Galileo High Accuracy Service (review)

Galileo High Accuracy Service (benefits)

Galileo is Europe’s GNSS. Until now, GNSS users have had to depend on American Global Positioning System (GPS) or the Russian GLONASS signals. With Galileo, users now have a new, reliable alternative that, unlike other programmes, remains under civil control.

This is important as satellite positioning has become an essential service that we often take for granted. Just think what would happen if GNSS signals were suddenly switched off. Truck and taxi drivers, ship and aircraft crews and millions of people around the world would suddenly be lost. Furthermore, financial and communication activities, public utilities, security and humanitarian operations and emergency services would all come to a standstill. With the addition of Galileo, we can minimise these risks.

Galileo provides improved positioning and timing information with positive implications for many European services, businesses and users. For example:

Thanks to the multi-constellation of receivers that Galileo adds to, users can now know their exact position with greater precision.
Galileo’s dual frequency capability offers significant advantages in terms of achievable accuracy, but also in terms of improved resistance to jamming.
The products that people use every day, from the GPS in your car to a mobile phone, benefit from the increased accuracy that Galileo provides.
Critical, emergency response-services benefit from Galileo.
Galileo helps make Europe’s roads and railways safer and more efficient.
Galileo boosts European innovation, contributing to the creation of many new products and services, creating jobs and allowing Europe to own a greater share of the global market for added value services, which is forecast to reach EUR 166 billion in 2029

HAS Service area is GLOBAL, while excluding regions identified in the figure above:

defined by Latitudes [60ºS – 60ºN] and Longitudes [90ºE – 180ºE]
defined by Latitudes [60ºS – 60ºN] and Longitudes [125ºW – 180ºW]

Any HAS user within the excluded regions may still use the Galileo HAS corrections, but the committed targets for the Minimum Performance levels (MPLs) ONLY apply to the Service area


DETAILS ON COMMITTED ACCURACY
Figure of merit	MPL target	Conditions and constraints
HAS orbit corrections	≤ 20 cm (95%) for Galileo ≤ 33 cm (95%) for GPS over the instantaneous constellation average (computed as RMS)	- Calculated over a period of 30 days - All HAS-corrected and valid Galileo/GPS satellites in view from any point in the Service area
HAS clock corrections accuracy	≤ 12 cm (95%) for Galileo ≤ 15 cm (95%) for GPS over the instantaneous constellation average (computed as the RMS)
HAS code biases accuracy	≤ 50 cm (95%) for both Galileo and GPS over the instantaneous constellation average (computed as RMS)
DETAILS ON COMMITTED AVAILABILITY
Figure of merit	MPL TARGET	Conditions and constraints
HAS corrections availability	≥ 87% Galileo only	- 5 degrees elevation mask - Calculated over a period of 30 days - At least 5 HAS-corrected and valid satellites in view - At the Worst User Location (WUL) of the Service area
HAS corrections availability	≥ 95% Galileo+GPS	- 5 degrees elevation mask - Calculated over a period of 30 days - At least 8 HAS-corrected and valid satellites in view - At the WUL of the Service area
DETAILS ON TYPICAL PERFORMANCE – POSITIONING ACCURACY (GALILEO ONLY)
Figure of merit	Typical performance	Conditions and constraints
HAS horizontal positioning accuracy	≤ 25 cm Galileo only	- 68th percentile confidence level - Over any 24 hours period - For the signal combinations supported by the HAS - Using the HAS performance characterisation user algorithm (HAS-UA) - At least 5 HAS-corrected and valid satellites in view above 5 degrees elevation under open sky conditions - Static user - Applying orbit and clock corrections and code biases for the involved signals - At the Average User Location (AUL) of the Service area - Usage assumptions as per HAS-SDD
HAS vertical positioning accuracy	≤ 30 cm Galileo only
DETAILS ON TYPICAL PERFORMANCE – POSITIONING ACCURACY (GALILEO + GPS)
Figure of merit	Typical performance	Conditions and constraints
HAS horizontal positioning accuracy	≤ 15 cm Galileo+GPS	- 68th percentile confidence level - Over any 24 hours period - For the signal combinations supported by the HAS - Using the HAS performance characterisation user algorithm (HAS-UA) - At least 8 satellites in view above 5 degrees elevation for Galileo + GPS users under open sky conditions - Static user - Applying orbit and clock corrections and code biases for the involved signals - At the Average User Location (AUL) of the Service area - Usage assumptions as per HAS-SDD
HAS vertical positioning accuracy	≤ 20 cm Galileo+GPS
DETAILS ON TYPICAL PERFORMANCE – POSITIONING AVAILABILITY
Figure of merit	Typical performance	Conditions and constraints
HAS positioning availability	≥ 90 %	- Fulfilling both horizontal and vertical positioning accuracy targets as per HAS-SDD- Calculated over a period of 30 days - For the signal combinations supported by HAS - Using the HAS performance characterisation user algorithm (HAS-UA) - Under open sky conditions- At least 5 HAS-corrected and valid satellites in view above 5 degrees elevation for Galileo-only users - At least 8 HAS-corrected and valid satellites in view above 5 degrees elevation for Galileo + GPS users - Static user - Applying orbit and clock corrections and code biases for the involved signals - At the Average User Location (AUL) of the Service area - Usage assumptions as per HAS-SDD