# Presentation: 615456

## GLOBAL POSITIONING SYSTEMStatus and U.S. Policy Update

- Swedish Radio Navigation Seminar
- Stockholm, Sweden
- October 21, 2008

**Charles Daniels**
**Senior Advisor, National Coordination Office **
**United States of America**

## Overview

- Introduction
- Global Positioning System
- Modernization Plans
- U.S. Policy

## Space-Based PNT Applications Impact A Wide Range of Economic Activities

- Space-Based PNT Applications Impact A Wide Range of Economic Activities

- 4

**Oil**
**Exploration**

**Fishing &**
** ****Boating**

**Aviation**

**Surveying &**
**   ****Mapping**

**Trucking & Shipping**

**Satellite Operations**

**Precision Agriculture**

**Power Grid**
**Management**

**Personal **
**Navigation**

**Communications**
**Network Synchronization**

## Introduction

- Like the Internet, GPS is a critical component of the global information infrastructure
- Scalable applications enabling broad new capabilities
- Facilitating innovations in efficiency, safety, environmental protection, public security and science
- During the past decade, GPS has grown into a global utility providing space-based positioning, navigation and timing (PNT)
- Consistent, predictable, dependable policy and performance
- Augmentations improve performance

## GPS Introduction

- Owned and operated by the U.S. Government
- Funded by U.S. taxpayers
- Managed at a national level as a multi-use asset
- Acquired and operated by the U.S. Air Force on behalf of the U.S. Government per US Law Title 10, Section 2281
- 30 years of operation – 1st launch February 1978
- GPS service is a one-way broadcast, like FM radio
- Unlimited number of users
- Civil GPS signals are free of direct user fees
- Public domain documentation
- Available on an equal basis to users and industry
- Anyone in the world can develop GPS user equipment

## Overview

- Introduction
- Global Positioning System
- Modernization Plans
- U.S. Policy

## The Global Positioning System

- Baseline 24 satellite constellation in medium earth orbit
- Global coverage, 24 hours a day, all weather conditions
- Satellites broadcast precise time and orbit information on L-band radio frequencies
- Two types of signals:
- Standard (free of direct user fees)
- Precise (U.S. and Allied military)
- Three segments:
- Space
- Ground control
- User equipment

## GPS Constellation Status

- 33 Satellites on Orbit
- 13 Block IIA
- 12 Block IIR
-   6 Block IIR-M
-   2 Block IIA Spares
- Next launchs:
- March 2009 – IIR-M 20
- August 2009 – IIR-M 21 (Last IIR)
- October 2009 – 1st Launch of IIF

- 31 Healthy SatellitesAs of October 17, 2008 (Baseline Constellation: 24)

## GPS Operational Control Segment (OCS)

** ****Ground**
**Antenna**

**Master Control Station (Schriever AFB)**

- Ascension

- Diego Garcia

- Cape Canaveral

- Hawaii

- Kwajalein

- Schriever AFB Colorado

- S Korea

- Australia

- Bahrain

- S Africa

- England

- Argentina

- Ecuador

- Tahiti

- USNO

- Alaska

**Monitor**
**Station**

- New
- Zealand

- Vandenberg AFB     California

- NGA Monitor Station

- OCS Monitor Station

- Ground Antenna

- Future Monitor Station

- Master Control Station

- Backup Master Control Station

## GPS Signal in Space Performance

- Global GPS civil service performance commitment
- continuously met since 1993 (15 yrs)

