In this study the maritime communication system VDES (VHF Data Exchange System) is proposed to distribute Network-RTK (NRTK) correction data to shipborne GNSS receivers in fairways, port areas, or inland water ways. The transport layer used for transmission of VDES messages (related to the standard IEC61162-450) is the UDP multicast protocol. This makes it possible to transmit the RTCM packages from the VDES transponder to the shipborne GNSS receivers as a UDP payload without any additional formatting. In order to minimize the impact on the overall VDES data capacity in a local service area, NRTK correction data shall at most occupy a single VDES slot with a net capacity of 650 bytes denoted Link ID 19. This is the fastest link in VDES. Update rates may vary but are preferably at 1Hz. However, depending on the number of visible satellites NRTK correction data size changes instantly and the data rate can therefore sometimes be in excess of 1000 byte/s per reference station to be distributed. In order to comply with the VDES requirements, the Lantmäteriet Adjustment Solution (LAS) for GNSS correction data adjustment was developed and is presented in this paper. The responsibility of this solution is to produce a correction data stream that complies with the bandwidth limitation of 650 bytes/s. To provide corrections for a potentially large number of users, dissemination is done by broadcasting corrections for a grid of VRSs. The proposed solution has therefore also the capability to combine several correction data streams from several Virtual Reference Stations (VRSs) into one single correction data stream. To reduce the required data rate, the LAS has the ability to filter streamed GNSS correction data in the RTCM3 MSM format constellation-wise, satellite-wise, and signal-wise. The objective is to achieve optimal performance in terms of accuracy for the ship's differential positioning solution, while at the same time adhering to constraints that might locally apply for individual transmitters. For this paper LAS was configured to interface with the SWEPOS to provide reference data to static and kinematic testing scenarios. The results presented here were obtained using RTK post-processing with RTKLib for a combination of GPS and Galileo multi-frequency observations. Results indicated that LAS solution can achieve robust positioning performance with decimeter-level accuracy which meet the requirements expected for the navigation safety at Sea. Adapted-NRTK correction data (LAS data) via VDES has the potential to be part of a world-wide standard VDES application for all vessels sailing under SOLAS and for ships that voluntarily uses VDES in the near future (inland, yachts, navies, leisure).

The increasing number of modernized GNSS signals and the availability of multi-constellation receivers are crucial for improvements of both precision and robustness of GNSS based positioning. However, the abundance of GNSS observations is not always useable as applications, using differential positioning or other techniques, may have limitations with respect to computational resources or communication bandwidth for reference data, and therefore require a qualified selection of a subset of observations for positioning. This paper is based on the work conducted in the project PREParE SHIPS funded by the European Union Agency for the Space Programme (EUSPA) on the specific application of Maritime Navigation using Network Real Time Kinematic (NRTK) and will focus on the satellite selection algorithms of the Prepare Ships dissemination solution. This study is motivated by data rate requirements and restrictions of the VDES dissemination solution developed in Prepare Ships. The restricted data rate for dissemination of RTK observations via VDES implies the need for a qualified pre-selection of satellite subsets to match the available bandwidth and the requirements of the positioning system. For this, multiple algorithms have been developed and tested in static and dynamic scenarios. Optimization techniques for height (for vertical position), two and three dimensions were examined. Different weighting schemes were used. During the evolution of the satellite selection study, it was concluded that it is necessary to retain satellites with the highest elevation as this will empirically improve integer ambiguity resolution for position fixing. Also fixing a minimum number of satellites for each constellation was required to enable a fair weightage to the different constellations used. Such algorithms should prove to be very useful for research on various Network RTK applications which require/prefer limited bandwidth such as for cadastral surveying and mapping, for airborne geo-referencing of aerial mapping data using Unmanned Aerial Vehicles (UAV) and on the road and sea for positioning and navigation of automated transport. Additionally, these algorithms could also be extended to consider satellite visibility in e.g. urban areas (i.e. urban canyons) by inclusion of true surface information for more robust GNSS positioning in automated transport applications [1]. This could either be for pre-evaluation or for dynamically considering spatial information. While this work is a part of PREParE SHIPS, it is also motivated by a more general applicability of the algorithms presented for other similar applications. RTK correction dissemination with limited bandwidth requirements is very promising for RTK research and therefore this study on optimized selection of satellite subsets is of vital importance and could tap multiple opportunities of huge potential such as those involving NRTK or combination of Precise Point Positioning with RTK. © 2021 Proceedings of the 34th International Technical Meeting of the Satellite Division of the Institute of Navigation, ION GNSS+ 2021. 

