Navigation system and method

In a global positioning system (GPS), such as the NAVSTAR/GPS system, wherein the position coordinates of user terminals are obtained by processing multiple signals transmitted by a constellation of orbiting satellites, an acquisition-aiding signal generated by an earth-based control station is relayed to user terminals via a geostationary satellite to simplify user equipment. The aiding signal is FSK modulated on a reference channel slightly offset from the standard GPS channel. The aiding signal identifies satellites in view having best geometry and includes Doppler prediction data as well as GPS satellite coordinates and identification data associated with user terminals within an area being served by the control station and relay satellite. The aiding signal significantly reduces user equipment by simplifying spread spectrum signal demodulation and reducing data processing functions previously carried out at the user terminals

Office of Spaceflight Standard Spaceborne Global Positioning System (GPS) user equipment project

The Global Positioning System (GPS) provides the following: (1) position and velocity determination to support vehicle GN&C, precise orbit determination, and payload pointing; (2) time reference to support onboard timing systems and data time tagging; (3) relative position and velocity determination to support cooperative vehicle tracking; and (4) attitude determination to support vehicle attitude control and payload pointing

Space shuttle navigation analysis. Volume 1: GPS aided navigation

Analytical studies related to space shuttle navigation are presented. Studies related to the addition of NAVSTAR Global Positioning System user equipment to the shuttle avionics suite are presented. The GPS studies center about navigation accuracy covariance analyses for both developmental and operational phases of GPS, as well as for various orbiter mission phases

Office of Space Flight standard spaceborne Global Positioning System user equipment project

The Global Positioning System (GPS) provides users autonomous, real-time navigation capability. A vehicle equipped with GPS user equipment can receive and process signals transmitted by a constellation of GPS satellites and derive from the resulting measurements the vehicle's position and velocity. Specified accuracies range from 16 to 76 meters and 0.1 to 1.0 meters/second for position and velocity, respectively. In a rendezvous and docking scenario, the use of a technique called relative GPS can provide range and range rate accuracies on the order of 1 meter and 0.01 meters/second, respectively. Relative GPS requires both vehicles to be equipped with GPS user equipment and a data communication link for transmission of GPS data and GPS satellite selection coordination information. Through coordinated satellite selection, GPS measurement errors common to both users are cancelled and improved relative position and velocity accuracies are achieved. The background, the design approach, the expected performance and capabilities, the development plan, and the project status are described. In addition, a description of relative GPS, the possible GPS hardware and software configurations, and its application to automated rendezvous and capture are presented

TECHNIQUES FOR OBTAINING INDOOR LOCATION MAP AND UNIFORM RESOURCE IDENTIFIER FROM AN ACCESS NETWORK

Many times, when a user is in a building and not aware of layout of the building, it becomes very difficult for the user to know in which part of the building the user is currently standing. While Third Generation Partnership Project (3GPP)/cellular systems offer various methods for determining the position of a wireless device of a user (often referred to as a user equipment (UE), the resulting positioning coordinates (e.g., Global Positioning System (GPS) coordinates) are of not of much use to the user. Presented herein are techniques through which a UE can be provided a user-friendly visual indication of the current location of the UE inside an unfamiliar building, layout, or other geographical area

GNSS Shadow Matching in a Changing Urban Environment

This publication describes apparatuses, methods, and techniques for performing Global Navigation Satellite System (GNSS) shadow matching in a changing urban environment. To do so, a user equipment (e.g., a smartphone) utilizes a comprehensive positioning algorithm. The smartphone can measure a signal strength of satellites of the GNSS. When the signal strength matches an expected shadow, the comprehensive positioning algorithm can utilize GNSS data, area network data, inertial data, and an Urban Canyon Positioning Algorithm. The Urban Canyon Positioning Algorithm uses GNSS shadow matching data to increase user location accuracy in the urban environment. When the signal strength does not match the expected shadow, the comprehensive positioning algorithm can estimate user position using GNSS data, area network data, inertial data, and other optional localization signals (e.g., step counting, visual matches against a known model of a street-level visual map). Then, the comprehensive positioning algorithm can compare and quantify differences between the signal strength with the expected shadows, and quantify discrepancies between an estimated user location from various localization signals. Based on the differences between the signal strength and the expected shadows, the comprehensive positioning algorithm can determine and map changes in the urban environment. When the GNSS shadow matching determines user location with a high degree of confidence and accuracy, the comprehensive positioning algorithm can use this information to find discrepancies in other localization signals that rely on a map model (e.g., terrain height data, street-level visual maps, WiFi® hot spots). Lastly, the comprehensive positioning algorithm can adjust updates from the Urban Canyon Positioning Algorithm near unmodeled physical features (e.g., buildings, bridges, tunnels) in the urban environment

