NAGU Information

NAGU (Notice Advisory to Galileo Users) format

There are two types of notice advisory to Galileo users. These are known as “NAGU SPECIFIC” and “NAGU GENERAL”. Both types are described below.

The format of the NAGU SPECIFIC is shown below in Fig 1.

With the exception of the NAGU GENERAL, all the NAGUs will follow the following format:

NOTICE ADVISORY TO GALILEO USERS (NAGU) YYYYNNN
DATE GENERATED (UTC): YYYY-MM-DD hh:mm
NAGU TYPE: AS PER NAGU DEFINITION
NAGU NUMBER: YYYYNNN
NAGU SUBJECT: AS PER NAGU TEMPLATE
NAGU REFERENCED TO: N/A OR YYYYRRR
START DATE EVENT (UTC): YYYY-MM-DD hh:mm
END DATE EVENT (UTC): YYYY-MM-DD hh:mm OR N/A
SATELLITE AFFECTED: SATELLITE_NAME
SPACE VEHICLE ID: SVID
SIGNAL(S) AFFECTED: E1, E5a, E5b, E6, E6-B, E6-C OR ALL
EVENT DESCRIPTION: AS PER NAGU TEMPLATE

Fig 1: NAGU SPECIFIC format

The format to be followed by the NAGU GENERAL is a simplified version of the format above with enhanced flexibility on the definition of the subject as shown in Fig 2.

NOTICE ADVISORY TO GALILEO USERS (NAGU) YYYYNNN
DATE GENERATED (UTC): YYYY-MM-DD hh:mm
NAGU TYPE: GENERAL
NAGU NUMBER: YYYYNNN
NAGU SUBJECT: FREE TEXT
NAGU REFERENCED TO: YYYYRRR OR N/A
START DATE EVENT (UTC): YYYY-MM-DD hh:mm
END DATE EVENT (UTC): YYYY-MM-DD hh:mm OR N/A
SATELLITE AFFECTED: SATELLITE_NAME OR ALL
EVENT DESCRIPTION: FREE TEXT

Fig 2: NAGU GENERAL format

Description of the “NAGU SPECIFIC” and “NAGU GENERAL” format are as follows:

NAGU SPECIFIC Format:

The NAGU SPECIFIC format is shown in Fig 1 and is described below.

The usage of the fields is explained below:

  1. Header: The first line of the text field includes the title “NOTICE ADVISORY TO GALILEO USERS (NAGU)”, which is followed by the NAGU SPECIFIC number given in the format YYYYNNN, where YYYY is the Gregorian year and NNN is the sequential number of NAGU, starting with 001 on the 1st of January every year and incrementing by 1 at each subsequent NAGU. 

  2. Date generated (UTC): The second line contains the date at which the NAGU was generated on the GSC website, in UTC time scale, format YYYY-MM-DD hh:mm where YYYY is the Gregorian year, MM is the number of the month from 1-12 in sequence starting with 1 being January and finishing with 12 being December, DD is the day within the Gregorian month, hh is the hour in the 24 hour format and mm is the minute.

  3. NAGU type: as per NAGU definition. See NAGU types table in the section below.

  4. NAGU Number:  This is defined in the format YYYYNNN (previously defined).

  5. NAGU Subject: subject of the NAGU summarizing the information provided in the “Event Description”. The text to be used in the subject is defined by the template of each NAGU.

  6. NAGU Referenced to: If the current NAGU refers to previous NAGU then the previous NAGU will be in this field in the form of YYYYRRR where YYYY is the Gregorian year the NAGU was issued and RRR is the number of the NAGU for that year. If there is no reference to previous NAGU then “N/A” (not applicable) will appear here instead.

  7. Start date event (UTC): The start date of the event notified in this NAGU in the UTC time scale with format YYYY-MM-DD hh:mm (see the definition of time in “2” above).

  8. End date event (UTC): The end date of the event notified in this NAGU in UTC time scale with format YYYY-MM-DD hh:mm (see the definition of time in “2” above).

  9. Satellite  affected: GSAT (Galileo SATellite) name of the satellite affected.

  10. Space Vehicle ID: SVID of the satellite affected.

  11. Signal(s) Affected: The signal(s) affected by the satellite referenced in the NAGU. The signals affected will be contained within a bracket after the word SIGNAL and can be one or a combination of the following: E1, E5a, E5b, E6, E6-B, E6-C, ALL. Partial outage/availability of the signales is indicated in the NAGU subject if ALL signals are not affected. 

