FGCS-FIXED REFERENCE STATION WORKGROUP A.ACTIVITIES AT THE NGS B.WHAT ARE THE ACTIVITIES OF OTHER AGENCIES? C. WHAT ARE THE NEEDS OF THE FGCS?

REAL-TIME ACTIVITIES AT THE NGS I.OPERATE AN NTRIP CASTER (Fed. Owned/operated – currently 6, soon 9) II.DEVELOP AND PUBLISH GUIDELINES DESCRIBING BEST PRACTICES.(RTK Users draft, RTN Operators draft, etc.) III.PARTICIPATE IN MEETINGS, FORUMS, WORKSHOPS, ETC., CONCERNING REAL-TIME NETWORKS. SEEK LEADERSHIP ROLES.(FIG, ESRI, ACSM, RTCM, etc.) IV.RESEARCH PHENOMENA AFFECTING ACCURATE REAL- TIME POSITIONING. (HTDP, IDOP, GEOID08, etc.)

POSITIONING GPS/GNSS POSITIONING PASSIVE MONUMENTS ACTIVE STATIONS STATIC NGS 58/59 GUIDELINES RTN FGCS ACCURACY STDS. VRS MAC FKP MFTRS. SOFTWARE & DOCS. ½ COST OR DOUBLE WORK DONE OPERATORS DRAFT GUIDELINES ≈ 75 IN USA, 200+ WORLDWIDE REAL-TIME SINGLE BASE MONUMENTS CLOSEST BASE CORS NGS CLASSICAL USER GUIDELINES-DRAFT

I. NGS Real Time Stream Team Product Manager Richard Snay Outreach and User Relations Bill Henning Pam Fromhertz CORS Data Streams Charlie Schwarz Neil Weston Giovanni Sella IT Team Bruce Sailer Hong Chen Sky Chaleff

Supporting New Products Real time - essential that CORS/NGS supports this activity. TO DO: compute ultra-rapid orbits, QC coordinates, provide data-streams. Currently CORS only supports 6 sites with limited data-streams GNSS: add GLONASS and new GPS frequencies to online storage in 2008 OPUS-flavors NOAA-sister products Space Weather Prediction Center went operational in 2007 GPS Met Program will go operational in 2010 Co-Ops coordinates for NWLON GNSS sites TO BE ADDED IN 2008

MDSI HNPT NGS HEADQUARTERS NGS TESTING SITES – CORS STATIONS HNPT, MDSI, VAGP, PRMI VAGP

NGS TESTING SITES –PRMI, VITH, VIKH VITH PRMI VIKH

NGS TESTING SITES –BARH ON LINE SOON BARH COLLEGE OF THE ATLANTIC GIS LABORATORY

EPRT

CORB

WELCOME & LINKS PAGE

REGISTRATION PAGE

DATA STREAM WEB PAGE

RTCM 3.0 MESSAGE TYPES FROM NGS CORS NOT

II. RT POSITIONING GUIDELINES -  GUIDELINES, SPECS, STANDARDS √ SINGLE-BASE USER – DRAFT OUT  RTN PLANNING & NETWORK DESIGN  RTN CONSTRUCTION/SITE EVALUATION  RTN ADMINISTRATIVE  RTN USER RTN TEAM – ADVISORS AND PARTNERS

WHY SINGLE- BASE? -ACCOMMODATE LEGACY USERS - CLOSEST BASE NETWORKS -AREAS WITH NO CELL COVERAGE - PROJECT SITE APPLICATIONS, SUCH AS MACHINE CONTROL WHY SINGLE- BASE? -ACCOMMODATE LEGACY USERS - CLOSEST BASE NETWORKS -AREAS WITH NO CELL COVERAGE - PROJECT SITE APPLICATIONS, SUCH AS MACHINE CONTROL WHY EMPIRICAL? -PLETHORA OF VARIABLES -TIMELINESS -PORT TO RTN USERS -DYNAMIC NATURE OF RT POSITIONING WHY EMPIRICAL? -PLETHORA OF VARIABLES -TIMELINESS -PORT TO RTN USERS -DYNAMIC NATURE OF RT POSITIONING

