ftp://ftp.ngs.noaa.gov/dist/whenning/GLRHMC/

THE CHANGE FROM LABOR INTENSIVE TO TECHNOLOGY!

2000+/-

1977

CHANGE…….23 YEARS

A CONFLUENCE OF TECHNOLOGY- USE OF RTK

•INTERNET DATA VIA CELL TECHNOLOGY

•SOFTWARE/FIRMWARE ALGORITHMS

•GNSS HARDWARE

•SATELLITE CONSTELLATIONS

•SATELLITE CODES/FREQUENCIES

POTENTIAL FUTURE DEVELOPMENTS (2005 – 2017?)

GPS MODERNIZATION – BLOCK IIF & III GLONASS ENHANCEMENTS (K & M)

EUROPEAN UNION - GALILEO CHINA - COMPASS

115+ Satellites Second and Third Civil Frequency - GPS

No Signal Encryption - GLONASS & GALILEO More Robust Signal Transmissions

Real-Time Unaugmented 1 Meter (or better!) Accuracy

GLOBAL NAVIGATION SATELLITE SYSTEMS(GNSS)

CHANGE…….

STANDALONE POSITIONING: BY 2017?

• L2C• L5 CARRIER• New Code on L5• L1C

1-3 m BETTER RESISTANCE TO INTERFERENCEFASTER AMBIGUITY RESOLUTIONAUGMENTED CODE APPLICATIONS

10-15 cm???

CHANGE…….

GET USED TO ACCELERATED CHANGE-PREPARE TO ADAPT

2000 ERROR BUDGET (POST S/A)

II. INS & OUTS OF REAL-TIME NETWORKS

NEW PLAYERS IN ”HIGH-ACCURACY” REAL-TIME POSITIONING

• √GIS – INFRASTRUCTURE, SIGNAGE, ENVIRONMENTAL, PHOTO CONTROL

• √AGRICULTURE• √MACHINE CONTROL• DEFORMATION MONITORING• TECTONIC/SEISMIC STUDIES• NAVIGATION TO/FROM PORTS• REMOTE SENSING/MAPPING – LIDAR• FAA – NAVIGATION, LANDING, TAXIING• (WEATHER SCIENTISTS – CO-LOCATED RT

IONO/TROPO SENSORS)

•

•GIS – INFRASTRUCTURE, SIGNAGE, ENVIRONMENTAL, PHOTO CONTROL

Real Time for Agriculture

DUAL FREQUENCY CARRIER RTK – NOT CODE

AGRICULTURE

Machine Control

Graphics Courtesy of Caterpiller Inc.Slide by Jim Waters, TNDOT

GRADE STAKES ARE BECOMING A RARITY ON LARGE SITES AND ROAD PROJECTS….

MACHINE CONTROL

CONTROL IS MOVING FROM SINGLE-BASE ON SITE

TOWARD RTN

RT DEFORMATION MONITORING-BRIDGES, BUILDINGS, DAMS, LEVEES,

SUPPORT WALLS

TRIPLE DIFFERENCING & KALMAN FILTERING

NAVIGATION TO/FROM PORTS-ELLIPSOID HEIGHTS

Representatives of the maritime industry unofficially estimate that NDGPS reference stations near ports and harbors would cause an annual increase of $16 billion in cargo value in domestic waters, and an annual increase of $640 million in tax revenue, or a $9.6 billion benefit over the projected15-year life of the NDGPS.

SOURCE:National Height Modernization StudyReport to Congress

U.S. DEPARTMENT OF COMMERCENational Oceanic and Atmospheric

AdministrationNational Ocean Service

National Geodetic SurveyJune 1998

LIDAR and Derivative Products CONTROLLED FROM RTN(Light Detection and Ranging )

DEM - Digital Elevation Model

Flood Zone BoundaryRed –Original

Blue – Improved with LIDAR

Height Modernization

Slide by Gary Thompson, NC Geodetic Survey

OLD FIRMS – SCALED HORIZONTAL

OLD REMOTE SENSING

REMOTE SENSING/MAPPING – LIDAR(currently around an order of magnitude

less precise than classical RTK, ie. .1 – .4 m)

