2. NAVTEX RECEIVER "NR-50
”
Saracom Co., Ltd. 4 Q/A
1.2 Theoretical features of NAVTEX
NAVTEX service uses a single frequency for transmissions from nominated stations within
each NAVAREA being arranged on a time-sharing basis to eliminate mutual interference as
following [Figure 1-4].
All necessary information is contained in each transmission. The power of each transmitter is
regulated so as to avoid the possibility of interference between transmitters. It may be adjusted to
provide a range of about 250 to 400 nautical miles.
Normally a dedicated NAVTEX receiver which has the ability to select messages to be printed
according to a technical code(B1, B2, B3, B4), which appears in preamble of each message and
whether or not the particular message has already been printed.
But certain essential classes of safety information such as navigational and meteorological
warnings and search and rescue information are non-reject able to ensure that ships using
NAVTEX always receive the most vital information.
According to [Figure 1-3] of the NAVTEX concept, NAVTEX coordinators exercise control of
messages transmitted by each station according to the information contained in each message
and the geographical coverage required. Thus a user may choose to accept messages, as
appropriate, either from the single transmitter which serves the sea area around his position or
from a number of transmitters.
文件使用
"pdfFactory Pro"
试用版本创建
www.fineprint.com.cn
上海聚祥电子通信设备有限公司
www.juxiangdianzi.com
电话：
28631117
