National Geodetic Survey 101

Brett Howe

Geodetic Services Division Chief

28 June, 2013

geodesy.noaa.gov

What is Geodesy?

Geodesy (geodetic control) is a foundational science that defines position & height

The Earth is an irregular surface and is difficult to model. Accurate positions are required for a wide variety of applications

(e.g. monitoring climate change impacts/sea level change)

Why is Geodesy important?

Constant monitoring of position and height is important because the Earth constantly changes

Benchmark set at 0.2m (1980)

NGS Mission StatementTo define, maintain and provide access to the

National Spatial Reference System (NSRS) to meet our nation’s economic, social, and

environmental needs.

The NSRS is a consistent coordinate system that defines latitude, longitude, height, scale, gravity, and orientation

throughout the United States.

geodetic control (the NSRS) is the foundation for all geospatial products.

without Geodetic Control as a “base map” layer, GIS applications will not work properly

Accurate positioning begins with accurate coordinates

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Foothills Lab Flagpole

NAD83

1000 m radius

500 m radius

2 mi2

Locations from different “map datums”

Some GPS units provide 70 different datums

Using Inconsistent Geospatial InformationResults in Inconsistent Positions

An example of the difference in lat/long from different Datums:

Riverside, CA location in

NAD 2734 22 43.99847 N, 118 56 27.89065 W

NAD 83 (1986):34 22 44.00314 N, 118 56 31.24680 W

NAD 83 (1992):34 22 44.00291 N, 118 56 31.25370 W

Passive Control

(Monuments)

Active Control(CORS)

The National Geodetic Survey (NGS) has been around a long time

NGS and the NSRS continue to evolve

United States Coast Survey

and the National Spatial Reference System continues to evolve with us

1878 1970

1807

GPS GNSS

The Expansion of the National Spatial Reference System

1816 - 2006

http://celebrating200years.noaa.gov/foundations/spatial/survey_network.html Video available at:

Major Programs of NGS1) How we are modernizing the NSRS

2) NGS Products and Services

OPUS GPS Satellite Orbits

CORS GRAV-DHeight Modernization ECO

Airport Surveys VDatum

State Advisor Program

Emergency Response Imagery

Coastal Mapping

Continuously Operating Reference Stations (CORS)

CORS Enable accurate positing and provide accurate interface between land and ocean observing systems

•Co-located with tide stations, CORS can contribute to local and global sea-level rise calculations by measuring land subsidence relative to water levels.

•CORS data can also used to monitor and predict the distribution of moisture and electrons in the atmosphere; as well as produce ionosphere models of total electron content (TEC) that impact GNSS-derived position accuracy.

~ 1900 Stations

2014 CORS Network

http://www.ngs.noaa.gov/CORS/

•Over 2.8 millions solutions processed since 2002

•Processed automatically on NGS computers

•Solution via email - in minutes

Fast, easy, consistent access to NSRS

Online Positioning User Service (OPUS)

http://www.ngs.noaa.gov/OPUS/

GPS Satellite Orbits

NGS is one of several Analysis Centers (AC) of the International Global Navigation Satellite Systems Service (IGS).•The accuracy of a user-determined GPS position is directly related to the accuracy of the GPS orbit information used. •Data from Continuously Operating Reference Stations (CORS) and IGS stations are used to determine GPS satellite orbits, station positions, and Earth orientation.

http://www.ngs.noaa.gov/orbits/

Height Modernization

Height Modernization is used to determine accurate heights using GPS/GNSS, along with traditional leveling, gravity, and modern remote sensing observations. Examples of Height Modernization applications:

– Dam, levee safety– Evacuation planning– Hazard mitigation– Flood-plain mapping– Subsidence monitoring– Determining high-water marks

http://www.ngs.noaa.gov/heightmod/Regional.shtml

Height Modernization is making evacuation routes safer for citizens who may need to escape from flood-prone areas.

