Search results
Results From The WOW.Com Content Network
VFR / VMC visibility requirements in the US. In aviation, visual meteorological conditions (VMC) is an aviation flight category in which visual flight rules (VFR) flight is permitted—that is, conditions in which pilots have sufficient visibility to fly the aircraft maintaining visual separation from terrain and other aircraft.
In architecture, visibility graph analysis (VGA) is a method of analysing the inter-visibility connections within buildings or urban networks.Visibility graph analysis was developed from the architectural theory of space syntax by Turner et al. (2001), and is applied through the construction of a visibility graph within the open space of a plan.
Visibility graphs may be used to find Euclidean shortest paths among a set of polygonal obstacles in the plane: the shortest path between two obstacles follows straight line segments except at the vertices of the obstacles, where it may turn, so the Euclidean shortest path is the shortest path in a visibility graph that has as its nodes the start and destination points and the vertices of the ...
Fog is reported when visibility is 1/2 mile or less; mist is reported for visibilities greater than 0.5 miles (0.80 km) but less than 7 miles (11 km). If the temperature is below freezing, [11] [12] humidity is high and visibility is 1/2 mile or less, freezing fog is reported. [13] ASOS CT12K ceilometer
A sky half full of clouds would have a circle that was half white and half black. Below the shape indicating sky cover, the station model can indicate the coverage of low clouds, in oktas, and the ceiling height in hundreds of feet. The ceiling height is the height at which more than half the sky is covered by clouds.
The analysis uses the elevation value of each cell of the digital elevation model (DEM) to determine visibility to or from a particular cell. The location of this particular cell varies depending on the needs of the analysis. For example, a viewshed analysis is commonly used to locate communication towers or determining the view from a road.
Thus, cloud ceiling and flight visibility are the most important variables for safe operations during all phases of flight. [3] The minimum weather conditions for ceiling and visibility for VFR flights are defined in FAR Part 91.155, and vary depending on the type of airspace in which the aircraft is operating, and on whether the flight is ...
With good visibility, pilots can determine the aircraft attitude by utilising visual cues from outside the aircraft, most significantly the horizon.Without such external visual cues, pilots may be subject to sensory illusions and must use an alternative reference for the attitude, which is usually provided by gyroscopically-driven instruments such as the attitude indicator ("artificial horizon").