Aviation User Requirements – GPS / Nav

Mike Stills Captain Bryn Jones Joe KunchesUnited Airlines, USA SolarMetrics Limited, UK Space Weather Services Branch

NOAA Space Weather Prediction Center Boulder, Colorado, USA

Aviation WorkshopNOAA SWPC Space Weather WorkshopBoulder, ColoradoApril 28, 2008

• Hazards

• Signal effect (Ionospheric delay)

• Scintillation (ADS-B impacts)

• Radio bursts

• Satellite effects

• Need information on real-time GPS errors (horizontal, vertical)

• WAAS, LAAS office input on requirements

• NextGen requirements

FAA – NAVIGATION, LANDING, TAXIINGNATIONAL WEATHER SERVICE/SPACE WEATHER

PREDICTION CENTER

ACADEMIC/SCIENTIFICSPATIAL REFERENCE CENTERSVARIOUS DOTSCOUNTYCITYGEODETIC SURVEYS (NC, SC)MANUFACTURERSVENDOR NETWORKSAGRICULTUREMA & PA NETWORKS

WHO IS RUNNING RTN IN THE USA?PUBLIC/PRIVATE COOPERATIVES ARE

EMERGING

RAPIDLYGROWING

RTK vs. RTN

RTK

RTN

WHY NETWORK RTK (RTN)?

No reconnaissance/recovery of passive controlNo reconnaissance/recovery of passive control No time lost setting up and breaking down a baseNo time lost setting up and breaking down a base No base baby sitting, therefore labor cost is reducedNo base baby sitting, therefore labor cost is reduced No base means with two rovers the project is No base means with two rovers the project is completed in half the time OR the user would only need completed in half the time OR the user would only need one roverone rover = $$$ savings= $$$ savings

Because the requirement for a user base Because the requirement for a user base station is removed:station is removed:

WHY NETWORK RTK (RTN)? NO (1ST ORDER)DISTANCE CORRELATED ERROR -

Atmospheric, ephemeris corrections for the site of survey Data degrade gracefully outside of the network or if a reference station is down

RTNS CAN BE SEAMLESSLY CONNECTED TO THE NSRS – This means: Regional inter-GIS compatibilityContinual accuracy and integrity monitoringEasy datum adjustment/change updates for the user

In other words - “Everything fits together”

RTN FLAVORS

A. NON-PHYSICAL RS – DUPLEX COMMS

B. MAC – DUPLEX OR BROADCAST COMMS

C. FKP – BROADCAST COMMS

ALL RTN SOLUTIONS END IN A SINGLE BASELINE SOLUTION, I.E., A DIFFERENTIAL VECTOR FROM A

“KNOWN” POINT

ALL IN ROVER No control center or “master” station All observables from all reference stations are sent to rover Rover does all modeling of corrections and processes baseline Major horsepower is needed at the rover, but eliminates the possibility of errors from differing modeling methods by different hardware.

CLOSEST STATION Rover uses broadcast from closest reference stationSingle baseline, no network modeled correctionsTypically a Ma & Pa network of “antennas on the roofs”

Back to accounting for 1 PPM error

REVERSE PROCESSING Rover sends observables to ServerServer processes data and returns position to Rover

RTN BIG PICTURE ISSUES• PASSIVE / ACTIVE – WHAT IS ‘TRUTH’?

• GEOID + ELLIPSOID / LOCALIZE – QUALITY OF GEOID MODELS LOCALLY.

ORTHOMETRIC HEIGHTS ON CORS?

• NATIONAL DATUMS / LOCAL DATUMS / ADJUSTMENTS- DIFFERENT WAYS RTN GET THEIR COORDINATES-VARIOUS OPUS, OPUS-DB, CORS ADJUSTED, PASSIVE MARKS.

VELOCITIES - NEW DATUMS, “4 -D” POSITIONS

• GNSS / GPS• ACCURACY / PRECISION- IMPORTANCE OF METADATA• SINGLE SHOT / REDUNDANCY• RTK / RTN• GRID / GROUND –

LOW DISTORTION PROJECTIONS- SHOULD NGS PLAY?

