Manual
Table Of Contents
- TITLE PAGE
- TABLE OF CONTENTS
- INTRODUCTION
- SECTION I
- CHARACTERISTICS OF HF SSB
- ACRONYMS AND DEFINITIONS
- REFERENCES
- HF SSB COMMUNICATIONS
- FREQUENCY
- SKYWAVE PROPAGATION - WHICH FREQUENCY TO
- WHY SINGLE SIDEBAND IS IMPORTANT IN HF
- AMPLITUDE MODULATION (AM)
- SINGLE SIDEBAND OPERATION
- SINGLE SIDEBAND (SSB)
- SUPPRESSED CARRIER VS. REDUCED CARRIER
- SIMPLEX AND SEMI-DUPLEX OPERATION
- AUTOMATIC LINK ESTABLISHMENT (ALE)
- FUNCTIONS OF HF RADIO AUTOMATION
- HOW ALE ASSURES THAT THE BEST COMMUNICA-TIONS
- CHARACTERISTICS OF HF SSB
- SECTION II
- SECTION III
- SECTION IV
- SECTION V
- SECTION VI
- SECTION VII
- ITU MARITIME RADIOTELEPHONE STATIONS
- DESCRIPTION OF SERVICES
- AT&T HIGH SEAS RADIOTELEPHONE SERVICE
- AT & T COAST STATION COVERAGE MAP
- COAST STATION COVERAGE & INFORMATION
- AIRCRAFT REGISTRATION
- OPERATING PROCEDURES FOR USING THE HIGH SEAS RADIOTELEPHONE NETWORK
- AT&T HIGH SEAS COAST STATIONS
- MOBILE MARINE RADIO, INC.
- WORLDWIDE LISTING OF PUBLIC CORRESPONDENCE STATIONS
- MARITIME RADIOTELEPHONE CHANNEL DESIGNATIONS
- SECTION VIII
- SECTION IX
- SECTION X
- SECTION XI
- SECTION XII
- SECTION XIII
SECTION IX
VOLMETS
VOLMET broadcasts are routine reports of meteorological informa-
tion for aircraft in flight. These broadcasts are made on VHF as well
as HF radio. The VHF reports contain current aerodrome weather
reports, with trend information where available. The current observa-
tion usually includes temperature, dew point and altimeter setting.
The HF reports include the current information as well as aerodrome
forecasts.
The ICAO outlines the contents of VOLMET broadcasts, but the
broadcasts themselves are made by such government agencies as
the FAA in the United States. The sequence in which VOLMETS are
broadcast for each aerodrome is published, as are the times of the
broadcasts. Consult current aeronautical publications for listings.
Each ground station may broadcast information for a variety of aero-
dromes on each HF frequency it is using for VOLMETS.
For example, the FAA’s International Flight Service Station at Islip,
Long Island, gathers weather information on a variety of airports in
the Northeast and upper Midwest. The current observations and fore-
casts are taken from teletype and used to prepare the VOLMET
broadcast which is made by the FAA in New York currently on four
HF frequencies: 3001, 5652, 8868 and 13272 kHz. These automated
voice broadcasts include the current weather observation for up to 25
airports plus 16 terminal area forecasts.
ICAO recommends that the aerodrome weather forecasts in VOL-
METS have a period of validity of nine hours, and should be issued
every three hours to ensure that a forecast reflects the latest opinion
of the meteorological office.
SIGMETS are also supposed to be included in VOLMET broadcasts,
or the word “NIL SIGMET”, which means there is no SIGMET.
Jeppesen publishes a meteorology section available as part of its
subscription service which includes the sequence of reports for VOL-
METS. For example, from 00 to 05 past the hour, New York broad-
casts forecasts for Detroit, Chicago and Cleveland, with hourly
reports on these three stations plus Niagara Falls, Milwaukee and
Indianapolis. The hourly sequence of reports is listed in chart form.
New York broadcasts on a 24 hour basis. Jeppesen also publishes
an index on its meteorological section where you may look up the air-
port you are seeking weather reports for (Windsor Locks, for exam-
ple) and find which ground station broadcasts the report (New York).
Services
9-1
KHF 950/990 Pilots Guide
Rev. 0
Dec/96