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Aerographer’s Mate: Module 4

2010 July 8

Aerographer's Mate

Snippets from the US Navy’s “Aerographer’s Mate: Module 4—Environmental Communications and Administration” 1999 training manual.

Aerographer’s Mate
Module 4—Environmental Communications and Administration

April 1999

There are several telecommunication networks dedicated solely to environmental information. The largest is the DOD Global Weather Communications System (GWCS). It is operated by the U.S. Air Force and provides rapid transmission of aviation weather support information to military facilities. The system includes the Automated Weather Network (AWN) and the Air Force Global Weather Intercept Program (GWIP) network.

Automated Weather Network

The AWN is a global network of satellite and landline circuits linked with Automated Weather Data Switch (AWDS) computers used to collect and disseminate environmental data and other aviation related information. The military segment of the AWN is composed of two major subsystems: the Air Force Meteorological Data System (AFMEDS), and the Notice to Airmen (NOTAM) service for all DOD activities. The center of the network is a computer complex at Tinker AFB, Oklahoma. These computers collect large quantities of unclassified environmental observations, forecast bulletins, and specialized guidance products from a variety of sources, including the National Weather Service (NWS), the Air Force Weather Agency (AFWA) at Offutt AFB, Nebraska, and the Fleet Numerical Meteorology and Oceanography Center. International environmental information is forwarded from the World Meteorological Organization (WMO) data collection center via the NWS and is also collected and entered into the AWN through the GWIP network.

The Fleet Numerical Meteorological and Oceanography Detachment (FNMOD) at Tinker AFB, Oklahoma, is responsible for coordinating and validating Navy and Marine Corps environmental data requirements for the AWN. They also manage and schedule Navy data requirements on the Fleet Environmental Broadcast circuits that are keyed to the AWN. FNMOD Tinker also provides guidance on AWN data formats and can assist with preparing request messages for AWN products. Detailed information on the AWN can be obtained from the FNMOD Tinker homepage at

AFMEDS.—The data network used to support Air Force, Navy, and Marine Corps meteorological facilities within the United States is called the Continental United States (COWS) Meteorological Data System, or COMEDS. In the early 1970’s, the service was expanded to include the European Meteorological Data System (EURMEDS), the Pacific Meteorological Data System (PACMEDS), the Atlantic Meteorological Data System (ALTMEDS), and an Alaskan Meteorological Data System (AKMEDS). These services are subsystems of the Air Force Meteorological Data System, or AFMEDS. Most of these dedicated landline circuits will be phased out by early next century as the NIPRNET becomes the
primary method of transmitting AWN data. Software known as the Message Format Transmitter (MFT) module will be incorporated into the Meteorological and Oceanographic (METOC) Interactive Data Display System (MIDDS) to complete this changeover. However, the actual AWN data formats will not change. Ships will continue to receive AWN data via the Fleet Environmental Broadcast, which is discussed later in
the chapter.

ARQ Requests.—Incoming environmental information is stored in the AWN computers in files identified with a MANOP heading. (MANOP headings will be discussed in more detail shortly). As each observation or product is received in the computer, the data is forwarded to all units that have listed that particular MANOP as part of their data requirements. Additionally, any activity connected to the system may request individual products that are not on their data requirements list by a process called Automatic Response to Query, or ARQ. Individual activities may also use the system to transfer specific support products from a forecast activity, such as a detachment, to any other activity on the system.

MANOP Headings.—The use of MANOP headings is the key to data retrieval from the system. MANOP headings conform to WMO product identification guidelines as well as to the International Civil Aviation Organization (ICAO) guidelines for station identification. Every MANOP must follow the general format where … (rb: see table in publication source)

Air Force Global Weather Intercept Program
The Air Force Global Weather Intercept Program (GWIP) is another major function of the GWCS. Air Force radio intercept sites around the world routinely intercept meteorological and oceanographic information broadcast from other nations that would otherwise be unavailable for use. This information is transmitted by other nations knowing that it will be intercepted and used. This is part of the data exchange program governed by the World Meteorological Organization data exchange agreements. The intercepted data is entered into the AWN, and large amounts are forwarded to the National Weather Service and FNMOC to supplement foreign data received from other sources. Most of the data is used for automated global scale analysis programs. Some selected data is
directed to the Fleet Environmental Broadcast, which is discussed later in this chapter.

Several shore sites receive the National Weather Service Digital Facsimile (DIFAX) satellite broadcast. The broadcast originates at the National Centers for Environmental Prediction (NCEP) located at Camp Springs, Maryland, and it is then distributed via a continuous satellite broadcast from the National Weather Service office at Silver Spring, Maryland. A small 18-inch dish antenna is used to capture the broadcast signal at each receiver site.

The MIDDS is equipped with a special receiver module that can ingest DIFAX products as necessary. A few weather offices still use a desktop computer to analyze the signal and print the graphic products on a standard printer. No operator maintenance is required for the equipment other than periodically reloading paper, replacement of printer ribbons, and a periodic vacuuming of lint and dust from the printer.

The Commander Naval Meteorology and Oceanography Command (CNMOC) tasked the Naval Oceanographic Office (NAVO) to develop the Meteorology and Oceanography (METOC) Integrated Data Display System (MIDDS). This system combines both government and commercial application software. The Windows-NT operating system is the base software.

MIDDS provides three primary functions. First, MIDDS is an environmental workstation where the weather forecaster or observer retrieves, processes, and displays various weather products. Second, MIDDS is a briefing station that features high-quality graphics and enhancement features. Finally, MIDDS distributes meteorology and oceanography products locally over a Bulletin Board System (BBS), the Internet, or Local Area Network (LAN). The MIDDS workstation is normally equipped with a four-monitor display unit that is used for pilot briefings and product visualization. Figure 1-7 shows the MIDDS workstation.

(rb: major snip of discussion of MIDDS work env)

Internet and Bulletin Board Access
MIDDS provides direct dial-in and Internet connectivity into the Navy Oceanographic Data Distribution System (NODDS), the Optimum Path Aircraft Routing System (OPARS), and the Joint METOC Viewer (JMV). All of these programs originate at FNMOC and are discussed in detail in chapter 2 of this module.