Showing papers on "Assisted GPS published in 2005"

Location-based Services: Fundamentals and Operation

Abstract: Preface. List of Abbreviations. 1 Introduction. 1.1 What are Location-based Services? 1.2 Application Scenarios. 1.3 LBS Actors. 1.4 Standardization. 1.5 Structure of this Book. Part I: Fundamentals. 2 What is Location? 2.1 Location Categories. 2.2 Spatial Location. 2.3 Conclusion. 3 Spatial Databases and GIS. 3.1 What are Spatial Databases and GIS? 3.2 Geographic versus Spatial Data Models. 3.3 Representing Spatial Objects. 3.4 Features and Themes. 3.5 Algorithms of Computational Geometry. 3.6 Geography Markup Language. 3.7 Conclusion. 4 Basics of Wireless Communications. 4.1 Signals. 4.2 Propagation of Radio Signals. 4.3 Multiplexing and Multiple Access. 4.4 Conclusion. 5 Cellular Networks and Location Management. 5.1 Overview of Cellular Systems. 5.2 Principles of Cellular Networks. 5.3 Mobility Management. 5.4 Common Concepts of Location Management. 5.5 Location Management in CS Networks. 5.6 Location Management in PS Networks. 5.7 Conclusion. Part II: Positioning. 6 Fundamentals of Positioning. 6.1 Classification of Positioning Infrastructures. 6.2 Basic Positioning Methods. 6.3 Range Measurements. 6.4 Accuracy and Precision. 6.5 Error Sources. 6.6 Conclusion. 7 Satellite Positioning. 7.1 Historical Background. 7.2 Orbital Motion of Satellite Systems. 7.3 Global Positioning System. 7.4 Differential GPS. 7.5 Galileo. 7.6 Conclusion. 8 Cellular Positioning. 8.1 Positioning in GSM Networks. 8.2 Positioning in UMTS Networks. 8.3 Assisted GPS in GSM and UMTS. 8.4 Positioning in other Cellular Systems. 8.5 Conclusion. 9 Indoor Positioning. 9.1 WLAN Positioning. 9.2 RFID Positioning. 9.3 Indoor Positioning with GPS. 9.4 Non Radiolocation Systems. 9.5 Conclusion. Part III: LBS Operation. 10 Interorganizational LBS Operation. 10.1 LBS Supply Chain. 10.2 Scenarios of the LBS Supply Chain. 10.3 Supplier/Consumer Patterns for Location Dissemination. 10.4 Privacy Protection. 10.5 Conclusion. 11 Architectures and Protocols for Location Services. 11.1 GSMand UMTS Location Services. 11.2 Enhanced Emergency Services. 11.3 Mobile Location Protocol. 11.4 WAP Location Framework. 11.5 Parlay/OSA. 11.6 Geopriv. 11.7 Conclusion. 12 LBS Middleware. 12.1 Conceptual View of an LBS Middleware. 12.2 Location API for J2ME. 12.3 OpenGIS Location Services. 12.4 Conclusion. 13 LBS - The Next Generation. Bibliography. Index.

Systems and methods for displaying location-based maps on communication devices

Abstract: Tickers are populated with location-based information that is selected according to the geographic location of communication devices. The location of a communication device is identified based on a GPS system, proximity to transmitters in a wireless network, user input, or using other techniques. Location-appropriate content is obtained either in real-time from the network or from a local data store at the communication device. In general location-based, context-aware content can be displayed on tickers associated with a variety of communication devices, including mobile communication devices and “immobile” or stationary personal computers. When a ticker item is selected from the ticker, a location associated with the selected ticker item and/or a location of the communication device is used to generate a map that is displayed on the display of the device to the user.

Assessing the accuracy of the Sydney Household Travel Survey with GPS

Abstract: This paper reports on a GPS survey that was conducted in conjunction with the Sydney 2003/2004 Household Travel Survey (HTS), and was commissioned by the NSW Roads and Traffic Authority (RTA). The objective of the study was to collect GPS data that can be used to provide information about under-reporting of travel activities in face-to-face household travel surveys. Each year the survey covers approximately 5,000 households in Greater Metropolitan Sydney. The data gathered from these surveys is used to assist transport planners and has and is being used to re-estimate the Sydney Strategic Travel Model. Subjects were issued a one-day place-based travel diary and were aided by verbal activity recall in a face-to-face interview. (a) For the covering entry of this conference, please see ITRD abstract no. E213716.

