Propagation
Index to Radio Propagation Information

# Radio Propagation Conditions

Information Pertaining to Current Radio Propagation Conditions

Sunspot Cycles
Where are we in the current sunspot cycle and what are radio conditions apt to be like in coming months and years?

Run these radio propagation programs from the web or download and run them from your hard drive without charge.

• Diffraction 1 Radio Propagation by Diffraction Over an Obstruction When there are two radio antennas located on or near the Earth's surface propagation can ordinarily occur between them by groundwave. If an obstruction, a hill, a mountain, a building intervenes, propagation can still occur via slant paths over the top edge of the obstruction. This depends on diffraction over the edge. So, in addition to the basic or spreading loss along the sum of the slant paths, D1+D2, there is an additional loss due to diffraction ...
• Diffraction 2 Radio Propagation by Diffraction Over Two Successive Obstructions This program calculates the overall transmitter-to-receiver loss when the radio path includes diffraction over two successive obstructions. Results include field strength at the receiving site. Antenna efficiency can be allowed for ...
• Groundwave Groundwave Propagation vs. Path-length & Frequency for Various Terrains Both transmitting and receiving antennas are verticals, height = 1/4-wavelength or less, above a system of buried radial wires. A 1/2-wave vertical has 1 dB more gain than a short vertical. A 5/8-wave vertical has 1.6 dB more gain ...
• Line-of-Sight Propagation Over Line-of-Sight Radio Paths This program covers just the essentials. Refraction in the Earth's atmosphere, ground reflections and antenna radiating efficiency are not taken into account ...
• Propagate Propagation of Radio Waves via Line-of-Site and Ionospheric Paths This program is intended to introduce newcomers to signal strengths expected from transmitters of given output power, over various radio path distances and under average propagation conditions ...
• Two-Hops Skywave Trigonometry For given one-hop ground path distance and height of reflecting layer this program calculates radio path distances and the radio-path elevation angle ...
• Sky-Trig Skywave Trigonometry 2 For given values of the elevation angle and height of an ionospheric reflecting layer this program calculates the one-hop ground path and radio path distances between the transmitter and places where the radio wave returns to Earth ...

Real-Time Sudden Ionospheric Disturbance Monitoring
The Stanford Space Weather Monitor Program is seeking Radio Amateurs and others qualified to help high school and community college students around the world setup and operate real-time space weather monitors.

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