# Presentation: 195474

## GPS Augmentation     Nationwide Differential GPS

- Presented by
- LTJG Mark E. Moriarty
- US Coast Guard

**Notes:**
Good Afternoon, ______________________________________________________

I’m Lieutenant junior grade Mark Moriarty, from Coast Guard Headquarters, the Radio Navigation Division.  

I’ll be presenting a brief synopsis of the Nationwide Differential GPS network.  I’ll be telling you a little about the system, it’s uses and updating you on the changes to the system since the last FRP was published.

I’ll answer any questions at the end of the presentation.

## Goals of the NDGPS Project

**Provide dual coverage of the continental U.S. and selected single coverage for Hawaii & Alaska. **** **
**Provide better than 10m navigation accuracy.**** **
**Provide Integrity warning to users when GPS satellite information is in error.  **** **
**Signal availability of 99.97%.**

**Notes:**
Goals of the NDGPS Project

Provide dual coverage of the continental U.S. and selected single coverage for Hawaii & Alaska.

Provide better than 10m navigational accuracy. Although Position Accuracy of the system is normally 1-3 meters.
Provide Integrity warning to users when GPS satellite information is in error. DGPS provides user notification of satellite failure within  6  seconds.

A Signal availability of 99.97%.  That’s probably a conservative estimate , once Dual signal coverage is achieved,  signal availability should be greater.

The overall goal system is to improve the accuracy and integrity of GPS for safety-of-life applications  for the Nation’s transportation infrastructure.

## NDGPS Funding 

**FY 1999 – 2002 Average Annual ****funding $5.7M.**
**FY 2003 funding provided to FAA, $6M.**** **
**FY04 estimated funding provided to ****FRA, $7M.**

**Notes:**
The Funding of the project has remained relatively consistent around 6 million dollars.

Next year, you as you can see, we’re hoping for a little more, around 7 million.

## Site Completion List

-      FY01                    FY02                   FY03-May

**Spokane, WA           Myton, UT                 Pahoa, HI****Polson, MT               Pine River, MN        Angleton, TX****Annapolis, MD        Acushnet, MA           Austin, NV****Hagerstown, MD     Albuquerque, NM    Hackleburg, AL****Hawks Run, PA       Medora, ND****Pueblo, CO****Summerfield, TX**

- There are 82 sites operating Nationwide

**Notes:**
Here’s a list of sites completed since the last FRP was published.  

16 new sites have come on line.

There are 82 sites operational now.

## Nationwide Control Station

**2002, The Coast Guard  completed Nationwide Control Station.**** **
**Capable of monitoring 200 NDGPS sites.**** **

**Notes:**
The Nationwide Control station was declared operational in 2002.

The CG operates two control stations, one at the CG Navigation Center in Alexandria, VA and one in Petaluma, CA, at a NAVCEN-Detachment.  

There’s also an engineering baseline control station located in Portsmouth, VA.  In the event of emergency all control stations are capable of controlling the entire network.

Each site has the capability to simultaneously monitor and control  200 DGPS broadcast sites.

