Campbell TX320, Инструкция по эксплуатации

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TX320 Transmitter
2. GOES System
Appendix A provides information about getting onto the GOES system and
eligibility.
2.1 Orbit
The TX320 transmitter sends data via Geostationary Operational
Environmental Satellites (GOES). GOES satellites have orbits that coincide
with the Earth's rotation, allowing each satellite to remain above a specific
region. This allows a user to point the GOES antenna at a fixed position in the
sky.
There are two satellites, GOES East and GOES West. GOES East is located at
75° West longitude and GOES West is located 135° West longitude. Both
satellites are located over the equator. Within the United States, odd numbered
channels are assigned to GOES East. Only even numbered channels are
assigned to GOES West. Channels used outside the United States are assigned
to either spacecraft.
2.2 NESDIS and Transmit
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Windows
GOES is managed by the National Environmental Satellite Data Information
Service (NESDIS). NESDIS assigns the platform ID, uplink channel number,
and self-timed or random transmit windows. Self-timed windows allow data
transmission only during a predetermined time frame (typically 10 seconds
every hour). The self-timed data is erased from the transmitter's buffer after
each transmission, random data is not. Random windows are for critical
applications (e.g., flood reporting) and allow transmission immediately after a
threshold has been exceeded. The transmission is then randomly repeated to
ensure it is received. A combination of self-timed and random transmission
can be executed by the TX320.
2.3 Data Retrieval
Data retrieval via the TX320 and the GOES system is illustrated in Figure 2-1.
The DAPS User Interface Manual, provided by NOAA/ NESDIS, describes the
process of retrieving the data from the NESDIS ground station. The data are in
the form of 3-byte ASCII (see Appendix B for a computer program that
converts the data to decimal). You can also retrieve data directly from the
NESDIS ground station via DOMSAT, LRGS, or LRIT. DOMSAT is only
practical for organizations with many GOES users. Contact NESDIS for more
information (
http://www.noaasis.noaa.gov/DCS/ ).
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