1. GPS Status and Modernization
Munich Satellite Navigation Summit
Munich, Germany
20 Feb 2008
Lt Col Harold Martin, US Air Force
PNT Command Lead
Air Force Space Command
This briefing is for information only.  No US Government commitment to sell, loan, lease, co-develop or co-produce defense articles or provide defense services is implied or intended.

2. Overview GPS Status Recent Modernization Improvements The Future
Summary

3. GPS – Serving the World IIR-21(M) - Sep 08
Constellation– the largest ever- 30 Healthy Satellites
13 Block IIA
12 Block IIR
5 Block IIR-M
31st satellite, SVN 23, still has a good clock – AF working to see if it can be set healthy to achieve 31 healthy satellite constellation for first time ever
Most Recent Launch
IIR-18(M) – 5th modernized SV
Launched Wednesday, 20 Dec 07
SVN 57, PRN 29, slot C1
Set healthy on 2 Jan 08
Next Launches
IIR-19(M) – Mar 08
IIR-20(M) – Jun 08 – L5 demo payload
IIR-21(M) - Sep 08
IIF-1 launch in Spring 09

4. GPS – Spectrum Block IIA 1990 Block IIR 1997 Previous since Dec 2005
P(Y)
C/A L5 M
L2C
L1C L1 L2
Previous
since Dec 2005
(5 SVs)
Block IIR-M, 2005
Planned
Block IIF, 2009
L1C
Block III, 2014
(artist’s concept)
ARNS Band RNSS Band ARNS Band

5. GPS Status – Serving the World
Performance – Our best ever accuracy
Current Performance
Average URE from 30 GPS SVs: 0.51 m
Source: JPL 2/10/2008

6. GPS Status – Serving the World
Recent Modernization Improvements:
Launched 5th of 8 Block IIR-M satellites
Architecture Evolution Plan – transition to a new Command and Control System at 2 SOPS for day-to-day operations
Launch, Anomaly and Disposal Operations (LADO) - transitioned from 1 SOPS to 2 SOPS

7. Recent Modernization Improvements
5 Block IIR-M Satellites on orbit now:
Second Civilian Signal, L2C
L2C provides increased accuracy for civilian receivers: applications from precision farming to construction surveying
5th satellite means more L2C coverage around the globe
Dual frequency receivers reduce ionospheric errors
Better performing atomic clocks than IIA
IIR-M 20 will fly a demonstration payload with an L5 signal

8. Recent Modernization Improvements
Architecture Evolution Plan (AEP)
New Master Control Station operational Sep 14, 2007
Modern distributed system replaced 1970’s era mainframe
New Alternate Master Control Station at Vandenberg AFB, CA
Increased capacity to monitor satellites
Utilizes dedicated Monitor Stations and NGA Monitor Stations to allow increased monitoring of GPS signals
Increased worldwide coverage to 100 % (was 96.4%) and have 99.8% of world double covered
Utilizes dedicated GPS Ground Antennas and allows use of 8 Air Force Satellite Control Network remote sites for increased commanding capability
Increased worldwide commanding capability daily from 92.7% of the time to 94.5% while providing nearly double the backup capability

9. Recent Modernization Improvements
Launch, Anomaly and Disposal Operations (LADO)
Transitioned capability from 1 SOPS to 2 SOPS - centralizes GPS operations into a single unit
Replaces 90’s mainframe based system with increased use of modern distributed technology with electronic technical orders while decreasing the maintenance burden
Used for launch of IIRM-17 on Oct 17, 2007 and IIRM-18 on Dec 20, 2007

10. The Future of GPS Satellites Control Systems User Equipment
GPS III (Block III)
Increased accuracy
Increased signal strength
Signal integrity
Search and Rescue
Common Galileo OS/GPS (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 (L1M, L2M)
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
Man Pack
MAGR, PLGR
RCVR-3A, 3S
OH, UH
FRPA, CRPA
Upgraded
DAGR
CSEL
GAS-1
MAGR2K
GB-GRAM
Modernized
MUE
MSR
OCX Block 2 C2
L1C
OCX Block 1 (Modernized)
New Architecture
L2C, L5, M-Code
Flex Power
OCX Block 3/4)
Spot Beam
Mission Planning
Near-real Time Command and Control 10

11. Future of GPS – Block IIF Satellites
PPS Signals: L1-L2 P(Y), L1-L2 M-code
SPS Signals: L1 C/A, L2C, and L5
L5 will provide second civil unique frequency in protected band
Program Status:
SV1 in qualification tests
Delivery to Cape Dec 08
First launch 2009
Program Description
2 Rb + 1 Cs clocks
12 year design life
Launch Atlas V or Delta IV
Satellite launch weight ~ 3720 lbs

12. Future of GPS – Block III Satellites
New L1C civil signal interoperable with Galileo/QZSS
Aggressive Capability Insertion Program to mature capabilities
Directional crosslink demo by IIIA; baselined on IIIB
High Power Spot Beam demo by IIIB; baselined on IIIC
Provides 20dB (100Xs) greater M-code power
Program Status:
Implementing “Block” approach to incrementally respond to warfighter capability requirements – reduces risk
Contract in Source Selection, expect award Spring 08
Program Description:
GPS IIIA includes all GPS IIR-M/IIF capabilities, plus:
Enhanced earth coverage M-code power (10x) enables improved operations in jammed & austere environments
GPS III guarantees 4x better User Range Error than IIF
GPS signal-in-space improves from <3m to <1m
GPS III Integrity guarantee supports safety-of-life applications
Probability of Misleading Signal-in-space Information (MSI) <0.0001/hr (Threshold)

13. The Future of GPS – New C2 System
Next Generation Operational Control Segment (OCX)
Enables modernized messaging
Controls more capable GPS constellation
Monitors all GPS signals
Two development contracts awarded – 21 Nov 07
Air Force Space Command (AFSPC) is standing up a Community of Interest (COI) to implement net-centric operations using OCX
GPS COI is a forum for users to recommend the data and services that should accessible from the global information grid (GIG)

14. The Future of GPS – User Equipment
Comm/Nav/Network Fusion
Benefit in comm/nav user equipment integration
Better accuracy, reduced time uncertainty, data stripping, network interference detection/location
A variety of approaches to comm/nav integration exist today and should be studied further
Additional investment and prototyping is required
Chip Scale Atomic Clocks
Software defined receiver

15. GPS – Serving the World as the Gold Standard in Space Based Navigation
Summary
Largest constellation in history with best accuracy ever
Modernized Command and Control System allows more signal monitoring and quicker satellite commanding than ever before
And we’re continuing to modernize and improve GPS even more!
GPS – Serving the World as the Gold Standard in Space Based Navigation