## GPS SPS PS UPDATE

- COMPARISON OF GPS SPS PERFORMANCE PARAMETERS

| GPS Performance  Standard Metric |  | SPS Signal      Specification 
August 1998
(user performance) | SPS Performance Standard          October 2001
(signal in space) | SPS Performance Standard
September  2008 *
(signal in space) | 
CY 2007
Performance** |
| --- | --- | --- | --- | --- | --- |
| 1 |   Global Accuracy
  All-in-View Horizontal 95%
  All-in-View Vertical 95% | 
≤ 100 meters
≤ 156 meters | 
≤ 13 meters
≤ 22 meters | 
≤ 9 meters
≤ 15 meters | 
2.32 meters
4.45 meters |
| 2 |   Worst Site Accuracy
  All-in-View Horizontal 95%
  All-in-View Vertical 95% | 
≤ 100 meters
≤ 156 meters | 
≤ 36 meters
≤ 77 meters | 
≤ 17 meters
≤ 37 meters | 
3.63 meters
4.95 meters |
| 3 |   User Range Error (URE) | NONE | ≤ 6 meters RMS
(Constellation RMS URE) | ≤ 7.8 meters 95%, 
(Worst Satellite URE) 
equivalent to 4 m RMS | 2.29 meters RMS
(Worst Satellite URE) |
| 4 |   Geometry (PDOP ≤ 6) |      ≥ 95.87% global
     ≥ 83.92% worst site  |       ≥ 98% global
      ≥ 88% worst site |          ≥ 98% global
         ≥ 88% worst site |  99.988% global
 98.958% worst site |
| 5 |   Constellation Availability | NONE | ≥ 95% Probability of 24 Healthy Satellites 
≥ 98% Probability of 21 Healthy Satellites 

(assumes 24 primary slots) | ≥ 95% Probability of 24 Healthy Satellites 
≥ 98% Probability of 21   Healthy Satellites
≥ 99.999% Probability of 20 Healthy Satellites (assumes 24 primary slots) | 100% Probability of 22 Healthy Satellites in 24 primary slots
(FY2008) *** |

- *   Green color indicates improvement in U.S. Government commitment to GPS civil service
- ** As measured and reported at web site (_[http://](http://www.nstb.tc.faa.gov/)__[www.nstb.tc.faa.gov](http://www.nstb.tc.faa.gov/)__[/](http://www.nstb.tc.faa.gov/)_)
- *** As measured and reported at web site (_http://www.gps.afspc.af.mil/gpsoc/_)

## International Augmentations

## Overview

- Introduction
- Global Positioning System
- Modernization Plans
- U.S. Policy

## Recent GPS Improvements

- Launched 3 modernized satellites in past year
- Largest GPS constellation size ever
- Second Civil Signal (L2C) now on orbit
- Transitioned to modernized master control station
- Improved operational flexibility and responsiveness
- Added backup control station
- Expanded GPS ground network to triple amount of monitor data sent to control station
- 10-15% improvement in accuracy of GPS data broadcast

## GPS Modernization Program

- Block IIA/IIR

- Block III

- Block IIR-M, IIF

-  Backward compatibility
-  4th civil signal (L1C)
-  Increased accuracy
-  Increased anti-jam power
-  Assured availability
-  Navigation surety
-  Controlled integrity
-  Increased security
-  System survivability

- _IIR-M_: IIA/IIR capabilities plus
-  2nd civil signal (L2C)
- M-Code (L1M & L2M)
- _IIF_: IIR-M capability plus
-  3rd civil signal (L5)
-  Anti-jam flex power

- _Basic GPS_
-  Standard Service
- Single frequency (L1)
- Coarse acquisition (C/A) code navigation
-  Precise Service
- Y-Code (L1Y & L2Y)
- Y-Code navigation

**Notes:**
Now in orbit	II-3, IIA-17, IIR-9
To go		IIR-3, IIRM-7/8, IIF-16, III-30

Explain relationship with other AF, DoD wide, or FMS programs.  Also Civil Agencies.
The Air Force is committed to being good stewards of GPS as a global civil utility and to maintaining the military capability GPS provides

Other (provide any other relevant information AF may get “pinged on”...currently available format is acceptable).
GPS II anti-jam capabilities are sufficient for warfighter needs through FY12; funding and schedule stability is focused on the deployment of already approved military and civil capabilities in the GPS II space and ground control segments
Additional info to provide:

## Modernized GPS – New Signals

- Second civil signal (“L2C”)
- Designed to meet commercial needs
- Higher accuracy through ionospheric correction
- Began with GPS Block IIR-M in Sep 2005;  24 satellites:  ~2014
- Third civil signal (“L5”)
- Designed to meet demanding requirements for transportation safety (safety-of-life)
- Uses highly protected Aeronautical Radio Navigation Service (ARNS) band
- First launch:  ~2009 (GPS IIR-M Demo); ~2009 (GPS IIF); 24 satellites:  ~2016
- Fourth civil signal (“L1C”)
- Designed with international partners to enable GNSS interoperability
- Begins with GPS Block III; First launch:  ~2014;  24 satellites:  ~2021

