# Presentation: 828610

## CGSIC ISC Asia-Pacific Meeting
Melbourne, Australia
10-11 February 2003

- Melbourne, Australia
- 10-11 February 2003

- GPS Information Sources

## Overview

- GPS System Information, Notification, and Reporting
- Coast Guard Navigation Center
- Federal Aviation Administration
- Civil GPS Service Interface Committee

**Notes:**
This presentation will discuss the primary information sources for GPS.
This includes system information, operational information, notification of problems with the system, and how users report a disturbance to their use.

## Background

** ****The Core **

**Notes:**
The primary sources of information create of a triad of organizations, each with their own responsibility.
The FAA National Operational Command Center is responsible for distributing NOTAMS and coordinating spectrum issues dealing with GPS.
The GPS Support Center supports the Defense user and handles information concerning operation of the satellites.
The Coast Guard Navigation Information Service located at NAVCEN is the contact point between non-military users and the system operators.

## NIS Information

- GPS System design information
- SPS Performance Standard
- Interface Control Document (ICD-200)
- Operational Information
- NANUs / GPS Status
- Static
- Listserver distribution
- NIS Mirror Site (http://www.nis-mirror.com/)
- Modernization
- Latest updates, L5 & L2 signal specification

## NIS Information

- Radionavigation Policy
- Federal Radionavigation Plan
- Presidential Decision Directives
- US Nationwide Differential GPS System
- Specifications
- High Accuracy DGPS
- U.S. Loran-C

##  GPS General Information

** ****GPS Status Reports**
** ****GPS Service Interruptions**
** ****GPS Almanac Information**
** ****Precise Ephemeris Info**
** ****Subscribe to Listserver Messages**
** ****Selective Availability**
** ****GPS Modernization**
** ****Report a GPS Problem**
** ****Frequently Asked Questions**
** ****Augmentation Systems**
** ****Reference Information**

## GPS Page Choices

** ****GPS Status Reports**
** ****GPS Service Interruptions**
** ****GPS Almanac Information**
** ****Precise Ephemeris Info**
** ****Subscribe to Listserver Messages**
** ****Selective Availability**
** ****GPS Modernization**
** ****Report a GPS Problem**
** ****Frequently Asked Questions**
** ****Augmentation Systems**
** ****Reference Information**

**GPS Page Choices**

## General Information

**Latest PDOP Chart (***displays overall Dilution of Precision Values***)**
**Status**
** ****Latest GPS Status Message**
**GPS Status Message Archives**
**NANUs **
**Active NANUs**
**NANU Abbreviations and Descriptions**
**NANU Archives (1990-2001) **
**Search the current year by NANU Number**
**Search a previous year by NANU Number**

**General Information**

## NANU Abbreviations

**FCSTDV             FCSTMX**
**FCSTEXTD        FCSTSUMM**
**FCSTCANC       FCSTRESCD**
**Unscheduled Outages **
**UNUSUFN         UNUSABLE**
**UNUNOREF**
**Other **
**USABINIT         LEAPSEC**
**GENERAL**

**NANU Abbreviations**

**Notes:**
Forecast Outages 
FCSTDV, or Forecast Delta-V - gives scheduled outage times for Delta-V maneuvers. The satellite is moved during this maintenance and the user may be required to download a new almanac. 
FCSTMX, or Forecast Maintenance - gives scheduled outage times for Ion Pump Operations or software tests. 
FCSTEXTD, or Forecast Extension - extends the scheduled outage time "Until Further Notice"; references the original NANU. 
FCSTSUMM, or Forecast Summary - gives the exact outage times for the scheduled outage, including the FCSTEXTD; sent after the maintenance is complete and the satellite is set healthy to users; references the original NANU. 
FCSTCANC, or Forecast Cancellation -.cancels a scheduled outage; new maintenance time not yet determined; references the original NANU. 
FCSTRESCD, or Forecast Rescheduled - reschedules a scheduled outage; references the original NANU 
Unscheduled Outages 
UNUSUFN, or Unusable Until Further Notice - notifies users that a satellite will be Unusable to all users until further notice. 
UNUSABLE, or UNUSABLE with a reference NANU - closes out an UNUSUFN NANU and gives the exact outage times for the outage; references the UNUSUFN NANU. 
UNUNOREF, or UNUSABLE with no reference NANU - gives times for outages that were resolved before a UNUSUFN NANU could be sent. 
Other 
USABINIT, or Initially Usable, notifies users that a satellite is set healthy for the first time. 
LEAPSEC, or Leap Second, is used to notify users of an impending Leap Second.
GENERAL, informs the user of general GPS information. 

## Outage Reporting

- Disruption to GPS service should be reported to:
- USCG NAVCEN
- http://www.navcen.uscg.gov
- On-line form
- An attempt will be made to identify the problem
- Report to user

## GPS Page Choices

** ****GPS Status Reports**
** ****GPS Service Interruptions**
** ****GPS Almanac Information**
** ****Precise Ephemeris Info**
** ****Subscribe to Listserver Messages**
** ****Selective Availability**
** ****GPS Modernization**
** ****Report a GPS Problem**
** ****Frequently Asked Questions**
** ****Augmentation Systems**
** ****Reference Information**

**GPS Page Choices**

## Outage Reporting

- 1. What indicated there was a problem?
- 2. How many Satellites were being tracked?
- 3. What SVs were being track?
- 4. Elevation of the receiver antenna?
- 5. Duration and number (approximate) of known occurrences?
- 6. Did any operator (you) action help?
- 7. Location of problem? *
- 8. Closest geographic region*
- 9. Type of equipment? (receiver model, antenna type, etc...)
- 10. Type of installation? (boat, car, handheld, plane)
- 11. Other probable causes? *
- 12. What was the receiver being used for at time of occurrence?
- 13. Contact Information

## Aviation Information

- GPS Implementation/ WAAS/ LAAS
-    http://gps.faa.gov/
- GPS NOTAMS
-    FAA NOCC
-    International NOTAMs

## Useful Links

- USCG Navigation Center
- http://www.navcen.uscg.gov
- Interagency GPS Executive Board Executive Secretariat
- http://www.igeb.gov
- FAA- WAAS, LAAS
- http://www.gps.faa.gov

**Navigation Information Service**
- http://www.navcen.uscg.gov
- http://www.nis-mirror.com (mirror site)
- E-mail: nisws@navcen.uscg.mil
- Phone:  +1 703 313 5900
- Fax:      +1 703 313 5920
**Civil GPS Service Interface Committee**
- E-mail: rcasswell@navcen.uscg.mil