coefficients printed on the nonperforated strip attached
to the punch-tape may also be entered manually.
TELEMETRY AND RECEIVER CHECK
The receiver may be retuned to the radiosonde,
following the procedures in the operators manual, and
the wide-band or narrow-band receiver mode selected.
The wide-band mode is always used unless locally
produced radio interference requires use of the narrow-
band mode. Normally, both the radiosonde and the
receiver should be retuned, to try to avoid the
interference before selecting the narrow-band mode.
The best reception of the radiosonde is indicated by five
asterisks in the reception LCD window, with fewer
asterisks indicating weaker reception. The absence of
any asterisks indicates the signal is about to be lost.
NAVAID SYSTEM SIGNAL RECEPTION
Navigation-aid radio signal strength from the eight
Omega stations are checked following procedures listed
in the operators manuals. If the receiver or transmitter
is, or will move to within 60 nautical miles of one of the
NAVAID transmitter sites, the receiver/processor will
not process the signal properly and could cause
incorrect wind data. The station must be deleted from
the program before the sounding begins. Use the
"SYSGEN" program edit mode as described in the
operators manual to delete a nearby Omega station.
Upgraded MRS units and radiosondes use GPS, which
is more reliable and accurate than the VLF-Omega
After the instrument checks have been completed
and the radiosonde is attached to the balloon, the
operator must contact the air traffic controller in the
shore-station control tower to obtain permission to
release a meteorological balloon. The air traffic
controllers are responsible for transmitting any
NOTAMs (Notice To Airmen) that may be required at
Naval and Marine Corps air stations. Aboard ship, the
operator must contact the officer of the deck (OOD) for
permission to release a meteorological balloon. The
OOD has the responsibility for contacting the Tactical
Action Officer (TAO), the shipboard air traffic
controllers, and the Air Boss to obtain release
authorization, and then to relay the authorization to the
observer. Since the shipboard process involves several
different departments, each of which may be extremely
busy with normal ship handling and flight-quarters
evolutions, it is best to obtain authorization well before
release time. Keep in mind that certain electronic
emissions control (EMCON) restrictions may preclude
a radiosonde launch.
SURFACE WEATHER OBSERVATION
Just before release of a meteorological balloon, a
weather observation must be made. Data from the
surface weather observation is entered into the
receiver/processor either before or after release, but
before the radiosonde instrument has passed the 14,000-
foot height. The surface observation data entry routine
will prompt the operator to enter the station pressure in
whole hectopascals, the air temperature to the nearest
1/10 Celsius degree, the relative humidity to the nearest
percent, true wind direction to the nearest degree, wind
speed to the nearest knot, and the cloud group
NhCLhCMCH, as described later in this chapter.
The surface observation data should be compared to
the surface raw data received from the radiosonde and
displayed by the computer. If the comparison values are
outside the range plus or minus 1°C for temperature and
10% relative humidity, the radiosonde should be
allowed to acclimate an additional 5 minutes. If the
radiosonde fails this check, another radiosonde should
When the balloon is released, the radiosonde
reports a decrease in pressure to the data processor,
which automatically starts the data recording and
Data will print out or be
transmitted to a computer 8 to 10 minutes after release.
During ascent through the first 15,000 feet, the
radiosonde instrument is most susceptible to
interference and loss of NAVAID/GPS signals used to
determine winds. To determine accurate winds, the
receiver should be maintained continuously in the
track mode during this time.
How are RS-80 radiosondes powered?
How can the radiosonde frequency be adjusted?
How is high quality reception indicated by the
Aboard ship, what person authorizes the release
of a radiosonde balloon?
What should be done with the surface
observation data before a radiosonde is