A new positioning system using television synchronization signals

Abstract: The technique discussed herein may be used to position a range of wireless devices that require location information when in inclement urban conditions, including PDA's, laptops, cellular phones, asset-tracking devices and radios for emergency response personnel. We make use of synchronization signals that are part of the standard for Television set forth by the Advanced Television Systems Committee. Consequently, the technique described herein requires no changes to the television broadcast stations. The signal can accommodate robust indoor positioning where the Global Positioning System (GPS) fails, since the television synchronization signals typically have a power advantage over GPS of more than 40 dB. In addition, the effects of multipath are substantially mitigated since the signals have a bandwidth of roughly 6 MHz, and substantially superior geometry for triangulating lateral position to that which GPS can typically provide in inclement environments. A wide range of VHF and UHF frequencies have been allocated to television stations; consequently, there is redundancy built into the system to protect against deep fades on particular channels. In addition, unlike GPS, the synch signals are not affected by transmitter Doppler, ionospheric propagation delays, or data that is modulated onto the signals. In overview, the technology exploits the considerable Digital TV infrastructure to achieve more reliable, accurate and rapid positioning than can be achieved with existing technologies.

System and method for displaying location-specific images on a mobile device

Abstract: A system is provided for providing location-specific images to a mobile device for display. The system generally comprises three components: a mobile device (20a, 20b, 20c) having a screen, a position identification system (e.g., a GPS receiver) that determines the position of the mobile device, and a database (43) containing location-specific images taken at various locations. Each location-specific image is associated with geographic coordinates of the location at which the image was taken. Based on the position of the mobile device as determined by the position identification system, a location-specific image is selected from the database and displayed on th screen of the mobile device. For example, when a user is using the mobile device as a car navigation system, a location-specific image of the user's destination location can be selected and displayed when the determined position of the mobile device comes within a certain distance from the geographic coordinates of the destination location.

LAD: localization anomaly detection for wireless sensor networks

Abstract: In wireless sensor networks (WSNs), sensors' locations play a critical role in many applications. Having a GPS receiver on every sensor node is costly. In the past, a number of location discovery (localization) schemes have been proposed. Most of these schemes share a common feature: they use some special nodes, called beacon nodes, which are assumed to know their own locations (e.g., through GPS receivers or manual configuration). Other sensors discover their locations based on the reference information provided by these beacon nodes. Most of the beacon-based localization schemes assume a benign environment, where all beacon nodes are supposed to provide correct reference information. However, when the sensor networks are deployed in a hostile environment, where beacon nodes can be compromised, such an assumption does not hold anymore. In this paper, we propose a general scheme to detect localization anomalies that are caused by adversaries. Our scheme is independent from the localization schemes. We formulate the problem as an anomaly intrusion detection problem, and we propose a number of ways to detect localization anomalies. We have conducted simulations to evaluate the performance of our scheme, including the false positive rates, the detection rates, and the resilience to node compromises.

Position information management system

Abstract: A position information management system in which a portable remote terminal includes a plurality of kinds of positioning means for positioning based on a GPS, positioning based on a portable-telephone or PHS base station, positioning based on a radio marker, and independent positioning based on a direction detector, so that the holder of the portable remote terminal can be navigated anywhere. The holder of the portable remote terminal can know the position of a third party similarly holding such a portable remote terminal, by inquiring of a central system, and he/she can supervise, for example, the action of an old person, a child, or a skier in a skiing area. Further, only the map data of a district which is often used by the holder is stored in the portable remote terminal. In this regard, when the holder is in a district not contained within the retained map data, he/she downloads corresponding map data from the central system and uses the downloaded map data.

