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Relationship of the atmosphere and ionosphere. The ionosphere (/ aɪ ˈ ɒ n ə ˌ s f ɪər /) [1] [2] is the ionized part of the upper atmosphere of Earth, from about 48 km (30 mi) to 965 km (600 mi) above sea level, [3] a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar ...
The Earth–ionosphere waveguide [1] is the phenomenon in which certain radio waves can propagate in the space between the ground and the boundary of the ionosphere. Because the ionosphere contains charged particles, it can behave as a conductor. The earth operates as a ground plane, and the resulting cavity behaves as a large waveguide.
Balloons cannot reach it because the air is too thin, but satellites cannot orbit there because the air is too thick. Hence, most experiments on the ionosphere give only small pieces of information. HAARP approaches the study of the ionosphere by following in the footsteps of an ionospheric heater called EISCAT near Tromsø, Norway. There ...
The ionosphere is a region of the upper atmosphere, from about 80 km (50 miles) to 1000 km (600 miles) in altitude, where neutral air is ionized by solar photons, solar particles, and cosmic rays. When high-frequency signals enter the ionosphere at a low angle they are bent back towards the Earth by the ionized layer. [ 1 ]
TEC plot for the continental USA, made on 2013-11-24. Total electron content (TEC) is an important descriptive quantity for the ionosphere of the Earth. TEC is the total number of electrons integrated between two points, along a tube of one meter squared cross section, i.e., the electron columnar number density.
Grundig Satellit 400 solid-state, digital shortwave receiver, c. 1986 [1]. Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (100 (exactly 99.930819333) to 10 (exactly 9.9930819333) meters); above the medium ...
HF's position in the electromagnetic spectrum.. High frequency (HF) is the ITU designation [1] for the band of radio waves with frequency between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one hundred meters).
Because of changing the Ionosphere during day and night, during daytime higher frequency bands under critical Frequency work best, but during nighttime the lower frequency bands work best. The D layer is present during the day and it is a good absorber of radio waves, increasing losses, Higher frequencies are absorbed less, so higher ...