMAR) EU FP7 project [1]. The purpose of our work is to provide technology solutions with their implementations for multi-system GNSS mass market receivers by motivating the need for both hardware and software research and present the functional blocks for a multi-constellation GNSS receiver.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125485496","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5653994
Tuomo Kröger, Yuwei Chen, L. Pei, T. Tenhunen, H. Kuusniemi, Ruizhi Chen, Wei Chen
Accurate and robust ubiquitous localization is one of the most demanding challenges that the navigation research community faces currently. The GNSS offers a perfect solution for open sky environment, however, in GPS-denied or unfavourable environments, for example urban canyons or indoors, the traditional GNSS standalone solution cannot provide the user's position at a reasonable accuracy. Therefore, dead reckoning algorithms are one of the research fields which have attracted most research attention in the last few years. A multi-sensor based PDR (pedestrian dead reckoning) algorithm is presented in this paper, which makes full use of the measurements from a barometer and a 3-axis accelerometer. User's dynamics and motion modes are recognized with different speeds. The walking distance is then calculated based on this information and the human physiological characteristics. Hence, the PDR solution can be propagated and a continuous position solution of the user is available. Seven user dynamics with 3 different speeds are tested with the system. The algorithm recognizes the speed of the pedestrian both in horizontal and vertical direction, which makes the algorithm suitable to be applied in a multi-floor building which is a more complex task than navigation in a one floor construction.
{"title":"Method of pedestrian dead reckoning using speed recognition","authors":"Tuomo Kröger, Yuwei Chen, L. Pei, T. Tenhunen, H. Kuusniemi, Ruizhi Chen, Wei Chen","doi":"10.1109/UPINLBS.2010.5653994","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5653994","url":null,"abstract":"Accurate and robust ubiquitous localization is one of the most demanding challenges that the navigation research community faces currently. The GNSS offers a perfect solution for open sky environment, however, in GPS-denied or unfavourable environments, for example urban canyons or indoors, the traditional GNSS standalone solution cannot provide the user's position at a reasonable accuracy. Therefore, dead reckoning algorithms are one of the research fields which have attracted most research attention in the last few years. A multi-sensor based PDR (pedestrian dead reckoning) algorithm is presented in this paper, which makes full use of the measurements from a barometer and a 3-axis accelerometer. User's dynamics and motion modes are recognized with different speeds. The walking distance is then calculated based on this information and the human physiological characteristics. Hence, the PDR solution can be propagated and a continuous position solution of the user is available. Seven user dynamics with 3 different speeds are tested with the system. The algorithm recognizes the speed of the pedestrian both in horizontal and vertical direction, which makes the algorithm suitable to be applied in a multi-floor building which is a more complex task than navigation in a one floor construction.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126174819","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5654302
J. Kovanen, T. Sarjakoski, L. Sarjakoski
An architecture for speech- and auditory cue-based route instructions is introduced in the paper. The server side architecture is composed of a set of web services. The architecture allows connecting different route services behind a single interface. The route instructions can be transferred as recorded speech, vibration patterns, auditory cues and in textual form between the server and client side. The OpenLS Route Service schema is extended to include in the route instruction responses references to the recorded speech, auditory cues, vibration patterns, encoded textual instructions and brief instructions. The auditory cues may include auditory icons, earcons or spearcons. The textual instructions are based on the Speech Synthesis Markup Language, and a text-to-speech engine on the client side can automatically translate them. The presented holistic approach is aiming to increase the accessibility of route services, especially for visually impaired and elderly people.
{"title":"A client-server architecture for audio-supported mobile route guiding for hiking","authors":"J. Kovanen, T. Sarjakoski, L. Sarjakoski","doi":"10.1109/UPINLBS.2010.5654302","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5654302","url":null,"abstract":"An architecture for speech- and auditory cue-based route instructions is introduced in the paper. The server side architecture is composed of a set of web services. The architecture allows connecting different route services behind a single interface. The route instructions can be transferred as recorded speech, vibration patterns, auditory cues and in textual form between the server and client side. The OpenLS Route Service schema is extended to include in the route instruction responses references to the recorded speech, auditory cues, vibration patterns, encoded textual instructions and brief instructions. The auditory cues may include auditory icons, earcons or spearcons. The textual instructions are based on the Speech Synthesis Markup Language, and a text-to-speech engine on the client side can automatically translate them. The presented holistic approach is aiming to increase the accessibility of route services, especially for visually impaired and elderly people.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116831153","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5653572
A. Kukko, H. Kaartinen, S. Kaasalainen, M. Vaaja, K. Anttila
This paper discusses the experiences gained in the research of monitoring the fluvial morphology and snow cover carried out by Mobile Mapping and EnviLaser teams of the Department of Remote Sensing and Photogrammetry, Finnish Geodetic Institute, in years 2008–2010. Finnish Geodetic Institute initiated the development of a mobile mapping system in 2003 with an aim to build a system that would maximize the automation of urban feature extraction at the post processing phase. Additionally, the system, called ROAMER, was aimed to be a prototype of a mapping instrument that could be flexibly adopted for various urban and environmental applications. To accomplish the high automation, a laser scanner capable of providing dense point clouds was set as the requirement for the system. Integrating laser scanner with mobile platforms (such as cars, tractors, or boats) has recently created a new field of applications thanks to its efficiency in covering relatively large areas with high resolution. In the study cases presented in this paper the mobile mapping system was mounted on a boat, a cart and snow mobile platforms. Vehicle-based systems are capable of faster and more effective data acquisition than current methods, such as photogrammetry, total station surveys and terrestrial laser scanning, used for field data collection. They also provide higher resolution and easier mobilization compared to the airborne laser scanning systems. Use of Mobile mapping has already become common in 3D modeling of, for example, urban areas and road environment.