GPS radio occultation with GRACE: Atmospheric profiling utilizing the zero difference technique

Abstract: [1] Radio occultation events recorded on 28–29 July 2004 by a GPS receiver aboard the GRACE-B satellite are analyzed. The stability of the receiver clock allows for the derivation of excess phase profiles using a zero difference technique, rendering the calibration procedure with concurrent observations of a reference GPS satellite obsolete. 101 refractivity profiles obtained by zero differencing and 96 profiles calculated with an improved single difference method are compared with co-located ECMWF meteorological analyses. Good agreement is found at altitudes between 5 and 30 km with an average fractional refractivity deviation below 1% and a standard deviation of 2–3%. Results from end-to-end simulations are consistent with these observations.

Server for updating location beacon database

Abstract: A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to reduce arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, Wi-Fi identity information and GPS location information is detected. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database.

A beacon-less location discovery scheme for wireless sensor networks

Abstract: In wireless sensor networks (WSNs), sensor location plays a critical role in many applications. Having a GPS receiver on every sensor node is costly. In the past, a number of location discovery schemes have been proposed. Most of these schemes share a common feature: they use some special nodes, called beacon nodes, which are assumed to know their own locations (e.g., through GPS receivers or manual configuration). Other sensors discover their locations based on the information provided by these beacon nodes. In this paper, we show that efficient location discovery can be achieved in sensor networks without using beacons. We propose a beacon-less location discovery scheme, based on the following observations: in practice, it is quite common that sensors are deployed in groups, i.e., sensors are put into n groups, and sensors in the same group are deployed together at the same deployment point (the deployment point is different from the sensors' final resident location). Sensors from the same group can land in different locations, and those locations usually follow a probability distribution that can be known a priori. With this prior deployment knowledge, we show that sensors can discover their locations by observing the group memberships of its neighbors. We model the location discovery problem as a statistical estimation problem, and we use the maximum likelihood estimation method to estimate the location. We have conducted experiments to evaluate our scheme.

Location beacon database and server, method of building location beacon database, and location based service using same

Abstract: A location beacon database and server (figure 8), method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle (801) is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to avoid arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, periodically receive the GPS coordinates of the GPS device.

Preventing cellphone usage when driving

Abstract: A method for preventing cellular phone usage while driving In one embodiment a GPS system incorporated into the workings of the cellular phone is used to detect that the phone is in motion, and that the rate of movement exceeds some preset value indicating that the phone is in a moving vehicle Having detected motion the phone will deliver a number of options ranging from complete shutdown until motion stops, to use only for emergency purposes, to only limited use, or to complete use by interjecting a preset PIN or other such password which will allow the cellular phone user to override the phone shutdown mechanism Other alternate means for detecting motion include triangulation between numerous towers, to signal strength variation from a single tower, to signals generated by miniature accelerometers and velocimeters imbedded in the phone specifically for detecting rate of movement

Location beacon database

Abstract: A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to avoid arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, periodically receive the GPS coordinates of the GPS device. While traversing the target area, detecting Wi-Fi signals from Wi-Fi access points in range of the Wi-Fi device and recording identity information of the detected Wi-Fi access point in conjunction with GPS location information of the vehicle when the detection of the Wi-Fi access point was made. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database. A user-device having a Wi-Fi radio may be located. A reference database of calculated locations of Wi-Fi access points in a target area is provided. In response to a user application request to determine a location of a user-device having a Wi-Fi radio, the Wi-Fi device is triggered to transmit a request to all Wi-Fi access points within range of the Wi-Fi device. Messages are received from the Wi-Fi access points within range of the Wi-Fi device, each message identifying the Wi-Fi access point sending the message. The signal strength of the messages received by the Wi-Fi access points is calculated. The reference database is accessed to obtain the calculated locations for the identified Wi-Fi access points. Based on the number of Wi-Fi access points identified via received messages, choosing a corresponding location-determination algorithm from a plurality of location-determination algorithms, said chosen algorithm being suited for the number of identified Wi-Fi access points. The calculated locations for the identified Wi-Fi access points and the signal strengths of said received messages and the chosen location-determination algorithm are used to determine the location of the user-device. The database may be modified with newly added position information to improve quality of previously determined positions, and error prone information is avoided.

