The improvement of the satellite high precision positioning to develop new scientific and technological applications in Antarctica is the objective of DemoGRAPE.
The upper atmosphere (from 50 km of height) of the Earth presents a region particularly rich of free electrons, termed ionosphere. Such high concentration makes the ionosphere the major natural contributor to the degradation of the GNSS (Global Navigation Satellite Systems: GPS, GLONASS, Galileo, etc…) signals received at ground. At high latitude this degradation is even more severe because the polar ionosphere is often hit by solar energetic particles driven by the cusps of the geomagnetic field into the high latitude atmosphere. The precise positioning based on GNSS can, thus, be heavily corrupted, resulting in positioning errors of tens of meters or, even worst, in the positioning blackout due to the loss of satellite lock.
As the global standard models used to assess the ionospheric contribution to the positioning errors fail when applied to the Antarctic ionosphere, DemoGRAPE adopts an empirical approach based on the local characterization of the natural threats affecting the GNSS signals propagation. To do this, DemoGRAPE will realize ad hoc measurement campaigns at the Antarctic stations of SANAE IV (South Africa) and EACF (Brazil) during the 2015-2016 Expedition. The new and the historical data will be processed by means of original algorithms designed by the project partners.
The project makes use of Cloud computing to share data and results among the scientists, and to run the necessary software, keeping the intellectual property ownership.
High precision positioning applications, such as geodetic prospections, land and glaciers monitoring, airport traffic management, just to mention a few, must be assisted by services capable to mitigate the ionospheric corruption on GNSS signals. DemoGRAPE will release the prototype of a new service based on local data and ad hoc processors, capable to demonstrate a significant improvement of the precise positioning over Antarctica. Thanks to the Cloud technology, the prototype will be accessible to a plethora of different stakeholders, from academic to private, interested in the high precision applications.
NavSAS tasks include a preparation phase, consisting of the design of a dual/tri band front-end, tailored to the polar installation, and the developement of a fully software receiver, featuring phase measurements capabilities. A data collection will be performed during the Antarctica campaign, both with the dedicated set-up and with a professional commercial receiver. Finally, GNSS data will be analyzed in post-processing to assess of the ionospheric impact, exploiting the flexibility and configurability of a software receiver, in terms of access to low level and intermediate processing stages and of analysis of unconventional outputs.
More information on the demoGRAPE website www.demogrape.net
Photos and pictures are taken from the demoGRAPE website.
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