Search results
Results From The WOW.Com Content Network
A diagram illustrating great-circle distance (drawn in red) between two points on a sphere, P and Q. Two antipodal points, u and v are also shown.. The great-circle distance, orthodromic distance, or spherical distance is the distance between two points on a sphere, measured along the great-circle arc between them.
The user may choose to replace the inclination angle by its complement, the elevation angle (or altitude angle), measured upward between the reference plane and the radial line—i.e., from the reference plane upward (towards to the positive z-axis) to the radial line. The depression angle is the negative of the elevation angle.
Note 1: Aperture-to-medium coupling loss is related to the ratio of the scatter angle to the antenna beamwidth. Note 2: The "very large antennas" are referred to in wavelengths; thus, this loss can apply to line-of-sight systems also.
The cosine rule may be used to give the angles A, B, and C but, to avoid ambiguities, the half angle formulae are preferred. Case 2: two sides and an included angle given (SAS). The cosine rule gives a and then we are back to Case 1. Case 3: two sides and an opposite angle given (SSA). The sine rule gives C and then we have Case 7. There are ...
This geometry also defines lunes of greater angles: {2} π-θ, and {2} 2π-θ. In spherical geometry, a spherical lune (or biangle) is an area on a sphere bounded by two half great circles which meet at antipodal points. [1] It is an example of a digon, {2} θ, with dihedral angle θ. [2] The word "lune" derives from luna, the Latin word for Moon.
Then the angle of the rotation is the angle between v and Rv. A more direct method, however, is to simply calculate the trace : the sum of the diagonal elements of the rotation matrix. Care should be taken to select the right sign for the angle θ to match the chosen axis:
where m is the Bragg order (a positive integer), λ B the diffracted wavelength, Λ the fringe spacing of the grating, θ the angle between the incident beam and the normal (N) of the entrance surface and φ the angle between the normal and the grating vector (K G). Radiation that does not match Bragg's law will pass through the VBG undiffracted.
Light rays enter a raindrop from one direction (typically a straight line from the Sun), reflect off the back of the raindrop, and fan out as they leave the raindrop. The light leaving the raindrop is spread over a wide angle, with a maximum intensity at 40.89–42°.