Advanced Driver Assistance Systems (ADAS) and Automated Driving (AD) vehicles rely heavily on optical sensors. Extensive testing of optical sensors is required and typically performed at test tracks like AstaZero. Soft surrogate targets are used for safety reasons, but the optical characteristics of surrogate targets may differ considerably from that of real vehicles. During tests the quality of the soft surrogate targets deteriorates due to repeated impacts and reassembly of the targets, and there is a need for methods to secure the quality of the soft surrogate targets over time.

RISE has conducted a project together with Volvo Cars and Veoneer to develop and validate accurate and repeatable measurement methods of the optical characteristics of 3D soft car targets. The goal is to support international standardisation (ISO) with standard methods enabling future verification and calibration of optical characteristics of active safety 3D soft car targets.

The poster presents results from optical measurements on soft car targets and real cars, performed in the project. One target was subjected to 100 rear-end collisions during which the reflectivity was measured.

This paper reports on results from a study of characteristics for 3D soft surrogate vehicle targets. Such targets are used extensively for testing and verification of optical sensor systems for Advanced Driver Assistance Systems and Automated Driving. However, the influence of wear-and-tear on the vehicle target is not well known. Consequently, no clear requirement exists on how many collisions a soft target can be exposed to before it no longer performs well.

Important characteristics for optical sensor systems are surface reflectance in the relevant wavelength range and geometry of the soft target. We report on measurements of spectral reflectivity and geometry performed before, during and after an accelerated ageing campaign involving 100 rear-end collisions at 50 km/h. The reflectivity was found to change very little while the geometry was strongly affected.

The objective of PRoPART is the development and demonstration of a high availability positioning solution for connected automated driving applications. It aims to develop and enhance an existing RTK (Real Time Kinematic) software solution developed by Waysure, by exploiting the distinguished features of Galileo signals as well as combining it with other positioning and sensor technologies. Besides the use of vehicle on board sensors, PRoPART will also use a low-cost Ultra Wideband (UWB) ranging solution for redundancy and robustness in areas where the coverage of GNSS is poor e.g. in tunnels or in urban canyons. In order to define the correct requirements for the PRoPART combined positioning solution, a cooperative automated vehicle application will be defined and developed. The vehicle application will rely on the high availability positioning solution and use it to couple its ADAS system with V2X and aggregate information received from other connected vehicles and Road Side Units (RSU).

The main objective of WP6 Task T6.2 and Task T6.3

is to spread PRoPART results among the main target groups identified during the development of the business plan studies. PRoPART dissemination activities aim to raise awareness about its real added value in technical terms.

Specific objectives:

• Definition of an agile communication strategy to be adapted to the different target groups and messages.
• Preparation of the corporative image and a set of materials for the promotion and comprehensive dissemination.
• Monitoring and execution of the communication plan with a continuous penetration in the main target groups with tailored messages.

Referring to the above mentioned aims PRoPART’s Communication and Dissemination plan addresses the following key issues: identification of stakeholders and project’s key impact fields; specific dissemination tools (logo, website, publications, conferences, events, press media, leaflets and posters, videos, cooperation with other projects, social networking, etc.). Finally, it will focus on the most relevant procedures related to communication and dissemination activities

The PRoPART public website has been implemented in month 3 of the project, and will be maintained over the lifetime of the project. The internet portal works as communication platform to assist the coordination of the project and its activities.

An individual domain has been acquired to host the website. The link to this PRoPART website is:

http://www.propart-project.eu/

Within the design phase of the website, perspectives from both specialized and non-specialized visitors have been considered in order to develop the interface.

The website will be the main communication tool for the project, where all the publicly available dissemination materials will be published in a timely manner. The website is an interactive environment that will give access to all the publishable development of PRoPART. It will give a very direct link to the main results and to the hottest project news.

Besides, this website gives a link to the objectives, partnership, activities and events related with the project, and it is planned to give access to all the aspects regarding the new technologies, best practices and recommendations for robust positioning for automated vehicles gathered from the project development. Contributions from the partners will be highly important to maintain the project’s website updated, in order to improve the website positioning in search engines and to reflect an active attitude to Internet users. In addition, partners are asked to link their website and platforms to the website of PRoPART project. In this sense, a SEO positioning analysis will be performed to ensure higher visibility in web search engines.

