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GPS Constellation Active Nanu Status
NOTE: The Global Positioning System Directorate has approved a change to the Navstar GPS Control Segment to User Support Community Interfaces (ICD-GPS-240 and ICD-GPS-870) which will remove GPS satellite plane/slot and clock information from the Operational Advisory message. This change proposal was approved by the GPS Interface Control Working Group in December of 2018. SVN/PRN, Block Type, and NANU details will continue to be included.

A depiction of the GPS constellation of satellites with slot and plane designations is provided here as an easy to read graphic for use by the GPS user community.
Slant ChartClick image for full size page.



GPS CONSTELLATION STATUS FOR 10/17/2019

Plane Slot Down ArrowSVN PRN Block-Type Clock Outage Date Nanu-Type Nanu-Subject
E 2 73 10 IIF RB
C 3 72 8 IIF CS
B 5 71 26 IIF RB
F 1 70 32 IIF RB
E 1 69 3 IIF RB
F 3 68 9 IIF RB
D 4 67 6 IIF RB
C 2 66 27 IIF RB
A 1 65 24 IIF CS 10 OCT 2019 FCSTSUMM 2019160 - SVN65 (PRN24) FORECAST OUTAGE SUMMARY JDAY 283/0700 - JDAY 283/1200
A 3 64 30 IIF RB
D 2 63 1 IIF RB
B 2 62 25 IIF RB
D 1 61 2 IIR RB
F 4 60 23 IIR RB
C 5 59 19 IIR RB
B 4 58 12 IIR-M RB
C 1 57 29 IIR-M RB
B 1 56 16 IIR RB
F 2 55 15 IIR-M RB
C 4 53 17 IIR-M RB
A 2 52 31 IIR-M RB
E 4 51 20 IIR RB
E 3 50 5 IIR-M RB
A 4 48 7 IIR-M RB
E 6 47 22 IIR RB
D 5 46 11 IIR RB
D 3 45 21 IIR RB
B 3 44 28 IIR RB
F 6 43 13 IIR RB
F 5 41 14 IIR RB
D 6 34 18 IIA RB DECOM 2019158 - SVN34 (PRN18) DECOMMISSIONING JDAY 282/2200
GENERAL INFORMATION NANUs
2014038

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014038 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
THE PURPOSE OF THIS NOTIFICATION IS TO INFORM USERS OF AN UPCOMING EVENT RELATED TO THE GPS SATELLITE CONSTELLATION. AIR FORCE SPACE COMMAND WILL BE IMPLEMENTING CNAV MESSAGES ON THE GPS L2C AND L5 SIGNALS BEGINNING J118/1430Z WITH UPDATES FROM THE CONTROL SEGMENT APPROXIMATELY TWICE PER WEEK. THE MESSAGE POPULATED SIGNAL CONTENT WILL INCLUDE BROADCAST MESSAGE TYPES (MT) 10, 11, 12, 30, AND 33. THERE ARE NO PLANNED GPS SATELLITE OUTAGES OR DEGRADATIONS FOR THIS ACTIVITY. L2C AND L5 CNAV MESSAGES SHOULD BE TRANSPARENT TO GPS RECEIVERS THAT DO NOT PROCESS L2C OR L5 CNAV MESSAGES. THESE POPULATED SIGNALS ARE INTENDED TO FACILITATE USER FAMILIARIZATION AND DEVELOPMENT OF COMPATIBLE USER EQUIPMENT.

NOTE: UNTIL FURTHER NOTICE, THE L2C AND L5 SIGNALS ARE CONSIDERED PRE-OPERATIONAL. A PRE-OPERATIONAL SIGNAL MEANS THE AVAILABILITY AND OTHER CHARACTERISTICS OF THE BROADCAST SIGNAL MAY NOT COMPLY WITH ALL REQUIREMENTS OF THE RELEVANT INTERFACE SPECIFICATIONS AND SHOULD BE EMPLOYED AT THE USERS? OWN RISK. THEREFORE THESE SIGNALS SHOULD NOT BE USED FOR SAFETY-OF-LIFE OR OTHER CRITICAL PURPOSES. ANY MILITARY OR CIVIL USERS WHO ENCOUNTER USER EQUIPMENT PROBLEMS FOLLOWING MESSAGE POPULATION OF THE L2C AND L5 SIGNALS SHOULD CONTACT THE APPLICABLE POCS IDENTIFIED BELOW AS SOON AS POSSIBLE. AVIATION USERS SHOULD FILE REPORTS CONSISTENT WITH FAA-APPROVED PROCEDURES.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2014039

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014039 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
REFERENCE NANU 2014038. UPDATE:


THE PURPOSE OF THIS NOTIFICATION IS TO INFORM USERS THAT THE CNAV MESSAGES ON THE GPS L2C AND L5 SIGNALS BEGINNING ON APPROXIMATELY J118/1430Z, WILL INCLUDE BROADCAST MESSAGE TYPES (MT) 10, 11, 30, AND 33, BUT WILL EXCLUDE BROADCAST MT 12.