EXAMPLE: GNSS DERIVED HEIGHTS• NOS-NGS 58 WITH DRAFT ORTHO

GUIDELINES-0.05 m TO NSRS, 0.02 m LOCAL

• DGPS – 15 SECONDS, 0.5 TO 2 m

• OPUS > 4 HRS = 0.02 M (h), 0.05 (H)

• CORS- SAME AS OPUS

• OPUS-RS 15 MINUTES =0.10 m

• SINGLE BASE RTK- “IT DEPENDS!” 5 SECONDS (better than 0.03 m expected)

• RTN – “IT DEPENDS!” 5 SECONDS ( better than 0.04 m expected)

CHANGE IN ACCESSING THE NSRS BY PASSIVE TO ACTIVE MONUMENTATION

PASSIVE vs. ACTIVE MONUMENTS SOME CONSIDERATIONS:

• NAD 83 IS REALIZED BY THE NATIONAL CORS• NAVD 88 IS REALIZED BY HIGH ACCURACY &

STABLE PASSIVE MARKS(DIFFICULT TO MAINTAIN)• PASSIVE MARKS ARE A SNAPSHOT IN TIME• ACTIVE STATIONS ARE 4-D• PASSIVE MARKS CAN BE MANDATED IN STATE

ANNOTATED CODES• RTN CAN ENCOMPASS MANY STATES AND RUN

ACROSS MANY CLASSICAL & GPS CAMPAIGNS OF VARYING TIME AND ACCURACY.

• PASSIVE MARKS USED IN DESIGN ARE PROJECT “TRUTH”

• DIFFERENT RTN CAN BE REALIZED IN DIFFERENT DATUMS AND ADJUSTMENTS

HARD TO ACCESS PASSIVE MONUMENTS

Disturbed Geodetic ControlCoordinates/Elevations

Questionable!

Destroyed Geodetic ControlNo Coordinates/Elevation

Monumented PointsDeterioration

MISSING MARKS- TYPICAL EXAMPLEDAVE ZILKOSKI’S

BASEMENT

WHEN WAS THE MONUMENT LAST LEVELED?

NEW JERSEY ANNOTATED CODE-PASSIVE MARKS

Movement from passive monumentation towards Active monumentation and from

traditional positioning and traversing towards RT positioning via GNSS RTN is a movement

from 3-D positioning towards 4-D Positioning in most of the conterminous USA.

This necessitates the recordation of metadata: source of coordinates, datum, datum epoch, alignment to the NSRS, grid/ground, date of

field survey, antennas, GNSS gear, etc.

NAD 83 VELOCITIES

(GOLD)

ITRF 2000VELOCITIES

(BLUE)

SANTA CRUZ, CA

ORTHO HEIGHTS - LOCALIZE OR NOT?

• PASSIVE MARKS ARE A SNAP SHOT OF WHEN THEY WERE LEVELED OR DERIVED FROM GPS

• IF YOU BUILD FROM A MONUMENTED BM AND THE DESIGN WAS DONE REFERENCED TO IT, IT IS “THE TRUTH”, UNLESS IN GROSS ERROR.

• LOCALIZATIONS ARE A GOOD WAY TO NOT ONLY LOCK TO THE SURROUNDING PASSIVE MARKS, BUT ALSO TO EVALUATE HOW THE CONTROL FITS TOGETHER.