## Nationwide DGPS Site Locations

** ****Hawk Run**

** **

**  ****Macon**

**  ****Grady**

**  **

**   **

**   ****Hackleburg**

**   ****Bobo**

** **

**  **

** **

**Oberlin**

** ****Topeka**

** **

** ****Onondaga**

** ****Medford**

** ****Edinburg**

** **

** ****Medora**

** ****Billings**

** **

** ****Great Falls**

** ****Polson**

** ****Spokane**

** ****Appleton**

** ****Klamath Falls**

** ****Austin**

** **

** **

** **

** ****Bakersfield**

** ****Essex**

** ****Flagstaff**

** **

** ****Albuquerque**

** ****Summerfield**

** **

** ****Pueblo**

** ****Hudson**** ****Falls**

**    ****Green - Operating**** **
**    ****Red - Planned**

** ****Whidbey Is**

** ****Robinson Pt**

** **

**Fort Stevens**

** **

**Cape ****Mendocino**

** **

**Point Blunt**

** **

**Pigeon Point**

** **

**Lompoc**

** **

**Point Loma**

** **

**Aransas Pass**

**Galveston**

** **

**English Turn **

** **

** **

**Mobile****Point**

**Tampa **

** **

**Key West**

** **

** **

** **

**Miami**

**Cape Canaveral**

** **

** **

** **

**Sandy Hook**

** **

**Moriches**

** **

**Portsmouth**

** **

**Brunswick**

** **

**Millers Ferry**

** **

**Vicksburg**

** **

**Memphis**

** **

**Sallisaw**

** **

**Kansas****City**

** **

**St Louis**

** **

**Rock****Island**

** **

**St. Paul**

** **

**Wisconsin****     Point**

**Upper****Keweenaw**

** **

** **

** **

**Pickford**

**Cheboygan**

** **

**Sturgeon Bay**

** **

**Detroit**

** **

**Saginaw****Bay**

** **

**Milwaukee**

** **

**Youngstown**

**Tucson**

** **

**Marshall**

**  **

**Jackson**

** **

** **

**Myton**

** **

**Carlsbad**

** **

**Gooding**

** **

**Dandridge**

** **

**Cincinnati**

** **

**Monterey**

** **

**Austin**

**  **

**Rawlins**

** **

**Kanab**

** **

**Hagerstown**

** **

**Martinsville**

**Middlebury**

** **

** **

** ****Jack Creek**

**Big Lake**

**    **

**Greensboro**

** **

**Omaha**

**Pine River**

** **

**St Mary**

** **

** **

**Louisville**

** **

** **

**05/2003**

** **

** **

**Acushnet**

**Elmira**

** **

** **

** ****Kensington **

** ****Fayetteville**

**New Bern**

**Annapolis**

** ****Canton **

**Iowa City**

**Pacific Junction**

** **

** **

** **

**Ledyard**

** ****Seneca**

**Lincoln**

** **

** **

** ****Wenatchee**

**Whitney**

**Clark**

**Chico**

**Penobscot**

**Charleston**

**Savannah**

** **

** **

** **

** **

** **

** **

**Hartsville**

** **

**Reedy Point**

** **

**Driver**

**Patten**

** **

**Isabela**

** **

** **

** **

** **

**Angleton**

** **

** **

** **

**Nationwide DGPS Site Locations**

** **

** **

** **

**Notes:**
The Stations indicated in GREEN are sites currently operational.

The stations indicated in RED are proposed future NDGPS sites.

36 Sites still need to be built. Not counting the sites currently under construction).

## Nationwide DGPS Site Locations

**Cold Bay**

**Kodiak**

**Kenai**

**Annette Island**

**Biorka**

**Gustavus**

**Potato Point**

**Cape Hinchinbrook**

** **

** **

** **

** **

** **

** **

** **

** **

** **

** **

** **

**Delta Junction**

** **

**Anderson**

**Level Island**

** **

**Trapper Creek**

**05/2003**

** **

** **

** **

**Kokole Point**

**Pahoa**

**Upolu Point**

- Hawaii

** **

** **

**Nationwide DGPS Site Locations**

**    ****Green - Operating**** **
**    ****Red - Planned**

**Notes:**
Again, the sites indicated in Green are operational, The Red indicated proposed sites.

There are nine DGPS sites operating in Alaska.  

There are three planned NDGPS sites are along the Anchorage – Fairbanks rail corridor.(Trapper Creek, Delta Junction, Clear AFB)

There are three operational sites covering the Hawaiian Islands.

## Current Coverage

**Notes:**
This is the Current US signal Coverage.  The gray area’s indicate single coverage, and the yellow area’s indicated dual signal coverage.

As you can see there are gaps existing in NorthWest, SouthWest, Mid East, Texas(Mexican Border area)

## Future Site Proposals

**Bakersfield, CA**
**Lincoln, CA**
**Greensboro, NC**
**St. Mary, WV**
**Kensington, SC**
**Topeka, KS**
**Seneca, OR**

**Dandridge, TN**
**Gooding, ID**
**Big Lake, TX**
**Milwaukee, WI**
**Klamath Falls, MT**
**Bobo, MS**

_**Under Construction**_

_**Sites being considered,  FY04 Appropriations**_

**Notes:**
The DOT’s Planning and Implementation Team (PIT) is considering to fund the sites listed on the right with FY04 funds.

There are 36 Sites still to be built. New site’s are coming online at a rate of approximately 5 per year. 

## Current Coverage with FY03 Funded Sites

**Notes:**
Once the sites listed as under construction on the previous slide become operational, California Single Coverage will be complete.  The single coverage gaps get  smaller.

