Search results
Results from the WOW.Com Content Network
Stopping sight distance (SSD) is the sum of reaction distance and braking distance SSD = d PRT + d MT SSD = 0.278 Vt + 0.039 V 2 ...
Assuming a perfect sphere with no terrain irregularity, the distance to the horizon from a high altitude transmitter (i.e., line of sight) can readily be calculated. Let R be the radius of the Earth and h be the altitude of a telecommunication station. The line of sight distance d of this station is given by the Pythagorean theorem;
The formula now becomes = (+) or = (+) = (+), where R is the radius of the Earth. The same equation can also be derived using the Pythagorean theorem. At the horizon, the line of sight is a tangent to the Earth and is also perpendicular to Earth's radius.
Sight distance, in the context of road design, is defined as "the length of roadway ahead visible to the driver".[1] Sight distance is how far a road user (usually a vehicle driver) can see before the line of sight is blocked by a hill crest, or an obstacle on the inside of a horizontal curve or intersection.
Free-space loss increases with the square of distance between the antennas because the radio waves spread out by the inverse square law and decreases with the square of the wavelength of the radio waves. The FSPL is rarely used standalone, but rather as a part of the Friis transmission formula, which includes the gain of antennas. [3]
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. [1]: 26‑1 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. [2]
Line-of-sight range; Line-of-sight (missile), the straight line between the missile and the target; Radar horizon; Line-of-sight propagation, electro-magnetic waves travelling in a straight line Non-line-of-sight propagation; Line-of-sight velocity, an object's speed straight towards or away from an observer
This reduces the shadow zone, but causes errors in distance and height measuring. In practice, to find D h {\displaystyle D_{h}} , one must be using a value of 8.5·10 3 km for the effective Earth's radius R e {\displaystyle R_{e}} (4/3 of it), instead of the real one.