A scintillation theory of the fading of HF waves returned from the F-region: receiver near transmitter |
| |
| Affiliation: | 1. Center for Nanoscience and Nanotechnology, Department of Environmental Sciences and Chemical Engineering, School of Engineering and Applied Sciences, National University of Mongolia, Ulaanbaatar 14201, Mongolia;2. Department of Chemistry, Chemical Engineering and Life Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan;3. Faculty of Engineering, New Mongol Institute of Technology, Ulaanbaatar 13372, Mongolia;1. College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China;2. Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China;3. Department of Mining and Materials Engineering, McGill University, Montreal, Canada H3A 0C5;4. Key Lab of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China;5. College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China;1. Institute of Physics, University of Brasília, 70.919-970 Brasília, Brazil;2. Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden;3. Swedish e-Science Research Centre (SeRC), Linköping University, SE-581 83 Linköping, Sweden;1. College of Optical and Electronic Technology, Institute of Microelectronics, China Jiliang University, Hangzhou 310018, China;2. School of Physical Science and Technology, Institute of Microelectronics, Lanzhou University, Lanzhou 730000, China |
| |
| Abstract: | Scintillation theory is used to study the fading of HF radio waves returned from the ionospheric F-region to a receiver close to the transmitter. Estimates are made of - 1.(i) the fluctuations of phase both for long term (∼ an hour) and for short term (∼ a fading correlation time),
- 2.(ii) the correlation distance,
- 3.(iii) the quasi-period of fading,
- 4.(iv) the angular divergence in the direction of arrival around the zenith and
- 5.(v) the correlation bandwidth.
The calculations are made as a function of wave frequency for two ionospheric penetration frequencies representative of high day-time values and low pre-sunrise values. Results are compared with observations of fading made with ionosondes over the past 40 years. Precise comparison is rendered impossible by omissions in the experimental data caused by lack of guidance from scintillation theory. Nevertheless, agreement is promising. When fading is deep but spread-F-region is not well-developed there is a slow modulation of the fading. This is what, for optical propagation in the troposphere, is called twinkling. The slow fluctuations observed by Bramley and Ross in the HF band constitute ionospheric twinkling. Calculated quasi-periods of twinkling range from about an hour down to about a couple of minutes, while calculated quasi-periods of fading range from about a couple of minutes down to about a tenth of a second. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