Evacuation Route Analysis

Gravity for the Redefinition of the American Vertical Datum (GRAV-

D)http://www.ngs.noaa.gov/GRAV-D/

• GRAV-D is a project to collect gravity data to redefine the Vertical Datum of the USA by 2022 (at current funding levels)

• Target: 2 cm accuracy relative to sea level (orthometric heights) using GPS/GNSS and a geoid model.

GRAV-D Status 5-1-14: 35%

Ellipsoidal Datums

Orthometric Datums

Tidal Datums

MHHW, MHW, MTL, DTL, LMSL, MLW, MLLW

NAVD 88, NGVD 29

WGS 84, NAD 83 (NSRS)

+17 others

(MSL)

VDatum

• All elevation data are referenced to a vertical datum

• BUT there are many different vertical datums in use around the nation

• For elevation data sets to be blended together they must be referenced to the same vertical datum:

VDATUM provides a solution!!

http://vdatum.noaa.gov/

• The NGS ECO program is working to apply precise positioning models, tools and techniques for marsh restoration and to support community resilience in response to climate change.

• ECO also develops guidelines for collecting elevation data and monitoring in restoration projects.

Courtesy USGS, Patuxent Wildlife Research Center

NGS Ecosystem and Climate Operations(ECO) Activities

http://www.ngs.noaa.gov/web/science_edu/ecosystems_climate/

Coastal Mapping Program (CMP)

NGS delineates produces the Nation’s national shoreline which defines our nation’s territorial limits.

•Up-to-date shoreline is an integral component of NOAA Nautical Charts and supports a wide range of coastal applications.

•NGS uses multiple remote sensing technologies (imagery, lidar, radar, etc) from various sources (aircraft, satellites) to survey the shoreline and we continually assess new technologies and workflows.

http://www.ngs.noaa.gov/RSD/cmp.shtml

Emergency Response Imagery

To support NOAA national security and emergency response requirements, NGS collects high resolution, geo-referenced imagery of the effects of disasters such as hurricanes, tornados and earthquakes.

http://storms.ngs.noaa.gov/eri_page/index.html

Aeronautical Survey Program

NGS has a long standing relationship with the FAA to conduct airport surveys used to develop runway approach procedures and obstructions charts. Activities include:

•QA/QC third party aeronautical survey data (primary function).•Develop survey standards, guidelines, tools, and models to assist surveyors conducting aeronautical surveys.•Provide positional, height, and orientation data to the FAA in support of the National Airspace System (NAS) and safe navigation.

http://www.ngs.noaa.gov/AERO/aero.html

State Advisor Program

for a current list, visit: http://www.ngs.noaa.gov/ADVISORS/AdvisorsIndex.shtml

The NGS Geodetic Advisor Program:

•Currently provides either a jointly-funded NOAA employee or a State designated coordinator residing in the state to guide and assist the state's geodetic and surveying programs.

•Is transitioning o a regional approach, meaning more coverage but fewer advisors.

http://www.ngs.noaa.gov/ADVISORS/AdvisorsIndex.shtml

SatelliteOperation

s

SatelliteOperation

s

Personal NavigationPersonal

Navigation

Fishing & BoatingFishing & Boating

Oil ExplorationOil Exploration

Trucking & Shipping

Trucking & Shipping

Surveying & Mapping

Surveying & Mapping

Precision AgriculturePrecision Agriculture

AviationAviation

NGS provides the Geospatial Infrastructure Critical to Our Economy through the NSRS

Disaster ResponseDisaster

Response

The NSRS Supports:

FEMA uses NSRS elevations to determine flood zones for the National Flood Insurance Program

Federal Emergency Management Agency

USACE uses NSRS elevations to determine levee heights and positions in their Levee Safety Program

United States Army Corps of Engineers

NSRS gravity data contributes to the geospatial mission of NGA National Geospatial Intelligence Agency

USGS uses the NSRS to geospatially reference their Topographic Maps and interior water data for the nation

United States Geological Survey

NSRS positioning data provides the reference for NOAA’s Nautical Charts, among many other geospatial applications

National Oceanic and Atmospheric Administration

Location, Location, and Elevation! NGS Positioning Products Worth Billions!

