A Statistical Description of Shipboard Environment and Emitter Signals within a 250 MHz Band at 1 GHz.
Professional paper for period ending Jun 87,
NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA
Pagination or Media Count:
Measurements are being taken to achieve and ensure Electromagnetic Compatibility between the shipboard Joint Tactical Information Distribution System, scheduled for introduction into the U.S. Navy in the 1990s, and existing shipboard radar, beacon and identification systems. The description of the electromagnetic environment in time and frequency is complicated by the inherent structure of the emitted signals because they are pulsed, some at irregular pulse periods, and radiated from rotating antennas. The signal level distribution is further complicated by reflections off other rotating antennas. The complex timefrequency structure of the signals and the statistical nature of the JTIDS system suggested that the signal level measurements should be statistical. The shipboard system used for the measurements presented in this paper is configured around a Hewlett-Packard 8566B spectrum analyzer85685A preselector operating at a 3 MHz bandwidth, which is comparable to the RF bandwidth of the JTIDS signal. The transducer is a circular array of eight vertical dipoles which can be wrapped around a ships mast. The instruments are HP-IB controlled with an HP9816 computer which also does real-time processing and transfers data to an HP9133H hardfloppy disc drive. A logging record is maintained on an HP ThinkJet printer with both alphanumeric and graphical data displayed.
- *ELECTROMAGNETIC COMPATIBILITY
- *ELECTROMAGNETIC ENVIRONMENTS
- ALPHANUMERIC DATA
- IDENTIFICATION SYSTEMS
- PRINTING EQUIPMENT
- REAL TIME
- ROTATING ANTENNAS
- VERTICAL ORIENTATION
- Radiofrequency Wave Propagation
- Active and Passive Radar Detection and Equipment