# Presentation: 589639

## GLOBAL POSITIONING SYSTEM

*Space Enterprise Council Capitol Hill Day*
*14 March 2008*

- Major Charlie Daniels, U.S. Air Force
- National Coordination Office

## What You Know...

- 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, public security and science
- Over the past decade, GPS has grown into a global utility providing space-based positioning, navigation and timing (PNT)
- Consistent, predictable, dependable performance
- Augmentations improve performance

## Briefing Overview

- GPS System
- GPS Applications
- GPS Modernization

## GPS Introduction

- Owned and operated by the U.S. Government
- Paid for by U.S. taxpayers
- Managed at a national level as multi-use asset
- Acquired and operated by the U.S. Air Force on behalf of the U.S. Government per Title 10, Section 2281.
- GPS service is a one-way broadcast, like FM radio
- Unlimited number of users
- Access to civilian GPS signals is 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

## GPS Segments

**Monitor****Stations**

**Ground**
**Antennas**

**AFSCN**

**Master Control Station**

**Space Segment**

**User Segment**

**Control Segment**

**Satellite Constellation**

## GPS Ground Control Segment

- Satellite position data
- Monitor L-Band signals
- Adjust GPS signal as needed

- Command & Control satellites
- Perform maneuvers
- Monitor satellite health

- The control segment keeps the GPS constellation
- operating and performing within specification

## GPS User Segment

- 18

- Unlimited
- Broadcast system
- More users can join system
- U.S. & International
- Multi purpose
- Civil
- Military
- Commercial

## GPS Space Segment

- 14 Block IIA satellites
- 12 Block IIR satellites
- 5 Block IIR-M satellites
- Transmitting new second civil signal (L2C)
- Transmitting new military signal (M code)
- Next launch:  March 15, 2008

- 31 GPS Satellites** **Set Healthy (as of 10 Mar 08)
- (Baseline Constellation: 24)

- 30 Years of Success
- First Operational Launch 22 Feb 1978

**Notes:**
Set Healthy (as of 14 Feb 08)

## Continuous Performance Improvement

***Accuracy***

- Global GPS civil service performance commitment
- continuously met since 1993

## GPS Constellation StatusSatellite Age as of March 2008

**2**

**4**

**6**

**8**

**10**

**Years**

**Satellite**

**39**

**35**

**34**

**36**

**33**

**40**

**30**

**38**

**43**

**46**

**51**

**44**

**12**

**41**

**54**

**56**

**14**

**45**

**16**

**47**

**59**

**60**

**61**

**53**

**25**

**26**

**27**

**32**

**37**

**52**

**58**

- GPS Constellation StatusSatellite Age as of March 2008

**24**

**23**

**55**

**57**

- BLOCK IIA

- BLOCK IIR

- BLOCK IIR-M

## GPS Applications

- 18

- Civil/Commercial briefed earlier
- Military Applications
- Force location
- Navigation
- Force employment
- Weapon guidance
- All weather ops
- Satellite positioning
- Comm network timing** **

## GPS – Force Multiplier

- WWII Schweinfurt-Regensburg  Raids:
- Dropped 24 million pounds of bombs to strike 5 ball bearing plants
- 376 B-17s

**= 5 Targets Hit**

## All Segment – GPS Modernization

**Increased accuracy **
**Increased signal strength**
**Signal integrity**
**Search and Rescue**
**Common Galileo****signal (L1C)**

_**Legacy**__** (Block IIA/IIR)**_
**Basic GPS**
**C/A civil signal (L1C/A)**
**Std Pos. Service**
**Precise Pos. Service**
**L1 & L2 P(Y) nav**

_**Modernized**__** (Block IIR-M**_**)**
**2nd civil signal (L2C)**
**M-Code signals**

**Satellites**

_**Modernized**__** (Block IIF**_**)  **
** ****3rd civil signal (L5)**

_**Upgraded**__** (AEP)**_
**IIR-M IIF TT&C**
**WAGE, AII, LADO**
**New MCS/AMCS**

_**Legacy**_
**TT&C**
**L1 & L2 monitoring**

**Control Systems**

**User Equipment**

_**Upgrading**_
**Military User Equipment**

_**OCX (**__**Modernized**__**)**_
**New Architecture**
**L1C, L2C, L5, M-Code**
**Flex Power**

## 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)
- Begins with GPS Block IIF
- First launch:  ~2008 (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
- Remain the pre-eminent space-based military PNT system
- Higher standalone accuracy
- More robust against interference
- Provides separate more secure Military signal
- Capability for second (L2C) and third (L5) civil signals
- Delivers L1C for interoperability with other GNSS
- Improved indoor, mobile, and urban use

## Summary

- GPS System
- 3 Segments; Ground Control, Space and User
- Sustaining aging constellation while providing best accuracy
- GPS Applications
- Unlimited civil/commercial global user capacity
- Military users
- GPS Modernization
- Key to meeting emerging civil/commercial demands
- Key to remaining the preeminent military space-based PNT service

*GPS* – The World’s Gold Standard in
- Space-Based PNT Services

## Contact Info

- Major Charles Daniels, U.S. Air Force
- National Coordination Office for Space-Based PNT
- 1401 Constitution Ave, NW, Room 6822
- Washington, DC  20230
- 			Tele:	202-482-6726
-                       Email:	charles.daniels@pnt.gov
- 		   Web sites:	http://pnt.gov
- 				http://gps.gov