## Benefits of GPS Modernization

- System-wide improvements in accuracy, availability, integrity, and reliability to:
- Meet increasing civil, commercial and military demands
- Higher standalone accuracy
- More robust against interference
- Provides separate more secure Military signal
- Full capability of second (L2C) and third (L5) civil signals
- Full Capability of L1C for interoperability with other GNSS
- Improved indoor, mobile, and urban use

## GPS III Update

- Contract for GPS III-A satellites awarded in May 08
- Selective Availability feature to be eliminated
- First Launch 2013
- Contracts for Next-Generation Operational Control Segment (OCX) awarded in January 08
- Will implement full functionality of L2C and L5
- Future increments of GPS III will incorporate additional capabilities
- As technology matures and new requirements are validated

## Overview

- Introduction
- Global Positioning System
- Modernization Plans
- U.S. Policy

## U.S. Policy History

- 1978: First GPS satellite launched
- 1983: U.S. President offers free civilian access to GPS
- 1996: U.S. policy establishes joint civil/military GPS management

- 1997: U.S. Congress passes law that civil GPS shall be provided free of direct user fees
- 2000: U.S. President set Selective Availability to “Zero”
- 2004: U.S. President issues U.S. Policy on Space-Based PNT
- 2007: U.S. President announces Selective Availability will no longer be built into modernized GPS III satellites

## U.S. Policy Promotes Global Use of GPS Technology

- U.S. Policy Promotes Global Use of GPS Technology

- No direct user fees for civil GPS services
- Provided on a continuous, worldwide basis
- Open, public signal structures for all civil services
- Promotes equal access for user equipment manufacturing, applications development, and value-added services
- Encourages open, market-driven competition
- Global compatibility and interoperability with GPS
- Service improvements for civil, commercial, and scientific users worldwide
- Protection of radionavigation spectrum from disruption and interference

## National Space-Based PNT Organization

- WHITE HOUSE

- Ad HocWorking Groups

## Keys to the Global Success of GPS

- Program Stability and Performance
- Civil service performance commitment met continuously since December 1993
- Continuity of constellation and signals ensured through Air Force operation and acquisition
- Continuous improvements in accuracy, availability, etc.
- Funding through U.S. taxpayers
- Policy Stability and Transparency
- Open access to civil GPS signals, free of direct user fees
- Open, free, and stable technical documentation
- Market-based competition worldwide
- Liberal export controls on GPS user equipment
- National-level policy coordination including civil and military leaders
- Commercial Entrepreneurship and Investment

## U.S. Cooperation Efforts

- Cooperative relationships established with Europe, Japan, Russia, India, Australia
- U.S. goals:
- Compatibility and interoperability
- National security
- Level playing field in global markets
- Multilateral cooperation
- International Committee on GNSS
- ICAO, IMO, NATO

## Goal of Civil Interoperability

- Ideal interoperability provides users a PNT solution using signals from different GNSS systems
- No additional receiver cost or complexity
- No degradation in performance

- Interoperable = Better Together Than Separate

## Summary

- GPS performance is better than designed
- New Civil GPS signal (L2C) now available on 6 satellites
- Modernization will bring additional improvements in Accurary and Availability.
-  Implementing U.S. National Space-Based PNT Policy
- National Executive Committee directly engaged
- U.S. policy encourages and promotes worldwide use of civil GPS and augmentations

- International cooperation through GNSS compatibility and interoperability is a U.S. priority

## For Additional Information...

- Briefing available at:
- http://PNT.gov

## Contact Info

- Charles Daniels
- National Coordination Office for Space-Based PNT
- Washington, DC  20230
- 			Tele:	202-482-6726
-                       Email:	charles.daniels@pnt.gov
- 		   Web sites:	http://pnt.gov
- 				http://gps.gov