# Presentation: 000167

## of the Transportation Infrastructure
Relying on GPS
DOT/OST Outreach Meeting
October 5th, 2001
Dr. James V. Carroll

- Relying on GPS
**DOT/OST Outreach Meeting**
**October 5****th****, 2001**
**Dr. James V. Carroll**
**  **

**Vulnerability Assessment**

**U.S. DOT/Volpe Center**

## Briefing Outline

***Briefing Outline***

**Overview**
**Risk, Vulnerabilities & Disruption Mechanisms**
**Mitigating Vulnerabilities**
**Findings & Recommendations**
**Summary**
**Conclusion**

## Assessment Overview

**Report Assessed Possible Impact to Civilian Users**
**GPS-Based Systems in the United States**
**Projected Over 10 Years**
**Covered All Transportation Modes**
**Also Telecommunications, Banking, Commerce**
**This Briefing ****• •**
**Examines Vulnerabilities**
**Recommends Mitigations**
_**BOTTOM LINE:**_
**GPS Users are Vulnerable to Signal Loss or Degradation**
**Awareness & Planning Can Mitigate the Worst Vulnerabilities**
_**The Vulnerability Will Not be Fully Eliminated**_

**Notes:**
THIS REPORT CAME FROM A LOW-BUDGET STUDY !!!

## Risk Considerations

**Consequences** of GPS
- Loss:

**Probability** of
- Loss/Degradation of
- GPS Signal

**Threats** –

***RISK***

-   Human Life & Health
-   Environment
-   Economy

- GPS System
**Vulnerabilities**

-   Unintentional
-   Intentional

**Notes:**
RISK TO USERS !!!

THERE WAS NO THREAT ASSESSMENT;  THIS NEVERTHELESS IS VERY IMPORTANT IN DEVELOPING THE OVERALL PICTURE.

## Civil Transportation Uses

**Aviation**
**Navigation, ATC, Surface Guidance**
**Maritime**
**Harbor, Inland Waterway**
**Traffic Service**
**Surface**
**Railroads**
**Intelligent Transportation Systems**
**Transportation Infrastructure**
**Timing;  Communication Networks; Power Grids**

**Notes:**
Based on an analysis of consequences if GPS was lost, these critical transportation applications were selected for further study.  For example, airline accidents, an oil tanker spill, train collision, can cause severe property damage, safety-of-life, economic, or environmental consequences.

There also are major civil uses  of GPS - timing, network synchronization - in banking, commerce, and the Internet.

## Timing & Synchronization Uses

**Global Fiber Networks **
**SDH, SONET**
**Global Wireless Networks **
**PCS, GSM, TDMA, CDMA**
**Transportation & Public Safety**
**National Airspace System (VDL, NEXCOM, UAT)**
**Land, Rail, Marine**
**GPS Features:**
**Low Cost, High Reliability & Performance**
**Big Asset for Synchronization of Digital Networks**
**GPS ( and Cesium, Loran-C) - Stratum 1**

**Notes:**
The planned NEXCOM (using VDL Mode 3), VDL Mode 4, and UAT rely on GPS in varying degrees to provide precise timing for synchronizing message transmissions.
SDH = Synchronous Digital Hierarchy
SONET = Synchronous Optical Network
PCS = ?
GSM = ?
TDMA = Time Division Multiple Access
CDMA = Code Division Multiple Access
VDL = “VHF Data Link”
UAT = “Universal Access Transponder”

## Factors Impacting GPS Vulnerability

**Very Low Signal Power**
**Single Civil Frequency**
**Known Signal Structure**
**Spectrum Competition**
**Worldwide Military Applications Drive a GPS Disruption Industry**
**Jamming Techniques are Well Known**
**Devices Available, or Can be Built Easily**

## GPS System Vulnerabilities

**Unintentional Interference**
**Radio Frequency Interference (RFI)**
**GPS Testing**
**Ionospheric;  Solar Max**
**Spectrum Congestion**
**Intentional Interference**
**Jamming**
**Spoofing – Counterfeit Signals**
**System Damage**
**Human Factors**
**User Equipment & GPS SV Design Errors**
**Over-Reliance**
**Lack of Knowledge/Training**

**Notes:**
SPOOFING – SPAWAR Meeting Reinforces its Importance as a Potential Threat, Along with RFI and Growing Dependence on GPS.

Meaconing is the Delay and Re-broadcast of the GPS signal.

UNINTENTIONAL INTERFERENCE GENERALLY IS SHORT_TERM

INTENTIONAL INTERFERENCE USUALLY IS SHORT TERM ALSO, BUT SYSTEM DAMAGE CAN BE LONG TERM.

GPS Constellation Damage – Space Attack

Ground Control Damage – Natural disaster (quake?);  Terrorist or Missile.