Geographical Location Information Sharing Among Wireless Devices

Abstract: A system and method for sharing geographical location information among a set of wireless telecommunication devices, such as mobile telephones. A first wireless telecommunication device generates geographical location information of that wireless telecommunication device, either through a resident device such as a GPS device, or has another computer device on the network provide the geographic location information, and then shares the geographical location information through sending the location information to one or more servers for relay to a predesignated target set of wireless telecommunication devices. The server stores the identity of member devices of the target set and controls communication between the first wireless telecommunications device and the member devices of the target set. A second server can be used to modify the geographical information, such as providing a map showing the location of the first wireless telecommunication device and other member devices of the target set.

Augmented display system and methods

Abstract: A mobile augments information system with capabilities of displaying information within field of view of the eyes a vehicle operator. The mobile augments information system includes a Head Up Display (HUD) apparatus consisting of a projector, a selectively reflecting visor and a HUD processing units. The Mobile HUD displays digital information that may be received from external sources such as a cellular phone, navigation system, automotive system, or remote information systems such as Location Based Services (LBS). The data may be received via a wireless link, or a wired link. The mobile HUD may be controlled locally, remotely by a vehicle operator using a wireless remote controller, or using voice commands. The mobile HUD system may also include internal information sources, such as a GPS receiver, or a cellular phone. The mobile augments information system can display textual and graphical information using monochrome or multicolor. Visor may be fixed or dynamically controlled.

Apparatus for enabling a mobile communicator and methods of using the same

Abstract: An apparatus and method for enabling a Mobile Communicator, such as a cell phone or Mobile Communication Device. A Mobile Communicator comprising: an Enabling System, wherein the Enabling System includes a Global Positioning System (GPS) and an Enabling Circuit, wherein a logic of the Enabling Circuit enables the Mobile Communicator because an at least one condition has been satisfied. A kit for enabling a Mobile Communicator, comprising a Mobile Communicator in a Default Disabled State; and an Enabling System. A method for enabling a Mobile Communicator, comprising: providing a GPS and an Enabling System of the Mobile Communicator, wherein satisfying an at least one condition for enablement enables the Mobile Communicator.

Method and apparatus for receiving a global positioning system signal using a cellular acquisition signal

Abstract: Method and apparatus for a GPS device that uses at least one cellular acquisition signal is described. More particularly, a GPS device is configured to receive at least one cellular acquisition signal for obtaining benefits associated with AGPS with only a small subset of AGPS circuitry to interact with a cell phone network. This facilitates use of GPS devices without subscription to a cell phone service provider, thus avoiding cellular subscription fees.

GPS interface for locating device

Abstract: A system for locating a position marker includes a locating device for locating the position marker, and a GPS device communicatively coupled to the locating device that provides GPS coordinate data when the position marker is located by the locating device. Electronic memory is provided in at least one of the locating device and the GPS device for storing a data record associating the GPS coordinate data with the located position marker.

Method and system for building a location beacon database

Abstract: A location beacon database and server, method of building location beacon database, and location based service using same. Wi-Fi access points are located in a target geographical area to build a reference database of locations of Wi-Fi access points. At least one vehicle is deployed including at least one scanning device having a GPS device and a Wi-Fi radio device and including a Wi-Fi antenna system. The target area is traversed in a programmatic route to avoid arterial bias. The programmatic route includes substantially all drivable streets in the target geographical area and solves an Eulerian cycle problem of a graph represented by said drivable streets. While traversing the target area, periodically receive the GPS coordinates of the GPS device. While traversing the target area, detecting Wi-Fi signals from Wi-Fi access points in range of the Wi-Fi device and recording identity information of the detected Wi-Fi access point in conjunction with GPS location information of the vehicle when the detection of the Wi-Fi access point was made. The location information is used to reverse triangulate the position of the detected Wi-Fi access point; and the position of the detected access point is recorded in a reference database. A user-device having a Wi-Fi radio may be located. A reference database of calculated locations of Wi-Fi access points in a target area is provided. In response to a user application request to determine a location of a user-device having a Wi-Fi radio, the Wi-Fi device is triggered to transmit a request to all Wi-Fi access points within range of the Wi-Fi device. Messages are received from the Wi-Fi access points within range of the Wi-Fi device, each message identifying the Wi-Fi access point sending the message. The signal strength of the messages received by the Wi-Fi access points is calculated. The reference database is accessed to obtain the calculated locations for the identified Wi-Fi access points. Based on the number of Wi-Fi access points identified via received messages, choosing a corresponding location-determination algorithm from a plurality of location-determination algorithms, said chosen algorithm being suited for the number of identified Wi-Fi access points. The calculated locations for the identified Wi-Fi access points and the signal strengths of said received messages and the chosen location-determination algorithm are used to determine the location of the user-device. The database may be modified with newly added position information to improve quality of previously determined positions, and error prone information is avoided.

