Consolidated Subcommittee and Working Group 1997 Report


Geodetic Control Subcommittee

The Federal Geodetic Control Subcommittee (FGCS) of the Federal Geographic Data Committee exercises government-wide leadership in coordinating the planning and execution of geodetic surveys, in developing standards and specifications for these surveys, and in the exchange of geodetic survey data and technical information. FGCS coordinates Federal agencies' aspects of surveying that are governmental responsibilities. These responsibilities include standards setting, testing new geodetic instrumentation and operational systems, coordination of user agency requirements, and dissemination of government data to user agencies.

The FGCS acts to ensure that the Global Positioning System (GPS) will continue to meet the positioning needs of the Federal civilian community and works to strengthen the ties between the GPS positioning and navigation communities. This responsibility will be implemented through its role as GPS Interagency Advisory Council (GIAC) to the Department of Transportation PosNav Executive Committee.

NSDI Strategic Goal 1
Increase the awareness and understanding of the vision and concepts of NSDI through outreach and education

Geodetic Control Subcommittee

Objective: Identify and address issues relating to long term planning of Position/Velocity/Timing (PVT) systems

    Action: The GPS Interagency Advisory Council (GIAC) provided input to the U.S. Air Force Capstone Requirements Document addressing future needs of users of the U.S. PVT systems.
    Outcomes: A compilation of future PVT requirements of GIAC member agencies and private sector constituents represented by GIAC.
    Date: May 9, 1997
    Responsible Party: FGCS/GIAC, NOAA

Objective: Identify and address issues associated with Global Positioning System (GPS) Modernization.

    Action: GIAC in collaboration with the Institute of Navigation (ION) held two GPS Modernization Technical Sessions/Workshops: August 26 and November 6. Ongoing.
    Outcomes: Three ION facilitated working groups were formed with GIAC participation to investigate topics associated with GPS modernization. Defined how GIAC user GPS accuracy requirements could be met with three levels of positional accuracy.
    Responsible Party: FGCS/GIAC, NOAA, co-sponsor: ION

    Action: Five GPS-Derived Orthometric Height Workshops given.
    Responsible Party: FGCS Vertical Reference Working Group, NOAA, Co-sponsors: California Land Surveyors Association, Oregon GPS Users Group, Washington GPS Users Group, Land Surveyors Association of Washington, American Society for Surveying and mapping (ACSM).

    Action: Continuously Operating Reference Stations (CORS) Workshop, Houston, TX.
    Responsible Party: FGCS Fixed Reference Station Working Group, NOAA, Co- sponsor: Texas Society of Professional Surveyors.

Objective: Identify and address issues associated with positioning accuracy, techniques, and reference frames.

    Action: Geospatial Positioning Accuracy Standards Workshops, Raleigh, NC and Williamsburg, VA.
    Responsible Party: FGCS Methodology Working Group, NOAA, Co-sponsor: ACSM.

    Action: Field Procedures Required to Meet Survey Standards and Specifications Workshop, Largo, MD.
    Responsible Party: FGCS Methodology Working Group, NOAA, Co-sponsor: Maryland Society of Professional Surveyors.

    Action: Four Development, Implementation and Future of the National Spatial Reference System Workshops.
    Responsible Party: FGCS Methodology Working Group, NOAA, Co-sponsors: California Land Surveyors Association, Massachusetts Association of Land Surveyors and Civil Engineers, Professional Land Surveyors of Wyoming, Florida GPS Users Group.

    Action: Three State Plane Coordinate and Datum Transformation Workshops. Responsible Party: FGCS Methodology Working Group, NOAA, Co-sponsors: ACSM, Fresno State University, Texas Society of Professional Surveyors.

Objective: Evaluate new technologies and approaches that are used in surveying systems, including the instrumentation, hardware, software, and procedures that comprise that system. Notify and pass on necessary data to the Methodology working group if it the National Geodetic Survey specifications and/or standards need to be revised. Outreach to the public about the technological changes within the surveying community.