HUMAN FACTORS – Royal Majesty incident epitomizes this issue.

MORE DETAIL – NIST Charts #17 & 18.

## Disruption Mechanisms - Jamming

**Jamming Power Required at GPS Antenna**
**On order of a Picowatt (10****-12**** watt)**
**Many Jammer Models Exist**
**Watt to MWatt Output – Worldwide Militaries**
**Lower Power (<100 watts);  “Hams” Can Make**
**Jamming Signal Types**
**Narrowband**
**Broadband**
**Spread Spectrum - PRN Modulation**

**Russian Jammer**

**Notes:**
“WATT TO MWATT OUTPUT – WORLDWIDE MILITARIES”  LAST 2 WORDS MAY MEAN THAT
MILITARY GROUPS CAN FIELD JAMMERS IN THIS RANGE.

“PRN”  =  pseudo-random noise.

## Disruption Mechanisms -               Spoofing/Meaconing

**Spoof – Counterfeit GPS Signal**
**C/A Code Short and Well Known**
**Widely Available Signal Generators**
**Meaconing – Delay & Rebroadcast**
**Applicability of EW Components**
**Possible Effects**
**Long Range Jamming**
**Injection of Misleading PVT Information**
**No “Off-the-Shelf” Mitigation**

**Successful Spoof**

**Notes:**
DRFM = Dynamic RF Memory.    ADC = Analog/Digital Converters.
Given the bandwidth, these components can execute the capture in the required time.

## Consequences of GPS Loss/Degradation

**Depending on ...**
**Transportation Mode Involved**
**Duration of GPS Loss/Degradation**
**Impact Can Be**
_**Minimal**_**   ****     -  Quick Recovery**
_**Operational**_** **** -  Reduced Effectiveness & Efficiency**
_**Safety**_** ****           -  Potential Loss of Life, Environmental, **
**                              ****Economic Damage**
**Timing & Synchronization**
**GPS Outage Can Disrupt Communications/Networks **

**Notes:**
#2  Reduced Effectiveness = Safe Operation

       Safety impact uses = “Critical Applications”

#3  Serious Consequences if Loss Lasts Days & if No Backup Accurate Clock.

Timing Linked to Transportation, Commerce, Banking, Web

## Impact of GPS Loss on Timing Applications

**Long-Term Outage (~ 2 or More Weeks) **
**Possible Severe Damage**
**Shorter-Term Outages **
**With Planning - Manageable**
**Many Timing Services are Involved:**
**E-911**
**GSM Wireless**
**CDMA Wireless**
**Tele-Medicine**
**Digital Video, Teleconferencing**

**Notes:**
LONG-TERM OUTAGES ARE VERY UNLIKELY.

## Mitigating GPS System Vulnerabilities 

**For Unintentional Disruptions -**
**GPS Spectrum Protection Efforts**
**GPS Modernization**
**For Intentional Disruptions -**
**Military Anti-Jam Technology **
**Characterize Civil Spoof Effects\Observables**
**Vulnerability Cannot Be Fully Eliminated**

**Notes:**
MITIGATION of RFI will involve location of source(s) and termination of 
Emission of harmful signals.

VHF, TV,  MSS, UWB, etc. (Bluetooth?)

“GPS MODERNIZATION:”	NEW CIVIL SIGNALS, B’CAST POWER
					GPS III

 - Heighten Awareness Among NON-AVIATION Modal Users

INTENTIONAL DISRUPTION MITIGATION	USER END HARDWARE (antennas, location, appliqués, etc.)
	AVIATION -	antenna arrays
		polarization discrimination
		spatial-temporal filtering
	MARINE, LAND -   address specific jam/spoofing threat

SPOOFING IS AN ONGOING CIVIL THREAT

## Mitigation of User Risk

**Implement Appropriate Mitigation Strategies**
- For Each Individual Mode, Choose or Maintain Appropriate Backup System or Procedure
- Be Cognizant of Timing Applications
- Reflect Interference Impact in Application Designs
- Implement Systems to Monitor/Report/Locate Interference
- Assess Applicability of Military Anti-Jam Technology
**Encourage User Training in Use of Backups**
**Determine Tolerable Levels of Risk and Cost for the Critical Infrastructure Applications**
- Determine Costs of Lowering Risks to an Acceptable Level

**Notes:**
#1  Convince service providers & users of need to mitigate the vulnerabilities.

#2  Routinely Validate GPS With Other Information Sources.