System and method for the emergency voice and image e-mail transmitter device

Abstract: A voice and image e-mail transmitter device with an external camera attachment that is designed for the emergency and surveillance purposes is disclosed. The device converts voice signals and photo images into digital format, which are transmitted to the nearest voice-image message receiving station from where the digital signal strings are parsed and converted into voice, image, or video message files which are attached to an e-mail and delivered to user pre-defined destination e-mail addresses and a 911 rescue team. The e-mail also includes the caller's voice and personal information, photo images of a security threat, device serial number, and a GPS location map of the caller's location. The digital signal data may be recorded and transmitted within few seconds. The victim's family or police may either check the GPS location map in an e-mail or apply a new GPS based people tracking system of the present invention to search for a missing victim.

Systems, methods, and apparatus for jammer rejection

Abstract: A method according to an embodiment obtains a list of peaks for each of a number of frequency hypotheses. Each peak has an energy result and corresponds to a code phase hypothesis. Embodiments include methods and apparatus that may be used in identifying a location of a signal (such as a GPS signal) in a two-dimensional search space. Location information may be further applied to operations such as signal acquisition, signal tracking, position location of a receiver, and timing operations such as the synchronization of one or more other processes.

Design of a system solution for relative positioning of vehicles using vehicle-to-vehicle radio communications during GPS outages

Abstract: Active safety applications for vehicles have been at the forefront of the automotive safety community for a number of years. Cooperative collision warning based on vehicle-to-vehicle radio communications and GPS systems is one such promising active safety application that has evoked considerable interest among automobile manufacturers and research communities worldwide. In this paper, we address one of the key functional components of the cooperative collision warning application, which is, accurate estimation of relative positions of all the neighboring vehicles based on real-time exchange of their individual GPS position coordinates, and then propose a novel system solution for achieving the same (relative positioning functionality) during persistent GPS outages. Based on survey results, we also qualitatively assess various radio based ranging and relative positioning techniques, experimentally evaluate the received signal strength based ranging technique, and comment on their suitability for our proposed solution.

Method, system and apparatus for detecting a position of a terminal in a network

Abstract: A method, system, and apparatus are provided for detecting a position of a terminal in a network accurately without a GPS receiver. In one example, a method for locating a position of a terminal includes calculating a position of a base station; detecting a clock time difference between the base station and another base station; measuring a reception timing of a signal received by the base station from the terminal; and locating the position of the terminal using at least the position of the base station, the clock time difference, and the reception timing.

Navigation apparatus for receiving delivered information

Abstract: In a communication-type navigation system for downloading map data according to the present invention, a reduction in the amount of map information to be transferred, correction of a position measured by a GPS, and delivery of advertisements are effected. In this system, a terminal 5 stores rough map data in advance. Then, when detailed map data is required, it is downloaded from a map data delivery center to the terminal 5 . Further, together with the map data, GPS correction information is delivered to the terminal 5 from the map data delivery center 80 . Still further, coupon information associated with an advertisement is displayed and an electronic mail on the coupon information is issued, by the map data delivery center.

Systems and methods for supporting E911 emergency services in a data communications network

Abstract: The present invention provides systems and methods for supporting enhanced 911 (E911) emergency services in data communications networks that includes Voice over Internet Protocol (VoIP) telephones, by facilitating the identification of the geographic location of a VoIP telephone. The invention generally provides GPS-based geographic location information to the E911 emergency services network. In one embodiment, an E911-enablement system including an E911-enablement device coupled to a GPS receiver is provided. The E911-enablement device then inserts geographic location information obtained from the GPS receiver into 911 call packet streams to provide accurate location information to the E911 emergency services network.