{"title":"Experiences of mobile mapping in environmental monitoring","authors":"A. Kukko, H. Kaartinen, S. Kaasalainen, M. Vaaja, K. Anttila","doi":"10.1109/UPINLBS.2010.5653572","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5653572","url":null,"abstract":"This paper discusses the experiences gained in the research of monitoring the fluvial morphology and snow cover carried out by Mobile Mapping and EnviLaser teams of the Department of Remote Sensing and Photogrammetry, Finnish Geodetic Institute, in years 2008–2010. Finnish Geodetic Institute initiated the development of a mobile mapping system in 2003 with an aim to build a system that would maximize the automation of urban feature extraction at the post processing phase. Additionally, the system, called ROAMER, was aimed to be a prototype of a mapping instrument that could be flexibly adopted for various urban and environmental applications. To accomplish the high automation, a laser scanner capable of providing dense point clouds was set as the requirement for the system. Integrating laser scanner with mobile platforms (such as cars, tractors, or boats) has recently created a new field of applications thanks to its efficiency in covering relatively large areas with high resolution. In the study cases presented in this paper the mobile mapping system was mounted on a boat, a cart and snow mobile platforms. Vehicle-based systems are capable of faster and more effective data acquisition than current methods, such as photogrammetry, total station surveys and terrestrial laser scanning, used for field data collection. They also provide higher resolution and easier mobilization compared to the airborne laser scanning systems. Use of Mobile mapping has already become common in 3D modeling of, for example, urban areas and road environment.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"73 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130967270","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 : 2010-12-03DOI: 10.1109/upinlbs.2010.5654015
Nazia Kanwal, H. Hurskainen, J. Nurmi
This paper presents vector tracking algorithm for tracking the pseudorandom code of satellite navigation signals, which is suitable for degraded signal environment. The benefits of the vector tracking in comparison of scalar tracking are also explained. This vector tracking algorithm is based on the discriminator function. Conventional GPS receivers use scalar tracking methods and signals from each channel are processed independently. On the contrary, vector tracking loops process the signals in aggregate and can provide better tracking in degraded signal environment, since the channels are closely correlated in vector mode. In vector tracking approach the tracking control input is generated by the navigation filter. The vector tracking loops can operate in weak signal conditions and can rapidly reacquire the weak or attenuated signals. In this paper the ability of vector tracking loop to reacquire the signals is explored and is compared with conventional scalar tracking method.
{"title":"Vector tracking loop design for degraded signal environment","authors":"Nazia Kanwal, H. Hurskainen, J. Nurmi","doi":"10.1109/upinlbs.2010.5654015","DOIUrl":"https://doi.org/10.1109/upinlbs.2010.5654015","url":null,"abstract":"This paper presents vector tracking algorithm for tracking the pseudorandom code of satellite navigation signals, which is suitable for degraded signal environment. The benefits of the vector tracking in comparison of scalar tracking are also explained. This vector tracking algorithm is based on the discriminator function. Conventional GPS receivers use scalar tracking methods and signals from each channel are processed independently. On the contrary, vector tracking loops process the signals in aggregate and can provide better tracking in degraded signal environment, since the channels are closely correlated in vector mode. In vector tracking approach the tracking control input is generated by the navigation filter. The vector tracking loops can operate in weak signal conditions and can rapidly reacquire the weak or attenuated signals. In this paper the ability of vector tracking loop to reacquire the signals is explored and is compared with conventional scalar tracking method.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123377338","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5653816
Yiguang Xuan, R. Sengupta, Y. P. Fallah
The paper describes algorithms required to enable the crowd sourcing of indoor building maps, i.e., where global positioning system (GPS) is not available. Nevertheless to enable crowd sourcing we use the 3-axis accelerometers and the 3-axis magnetometers available in many smart phones. Volunteers carry the phones while walking around in buildings, and use some application on their smart phones to send the data to a mapping server. We present the algorithms to obtain walking trajectories from the data by dead reckoning, and to estimate indoor maps with multiple walking trajectories.
