Globalstar Product Management – Technical Support

Satellite Antenna Installations in Extreme Environments

As described more fully below, the proper method for protecting an antenna against the environment is simply to use a weatherproof, application-appropriate radome. This recommendation applies to virtually all antennas, for all extreme environments.

In general, maritime installations of Globalstar phones should include use of a weatherproof radome such as a Globalstar Extreme Enclosure.

  1. High reliability communications and long installation life are of utmost importance.
    1. High Reliability – Maritime users are often far from any emergency response agency or other source of mutual aid. Communications are critical for carrying out the user’s basic mission, for knowledge of weather and other external events, for personal safety and for getting assistance in recovering from problems with the vessel itself
    2. Long Installation Life – Repairs are usually difficult, and there is often no external source of spare parts
  2. Maritime environments are extremely harsh.
    1. There are many types of maritime environments, including salt water and fresh water, acid fog diesel environments, installations subject to anodic corrosion and other types of corrosion, and a wide range of temperatures
    2. Some maritime environments involve constant splashing and some installations are more protected from waves. Although splashing can wash away surface corrosion, it provides fresh corrosive raw materials. On the other hand, surfaces that are protected from splashing are subject to longer term corrosive forces.
    3. There are a number of different types of corrosive mechanisms – chemical, electrical, thermal and others.
    4. Most maritime environments involve a combination of corrosive mechanisms. The impact and corrosion rates of these combined mechanisms varies greatly. Mechanical stresses can augment the rate of component deterioration.
    5. It is virtually impossible, or at least cost-prohibitive to have a general-purpose product that self-protects against all possible corrosive mechanisms and environments simultaneously
  3. Use a radome.  It is one of the most effective, adaptable, and inexpensive methods for protecting an antenna in any environment, because a radome
    1. Protects the Antenna from corrosion and provides additional shielding from wind
    2. Protects the RF cable connectors on the antenna
    3. Provides a weatherproof location for connecting antenna cable pigtails to long heavy RF extension cables, thus protecting those RF connectors from the environment
  4. Availability of Radomes:
    1. Each type of maritime market has already developed very effective and inexpensive radome solutions.
    2. In practice, general purpose radome solutions, for example the Globalstar Extreme Enclosures, have been found to be able to provide protection for a wide range of environments.
    3. Special purpose industry-specific radomes are typically available for all of the other environments which may need special consideration.
  5. The Globalstar GAT-17MR maritime antenna, which can be used with the GIK-1700 and the GSP-1720, provides increased protection against the elements.  The antenna is designed for long term exposure to the maritime environment.  However, because of the above-mentioned reasons, the only way to completely protect even the GAT-17MR antenna, and achieve the longest antenna life, is to use a weatherproof radome, such as a Globalstar Extreme Enclosure. Therefore, Globalstar recommends:
    1. Short-term Installations: If an antenna is going to be installed for short periods in a maritime environment, such as on seasonal part-time pleasure craft, where the antenna is only deployed for short periods, the GAT-17MR is often able to provide sufficient protection from moisture and corrosion.
      1. The ability to use the stand-alone antenna for short-term installations provides increased ease of use for the customer, but also means that the antenna may need to be replaced earlier than if it had been enclosed in a radome.
      2. The antenna should be inspected whenever it is installed and uninstalled, and appropriate measures should be used to clean and protect the antenna and its connections, and to make sure that if any corrosion occurs, it is identified and halted as early as possible.
    2. Long term Installations (3 months or more): Use a Globalstar Extreme Enclosure whenever an antenna will remain installed in a maritime environment for more than 3 months
      1. Use the GCK-0009A for patch antennas.
      2. Use the mini-stick dome for the GAT-17MR, GAT-17HX, and other mini-stick antennas.  The mini-stick dome can also be used for patch antennas.

Keywords:  GIK-1700 GCK-1410 GSP-2900, 1720, sdvm, 1700, 2900

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Written by Joseph Crowley

November 20, 2013 at 2:36 pm

Posted in Uncategorized

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