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  • pg 1
									H88 = h83 – N03
     THE TECHNOLOGY SWEET SPOT
•   SBAS: 2 M H, 6 M V, 0.3 M SMOOTHED H, CHEAP
•   COMMERCIAL DGPS: FEW DM, $$
•   USCG BEACON: METER+, CHEAP
•   CORS/OPUS: 2 CM h, 5 CM H POST PROCESSED
•   DIFFERENTIAL LEVELING: 2-4 CM, LABOR/TIME INTENSIVE, $$$
•   GEODETIC LEVELING: mm, LABOR/TIME INTENSIVE, $$$$$
•   USER BASE RTK: 2-4 CM H, 2-5 CM V, REQUIRES INITIAL
    INVESTMENT, OUTCOME KNOWN IN FIELD
•   RTN: 3-4 CM H, 5-7 CM V, REQUIRES INITIAL INVESTMENT(BUT ½
    OF RTK), OUTCOME KNOWN IN FIELD
•   AERIAL MAPPING: .10 M H, .20 M V, $$$
•   LIDAR: 0.10 – 0.3 M V
•   SATELLITE IMAGERY: 0.5 METER H RESOLUTION, 3 M LOCATION,
    $$$
•   LOW ALTITUDE AERIAL IMAGERY: 2-4 CM H, 3-5 CM V, $$$
•   TERRESTRIAL LASER SCANNING: PROJECT SITES ONLY, 0.015 M H,
    0.02 M V, REQUIRES INITIAL INVESTMENT
                        RTN IN THE USA
≥200 RTN
WORLDWIDE                 (JAN 2010)
≥80 RTN USA
≥37 DOT

ACADEMIC/SCIENTIFIC
SPATIAL REFERENCE
CENTERS
VARIOUS DOTS +
MACHINE GUIDANCE
COUNTY
CITY
GEODETIC SURVEYS (NC,
SC)
MANUFACTURERS
VENDOR NETWORKS
AGRICULTURE
MA & PA NETWORKS
          RT FOR ORTHO HEIGHTS
ADVANTAGES:
• LESS TIME- SECONDS ON POINT
• LESS LABOR- NO POST PROCESSING, MINIMAL PERSONNEL
• LESS EQUIPMENT – ONLY ONE RT UNIT NECESSARY WITH RTN
• = LESS $$$

• USER KNOWS POSITION HAS BEEN CAPTURED AT REQUIRED
PRECISION

• “GOOD” RELATIVE PRECISION IN HOMOGENEOUS TERRAIN
AND USING THE SAME INITIALIZATION

• NEW GEOPOTENTIAL DATUM WILL BE ACCESSED THROUGH
ACTIVE STATIONS

DISADVANTAGES:
• LESS ACCURACY THAN LEVELING OR STATIC GNSS
• REQUIRES ADEQUATE USER KNOWLEDGE OF ALL EFFECTS ON
RT GNSS POSITIONING
RT IN RELATION TO GOALS OF NHMP
 • Access to accurate, reliable heights
   nationally- Geoid quality, New
   geopotential datum via active stations
 • Consistent Standards across the
   nation- RTN validation, RTN guidelines
 • Consistent Results. Data, technology,
   and tools that yield regardless of terrain
   and circumstances- Alignment to NSRS
 • Maintainable system/process that will
   stand the test of time – ARP velocities,
   Integrity monitoring, User gets new
   datum via RTN
NEW APPLICATIONS IN ”HIGH-ACCURACY”
       REAL-TIME POSITIONING
 • GIS – INFRASTRUCTURE, SIGNAGE,
   ENVIRONMENTAL, PHOTO CONTROL
 • AGRICULTURE
 • MACHINE GUIDANCE
 • 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)
        PRECISION VS. ACCURACY

•“PRECISION” IS A COMPUTED STATISTICAL
QUANTITY TO THE SOURCE OF THE
MEASUREMENT - ALIGNMENT TO THE RTN
OR PASSIVE MARK BASE SHOWS PRECISION
OF THE OBSERVATION (PER THE DATA
COLLECTOR).

•“ACCURACY” IS A COMPUTED STATISTICAL
QUANTITY TO THE REALIZATION OF THE
DATUM - ALIGNMENT OF THE RTN OR
PASSIVE MARK BASE TO THE NSRS SHOWS
ACCURACY (PER ESTABLISHED
METHODOLGY)
•
   • B ≥ 4 H & V, KNOWN & TRUSTED POINTS?
   • B LOCALIZATION RESIDUALS-OUTLIERS?
   • B DO CAN PROVIDE GOOD RELATIVE
FYI: GNSS ANY PASSIVE MARKS NEED TO BE
      HELD?
POSITIONS IN A PROJECT WHILE STILL
   • RT BASE WITHIN CALIBRATION (QUALITY
NOT CHECKING TO KNOWNS IN AN
ABSOLUTE SENSE
      TIE TO NEAREST CALIBRATION POINT)?
   • B SAME OFFICE & FIELD CALIBRATION
      USED?
BLUNDER CHECKING POINTS
     WITH OPUS-RS
 NGS SINGLE BASE
   GUIDELINES
• LEGACY EQUIPMENT