{"title":"Making indoor maps with portable accelerometer and magnetometer","authors":"Yiguang Xuan, R. Sengupta, Y. P. Fallah","doi":"10.1109/UPINLBS.2010.5653816","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5653816","url":null,"abstract":"The paper describes algorithms required to enable the crowd sourcing of indoor building maps, i.e., where global positioning system (GPS) is not available. Nevertheless to enable crowd sourcing we use the 3-axis accelerometers and the 3-axis magnetometers available in many smart phones. Volunteers carry the phones while walking around in buildings, and use some application on their smart phones to send the data to a mapping server. We present the algorithms to obtain walking trajectories from the data by dead reckoning, and to estimate indoor maps with multiple walking trajectories.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115481922","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5654087
Timo Jokitalo, Kim Kaisti, V. Karttunen, V. Salo, Stefan Söderholm
We present our recent work on developing a more flexible client-server software architecture for software GNSS receivers, targeted mainly for applications where position fixes are needed only occasionally. The receiver architecture is based on an IQ snapshot approach, where instead of tracking a continuous stream of IQ samples, the receiver stores a snapshot of IQ data and processes the stored samples separately. This approach relaxes the strict real time requirements of the software, compared to a continuously tracking software receiver. We present a number of operating contexts to which the software architecture can easily be adapted, and show our preliminary test results.
{"title":"A CPU-friendly approach to on-demand positioning with a software GNSS receiver","authors":"Timo Jokitalo, Kim Kaisti, V. Karttunen, V. Salo, Stefan Söderholm","doi":"10.1109/UPINLBS.2010.5654087","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5654087","url":null,"abstract":"We present our recent work on developing a more flexible client-server software architecture for software GNSS receivers, targeted mainly for applications where position fixes are needed only occasionally. The receiver architecture is based on an IQ snapshot approach, where instead of tracking a continuous stream of IQ samples, the receiver stores a snapshot of IQ data and processes the stored samples separately. This approach relaxes the strict real time requirements of the software, compared to a continuously tracking software receiver. We present a number of operating contexts to which the software architecture can easily be adapted, and show our preliminary test results.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121691331","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 : 2010-12-03DOI: 10.1109/UPINLBS.2010.5654329
Thomas J. Gallagher, Binghao Li, A. Dempster, C. Rizos
Wi-Fi fingerprinting is a technique which can provide location in GPS-denied environments, relying exclusively on Wi-Fi signals. It first requires the construction of a database of “fingerprints”, i.e. signal strengths from different access points (APs) at different reference points in the desired coverage area. The location of the device is then obtained by measuring the signal strengths at its location, and comparing it with the different reference fingerprints in the database. The main disadvantage of this technique is the labour required to build and maintain the fingerprints database, which has to be rebuilt every time a significant change in the wireless environment occurs, such as installation or removal of new APs, changes in the layout of a building, etc. This paper investigates a new method to utilise user feedback as a way of monitoring changes in the wireless environment. It is based on a system of “points” given to each AP in the database. When an AP is switched off, the number of points associated with that AP will gradually reduce as the users give feedback, until it is eventually deleted from the database. If a new AP is installed, the system will detect it and update the database with new fingerprints. Our proposed system has two main advantages. First it can be used as a tool to monitor the wireless environment in a given place, detecting faulty APs or unauthorised installation of new ones. Second, it regulates the size of the database, unlike other systems where feedback is only used to insert new fingerprints in the database.
{"title":"Database updating through user feedback in fingerprint-based Wi-Fi location systems","authors":"Thomas J. Gallagher, Binghao Li, A. Dempster, C. Rizos","doi":"10.1109/UPINLBS.2010.5654329","DOIUrl":"https://doi.org/10.1109/UPINLBS.2010.5654329","url":null,"abstract":"Wi-Fi fingerprinting is a technique which can provide location in GPS-denied environments, relying exclusively on Wi-Fi signals. It first requires the construction of a database of “fingerprints”, i.e. signal strengths from different access points (APs) at different reference points in the desired coverage area. The location of the device is then obtained by measuring the signal strengths at its location, and comparing it with the different reference fingerprints in the database. The main disadvantage of this technique is the labour required to build and maintain the fingerprints database, which has to be rebuilt every time a significant change in the wireless environment occurs, such as installation or removal of new APs, changes in the layout of a building, etc. This paper investigates a new method to utilise user feedback as a way of monitoring changes in the wireless environment. It is based on a system of “points” given to each AP in the database. When an AP is switched off, the number of points associated with that AP will gradually reduce as the users give feedback, until it is eventually deleted from the database. If a new AP is installed, the system will detect it and update the database with new fingerprints. Our proposed system has two main advantages. First it can be used as a tool to monitor the wireless environment in a given place, detecting faulty APs or unauthorised installation of new ones. Second, it regulates the size of the database, unlike other systems where feedback is only used to insert new fingerprints in the database.","PeriodicalId":373653,"journal":{"name":"2010 Ubiquitous Positioning Indoor Navigation and Location Based Service","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130654124","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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