Advances in global navigation satellite system (GNSS) technology have resulted in smaller and more accurate GNSS receivers, which have become increasingly suitable for calculating instantaneous performance parameters during sports competitions, for example by providing the difference in time between athletes at any location along a course. This study investigated the accuracy of three commercially available GNSS receivers directed at the sports market and evaluated their applicability for time analysis in endurance racing sports. The receivers evaluated were a 1 Hz wrist-worn standalone receiver (Garmin Forerunner 920XT, Gar-920XT), a 10 Hz standalone receiver (Catapult Optimeye S5, Cat-S5), and a 10 Hz differential receiver (ZXY-Go). They were validated against a geodetic, multi-frequency receiver providing differential position solutions (accuracy < 5 cm). Six volunteers skied four laps on a 3.05 km track prepared for cross-country skiing, with all four GNSS receivers measuring simultaneously. Deviations in position (horizontal plane, vertical, direction of travel) and speed (horizontal plane and direction of travel) were calculated. In addition, the positions of all receivers were mapped onto a mapping trajectory along the ski track, and a time analysis of all 276 possible pairs of laps was performed. Specifically, the time difference between any two skiers for each integer meter along the track was calculated. ZXY-Go, CAT-S5, and GAR-920XT had horizontal plane position errors of 2.09, 1.04, and 5.29 m (third quartile, Q3), and vertical precision 2.71, 3.89, and 13.35 m (interquartile range, IQR), respectively. The precision in the horizontal plane speed was 0.038, 0.072, and 0.66 m s-1 (IQR) and the time analysis precision was 0.30, 0.13, and 0.68 s (IQR) for ZXY-Go, Cat-S5, and Gar-920XT, respectively. However, the error was inversely related to skiing speed, implying that for the low speeds typically attained during uphill skiing, substantially larger errors can occur. Specifically, at 2.0 m s-1 the Q3 was 0.96, 0.36, and 1.90 s for ZXY-Go, Cat-S5, and Gar-920XT, respectively. In summary, the differential (ZXY-Go) and 10 Hz standalone (Cat-S5) receivers performed substantially better than the wrist-worn receiver (Gar-920XT) in terms of horizontal position and horizontal speed calculations. However, all receivers produced sub-second accuracy in the time analysis, except at very low skiing speeds.

/pdf/tracking-performance-in-endurance-racing-sports-evaluation-9pxf2sinmr.pdf

Tracking Performance in Endurance Racing Sports: Evaluation of the Accuracy Offered by Three Commercial GNSS Receivers Aimed at the Sports Market

Editorial : Wearable Sensor Technology for Monitoring Training Load and Health in the Athletic Population

/pdf/editorial-wearable-sensor-technology-for-monitoring-training-8wflx1hfnx.pdf

Editorial: Wearable Sensor Technology for Monitoring Training Load and Health in the Athletic Population

GPS (Global Positioning System) is a satellite based navigation system and is used in a variety of applications such as mapping, vehicle navigation and surveying. In this work, a detailed background of GPS is included. First, historical development of GPS technology is provided. This is followed by a detailed theoretical background of GPS and GNSS (Global Navigation Satellite System). Afterwards, the topics of “GPS estimation error” and “increasing GPS position accuracy” are covered. Then, various counterparts of GPS technology, developed by rival countries are discussed. Finally, future expectations of scientific world from the GNSS technology are presented.

A broad overview of GPS fundamentals: Now and future

Prior to an excavation for a construction project, fieldwork is necessary to identify the location of all underground utilities. There is a demand for identifying the accurate positioning of the underground utilities, in order to support the contractors in avoiding damages to existing underground infrastructures. Such damages could cost thousands of euros, needless to underline the danger in human lives, in the presence of gas and electricity. There is a concrete market request for solutions that are able to effectively handle underground utilities’ data and function in support to the fieldwork. The fusion of technologies such as global navigation satellite systems (GNSS), sensors, geographic information systems (GIS) and geodatabases, augmented and virtual reality (AR/VR) can lead to products and services for monitoring, documenting and managing the utility-based geospatial data. The LARA project, a H2020 co-funded project by the European Commission (EC), embraced these needs and developed a software and hardware (S/H) system. The LARA hand-held and mobile device involves state-of-the-art technologies in the domain of positioning and sensors, AR and 3D GIS geodatabases and aids the users in “seeing” beneath the ground by rendering the complexity of the 3D utilities’ models. The visualization of underground utilities is made using a mixed reality paradigm, where the user can see at the same time the surroundings and the utilities rendered at their exact location in 3D. In order to cope with the end-users expectations, two types of visualizations have been implemented and tested. LARA system tested in two case studies during the project lifetime and the results are promising.

Augmented Reality Geovisualisation for Underground Utilities

We present a mobile-based navigation system with the emphasis on the pedestrian navigation for Hospital Kuala Lumpur (henceforth, HKL) named as HKLNS. This practical research aimed to provide support and help for the people who come to the HKL. Despite having signages, layouts and other types of guidance to help them navigate, they might not be sure their current location and the destination’s paths. By using the OpenStreetMap (OSM) and Graphhopper API as a solution, it managed to help people to navigate the surrounding of the HKL. The findings showed that users were able to know their current location and the system generated the shortest pedestrian paths to the desired location using both mappings. The functionality testing and experimental results surrounding HKL demonstrated the effectiveness of this approach. The HKLNS was reliable based on the functionality and validation testing conducted towards 5 respondents with 5 different case study, in which it manage to reduce more than 50% time taken with the t-test result of 0.00041 ( p<0.05 ), indicated that the system was accepted.

https://www.beei.org/index.php/EEI/article/download/2082/1370

Mapping a hospital using OpenStreetMap and Graphhopper: A navigation system

Chapter 1. Global Navigation Satellite Systems.- Chapter 2. Doppler Satellite Positioning, Telemetry and Data Systems.- Chapter 3. Precision and Navigational PNT Systems.- Chapter 4. Aided and Augmentation Systems, and Differential GPS.- Chapter 5. Applications of PNT Systems.- Chapter 6. National and International Governmental Policy Issues.- Chapter 7. Conclusions and Future Directions.- 8. Top Ten Things to Know About GNSS.- Appendix 1. Key Terms and Acronyms.- Appendix 2. Selected Bibliography.- Appendix 3. Selected Websites.

Scott Madry

Papers

Global Navigation Satellite Systems and Their Applications