SOME RT FIELD CONSIDERATIONS - Multipath - Position Dilution of Precision (PDOP) - Baseline Root Mean Square (RMS) - Number of satellites - Elevation mask (or cut-off angle) - Base accuracy- datum level, local level - Base security - Redundancy, redundancy, redundancy - Part(s) Per Million Error (ppm) – iono, tropo models, orbit errors - Space weather- sunspot numbers, solar maximum - Geoid quality - Site calibrations (a.k.a. Localizations) - Bubble adjustment - Latency, update rate - Fixed and float solutions - Accuracy versus Precision - Signal to Noise Ratio (S/N or C/N0) - Float and Fixed Solutions - Carrier phase - Code phase - VHF/UHF radio communication - CDMA/SIM/Cellular TCP/IP communication - WGS 84 versus NAD 83, or other local datumslocal and national datums - GPS, GLONASS, Galileo, Compass Constellations

RT SINGLE-BASE ACCURACY CLASSES

NGS HOME WEB PAGE

ACADEMIC/SCIENTIFIC SPATIAL REFERENCE CENTERS VARIOUS DOTS COUNTY CITY GEODETIC SURVEYS (NC, SC) MANUFACTURERS VENDOR NETWORKS AGRICULTURE MA & PA NETWORKS EXAMPLES OF RTN ADMINISTRATORS IN THE USA RAPIDLY GROWING

REAL TIME NETWORKS (RTN) HOW ARE THEY ESTABLISHED? HOW ARE THEIR COORDINATES COMPUTED? ARE THEY CONSISTENT? HOW IS THE NETWORK ADJUSTED? HOW DOES THE RTN ALIGN TO THE NSRS? CAN USERS USE ANY MANUFACTURERS’ EQUIPMENT IN THE RTN? DO OVERLAPPING NETWORKS GIVE THE SAME COORDINATES? WHAT ARE THE FIELD ACCURACIES? ?

3. Develop standards, specifications, and guidelines for administrating RTN. This may include: a. Reference station siting and construction considerations. b. Policy to promote the use of open source, generic data formats such as RTCM via the use of the most current Networked Transport of RTCM via Internet Protocol (NTRIP) programs. d. Policy to encourage the RTN to support as many different GNSS hardware and firmware packages as possible. e. Guidelines to recommend methods to enable RTN results to be aligned with the NSRS. This may include methods to archive and quality check RTN data. f. Guidelines to recommend methods to determine accurate positional coordinates and velocities for RTN reference stations. II. RTN GUIDELINES IN NGS POLICY STATEMENT ftp://ftp.ngs.noaa.gov/dist/whenning/RTNteam/REVIEW/ RTpolicy.June2008.doc

OPERATING A RTN- CHAPTER ONE DRAFT ftp://ftp.ngs.noaa.gov/dist/whenning/RTNteam/REVIEW/ #1 Include a subnetwork of the RTN into the National CORS network. This would be three stations If RTN has less than 30 stations, 10% of RTN with greater than 30 stations. #2 Align all RTN reference stations coordinates to the CORS network at 2-cm horizontal and 4-cm vertical #3 For each reference station in the RTN, use the Online Positioning User Service (OPUS) at to test for the continued consistency of its adopted positional coordinatesand velocity on a daily basis, and revise the station’s adopted coordinates and/or velocity if the tests reveal a need to do so. RTNguidelines.June08.doc

BAKERSFIELD2 CORS- SEASONAL N/S & VERTICAL MOVEMENT

EXAMPLE OF WHY RTN REFERENCE STATIONS SHOULD BE MONITORED ≈ 6 MM / YEAR ENGLISH TURN CORS SUBSIDENCE

IDOP WITH SCALE COULD CORRELATE TO ACCURACY III.

IDOP VALUES – 4 CORS EXAMPLE BEST IDOP = 1 √ N THEREFORE, WITH 9 CORS, THE IDOP AT THE CENTROID WOULD BE.33, WITH 4 CORS IT WOULD BE.5 AT THE CENTROID ADDITION OF RMS OF DISTANCE TO CORS CONTRIBUTING TO THE SOLUTION GIVES FINAL UNITLESS NUMBER “IDOP” WILL BE THE SUBJECT OF A FORTHCOMING PAPER BY DRS. RICHARD SNAY, TOM SOLER AND CHARLES SCHWARZ

OPUS-RS Accuracy for 15-minute data sets

ACTIVITIES IN OTHER AGENCIES? WHAT GUIDANCE OR PRODUCTS ARE NEEDED? WORKGROUP ISSUES ftp://ftp.ngs.noaa.gov/dist/whenning/FGCS