ESA/ESOC was one of the founding members of the IGS, and at the time the Navigation Support Office was implemented at ESOC, all of the IGS activities were transferred to the Navigation Support Office having originally been developed in the ESOC Flight Dynamics Department. The Navigation Support Office has been a continuous IGS member since its inception in 1992, and has always been an active participant in all the analysis activities of the IGS aiming to provide the best-in-class solutions to all products using GNSS data. ESA Analysis Centre products are among the best products available from the individual IGS Analysis Centres. Additionally the ESA products are among the few multi-constellation GNSS products. ESA was the first IGS analysis centre to provide a consistent set of orbit and clock products for all available GNSS satellites. These products constituted the very first products that have been used for true GNSS precise point positioning.
Final, Rapid and Ultra-Rapid Processing
The ESA/ESOC IGS Analysis Centre contributes to all of the core IGS analysis centre products: Final GNSS products (GPS+GLONASS) provided weekly based on 24-hour solutions using 150 stations from true GNSS solutions simultaneously and fully consistently processing GPS and GLONASS measurements for a total of around 55 satellites, consisting of orbits, clocks, coordinates, ionosphere, and Earth orientation parameters (EOPs). Rapid GNSS products (GPS+GLONASS) (available within 3 hours after the end of the observation day) and Ultra-Rapid GNSS products (GPS+GLONASS) 4 times per day, available within 3 hours after the end of the observation interval with estimated and predicted GNSS orbits and clocks . The sampling rate of the ESA final GPS+GLONASS clock product is 30 seconds. These products are publicly available to the scientific community, being published at several data servers, such as navigation-office.esa.int , and the CDDIS at NASA’s Goddard Space Flight Center. The ESOC GNSS products are also finding applications in testing of experimental and commercial endeavours, becoming the standard reference for many high-precision GNSS applications.
Over the last 10 years, ESOC has embarked on a program to build a Real-Time GNSS software infrastructure. The main justification for this effort is the realisation that the delivery of precise GNSS products in real-time will become increasingly more important for the user community. ESOC is at the forefront of the IGS Real-Time developments, particularly with respect to products related to Galileo. The system for REal TIme NAvigation (RETINA) has been modelled after ESOC’s experience in real-time satellite control systems and includes many of the elements for data processing, archiving, and visualisation that are common to such ground systems for controlling orbiting satellites. In particular, it implements a specially designed circular filing system for streaming data, allowing maintenance-free operations for processing and archiving of data and products, and seamless transitions from historical to live data processing.
The investment in GNSS software and receiver infrastructure has enabled ESOC to participate in the IGS Real-Time Pilot Project, assuming the roles of Real Time Analysis Centre and Analysis Centre Coordinator. In the latter role, ESOC has been generating and disseminating the IGS Real-Time Combination stream after processing the real-time solutions from up to ten analysis centres. Included in these solutions are two streams generated by the ESOC Real Time Analysis Centre.
GNSS Receiver Stations Network
ESOC Navigation Support Office operates a set of worldwide GNSS receivers installed to geodetic quality and for about half of the network of stations ESOC cedes the data to the IGS GNSS Station Network for the benefit of the entire international community. The ESOC Ground Station Network provides Daily, Hourly, 15 min in RINEX 2 and RINEX 3 formats, plus streamed data to registered users. All this data is regularly used by all parts of the IGS community and beyond for Geodesy studies, Earth monitoring activities, GNSS constellation activities, Atmospheric monitoring (troposphere and ionosphere), etc. The maintenance and operations of the stations together with the best-in-class data processing capabilities make ESOC capable of detecting, researching, resolving and adapting to any GNSS related issue whether related to station data, Earth changes, or spacecraft modelling.
Having an entire proprietary and complete GNSS value chain sets ESOC Navigation Support Office apart even within IGS and the world and ensures future adaptability and growth as GNSS increases in importance.
Participation in the IGS Real-Time activities has stimulated ESOC’s involvement in the development of standards and formats for GNSS data and products. ESOC has been instrumental in the decision of the IGS to join the Radio Technical Commission for Maritime Services (RTCM) , which is the primary standards-setting organisation for real-time GNSS services. ESOC is now one of two agencies that represent the IGS at the RTCM meetings.
Work with the RTCM focuses on:
Development of standards and formats for transmission of multi-constellation observations in real time (RTCM-MSM).
Development of standards and formats for the transmission of real-time orbit and clock products (RTCM-SSR).
Further development of the RINEX standard for generation of multi-GNSS batch observation files
The Navigation Support Office takes its committment to the IGS very seriously also in terms of contributing know-how and experience and not just results, data and products. Three Navigation Support Office staff are directly involved in the IGS governing structure as follows:
Dr. Werner Enderle
Appointed IGS Governing Board Member. (2016-2018)
As head of the Navigation Support Office and a full member of the IGS Governing Board assisting in the overall coordination, strategic planning and management of the IGS.
Dr. Loukis Agrotis
Real-Time Analysis Center Coordinator (IGS Governing Board Member 2014-2017)
As ACC of the IGS Real-Time Service, and a full member of the IGS Governing Board, preparing the combined IGS Real-Time orbit and clock product, monitoring the contributions of all the Analysis Centers.
Dr. Ignacio Romero
Chair of the IGS Infrastructure Committee (non-voting IGS Governing Board Member 2010-2017)
As Chair of the Infrastructure Committee and with an advisory role to the Governing Board, ensuring that the data requirements for the highest quality GNSS products are fully satisfied, while also anticipating future needs and evolving IGS infrastructure needs.