SERVice for ImproviNg Galileo operation over Cyprus

The objective of this proposal is to establish a single-frequency GNSS positioning regional ionospheric mitigation service over the eastern Mediterranean based on the more accurate representation of the state of the ionosphere. This improvement will be possible through the adjustment of the NeQuick-G algorithm, which is the basis for the ionospheric single-frequency GNSS correction algorithm adopted by GALILEO GNSS system, using ionospheric characteristics measured over Cyprus.

The proposed service will depend on a modern digital digisonde (DPS-4D) and a collocated dual-frequency total electron content (TEC) monitor in Cyprus in the frame of real time monitoring of ionospheric propagation predictions. This service will aid towards improved representation of the regional ionosphere in its median (long-term) as well as near real-time  representation and will therefore reduce ionospheric positioning errors both in a climatological sense but also in a weather-like mode of NeQuick-G in the frames of the Galileo system operation.

The project consists of 6 work packages:

    WP1. Project Management

    WP2. Dissemination Activities and Commercialization Plan

    WP3. Assessment of NeQuick over the eastern Mediterranean

    WP4. Improvement of long-term ionospheric characteristics’ representation in NeQuick over the eastern Mediterranean

    WP5. Improvement of near real-time NeQuick behaviour over the eastern Mediterranean by applying a regional ionization level

    WP6. Validation of improvement techniques and service deployment

The objective of this proposal is to establish a single-frequency GNSS positioning regional ionospheric mitigation service over Cyprus based on the more accurate representation of the state of the ionosphere over the area under consideration. This improvement will be possible through the adjustment of the NeQuick model which is the basis for the ionospheric single-frequency GNSS correction algorithm (NeQuick-G) adopted by European Space Agency (ESA) Galileo GNSS system (operational just recently on 15 December 2016) using ionospheric characteristics measured over Cyprus.

The long-term improvement provided by the proposed service will be primarily depend on the dataset of a modern digital digisonde (DPS-4D) compiled over the last eight years. The short-term improvement provided by the proposed service will depend on total electron content (TEC) data provided by a GNSS reference station that will be deployed in the frames of the project in the context of real time monitoring of ionospheric propagation predictions. The operation and subsequent corrections provided through this service will aid towards improved representation of the regional ionosphere in its median (long-term) as well as in its near real-time representation and will therefore provide significant improvement on the level of mitigation of the ionospheric positioning error both in a climatological sense but also in a weather-like mode of NeQuick in the frames of the Galileo system operation.

The operation of this novel service will facilitate the automatic collection and processing of ionospheric characteristics that define the ionospheric electron density profile and therefore provide a direct indication of the extent of the positioning errors which are attributed to TEC in the ionosphere and which directly affect the trans-ionospheric propagation of GNSS satellite signals. The median ionospheric characteristics over Cyprus will be processed and used into the NeQuick model by adjusting its relevant parameters (anchor points of the electron density profile) and the users will have the option to download files that represent more accurately the median behaviour of the local ionosphere and/or also update Az (an ionization index that drives the model) based on a more accurate current local ionospheric representation. In this way the improvement will be provided on short and long term levels depending on the nature of the positioning application in question and its network connectivity attributes.

This service will ultimately propose a novel regional mode for ionospheric positioning error mitigation that may be fully or partially adopted in other parts of the globe as a means to enhance the accuracy of single-frequency positioning devices in real-time operation or in post-processing approaches such as Precise Point Positioning (PPP).

Researchers

Agis Agisilaou / GeoImaging Ltd

Kostas Smagas GeoImaging Ltd

Vasilis Giannoglou / GeoImaging Ltd

Zacharias Kakoutsis / GeoImaging Ltd

Haris Haralambous / Frederick Research Center

Christina Oikonomou / Frederick Research Center

Theodoros Leontiou / Frederick Research Center