• NO CELL COVERAGE

• NEW RT CLOSEST BASE
NETWORKS

• MACHINE GUIDANCE AND
PRECISION AGRICULTURE
USE

http://www.ngs.noaa.gov/PUBS_LIB/NGSRealTimeUserGuidelines.v1.1.pdf
RTN GUIDELINES FOR
GNSS POSITIONING–
  WILL NOT SPECIFY OR
DEFINE A STANDARD, BUT
       WILL HELP
 ADMINISTRATORS AND
 USERS TO BE AWARE OF
ALL THE ISSUES INVOLVED
     WITH THIS NEW
      TECHNOLOGY
    60+ CONTRIBUTORS:

       •NGS ADVISORS
             •DOT
      •STATE GEODETIC
           SURVEYS
   •GNSS MANUFACTURERS
            •SRCs
          •BLM, NPS
 THOUGHTS ON ORTHO HEIGHTS ON RTN ARP
• LEVELING TO ARP CREATES A NEW BM EASILY USED IN
  HT MOD PRACTICES
• DENSIFIES GNSS ON BENCH MARKS = BETTER HYBRID
  GEOID MODEL
• ARP MONITORED 24/7/365 UNLIKE PASSIVE MARKS
• MANY STATE DOTs ARE LEVELING TO THEIR RTN ARP
• ROVER HEIGHTS STILL DEPENDENT ON GEOID MODEL
  FOR ORTHOS
• BY ESTABLISHING PASSIVE BMs AT RTN SITE, ELLIPSOID
  DIFFERENCE CAN PRODUCE ARP ORTHOS (IF DESIRED) –
  BUT THIS EFFECTIVELY GIVES A MEANS OF MONITORING
  THE PASSIVE BM USING THE RTN STATION BECAUSE THE
  ARP POSITION IS ALWAYS KNOWN.
     NTRIP & RTCM-
IMPROVING 3D POSITIONING
   WITH NEW MESSAGES
      Improving RTK with RTCM Network
             Residual Messages

                             Standard Solution (RMS:21 mm)
                            Optimized Solution (RMS:13 mm)

                            2




    Herbert Landau, Xiaoming Chen, Adrian Kipka, Ulrich Vollath -
      Trimble Terrasat GmbH
Positioning improved by up to a factor of 2
Initialization time reduced by 30%
                                       RTCM Paper 014-2007-SC104-462
   RTN RESIDUAL RTCM 3.x MESSAGE TYPES




https://ssl29.pair.com/dmarkle/puborder.php
STATE SPACE RTCM 3.x MESSAGE TYPES
EMERGING NGS ACTIVITIES…..
POSSIBLE METHODS OF RTN VALIDATION
•OPUS-PROJECTS – NGS APPROVED PROGRAM TO VALIDATE A
RTN ADJUSTMENT THAT WAS PERHAPS ACCOMPLISHED WITH
GNSS MANUFACTURER’S SOFTWARE OR ANOTHER PROGRAM.
•OPUS-S – 3 OR 10% OF RTN ARE NGS CORS WHICH THEN
GENERATE OPUS-S SOLUTIONS ON ALL OTHER RTN REFERENCE
STATIONS. THESE CAN BE PUSHED TO NGS AND PUBLISHED AS 60
DAY PLOTS, OR MAINTAINED ON A PUBLIC SITE AT THE RTN
ADMINISTRATION LOCALE.
• FIDUCIAL STATIONS - HIGH STABILITY MARKS ARE
CONSTRUCTED WITHIN A RTN. GNSS STATIC PROVIDES X,Y,Z.
GEODETIC LEVELING PROVIDES NAVD 88. STATIONS MAY BE
BLUE BOOKED. USERS CAN THEN TEST THEIR ROVERS AT THE
MARKS TO COMPARE THEIR RESULTS FROM THE RTN WITH THE
PUBLISHED VALUES. PILOT PROGRAMS PLANNED IN OREGON
AND LOUISIANA.
• LETTER OF CERTIFICATION - RTN ADMINISTRATOR SENDS A
STATEMENT CERTIFYING THAT AS OF A PARTICULAR DATE THE
RTN IS ALIGNED TO THE NATIONAL DATUM AT A CERTAIN LEVEL
(2 CM LAT/LONG, 4 CM h ?)
• NGS REVIEW - NGS DOES A PERIODICAL REVIEW OF THE RTN
STATIONS AND ADJUSTMENTS
        IDOP VALUES – 4 CORS EXAMPLE
BEST IDOP =   1                                      “IDOP” :THE
                     .87                  .87
          √N                                         SUBJECT OF A
THEREFORE, WITH                                      PAPER BY DRS.
9 CORS, THE IDOP                                     CHARLES
AT THE CENTROID            .7
                                                     SCHWARZ, TOM
WOULD BE .33,
WITH 4 CORS IT
                                                     SOLER AND
                                .6
WOULD BE .5 AT                                       RICHARD SNAY
THE CENTROID
                                                .8

ADDITION OF RMS                 .5
OF DISTANCE TO
CORS
CONTRIBUTING
TO THE SOLUTION                 .6
GIVES FINAL     .8                   .7
UNITLESS
NUMBER                                          APPLICATION
                                                FOR RTN?
                     .87                  .87
 KNOW YOUR METADATA- UNIFYING
THE VERTICALS TO A COMMON DATUM
                    ALL THESE COME
                    INTO PLAY TO
                    ENABLE THE
                    STRUCTURE TO
                    CLEAR THE
                    BRIDGE!

                    •LMSL
                    •NAD 83
                    •NAVD 88
                    •BATHYMETRY
                    •CHART DATUM
                    •BRIDGE DYNAMICS
                    •BRIDGE DIMENSIONS
                    •SHIP SQUAT
                    •SHIP DIMENSIONS

								
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