## Findings (1 of 3)

**Transportation Community is Aware of Risks in Using Sole Means GPS in Critical Applications**
**GPS is Vulnerable to Radiofrequency Interference**
**GPS Augmentations (e.g., WAAS, NDGPS) Improve**
**Accuracy**
**Availability**
**Reliability**
**Integrity**
**    ****BUT:  Use of GPS Can Still be Disrupted**

## Findings (2 of 3)

**GPS Will Become an Increasingly Tempting Target as its Civil Uses Proliferate**
**Increasing Civil Dependence**
**GPS is Susceptible to Unintentional Disruptions**
**Ionospheric, Solar**
**Blockage**
**Narrowband & Wideband RFI**
**Use of GPS-based Timing Synchronization Must be Assessed, Application by Application**
**Transportation, Communications, Commerce**

## Findings (3 of 3)

**Military Experience:  Hostile Interests Will Attempt to Disrupt/Destroy GPS if They See an Advantage in Doing So**
**Risk Can be Reduced, But Not Eliminated**
**GPS Cannot be Sole Source in Critical Applications**
**Safety of Civilians is “Number 1”**
**Backup Systems or Procedures are Necessary for All Critical Applications Involving GPS**

## Candidate Independent Backup Systems

**Ground-Based Aviation Systems - VOR/DME, ILS**
**Inertial Systems**
**Loran-C**
**Other Satellite Navigation Systems**
**“****Procedures”**
**Missed Approach (Radar, Ground Support)**
**Maritime:  Radar, Radio, Sextant, Lighthouse, etc.**
**• • • •**

## Recommendations (1 of 4)

**Public Policy Must Ensure Safety if GPS Use is Lost**
**Acceptable Level of Risk Must be Determined for Critical Applications**
**Costs to Lower Present Risk to this Level Must be Determined**
**Continue GPS Modernization**
**More Civil Signals & Improved Code**
**Higher Broadcast Power**
**Continue Spectrum Protection Activities**
**Enhance Receiver Performance & Certification Standards in All Modes Where Feasible**

**Notes:**
LAND TRAVEL - HAZMAT, EMERGENCY RESCUE OPS

## Recommendations (2 of 4)

**All Critical Applications Need Quick Alert of GPS Disruption **
**Reporting**
**User Training**
**Civil Community Should Track Military Anti-Jam Developments for Possible Use**
**Anti-Spoofing Technology**
**Identify, Use Spoof Indicators**

## Recommendations (3 of 4)

**Whenever Possible, Maximize Military-Civil Exchange of System Status, Incipient Threats**
**Create Awareness of Need for Backups in Critical Applications**
**All GPS Receivers Used in Critical Applications Need to Provide Integrity Warnings**
**Consider Autonomous Integrity Monitoring**
**Augment, Enhance, and Implement Appropriate Backup Systems or Procedures**
**Assess Impact of GPS-Based Timing Loss**

## Recommendations (4 of 4)

**Continue Re-Capitalization and Enhancement of Loran-C**
**Modes Should Assess Potential Role of “New” Loran**
**Firm Decision Needed Soon - Industry Needs Direction**
**DOT Take an Active Role in Developing Roadmap for the Future Navigation Infrastructure**
**Federal Radionavigation Plan**
**Modal Agencies to Assess Risk Impacts**

## Report Summary

**GPS Vulnerability Can be Reduced But Not Fully Eliminated **
**Augmentations are Important for Integrity, But Can Not Eliminate Disruptions**
**GPS Disruptions also Impact Timing**
**Increasing Use Makes GPS a Tempting Target**
**Independent Backup Systems or Procedures Essential in Critical Civil Transportation Uses**

**Notes:**
# 4   -   INVITE A LOW-COST, ASYMMETRIC ATTACK

## Main Message to the Civil GPS Community:

***GPS provides many benefits to civilian users.  It is vulnerable, however, to interference and other disruptions that can have harmful consequences.  GPS users must ensure that adequate independent backup systems or procedures can be used when needed.***

**Notes:**
•  Right now, unintentional disruptions occur fairly often (e.g., Florida ~ 2/8/01).

•   Besides backup systems, user training for awareness of when to switch to  backup, etc., are important

## Conclusion

***and executes a plan based on these ***
***recommendations, there is every reason to***
***be optimistic that GPS will fulfill its potential***
***as a key element of the national transportation***
***infrastructure.”***

***Conclusion***

**Report available from the U.S. Coast Guard Navigation Center website**
-           http://www.navcen.uscg.gov

## Contacts

**Jim Carroll**
**U.S. Dept. of Transportation**
**Volpe National Transportation Systems Center**
**55 Broadway, Kendall Sq., Cambridge, MA 02142**
**(617) 494-2908;  fax: (617) 494-2628**
_**[carrollj@volpe.dot.gov](mailto:carrollj@volpe.dot.gov)**_
**Chuck Rodgers**
**OPTIMUS Corp.**
**8601 Georgia Avenue, Suite 700**
**Silver Spring, MD  20910**
**(301) 585-7075;  fax:  (301) 585-7976**
_**[Chuck.Rodgers@optimuscorp.com](mailto:Chuck.Rodgers@optimuscorp.com)**_