Europe's latest Galileo satellites in space have joined the operational constellation, providing navigation signals to three billion users throughout planet Earth as well as relaying distress calls to rescuers. Following a summer test campaign, their deployment will result in a noticeable increase in positioning accuracy and enhanced data transmission performance for the whole Galileo system.
Galileo satellites 27 and 28 were launched at the end of last year and were subjected to an in-orbit test review at the end of April by ESA, satellite manufacturer OHB, and navigation payload manufacturer Surrey Satellite Technology Ltd. (SSTL). Their significant results include the fact that the payloads on both spacecraft are working exceedingly well, ranking among the finest in the entire constellation, and that both satellites entering operation improve the overall location accuracy and robustness of the Galileo system.
Following a successful system/operations in-orbit test assessment co-chaired by ESA and EUSPA, the EU Agency for Space Program, in overall charge of commissioning, the satellites' health was verified. Following a successful test campaign this summer, these two new Galileo satellites are the first to transmit an updated navigation message, resulting in three significant enhancements for Galileo's public Open Service users.
Users can establish a first location fix more quickly with faster navigation data gathering.
Improved resilience in difficult situations, such as metropolitan areas where towering structures might impair satellite sight.
Users with only a rough estimate of the timing of 1-2 seconds will have easier access to timing information in the navigation message.
Thales Alenia Space in Italy, SSTL, OHB, and ESA created new software for the Navigation Signal Generation Unit that was transferred to the two satellites for testing and broadcasting of this new navigation message. During the summer, ESA did intensive testing to ensure that the upgraded message was compatible with the complete Galileo system at the unit, payload, satellite, ground, and system levels. EUSPA monitored receiver testing as part of this endeavor to verify that this compatibility extended to the market's Galileo receivers and chipsets. These most recent satellite launches provided appropriate test scenarios for the program and the enhanced navigation message.
According to Stefan Wallner, Head of the G1 Signal in the Space Engineering Unit, this testing was critical for the whole Galileo system since it means end-users may now receive an initial positional fix twice as quickly, in only 16 seconds. The team was able to confirm its correct installation and describe its long-term performance thanks to the transmission of enhanced signals from Galileo satellites 27-28. The satellites were returned to operation on August 29 after a successful Test Review Board.
According to Bastiaan Willemse, head of the European Space Agency's Galileo Full Operational Capability Satellite Management Service, "now that the testing is complete, we reach an exciting moment for the entire Galileo family because this is the point at which users can begin to benefit from these new Galileo satellites." Furthermore, the modifications will improve the overall performance of the Galileo system. This new software will be implemented not only into the Galileo satellites that are presently in orbit but also into the satellites that will be deployed in the coming months.