Probabilistic Ray-Tracing Aided Positioning at mmWave frequencies

We consider the following positioning problem where several base stations (BS) try to locate a user equipment (UE): The UE sends a positioning signal to several BS. Each BS performs Angle of Arrival (AoA) measurements on the received signal. These AoA measurements as well as a 3D model of the environment are then used to locate the UE. We propose a method to exploit not only the geometrical characteristics of the environment by a ray-tracing simulation, but also the statistical characteristics of the measurements to enhance the positioning accuracy.Comment: Accepted at the conference Indoor Positioning and Indoor Navigation (IPIN) 202

GPS & Galileo: Prospects for Building the Next Generation of Global Navigation Satellite Systems

In the next 5 to 10 years, the world will experience the emergence of a true Global Navigation Satellite System (GNSS) - a compatible and, in many respects, interoperable system of systems. The U.S. Global Positioning System, Europe\u27s Galileo, perhaps Russia\u27s Glonass system, and regional augmentations including the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), radiobeacon-based systems such as the U.S. Nationwide Differential GPS, and compatible commercial differential correction services will comprise this multifaceted GNSS. Common signal structures and frequency plans will enable combined user equipment that reduces the technical complexity and cost, while vastly expanding related applications. Additional satellites and signals, both more powerful and with improved designs, will increase the availability of robust signal reception outdoors and strengthen the potential of indoor positioning using only GNSS user equipment. But the path to the future is not without its risks: political, technical, economic, and cultural

Performing GNSS Shadow Matching for User Equipment with Varied Carrying Positions

This publication describes apparatuses, methods, and techniques for performing Global Navigation Satellite System (GNSS) shadow matching for user equipment (e.g., smartphones) with varied carrying positions, such as in a user’s hand, pocket, purse, backpack, and so forth. To do so, the smartphone utilizes an Urban Canyon Positioning Algorithm to find line-of-sight (LOS) signals of satellites of the GNSS. Then, the Urban Canyon Positioning Algorithm estimates a signal-strength degradation of the LOS signals due to the carrying position, such as when the user puts their smartphone in their pocket. After estimating the signal-strength degradation of the LOS signals, the Urban Canyon Positioning Algorithm adjusts LOS signals and non-line-of-sight (NLOS) signals with the estimated signal-strength degradation of the LOS signals. Finally, the Urban Canyon Positioning Algorithm computes GNSS shadow matching by adjusting parameters (e.g., the median and the standard deviation) of the signal strength of all the signals (LOS and NLOS) received by the smartphone

LabVIEW interface with Tango control system for a multi-technique X-ray spectrometry IAEA beamline end-station at Elettra Sincrotrone Trieste

A new synchrotron beamline end-station for multipurpose X-ray spectrometry applications has been recently commissioned and it is currently accessible by end-users at the XRF beamline of Elettra Sincrotrone Trieste. The end-station consists of an ultra-high vacuum chamber that includes as main instrument a seven-axis motorized manipulator for sample and detectors positioning, different kinds of X-ray detectors and optical cameras. The beamline end-station allows performing measurements in different X-ray spectrometry techniques such as Microscopic X-Ray Fluorescence analysis (µXRF), Total Reflection X-Ray Fluorescence analysis (TXRF), Grazing Incidence/Exit X-Ray Fluorescence analysis (GI-XRF/GE-XRF), X-Ray Reflectometry (XRR), and X-Ray Absorption Spectroscopy (XAS). A LabVIEW Graphical User Interface (GUI) bound with Tango control system consisted of many custom made software modules is utilized as a user-friendly tool for control of the entire end-station hardware components. The present work describes this advanced Tango and LabVIEW software platform that utilizes in an optimal synergistic manner the merits and functionality of these well-established programming and equipment control tools