• HOW GOOD IS THE NGS HYBRID GEOID MODEL IN YOUR AREA? GEOID 09 IS THE CURRENT MODEL

ELLIPSOID, GEOID & ORTHO HEIGHTS

H88 = h83 – N09

EACH COMPONENT HAS ERRORS

NGS Data Sheet - GEOID03Published NAVD88 to GPS Derived

HT2268 DESIGNATION - S 1320 HT2268 PID - HT2268 HT2268 STATE/COUNTY- CA/SAN FRANCISCO HT2268 USGS QUAD - SAN FRANCISCO NORTH (1975) HT2268 HT2268 *CURRENT SURVEY CONTROL HT2268 ___________________________________________________________________ HT2268* NAD 83(1992)- 37 45 25.30727(N) 122 28 36.34687(W) ADJUSTED HT2268* NAVD 88 - 102.431 (meters) 336.06 (feet) ADJUSTED HT2268 ___________________________________________________________________ HT2268 EPOCH DATE - 1997.30 HT2268 X - -2,711,121.437 (meters) COMP HT2268 Y - -4,259,419.310 (meters) COMP HT2268 Z - 3,884,200.262 (meters) COMP HT2268 LAPLACE CORR- 5.53 (seconds) DEFLEC03 HT2268 ELLIP HEIGHT- 69.78 (meters) GPS OBS HT2268 GEOID HEIGHT- -32.60 (meters) GEOID03 HT2268 DYNAMIC HT - 102.363 (meters) 335.84 (feet) COMP HT2268 MODELED GRAV- 979,964.0 (mgal) NAVD 88 HT2268 HT2268 HORZ ORDER - FIRST HT2268 VERT ORDER - FIRST CLASS I HT2268 ELLP ORDER - FOURTH CLASS I HT2268

H =102.431 =

102.431 102.3869.78 - (-32.60)

- NhGEOID96 = 0.17 mGEOID99 = 0.11 mGEOID03 = 0.05 mGEOID09 = 0.017 m

• “INCLINED PLANE”

“LOCALIZATION” = PROPER TIE TO PASSIVE CONTROL (IMPROPER HINGED LOCALIZATION)

• “GEOID XX” (MODELED + ELLIPSOID)

• “ELLIPSOID ONLY” (GNSS VERTICAL DIFFERENCE ONLY)

• LOCALIZATION + GEOID = METHOD OF CHOICE!

RT DERIVED ELEVATION CHOICES

BEST FIT PLANAR PROJECTION TO PASSIVE MARKS (CALIBRATIONS/LOCALIZATIONS)

PASSIVE/ACTIVE ORTHOS

• GNSS ECEF X,Y,Z (WGS 84 & PZ90) NAD 83 (,,h) SPC N,E,h

+ GEOID XX = SPC N,E,H

OR

CALIBRATE TO 4-5 SITE POINTS IN THE DESIRED DATUM. THIS IS USED TO LOCK TO PASSIVE MONUMENTATION IN THE PROJECT AREA.

GNSS TO ANY DATUM

PROJECT SURFACE VS. GRIDIS YOUR DATA COLLECTOR CONFIGURED TO

HANDLE THE TRANSFORMATION?• FEATURES AND WORK ARE REFERENCED TO THE

GROUND• CONTROL MONUMENTATION IS USUALLY

REFERENCED TO THE GRID• THERE ARE DIFFERENT WAYS TO RESOLVE THIS:

1. MODIFIED SPC2. LDP3. LOCALIZATION TO PASSIVE MONUMENTATION4. ASSUMED (TANGENT PLANE)

RTN CAN ENCOMPASS LARGE REGIONS COMPOSSED OF MANY STATES!

DATA COLLECTORS MUST HAVE CORRECT PROJECTION

PARAMETERS-EG., UTM, SPC, LDP, ASSUMED

EXAMPLE 1

MESA COUNTY RTN & LOCAL COORDINATE ZONESEXAMPLE 2

LOYOLA SPATIAL SYSTEMS- RTKNET

WILL OVERLAPPING RTN PRODUCE THE SAME COORDINATES?

KEYSTONE - KEYNET

CARON EAST -

NO OBSTRUCTIONS

WHAT ABOUT GLONASS?

Dilution Of Precision - DOP

NHUN-DOP/ NO OBSTRUCTIONS

NHUN – SATELLITES/ WITH OBSTRUCTIONS

NHUN – DOP / WITH OBSTRUCTIONS

URBAN CANYONSGNSS vs GPS – MIGHT HELP

HIGHWAY CORRIDORSGNSS vs GPS – MIGHT HELP

ROUTE OBSTRUCTIONSGNSS vs GPS – MIGHT HELP

ftp://ftp.ngs.noaa.gov/dist/whenning/GLRHMC/