What is K factor in microwave transmission?
What is K factor in microwave transmission?
K is a correction factor to show the behaviour of the microwave beam when it leaves the antenna.)
What are the factors that affect the propagation of radio waves?
As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering.
What is the maximum allowed frequency that can be used in Grand wave propagation?
In figure xx, the MUF for a receiver at 1400 miles is 5 MHz. Lowest Useable Frequency (LUF): again defined for two stations. At low frequencies, the signal will be attenuated before it can be reflected. The LUF increases with sunlight and is a maximum near noon.
How is Fresnel zone calculated?
Fresnel zone formulas The formula for the radius of the n -th Fresnel zone reads: rn = √(n * λ * d1 * d2 / (d1 + d2)) , where: λ is the wavelength of the wireless beam transmitted by the antenna; and.
How do you calculate a fade margin?
Adjacent channel interference fade margin is calculated as the difference between the median signal level and the total adjacent channel interference level, minus the required desired carrier-to-adjacent channel interference level to achieve acceptable performance.
What affects propagation?
Factors affecting radio propagation The properties of the path by which the radio signals will propagate governs the level and quality of the received signal. Reflection, refraction and diffraction may occur. The resultant radio signal may also be a combination of several signals that have travelled by different paths.
How multipath propagation affects signal quality?
Multipath propagation can give rise to interference that can reduce the signal to noise ratio and reduce bit error rates for digital signals. One cause of a degradation of the signal quality is the multipath fading already described.
What is the frequency range of space wave propagation?
between 30 MHz to 300 MHz
space waves are the radio waves of very high frequency (i.e. between 30 MHz to 300 MHz or more). The space waves can travel through atmosphere from transmitter antenna to receiver antenna either directly or after reflection from ground in the earth’s stratosphere region as shown in Fig.
Which zone of Fresnel has strongest?
The strongest signals are on the direct line between transmitter and receiver and always lie in the first Fresnel zone.
What is first Fresnel zone?
The first Fresnel zone is defined as a series of imaginary rings surrounding the centerline of the direct path such that the distance from the transmitting antenna to each ring plus the distance from the ring to the receiving antenna is equal to one-half wavelength more than the direct path between the antennas.
Why do we need fading margin?
The level of received power in excess of that required for a specified minimum level of system performance is referred to as the fade margin. So called, because it provides a margin of safety in the event of a temporary attenuation or fading of the received signal power.
Why is radio propagation along the grey line efficient?
Radio propagation along the grey line is very efficient. One major reason for this is that the D layer, which absorbs HF signals, disappears rapidly on the sunset side of the grey line, and it has not yet built upon the sunrise side.
What is the forecast discussion?
Users requiring a more detailed explanation of events should refer to the Forecast Discussion. A plain language, single page forecast text product issued every 12 hours, at 0030 and 1230 UTC, with both forecast and observed criterion now broken down for each of the three NOAA Scale categories.
How is the estimated 3-hour planetary Kp-index derived?
The Estimated 3-hour Planetary Kp-index is derived at the NOAA Space Weather Prediction Center using data from the following ground-based magnetometers: Sitka, Alaska; Meanook, Canada; Ottawa, Canada; Fredericksburg, Virginia; Hartland, UK; Wingst, Germany; Niemegk, Germany; and Canberra, Australia.
Why does the conversion table from NT to K-index vary by Observatory?
The conversion table from maximum fluctuation (nT) to K-index, varies from observatory to observatory in such a way that the historical rate of occurrence of certain levels of K are about the same at all observatories. In practice this means that observatories at higher geomagnetic latitude require higher levels of fluctuation for a given K-index.