ADDITIONALLY, THE CNAV MESSAGE HEALTH BITS WILL INDICATE THAT THE L1 AND L2 SIGNALS ARE HEALTHY, BUT THAT THE L5 SIGNAL IS UNHEALTHY. THE CNAV MESSAGE HEALTH BITS MAY FUNCTION INDEPENDENTLY FROM THE LEGACY MESSAGE HEALTH BITS AND SHOULD NOT BE CONSIDERED RELIABLE INDICATORS OF SIGNAL QUALITY OR PERFORMANCE DURING PRE-OPERATIONAL USE.


REMINDER: UNTIL FURTHER NOTICE, THE L2C AND L5 SIGNALS ARE CONSIDERED PRE-OPERATIONAL. A PRE-OPERATIONAL SIGNAL MEANS THE AVAILABILITY AND OTHER CHARACTERISTICS OF THE BROADCAST SIGNAL MAY NOT COMPLY WITH ALL REQUIREMENTS OF THE RELEVANT INTERFACE SPECIFICATIONS AND SHOULD BE EMPLOYED AT THE USERS? OWN RISK. THEREFORE THESE SIGNALS SHOULD NOT BE USED FOR SAFETY-OF-LIFE OR OTHER CRITICAL PURPOSES. ANY MILITARY OR CIVIL USERS WHO ENCOUNTER USER EQUIPMENT PROBLEMS FOLLOWING MESSAGE POPULATION OF THE L2C AND L5 SIGNALS SHOULD CONTACT THE APPLICABLE POCS IDENTIFIED BELOW AS SOON AS POSSIBLE. AVIATION USERS SHOULD FILE REPORTS CONSISTENT WITH FAA-APPROVED PROCEDURES.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2018010

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2018010 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
ON 07 MAR 2018, AFTER 2200Z, GPS WILL TRANSITION SVN34 (PRN18) INTO THE BROADCAST ALMANAC FOR ALL SATELLITES. THE ALMANAC TRANSITION, ONE SATELLITE AT A TIME, WILL REQUIRE APPROXIMATELY 24 HOURS TO COMPLETE. ALSO, ON APPROXIMATELY 08 MAR 2018, SVN34 WILL RESUME TRANSMITTING L-BAND UTILIZING PRN18. SVN34/PRN18 WILL BE UNUSABLE UNTIL FURTHER NOTICE. FUTURE NANUS WILL NOTIFY USERS OF ANY CHANGES TO THE ABOVE STATED STATUS.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTPS://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2019001

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2019001 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
GPS III SVN74 (PRN04) WAS LAUNCHED ON 23 DEC 2018 (2018 JDAY 357) AT 1351 ZULU. THIS SATELLITE WILL UNDERGO EXTENSIVE ON-ORBIT CHECK OUT AND TESTING PRIOR TO BEING SET HEALTHY.
A USABINIT NANU WILL BE SENT WHEN THE SATELLITE IS SET ACTIVE TO SERVICE.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTPS://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2019040

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2019040 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS *** GPS WEEK ROLLOVER WILL OCCUR 06-APR-2019, USERS MAY ACCESS THE FOLLOWING ARTICLE FOR FURTHER INFORMATION: HTTPS://WWW.SCHRIEVER.AF.MIL/NEWS/ARTICLE-DISPLAY/ARTICLE/1776011/GPS-WEEK-NUMBER-TO-ROLLOVER/
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTPS://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2019104

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2019104 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
ON APPROXIMATELY 18 JUL 2019 SVN36 WILL RESUME TRANSMITTING L-BAND UTILIZING PRN04.
AT L-BAND ACTIVATION, SVN36/PRN04 WILL BE UNUSABLE UNTIL FURTHER NOTICE. ADDITIONALLY, NO
BROADCAST ALMANACS WILL INCLUDE SVN36/PRN04 UNTIL FURTHER NOTICE.
*** GENERAL MESSAGE TO ALL GPS USERS ***

POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTPS://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPSOPERATIONSCENTER@US.AF.MIL, HTTPS://GPS.AFSPC.AF.MIL
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514,
COMM 805-606-3514, JSPOCCOMBATOPS@VANDENBERG.AF.MIL

2019159

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2019159
SUBJ: SVN74 (PRN04) LAUNCH JDAY 357
1. NANU TYPE: LAUNCH
NANU NUMBER: 2019159
NANU DTG: 100122Z OCT 2019
SVN: 74
PRN: 04
LAUNCH JDAY: 357
LAUNCH TIME ZULU: 1351

2. GPS SATELLITE SVN74 (PRN04) WAS LAUNCHED ON JDAY 357.
A USABINIT NANU WILL BE SENT WHEN THE SATELLITE IS SET ACTIVE TO SERVICE.

3. POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV
MILITARY - GPS OPERATIONS CENTER AT HTTPS://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
COMM 719-567-2541, GPS_SUPPORT@SCHRIEVER.AF.MIL, HTTP://GPS.AFSPC.AF.MIL/GPSOC/GPS
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3514. COMM 805-606-3514.
JSPOCCOMBATOPS@VANDENBERG.AF.MIL



GPS Expandable Slot Designations
B D F
B5=B1F D5=D2F F5=F2F
B1=B1A D2=D2A F2=F2A