  12. Event description: The event description following the templates defined for each NAGU.

NAGU GENERAL Format:

The NAGU GENERAL format is shown in Fig 2 and is described below:          

  1. Header: The first line of the text field includes the title “NOTICE ADVISORY TO GALILEO USERS (NAGU)”, which is followed by the NAGU SPECIFIC number given in the format YYYYNNN, where YYYY is the Gregorian year and NNN is the sequential number of NAGU, starting with 001 on the 1st of January every year and incrementing by 1 at each subsequent NAGU.

  2. Date generated (UTC): The second line contains the date at which the NAGU was generated on the GSC website, in UTC time scale, format YYYY-MM-DD hh:mm where YYYY is the Gregorian year, MM is the number of the month from 1-12 in sequence starting with 1 being January and finishing with 12 being December, DD is the day within the Gregorian month, hh is the hour in the 24 hour format and mm is the minute.

  3. NAGU type: as per GENERAL NAGUs definition. See GENERAL NAGU types table in the section below.

  4. NAGU Number: This is defined in the format YYYYNNN (previously defined)

  5. NAGU Subject: This will be a free text message giving information on the subject of the NAGU.

  6. Event Description: This will be a free text message giving information on the event description that this NAGU refers to.

NAGU Types1

NAGU Type (abbreviation)

NAGU Type

NAGU Description

PLN_MANV

Planned maneouver

Planned activity affecting the attitude and/or orbit. The planned outage start time and end times are indicated.

PLN_OUTAGE

Planned outage

Planned activity, in space or ground segment, that causes an outage of the satellite Signal In Space broadcasted. The planned outage start and end times are indicated.

AVAILINIT

Satellite first time available

The satellite is for first time providing healthy SIS following completion of satellite in-orbit commissioning activities.
The type of clock being used to drive the navigation payload is also indicated.
Satellite is not yet contributing to service provision.

USABINIT

Satellite first time usable

The satellite is for the first time providing signals and navigation messages according to the service performance commitment.
The type of clock being used to drive the navigation payload is also indicated.
Satellite enters into service and contributing to service provision.

AVAILABLE

Available for testing

The satellite starts transmitting healthy SIS following the end of a planned outage or recovery of an unplanned outage.
The exact outage start and end times are indicated.
The type of clock being used to drive the navigation payload is also indicated.
This NAGU type is used prior to Service Declaration.

USABLE

Usable for Service provision

The satellite starts transmitting healthy SIS following the end of a planned outage or recovery of an unplanned outage.
The exact outage start and end times are indicated.
The type of clock being used to drive the navigation payload is also indicated.
This NAGU type is used following Service Declaration.

PLN_CANCEL

Cancellation

Cancellation of published NAGUs.

PLN_RESCH

Reschedule

Provision of new start/end times for published planned NAGU.

PLN_EXTNS

Extension

Provision of new end time for published planned NAGUs or notification of the planned outage end time for published unplanned NAGU (UNP_UNUFN).

DECOMMSNG

Satellite decommissioned

Commencement of satellite decommissioning phase.

UNP_UNUFN

Unavailable until further notice

Unscheduled outage of the satellite SIS broadcasted of undefined duration.

UNP_SHTRCVR

Short term outage recovered

Events (short term) that have been recovered before a NAGU could be published.

GENERAL (NOTICE)

General Notice

General notifications such as announcing the IOV campaign, Initial Service validation, announcement of Initial Service declaration, introduction of Services, IOC, FOC ,etc.
GENERAL (LAUNCH) Launch Notification of the satellite launch.
GENERAL (LEAP SECOND) Leap second Notification of leap second adjustment.
GENERAL (TIMING PLN_OUTAGE)
Planned outage timing services
Notification of a planned operation entailing an outage of timing services.
GENERAL (TIMING AVAILABLE)
Availability of timing services
Notification of availability of timing services following the end of a planned operations/recovery of an unplanned outage with impact related only to timing services.
GENERAL (TIMING  PLN_CANCEL)
Cancellation of planned outage timing services
Cancellation of published general NA GU notification for a planned operation entailing
an outage of timing services
GENERAL (TIMING  PLN_RESCH)
Reschedule of planned outage timing services
Provision of new start/end times for published general NA GU notification for a planned operation entailing an outage of timing services.
GENERAL (TIMING  PLN_EXTNS)
Extension of planned outage timing services
Provision of new end time for published planned NAGU
GENERAL (TIMING UNP_UNUFN)
Unplanned outage timing services
This general NAGU provides notification of an unplanned outage related with timing services.
GENERAL (TIMING UNP_SHTRCVR)
Short term outage timing services
This general NAGU provides notification of short term timing services outage that have been recovered before a NAGU could be published.

1: NAGU types are still under development during the service preparation phase and therefore are subject to change and additions.