# Presentation: 733184

## Vulnerability Assessment of the Transportation Infrastructure Relying on the Global Positioning System 

**               ****Dr. James Carroll        U.S. DOT/Volpe Center **
**                 ****Chuck Rodgers         OPTIMUS Corp.**
**                   **
**September 10, 2001**

**Notes:**
PROJECT INVOLVED < $500K EFFORT

PROJECT SCOPE IS
				ALL CIVIL TRANSPORTATION MODES
				POLICY FOCUS MORE THAN TECHNICAL

## 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 !!!

## 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 Well Known
- Devices Available, or Easily be Built

## GPS System Vulnerabilities

- Unintentional Interference
- Radio Frequency Interference (RFI)
- GPS Testing
- Ionospheric;  Solar Max
- Spectrum Congestion
- Generally Short Term Duration
- Intentional Interference
- Jamming – Denial of Use
- Spoofing (& its Variations)  – Counterfeit Signals
- System Damage
- GPS Constellation, Ground Control Segment
- Could Be Long Term Duration
- Human Factors
- Errors, Over-Reliance, Lack of Knowledge/Training

**Russian Jammer**

**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.

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.

## Consequences of GPS Loss/Degradation

- Depending on ...
- Transportation Mode
- Duration of GPS Loss/Degradation
- Impact Can Be
- _Minimal_       -  Quick Recovery
- _Operational_  -  Reduced Effectiveness, but Safe Operation
- _Safety_           -  Potential Loss of Life, Environmental/Economic
-                             Damage
- Timing & Synchronization
- GPS Outage Can Disrupt Communications\Networks
- Timing Linked to Transportation, Commerce, Banking, Web

**Notes:**
#2  Safety impact uses = “Critical Applications”

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

## Mitigating GPS System Vulnerabilities 

- Unintentional Disruptions
- GPS Spectrum Protection Efforts
- Mitigate Against Interference Sources
- VHF, TV,  MSS, UWB, etc. (Bluetooth?)
- Jam-Resistant User Equipment
- GPS Modernization
- Intentional Disruptions
- Military Anti-Jam Technology
- Applicability to Civil Sector
- Characterize Civil Spoof Effects\Observables
- Vulnerability Cannot Be Fully Eliminated

**Successful Spoof**

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

“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

## Recommendations –Mitigation of User Risk

- Create Civil Awareness of GPS Issues
- Discourage Overconfidence & Over-Reliance
- Educate Users
- Recognizing GPS Disruption
- Alternate Procedures\Systems
- Promptly Reporting Interference\Disruption
- Educate System Developers – Over-Reliance
- Critical Infrastructure Applications
- Determine Tolerable Levels of Risk and Cost
- Implement Appropriate Mitigation Strategy

**Notes:**
#1  Convince service providers & users of need to mitigate the vulnerabilities.
For Each Individual Mode, Choose or Maintain Appropriate Backup System or Procedure - Low Cost where Possible
Timing Applications Threatened by Loss Lasting Days Need Cesium or Loran
Reflect Interference Impact in Application Designs
Implement Systems to Monitor, Report & Locate Interference
Assess Applicability of Military Anti-Jam Technology

#2  Routinely Validate GPS With Other Information Sources.

# 3
Determine Costs of Lowering Risks to an Acceptable Level
Determine Funding Mechanisms

## Recommendations (Continued)

- All GPS Receivers Used in Critical Applications Need to Provide Integrity Warnings
- Continue GPS Modernization & GPS III Programs
- More Civil Signals & Improved Code
- Higher Broadcast Power
- DOT Needs to Take an Active Role in Developing a Roadmap for the Future Navigation Infrastructure
- State in the Federal Radionavigation Plan
- Encourage Modal Agencies & System Users to Follow
- Policy Response in Preparation

**Notes:**
LORAN – IF YOUR MODE DOESN’T HAVE A USE, MAYBE OTHERS DO:  TIMING, LAND, etc.

LAST BULLET - VOR/DME, ILS, Loran-C, Inertial Systems, plus operating procedures.

## Summary

- GPS Vulnerability Can be Reduced but Not Fully Eliminated
- Augmentations Are No Benefit During Disruption
- WAAS, LAAS, MDGPS, & NDGPS
- GPS Disruptions Impact Timing Applications
- Increasing Use Makes GPS a Tempting Target
- Low-cost, Asymmetric Attack
- Possible Serious Effects on USA
- Independent Backup Systems or Procedures are Essential in Critical Civil Transportation Uses

- 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)_

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