    Action: Completed testing of NovAtel L1/L2 Outrider GPS survey system.
    Outcomes: Work was accomplished on the web site to allow this set of data to be posted onto the FGCS Instrument Work Group (IWG) area of the FGCS web pages. NovAtel has introduced many new antenna types into the GPS world. Although the newest antenna from NovAtel was not available for the test, it was sent soon after. Testing of the antenna was accomplished at the NGS Corbin, Virginia, facility. This data was also posted to the web. Results were good and it is anticipated that the NovAtel test was successful. A preliminary letter of acceptance will be drafted pending review of recently received data from NovAtel.
    Date: June 15-20, 1997
    Responsible Party: FGCS/Instrument Working group, DOT, USGS, and NOAA

    Action: Completed testing of two Ashtech surveying systems: the GPS based Ashtech Z-Surveyor, and the GPS and GLONASS based Ashtech GG-Surveyor.
    Outcomes: This was the first FGCS test of a surveying system that uses the Russian GLONASS constellation of satellites. At the insistence of the FGCS testing team, the kinematic tests for the GG-Surveyor system were accomplished, and a comparison of the results with the Ashtech software and the TerraSat software was accomplished. Both software sets are available for purchase, but no comparison for consistency of results between the two software packages using the same set of data had been done for public dissemination. The FGCS pointed out that the reference systems and the transformation parameters used need to conform to published standards. The results were satisfactory and it is anticipated that both Ashtech systems will receive a preliminary letter of acceptance will be drafted.
    Date: November 15-21, 1997
    Responsible Party: FGCS/Instrument Working group, DOT, USGS, and NOAA

    Action: Performed preliminary testing of the Zeiss digital bar code level DiNi 10.
    Outcomes: It has been a goal to test other digital levels than the Leica. This goal has now been achieved, alleviating the concern about one manufacturer claiming to have the only FGCS tested system. Some of the data necessary for evaluation has been collected.
    Date: December 5, 1997
    Responsible Party: FGCS/Instrument Working group, DOT, USGS, and NOAA

    Action: Provided Internet access for test data and existing reports.
    Outcomes: There have been several upheavals in this process. Work was, therefore, focused on standardizing certain processes that the FGCS IWG for every test and improving coordination with NGS. Several draft reports, notices, maps of the test course, and other information are now posted on the web. The United States Coast Guard (USCG) Navigation Center (NAVCEN) is the official outreach to the civilian community on GPS matters, which maintains a web site to outreach to the civilian community from DoD on information on GPS per Memorandum of Agreement between DoD and DOT. The USCG NAVCEN maintains a web site on GPS and other radionavigation systems and issues. This site obtains over 650,000 hits per month. A link for FGCS information was established with this web site and some support was obtained.
    Date: 1997
    Responsible Party: FGCS/Instrument Working group, DOT, USGS, and NOAA

    Action: Opened GPS test course to manufacturers.
    Outcomes: Magellan came through and used the FGCS test course in August, 1997.
    Date: 1997
    Responsible Party: FGCS/Instrument Working group, DOT, USGS, and NOAA

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NSDI Strategic Goal 3
Use community-based approaches to develop and maintain common collections of geospatial data for sound decision-making

Geodetic Control Subcommittee

Objective: Monitor compatibility of Federal fixed reference stations with NAD 83 and their relationship to the development of a single Continuously Operating Reference Station (CORS) system to meet the requirements of Federal GPS post-processing procedures. Ongoing.

    Action: Twenty-eight CORS brought online.
    Responsible Party: FGCS Fixed Reference Stations Work Group, NOAA

Objective: Ongoing development, publishing, and maintenance of accuracy, collection, content, transfer, and archive standards for geodetic, land and resource surveys, and their related metadata. Promote the use of these standards by Federal, state, and local levels of government and the private sector.

    Action: Develop "SDTS Part 6, Point Profile", completed and approved by the FGDC Steering Committee.
    Responsible Party: FGCS Methodology Working Group, NOAA

    Action: Develop "Geospatial Positioning Accuracy Standard". The comment period is over. Any further action is dependent upon decision by the FGDC Standards Working Group resulting form their review of the comments.
    Responsible Party: FGCS Methodology Working Group, NOAA

Objective: Ongoing participation in the nationwide implementation of NAVD 88 and in the development of the Nation's geodetic height system using GPS. Ongoing.

    Action: Submitted "Guidelines for Establishing GPS-derived Ellipsoid Heights (Standards: 2 cm and 5 cm)".
    Responsible Party: FGCS Vertical Reference Systems Work Group, NOAA

Objective: Ongoing participation in the implementation of the geodetic data framework.

    Action: Completed Geodetic Control Framework Profile
    Responsible Party: FGCS, NOAA