Navigation Center Website Top Header Banner
Home | LNMs | BNMs | Nav Rules | AIS Data Requests | AIS Overview | GPS Constellation | GPS Testing | GPS Almanacs | USCG Int'l Ice Patrol | Contact Us | Search
GPS
Maritime Safety Data
Nav Systems and Services
Maritime Safety Information
Report a Problem

Print friendly version  
GPS Constellation Active Nanu Status
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 which will be updated as satellites enter or leave the constellation. During the GPS modernization process, the orbital configuration, as indicated by the constellation slant chart, and control station configuration may not match over the long term. For modelling purposes, the slant chart indicates actual orbital slot and plane assignments. It should be noted that the graphic merely identifies orbital slot and plane assignments and does not reflect the operational status of GPS satellites. The operational status of the GPS constellation is detailed below.

NOTE: While SVN-74/PRN-04 occupies Plane/Slot F4 in the GPS constellation, as indicated by the constellation slant chart, it is designated A6 in the GPS Operational Advisory (OA) for control station purposes only.
Slant Chart

Click image for full size page.



GPS CONSTELLATION STATUS FOR 11/24/2020

Plane Slot Down ArrowSVN PRN Block-Type Clock Outage Date Nanu-Type Nanu-Subject
E 5 76 23 III RB 01 OCT 2020 USABINIT 2020046 - SVN76 (PRN23) USABLE JDAY 275/1627
D 6 75 18 III RB
A 6 74 4 III RB
E 2 73 10 IIF RB 23 NOV 2020 FCSTSUMM 2020085 - SVN73 (PRN10) FORECAST OUTAGE SUMMARY JDAY 328/2008 - JDAY 328/2311
C 3 72 8 IIF CS 20 NOV 2020 FCSTSUMM 2020084 - SVN72 (PRN08) FORECAST OUTAGE SUMMARY JDAY 325/1245 - JDAY 325/1549
B 5 71 26 IIF RB 16 NOV 2020 FCSTSUMM 2020081 - SVN71 (PRN26) FORECAST OUTAGE SUMMARY JDAY 321/2038 - JDAY 322/0025
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
A 3 64 30 IIF RB
D 2 63 1 IIF RB
B 2 62 25 IIF RB
D 1 61 2 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 DECOM 2020075 - SVN46 (PRN11) DECOMMISSIONING JDAY 315/2200
05 OCT 2020 FCSTCANC 2020050 - SVN46 (PRN11) FORECAST OUTAGE CANCELED
D 3 45 21 IIR RB 18 NOV 2020 FCSTSUMM 2020082 - SVN45 (PRN21) FORECAST OUTAGE SUMMARY JDAY 323/0716 - JDAY 323/1449
B 3 44 28 IIR RB
F 6 43 13 IIR RB
F 5 41 14 IIR RB
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

2020077

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2020077
SUBJ: SVN77 (PRN14) LAUNCH JDAY 310
1. NANU TYPE: LAUNCH
NANU NUMBER: 2020077
NANU DTG: 130051Z NOV 2020
SVN: 77
PRN: 14
LAUNCH JDAY: 310
LAUNCH TIME ZULU: 2324

2. GPS SATELLITE SVN77 (PRN14) WAS LAUNCHED ON JDAY 310.
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, HTTPS://GPS.AFSPC.AF.MIL/GPSOC
MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-3526. COMM 805-606-3526.
JSPOCCOMBATOPS@US.AF.MIL



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