Remote current sensor monitoring system and GPS tracking system and method for mechanized irrigation systems

Abstract: A wireless interface remote monitoring system for self-propelled irrigation systems (center pivot and lateral move sprinklers) includes a remote terminal unit (RTU) mounted on an outer drive tower of the irrigation system. The RTU includes a radio transceiver capable of sending and receiving data packets over a satellite or terrestrial telemetry backbone to and from a central control computer. The RTU further includes a current sensor and a GPS receiver both for detecting movement or non-movement of the sprinkler, a microprocessor with nonvolatile memory for storing current data and GPS coordinate data from readings taken in series over time, and a pressure or flow sensor for detecting the presence or absence of water flow at the outer drive tower of the sprinkler. The current sensor connected between the RTU and a tower drive motor, allows the RTU to calculate the “movement” or “non-movement” of the irrigation system over a specified time period. Redundantly, the GPS receiver records changes in position to indicate movement or non-movement within the GPS error tolerance. Once a change from movement to non-movement or vice-versa is determined, the RTU transmits the data by satellite or radio telemetry to a central control computer which logs the movement or non-movement of the monitored drive tower, the GPS coordinate data and the water status readings, all with time and date stamp. The central control computer creates “page message” and “text message” updates as necessary on the status of individual irrigation systems and “groups” of irrigation systems that are in turn delivered to wireless devices and computers for sprinkler operators.

Investigating the Impact of Ionospheric Scintillation using a GPS Software Receiver

Abstract: Ionospheric scintillations cause RF signal amplitude fading and phase variations as GPS satellite signals pass through the ionosphere. This is a particular concern for GPS operations in high latitude regions, such as Canada, where scintillations are associated with strong aurora – effects which persist even during solar minimum. In general, scintillations can cause degraded receiver tracking performance and, in extreme cases, loss of navigation capabilities entirely. Such effects are an issue for reliable GPS operations in the northern United States and Canada. The University of Calgary currently operates the Canadian GPS Network for Ionosphere Monitoring (CANGIM), which makes scintillations observations at various latitudes in the auroral and sub-auroral regions. These measurements are used to characterize high-latitude scintillation effects, and develop models for assessing GPS receiver performance in the presence of such effects. The focus of this paper is a study of the effects of ionospheric scintillation on GPS signals, based on a GPS software receiver developed at University of Calgary. This study consists of several components: simulating ionospheric scintillation effects on L1 using an intermediate frequency (IF) GPS software signal simulator, investigating phase lock loop (PLL) performance under scintillation conditions using a software receiver, and developing improved tracking loop models to minimize phase errors and loss of signal lock during scintillation events. Results indicate that PLL performance is degraded for moderate to severe scintillations, with loss of lock occurring for narrow bandwidths. By employing a fast adaptive bandwidth approach, reliable signal tracking can be achieved.

System for guiding a farm implement between swaths

Abstract: An apparatus, method and tangible medium using GPS for guiding a farm implement along a turn path between swaths. The apparatus includes a GPS receiver and a turn computer. The turn computer calculates or stores a turn path between swaths, calibrates GPS positions to a swath end position and uses the calibrated GPS positions to guide the implement along the turn path to the start of the next swath. A steering wheel autopilot may be included to steer a powered vehicle according to a cross track error between the calibrated GPS positions and the turn path.

Systems and methods for acquisition and tracking of low CNR GPS signals

Abstract: A receiver for continuous carrier phase tracking of low carrier-to-noise ratio ("CNR") signals from a plurality of radio navigation satellites while the receiver is mobile. The receiver may have: a radio frequency (RF) front-end that provides satellite data corresponding to signals received from the plurality of radio navigation satellites; an inertial measurement unit (IMU) that provides inertial data; and a processor circuit in circuit communication with the RF front end and the IMU, the processor circuit being capable of using satellite data from the RF front-end and inertial data from the IMU to perform continuous carrier phase tracking of low CNR radio navigation satellite signals having a CNR of about 20 dB-Hz, while the receiver is mobile. The receiver may be a GPS receiver for continuous carrier phase tracking of low-CNR GPS signals.