Personal tools
You are here: Home Participation Working Groups & Subcommittees Federal Geodetic Control Subcommittee Instruments Work Group Instruments Work Group Charter
Document Actions

Instruments Work Group Charter


The opinions of individual Federal agencies are frequently solicited for test results on new survey equipment.  All too often, only unofficial opinions are available.  Through the Instrument Work Group (IWG), the Federal Geodetic Control Subcommittee (FGCS) performs scientific tests of new survey equipment, analyzes the data obtained, comments on the results, and publishes reports.  This effort to utilize the combined wisdom of all the Federal agencies involved is beneficial for both the agencies and the general  public.  The test information is now made available to the public through hard copy and internet methods.
The IWG originated as an Ad Hoc Instrument Group under the Federal Geodetic Control Committee (FGCC), and was reorganized in 1973 into the Instrument Subcommittee.  When FGCC became FGCS, the FGCC Instrument Subcommittee became the FGCS Instrument Work Group.


The IWG provides FGCS the technical means for evaluation of surveying systems, including the instrumentation, hardware, software, and procedures that comprise that system.  Examples of the systems tested include satellite, stellar, photogrammetric, gravimetric, inertial, and conventional terrestrial equipment and calibration facilities.  The IWG, through close coordination with the FGCS Methodology Work Group, also provides input on the development of appropriate survey techniques.  This testing should not be considered a certification process.


Membership in the IWG shall include a Chairperson and representatives from the member agencies of FGCS.  The IWG Chair shall be appointed by the FGCS Chair, with concurrence of the agency representatives.  The position of Chair can be held by a Federal employee of any FGCS member agency.
Agency representatives shall propose to the FGCS Chair at least one member for IWG representative. Each member should be knowledgeable in surveying instrument operations and capabilities.  Subject matter specialists from other agencies and state, local, and private surveying firms may be invited to assist with the testing efforts, but not to the extent that the objectivity of the testing and subsequent reports are in any way compromised.  Representatives from manufacturing firms are encouraged to observe and contribute to discussions as deemed appropriate by IWG.

Operating Procedures

The IWG shall meet as often as necessary to accomplish their objectives, but not less than twice per year, as directed by the IWG Chair.  The IWG Chair appoints the Test Coordinator who shall coordinate and schedule relevant testing and public announcements with the IWG Chair and FGCS Secretariat.  The official reporting of test results should be coordinated by the IWG Chair at the FGCS meetings.  Procedures for testing and reporting are as follows:
  • Requests -

    Requests for testing may be submitted by any interested sponsor to IWG, through either the FGCS Chair, IWG Chair, or the FGCS Test Coordinator.  IWG shall establish its own internal operating procedures and rules regarding test scheduling.  FGCS, after IWG review, reserves the right to refuse requests for tests.  Note that FGCS testing is not meant to be considered a certification process.

  • Resources -

    The IWG Chair and Test Coordinator shall coordinate and schedule relevant testing.  Final coordination shall be made through the FGCS Chair before resources are committed to the testing. Sponsors will supply the necessary equipment and personnel to conduct the test.  FGCS will provide a sufficient number of observers for oversight and assistance, if available.  Private, state or local government, professional society, and university assistance can be used so long as the integrity of the tests are not compromised.

  • Results -

    A letter of preliminary results shall be provided to the sponsor as soon as possible after the test completion.  A final report shall be prepared detailing the specifics of the test and other pertinent information as determined by FGCS.  This report shall be prepared by IWG and any interested FGCS parties.  The report will undergo a review process before publication that will include the FGCS membership.  Coordination with the sponsor will also be made.  IWG is under no obligation other than to consider the input of suggested changes and comments to the reports.  IWG will forward the final report to the FGCS Secretariat for release and publication.  To facilitate public access, these reports are available through two primary sources:
    1. Reports will be available in hard copy through the NGS Info Services Branch
    2. Reports and other pertinent information will be posted on the Internet under the FGCS home page.


    The FGCS Secretariat will assist in arranging meeting sites, preparing records of meetings, and finalizing reports and plans for public release.

    For more information, contact the Chair, Instrument Work Group

    Last Updated: Feb 01, 2007 10:44 AM
    Spinner Image