The following points describe the different sections

and functionalities of the website, supported by screenshots to better understand its use.

Advanced Driver Assistance Systems (ADAS) and Autonomous Driving (AD) vehicles rely heavily on sensors for achieving their goal of protecting the driver and passengers from potentially dangerous situations. Optical sensors are used to measure locations and velocities of objects at distances of up to 150 meters. Optical sensors could be cameras (for visible light or IR) used to detect either objects or road features (like e.g. road edges and markings). They are a common choice for high-end ADAS and are found in sensor sets of most AD vehicles.

To ensure reliable performance of object detection, extensive testing of optical sensors is required. In vehicle testing performed at test tracks like AstaZero, 3D soft car targets are used for safety reasons. However, due to non-perfect shape and materials, the optical characteristics of 3D soft car targets may differ considerably from that of real vehicles in traffic, resulting in different detection performance, and hence different activation of the functions. Moreover, during tests the quality of the 3D soft car targets deteriorates due to repeated impacts and reassembly of the targets, which implies that there is a need of methods for securing the quality of the 3D soft car targets over time.

By addressing these challenges, the goal of the project has been to contribute to improved testing methods of optical and geometrical characteristics of 3D soft car targets by:

• developing measurement methods and specifying measurement setups for the optical and geometrical characteristics of 3D soft car targets;
• developing simplified measurement methods for quality check on 3D soft car targets to secure the quality over time;
• providing input to international standardization regarding methods for measurement of optical and geometrical characteristics of real and soft car targets.

The results include test of different measurement methods, different 3D soft car targets as well as real vehicles and also an accelerated ageing test of a 3D soft car target from DRi.

Advanced Driver Assistance Systems (ADAS) and Automated Driving (AD)vehicles rely on a variety of sensors and among them optical sensors. Extensivetesting of functions using optical sensors is required and typically performedat proving grounds like AstaZero. Soft surrogate targets are used for safetyreasons but the optical and geometrical characteristics of soft car targets maydiffer considerably from that of real vehicles. During tests the quality of thesoft car targets deteriorates due to repeated impacts and reassembly of thetargets, and there is a need of methods for securing the quality of the softcar targets over time. One of the main goals of the HiFi Visual Target project isto develop and validate accurate and repeatable measurement methods of theoptical and geometric characteristics of soft car targets.

Future automated vehicles and advanced driver assistance systems are highly dependent on sensors to detect their environment as well as robust, accurate, and cost-effective sensor systems for positioning. 

Global Navigation Satellite systems (GNSS) provide a key technology that enables an absolute position estimate and Network-RTK (Real Time Kinematic) has the potential to meet the requirements of cost, accuracy, and availability. This technology is based on correction data being received from a fixed reference station via e.g. mobile communication. Current implementations have been driven by requirements from applications which operate within a limited region for lengthy periods of time, such as surveying and precision agriculture. These applications can tolerate relatively long initialization times and can afford expensive equipment.

The mass market wants to benefit from infrastructure in place for these applications, but the requirements are somewhat different. Problems occur when the device moves from the coverage area of one reference station to another and reinitialization must be made. Consumer devices must also deliver similar performance with inexpensive components. In addition to this, the existing public-sector system for distribution of correction data, in Sweden governed by Lantmäteriet/ SWEPOS, is not designed for handling a large number of clients and efficiently distributing correction data to these clients based on their location.The telecom industry in 3GPP (Third generation partnership project) is currently addressing the need for a scalable provisioning of network RTK corrections. Based on the 3GPP specification, the project aimed to develop, implement, test and demonstrate an efficient distribution system for Network-RTK correction data in order to enable cm-level accuracy GNSS positioning for a large number of mobile platforms e.g. automated vehicles.

The NPAD project has:

• Leveraged the existing Lantmäteriet/SWEPOS GNSS reference infrastructure to implement a virtual network of reference stations that provided coverage over selected test areas suitable for supporting a large number of simultaneous users.
• Implemented a scalable GNSS correction data provisioning based on the ongoing work in 3GPP that provides correction data from the reference network to mobile devices;
• Developed test cases for automated vehicle platforms related to positioning and implemented demonstrators;
• Investigated tools and methods for validating the accuracy of integrated GNSS positioning and navigation systems.

The project was coordinated by RISE Research Institutes of Sweden and involved besides Lantmäteriet and AstaZero the following industrial partners: AB Volvo, Caliterra, Einride, Ericsson, Scania, and Waysure.