(We added:   Bakersfield, CA    Lincoln, CA    Greensboro, NC    St. Mary, WV                    Kensington, SC    Topeka, KS   Seneca, OD)

## Research & Development

- Low Data Rate Broadcast of GPS Observables
- Improved Ionosphere and Troposphere models
- Applications of Nationwide Control Station
- Dual Beacon Receivers/Enhanced Almanac
- Network Synergy
- Receiver Enhancements

**Notes:**
We’re continuing  to look for ways to meet additional demands on our Federal radionavigation systems.  

There’s considerable research going on to improve the accuracy and reliability of the NDGPS system.

I won’t go into the technical details on these improvements. 

## NOAA Atmospheric Correction

**NOAA’s weather model will interpolate a ionospheric and a wet/dry tropospheric correction.**** **
**The NOAA model will generate a quality factor.**** **
**Corrections expected to be useful for up to 30 minutes.**

**Notes:**
The Weather data NOAA’s collecting at the NDGPS sites can also be used to improve the GPS corrections being made at the NDGPS site.

##  NDGPS : A National Asset

- Integrated into the National Continuously Operating Reference Station (CORS) network.
- Integrated Precipitable Water vapor.
- Used for measuring plate tectonic movement.
- Support USCG NAVTEX broadcast to fill coverage gap.

**Notes:**
All of DGPS sites are integrated into the CORS network. 

Improves short term precipitation forecast and frontal boundary forecast.

The NAVTEX system is the primary means for transmitting coastal urgent marine safety information to ships worldwide

## Outside Federal Agencies interest in NDGPS

**DOC**
**NOAA**
**NGS**
**Census Bureau**
**USDA**
**NRCS**

**DHS**
**USCG**
**FEMA**
**DOI**
**NPS**
**ACOE**

**Notes:**
Listed here are some other Federal agencies using the NDGPS system.

Under the DOC – Department of Commerce   NOAA – (DOC) National Oceanic and Atmospheric Administration (Weather Forecasting equip)
  NGS- (DOC) National Geodetic Survey (used in CORS network) GPS data sent Boulder, CO.  US Census Bureau – Mapping rural homes

USDA – US Dept of Agriculture (Soil Plant Nutrient Research Unit)  NRCS – Natural Resources Conservation Service              (assisting in Precision Farming)

DHS – Department of Homeland Security FEMA  – Federal Emergency Management (National Height Modernization Study, Flood plain              mapping)
 USCG – Aids to Navigation positioning, Maritime navigation, AIS, NAVTEX Broadcast

DOI- Department of the Interior  NPS- (DOI) National Park Service (Precision Forestry)

ACOE – Army Corp of Engineers, inland waterways dredging and maintenance 

- Not mentioned are State uses (Wastewater Management, Mapping Flood Plains , Land Use Planning , emergency response services :police, fire, and rescue. 
Canadian CG- Interest from the president’s National Transportation Safety Board on PTC completion.

There are also many non-transportation benefits derived from DGPS, but no other established public agency requirement for the system. 

## Users

***Users***

**Notes:**
Some photo’s of DGPS users.

## Question ?

*D*

- Continuity

- Integrity

*G*

*P*

*S*

- Availability

- Accuracy

## Back up Navigational Accuracy

- Back up Navigational Accuracy

- Navigation Accuracy at the reference station.

-   95 centimeters, 95%, three dimensional.
- 67 centimeters, 95%, horizontal

**Notes:**
Longitude vs Latitude at NDGPS site TAMPA, FL 04 Feb 2002.  Provided by Federal Highway Administration.
Grid is 1 meter each direction from center.  20cm small divisions.

## Back up What is NDGPS?

**A DOT program to improve the accuracy and integrity of GPS for safety-of-life applications for the Nation’s transportation infrastructure.**
**NDGPS is a coast to coast expansion of the Coast Guard's maritime DGPS system.**
**The USCG, FRA, FHWA, FAA, NOAA, and ACOE are the core contributors to creating the NDGPS system.**

**Notes:**
The DOT’s concept is to provide precise positioning information for a multitude of government and civilian transportation users: Railroads, Highways, and Waterways.

The DGPS Signal Characteristics are ideal for terrestrial environment
Protected spectrum Low/Medium Freq Signals (285 to 335 kHz) 
Ground wave propagation mode reaches terrestrial users
Signals avoid terrain masking (not line of sight).

The DGPS system is not as useful for aircraft in the air.  

The FAA is developing their own GPS augmentation system better suited for Aircraft : WAAS (Wide Area Augmentation System)

The WAAS system, Satellite based, is not well suited for terrestrial users due to signal masking.  The WAAS satellite system is GEO-stationary on the Equator.