Datasheet

NEO-M8U - Data Sheet
UBX-15015679 - R06 Functional description Page 8 of 27
Product Information
1.5.1 GPS
The NEO-M8U positioning module is designed to receive and track the L1C/A signals provided at
1575.42 MHz by the Global Positioning System (GPS). The NEO-M8U can receive and process GPS
concurrently with Galileo and one of GLONASS or BeiDou.
1.5.2 GLONASS
The NEO-M8U positioning module can receive and process GLONASS concurrently with GPS and
Galileo together or BeiDou. The Russian GLONASS satellite system is a fully deployed alternative to
the US-based Global Positioning System (GPS). The NEO-M8U module is designed to receive and
track the L1OF signals GLONASS provides around 1602 MHz. The ability to receive and track
GLONASS L1OF satellite signals allows design of GLONASS receivers where required by regulations.
1.5.3 BeiDou
The NEO-M8U positioning module can receive and process BeiDou concurrently with GPS and Galileo
together or GLONASS. The NEO-M8U module is designed to receive and track the B1 signals provided
at 1561.098 MHz by the BeiDou Navigation Satellite System. The ability to receive and track BeiDou
B1 satellite signals in conjunction with GPS results in higher coverage, improved reliability and better
accuracy. Global coverage is scheduled for 2020.
1.5.4 Galileo
The NEO-M8U positioning module can receive and track the E1-B/C signals centered on the GPS L1
frequency band. GPS and Galileo signals can be processed concurrently together with either BeiDou
or GLONASS signals, enhancing coverage, reliability and accuracy. The SAR return link message
(RLM) parameters for both short and long versions are decoded by the receiver and made available to
users via UBX proprietary messages.
☞ Galileo has been implemented according to ICD release 1.2 (November 2015) and verified with live
signals from the Galileo in-orbit validation campaign. Since the Galileo satellite system has not yet
reached Initial (IOC) nor Full Operational Capability (FOC), changes to the Galileo signal
specification (OS SIS ICD) remain theoretically possible.
☞ Galileo reception is by default disabled, but can be enabled by sending a configuration message
(UBX-CFG-GNSS) to the receiver.
1.6 Assisted GNSS (A-GNSS)
Supply of aiding information, such as ephemeris, almanac, approximate position and time, will reduce
the time to first fix significantly and improve the acquisition sensitivity. The NEO-M8U product
supports the u-blox AssistNow Online and AssistNow Offline A-GNSS services, supports AssistNow
Autonomous, and is OMA SUPL compliant.
1.6.1 AssistNow
TM
Online
With AssistNow Online, an internet-connected GNSS device downloads assistance data from u-blox’s
AssistNow Online Service at system start-up. AssistNow Online is network-operator independent and
globally available. Devices can be configured to request only ephemeris data for those satellites
currently visible at their location, thus minimizing the amount of data transferred.
1.6.2 AssistNow
TM
Offline
With AssistNow Offline, users download u-blox’s long-term orbit data from the Internet at their
convenience. The orbit data can be stored in the NEO-M8U GNSS receiver’s SQI flash memory. Thus
the service requires no connectivity at system start-up, enabling a position fix within seconds, even
when no network is available. AssistNow Offline offers augmentation for up to 35 days.