Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - PARADISE (Precise and Robust Navigation enabling Applications in Disturbed Signal Environments)

Teaser

The objective of PARADISE was to develop innovative signal processing and navigation algorithms bringing precise GNSS positioning to applications where to date GNSS could not be adopted due to prohibitively bad signal conditions, such as urban canyon and forest environment.To...

Summary

The objective of PARADISE was to develop innovative signal processing and navigation algorithms bringing precise GNSS positioning to applications where to date GNSS could not be adopted due to prohibitively bad signal conditions, such as urban canyon and forest environment.
To be able to validate these new algorithms in user applications a PARADISE prototype receiver supporting the new signal processing was developed. The PARADISE receiver was demonstrated for different user applications within the scope of the project. The major focus within the PARADISE project was on the following application scenarios, with the clear aim to increase the overall efficiency of the work flow of these applications by introducing GNSS based positioning:
• Cadastral surveying inside and near forests
• Mapping of underground lines in construction work in urban canyons
• Navigation of forestry machines (harvester/forwarder)

Those applications generally demand high accuracies. But they all face the problem of a limited or distorted visibility to the GNSS satellites. Currently available GNSS solutions cannot cope with this problem resulting in unacceptable positioning errors of several meters. Thus PARADISE targeted the development and demonstration of
• Algorithms for GPS/Galileo dual-frequency precise positioning
• Algorithms for MEMS integration for attitude determination
• Demonstration of 3 user applications

Work performed

The PARADISE project provides GPS/Galileo L1/E1 & L5/E5 PPP/RTK based positioning with synthetic aperture signal processing with the developed PARADISE prototype receiver. The receiver is equipped with an L1/E1 & L5/E5a RF front-end providing 1-bit IF-Samples for synthetic aperture processing.

Although the satellite systems as needed by PARADISE are not yet fully deployed it was already possible to demonstration precise position accuracy also in adverse environments like forest roads. It is expected that with further deployment of the Galileo constellation and the upgrade of GPS with further L5 capable satellites the precise positioning will also be available to more demanding environments like deep forest areas.

The surveying inside and near forests was demonstrated with the application partner ‘Vermessung Abwerzger’. The PARADISE receiver showed during the surveying tests equal performance to the COTS RTK GPS/GLONASS receiver used for comparison for the open field and edge of forest application case. For the forest road application case, the PARADISE receiver showed superior performance in succeeding in an RTK fixed accurate position whereas the COTS RTK receiver did not achieve a position fix. For the deep forest application case both receiver did not succeed in providing a position with the required accuracy and were of equal performance. The PARADISE receiver therefore provides additional benefit to surveying inside or near the forest. At least for the forest road case it is no longer needed to measure reference points by terrestrial methods from an open field position nearby. This saves considerable time and effort.

The forest machine guidance was demonstrated with the application partner ‘HSM’. As forest machine a \'skidder\' was equipped with the PARADISE receiver and sensors and operated on two different forest ‘road’ types.
The PARADISE receiver showed good performance and repeatability of the position solution in the forest drives. Furthermore, contrary to the COTS GPS it provided a position solution for every epoch during the tests.
It is expected that with the already mentioned completion of the satellite constellations sub-meter accuracy could be achieved with the PARADISE solution also for normal forest machine working application use cases.

The Augmented Reality Construction demonstration application showed the possibility to provide object construction of cadastral features by the use of the laser range distometer in combination with the table camera and IMU measurement. The internal tests showed that the tablet provided IMU did not have the necessary accuracy for the needed angle determination to reach the required accuracy for the laser distometer measurement for object construction.

Final results

The PARADISE prototype receiver tests and the user application demonstrations together with the application partners showed the expected advantage of the new PARADISE signal processing algorithms combined with MEMS IMU technology.
The main obstacle to reach full performance of the PARADISE receiver is currently the status of the GPS & Galileo satellite constellations. With the required usage of GPS L1/L5 and Galileo E1/E5a frequencies for the PARADISE signal processing, full performance of the PARADISE signal processing is achievable only come with the availability of the full Galileo and GPS L5 constellations. According to current schedules this will be sometime around the year 2021.
PARADISE is expected to pave the way of using GNSS in all outdoor environments, from open sky to adverse environments, requiring high accuracy and availability.
Extrapolating the achieved results with the currently very limited number of available GPS/Galileo satellites to the year 2021 with full Galileo FOC constellation available, it is confirmed that the results achieved with PARADISE can have a considerable impact on the three target markets.
For the urban case (considered the most ‘simple’ case), the PARADISE results are definitely suited to meet the requirements of the ‘urban under-ground construction/mapping’ application. The challenge here is to achieve a fully integrated and user-friendly solution (position, accuracy, distance measurement, GIS).
For the forest applications only satellites above 30 to 35 degree elevation angle can contribute to an accurate RTK position solution. With full availability of Galileo FOC in 2021 with 30° elevation mask, min. 7-9 satellites will be visible (35° elevation mask: min. 6-8 satellites).
The wood harvesting/transportation application can be definitely covered as planned, as harvester/forwarder/skidder all operate on forest roads or logging trails, where even a small part of the sky is not disturbed by trees. Therefore, this application together with the coming digitalization of forest (knowing position of every tree with a diameter or more than 10-20 cm) is expected to provide a huge impact in wood harvesting market in the future. Today wood logistics using ‘GNSS position’ information is starting after the logs are assembled on the forest roads. With the PARADISE driven position availability, the wood logistics can start now from the beginning with the planning of the selected trees for cutting, harvesting and forwarding the trees to the assembly places, thus enabling for the first time a complete digital workflow. Beyond this economic advantage, also compliance to the forest standards from FSC/PFEC to keep the vehicles within the 4 m logging trail swath can be achieved for the first time now which is beyond state-of-the-art.
For the ‘surveying in forest’ application with its very high requirements on accuracy, a clear beyond state-of-the-art capability could be achieved, for surveying at the ‘edge of forest’ (canopy cover of 50%, one half of the hemisphere) or ‘track forest’ (canopy cover of 70-90%), where PARADISE solution was superior to the current COTS solution.

Website & more info

More info: http://www.ifen.com/rd/gnss-receiver-research/paradise.html.