Differential GPS (DGPS)

Nationwide Differential Global Positioning System (NDGPS)

Differential GPS (DGPS) Differential GPS (DGPS)

ReferenceReferenceStationStation

.

Expanding the Maritime System

into theNationwide DGPS

Nationwide Differential Global Positioning SystemNationwide Differential Global Positioning System


What does NDGPS give me?What does NDGPS give me? System CharacteristicsSystem Characteristics

AccuracyAccuracy 0.5 meter near the reference station0.5 meter near the reference station Can degrade up to 1 meter/150 kmCan degrade up to 1 meter/150 km Typical accuracy is 1 to 3 metersTypical accuracy is 1 to 3 meters 2 to 5cm accuracy with Post Processing2 to 5cm accuracy with Post Processing

IntegrityIntegrity 5 seconds at 100 bps5 seconds at 100 bps 2.5 seconds at 200 bps2.5 seconds at 200 bps

Availability isAvailability is >99.7% in areas of single coverage>99.7% in areas of single coverage >99.9% in areas of dual coverage>99.9% in areas of dual coverage


International StandardInternational Standard

NDGPS is designed to an international, non-proprietary standardNDGPS is designed to an international, non-proprietary standard Compliant with RTCM SC-104 and ITU-R M.823 Compliant with RTCM SC-104 and ITU-R M.823 Greatly increases market for manufacturers Greatly increases market for manufacturers Enhances Global interoperabilityEnhances Global interoperability

Signal is free to all usersSignal is free to all users 35 countries operate compatible systems35 countries operate compatible systems Many other countries are planning Many other countries are planning

systemssystems Resulting in a seamless international Resulting in a seamless international

navigation systemnavigation system

Acceptance of the international standardAcceptance of the international standardis leading to a seamless worldwide service.is leading to a seamless worldwide service.


Maritime UseMaritime Use

DGPS guides every type of craft fromDGPS guides every type of craft fromsmall pleasure boats to large containersmall pleasure boats to large containershipsships


Army Corps of EngineersArmy Corps of Engineers DGPS in DredgingDGPS in Dredging

Army Corps of Engineers needs 2 meter accuracy to position their dredges.


Provide Situational AwarenessProvide Situational Awareness Prevent accidents, saving over Prevent accidents, saving over

$60 million per year$60 million per year Reduce fuel consumption by Reduce fuel consumption by

better pacing trainsbetter pacing trains Increase rail line capacity through closer Increase rail line capacity through closer

train spacing, thus reducing the need for train spacing, thus reducing the need for additional capital investment in plant and additional capital investment in plant and equipmentequipment

NDGPS RequirementsNDGPS RequirementsPositive Train ControlPositive Train Control


NDGPS use in SurveyingNDGPS use in Surveying

GPS has revolutionized the surveying industry. NDGPS provides survey grade accuracy when used in post processing applications.


Automatically notify emergency personnel when an air bag Automatically notify emergency personnel when an air bag is deployed, allowing for faster response to the exact is deployed, allowing for faster response to the exact location, thus saving some of the 41,000 people who die on location, thus saving some of the 41,000 people who die on U.S. roads each year.U.S. roads each year.

Nationwide DGPS Nationwide DGPS Intelligent Transportation SystemIntelligent Transportation System

An integrated vehicle safety system consisting of DGPS An integrated vehicle safety system consisting of DGPS & communication links will: & communication links will:

Gives drivers Situational Gives drivers Situational Awareness, preventing multi-car Awareness, preventing multi-car pile-upspile-ups

Automatically reroute trafficAutomatically reroute trafficaround an accident, improvingaround an accident, improvingtraffic flow.traffic flow.


Hydrographic Surveys Hydrographic Surveys and Aerial Mappingand Aerial Mapping


NOAA’s Forecast Systems LabNOAA’s Forecast Systems LabMeasuring Water VaporMeasuring Water Vapor

NDGPS Site in Whitney, NENDGPS Site in Whitney, NE

Water vapor is the most important component of weather and Water vapor is the most important component of weather and the least observed. DGPS reference stations continuously the least observed. DGPS reference stations continuously measure the water vapor in the atmosphere above the reference measure the water vapor in the atmosphere above the reference station, thus greatly improving short term weather forecasts. station, thus greatly improving short term weather forecasts.


Precision AgriculturePrecision Agriculture

Maximize use of resourcesMaximize use of resources Optimized plowing of crop rowsOptimized plowing of crop rows Tailored applications of seeds, fertilizer, Tailored applications of seeds, fertilizer,

water, pesticideswater, pesticides Improved management of land, machinery, Improved management of land, machinery,

personnel, timepersonnel, time Greater crop yieldsGreater crop yields Net benefit: $5-14 per acreNet benefit: $5-14 per acre

Minimize environmental impactsMinimize environmental impacts Localized identification and treatment of Localized identification and treatment of

distressed crops reduces chemical usedistressed crops reduces chemical use Precise leveling of fields prevents fluid Precise leveling of fields prevents fluid

runoffrunoff


Projected CoverageProjected Coverageby the End of 2000by the End of 2000


Captain Tom RiceCaptain Tom Rice

Commanding OfficerCommanding Officer

U.S. Coast Guard Navigation CenterU.S. Coast Guard Navigation Center

www.navcen.uscg.milwww.navcen.uscg.mil

USCG Navigation CenterUSCG Navigation Center7323 Telegraph Road7323 Telegraph RoadAlexandria, VA 22315-3940Alexandria, VA 22315-3940

Nationwide Differential Global Nationwide Differential Global Positioning System (NDGPS)Positioning System (NDGPS)

Phone: (703) 313-5888Phone: (703) 313-5888Fax: (703) 313-5800Fax: (703) [email protected]@navcen.uscg.mil

Documents

Differential GPS (DGPS)