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    IMCA publishes guidelines on DGNSS

    Publications // August 28, 2009

    The latest document about DGNSS (differential global navigation satellite systems) from the International Marine Contractors Association (IMCA) shows the strength of different sectors of the industry working together.

    “’Guidelines on installation and maintenance of DGNSS-based positioning systems’ has been produced jointly by the committees of two of our four technical divisions – Marine and Offshore Survey,” explained the Association’s Chief Executive, Hugh Williams. “The new document (IMCA M 199 / S 012) offers broad guidelines on the installation of global navigation satellite systems (GNSS), including GPS and other satellite systems available such as the GLONASS system. Users of this equipment need to be aware of many technical, procedural and contractual issues before, during and after installation.”

    The 21-page document covers the basic components of a satellite system and highlights some of the consequences of a poor installation, before going into some detail on the phases of installation. Checklists for pre-installation work are offered, including such matters as antenna location and cable routing.

    The installation phase is covered in some detail, particularly the matter of proper siting and fitting of antennae and cabling and the possible issues affecting reception of satellite signals, such as multi-path, obscured satellites and interference from other radio sources. There is also information on the below-decks equipment required for GNSS systems and a section on the operational phase, including configuration and calibration of equipment, validation of data and ongoing maintenance.

    The guidelines are available for downloading via the IMCA members-only website, with additional printed copies available priced at £2.50 each for members and £5.00 each for non-members (plus 20% for delivery outside Europe.)

    Further information on IMCA and its publications is available from the IMCA website at and from the association at 5 Lower Belgrave Street, London SW1W 0NR, UK. Tel: +44 (0)20 7824 5520; Fax: +44 (0)20 7824 5521. Email:


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