NSRS worth $2.4 billion per year, $22 billion over 15 years at a discounted rate.

CORS worth $758 million per year; $6.9 billion over 15 years at a discounted rate.

GRAV-D worth $522 million per year through implementation of a new national vertical datum; $4.8 billion over 15 years at a discounted rate, which includes $2.2 billion for improved floodplain management alone.

One page handout available at:http://www.ngs.noaa.gov/INFO/OnePagers/socio_eco_handout.pdf

http://www.ngs.noaa.gov/PUBS_LIB/Socio-EconomicBenefitsofCORSandGRAV-D.pdf

Coastal Mapping Program Benefitshttp://www.ngs.noaa.gov/web/news/Big_Benefits_from_NGS_Coastal_Mapping.shtml

Total economic Benefits estimated in excess of $200 million per year

Combined direct and indirect return of $35 for every $1 in program cost

CMP supports ~1500 jobs including 40 FTE jobs within the CMP and its contractors.

There is a huge cost-benefit associated with NGS’ Coastal Mapping Program:

The National Geodetic Survey 10 year plan

Support the Users of the National Spatial Reference System.

Modernize and Improve the National Spatial Reference System.

Expand the National Spatial Reference System Stakeholder Base through Partnerships, Education and Outreach.

Develop and Enable a Workforce with a Supportive Environment.

Improve Organizational and Administrative Functionality.

http://www.ngs.noaa.gov/web/news/Ten_Year_Plan_2013-2023.pdf

What’s Next for Geodetic Datums?

New Datums Coming in 2022• A new geometric and a new

geopotential (vertical) datum will be released together in 2022

• The realization of the new datums will be through GNSS receivers

• NGS will provide tools to allow for easy transformation between the new and old datums

How the New Datums Will Affect You

• New geometric datum will change latitude, longitude, and ellipsoid height by between 1 and 2 meters.

• The new vertical (geopotential) datum will change heights on average 50 cm (20”), with a 1 meter (39”) tilt towards the Pacific NW

How can you prepare (generally)?• Watch for upcoming NGS status

conferences/reports/webinars

• Understand the impact of changing positions and heights for your community, company or agency

• Communicate your issues directly to NGSo NGS Info Centero State /Regional Geodetic Advisor

http://www.ngs.noaa.gov/ADVISORS/AdvisorsIndex.shtml

o Joe Evjen – joe.evjen@noaa.gov – Geometric Datum Manager

o Mark Eckl – mark.eckl@noaa.gov – Geopotential Datum Manager

http://www.ngs.noaa.gov/INFO/NGSinfo.shtml

How can you prepare (technical version)?

• Move to newest realizations– NAD 83(2011) epoch 2010.00– USGG12 (gravimetric geoid) / GEOID12A (hybrid geoid)

• Obtain precise ellipsoid heights on NAVD 88 bench marks (OPUS-DB, contact NGS Geodetic Advisor)

– Improves hybrid geoid models and provides “hard points” in new vertical datum

– Follow new NGS Guidelines when released

• Move off of NGVD 29 to NAVD 88– Understand the accuracy of VERTCON in your area

• Move away from passive marks to GNSS– Especially move off of classical passive control

• Require/provide complete metadata for all mapping contracts

– How did they get the positions/heights? Document it!!

NGS Workshop, Conference and Training Opportunities

http://www.ngs.noaa.gov/web/science_edu/training/

Workshops/Conferences

Training Classes

Online Learning Resources

http://oceanservice.noaa.gov/multimedia/

NGS Presentations Libraryhttp://www.ngs.noaa.gov/web/science_edu/presentations_library/

Sign up for NGS Training Notifications

http://www.ngs.noaa.gov/web/science_edu/training/

Sign up for NGS ListServe

http://www.geodesy.noaa.gov/

Questions?