Convergence of Meridians definition of Convergence of Meridians in the Free Online Encyclopedia.

convergence of meridians [kən′vər·jəns əv mə′rid·ē·ənz]

(mapping)

The angular drawing together of the geographic meridians in passing from the equator to the poles.

The relative difference of directions of meridians at specific points on the meridians; it is equal to the product of the difference of longitude and the convergence factor.

Convergence of Meridians

The convergence of the meridians at any point of the earth ellipsoid is the angle γ^s between the tangent to the meridian at the point and that tangent to the ellipsoid at the point that is parallel to the plane of some initial meridian. The convergence is a function of the difference in longitude l of the indicated meridians, the latitude B of the point, and the parameters of the ellipsoid. An approximate expression for the convergence is given by the equation γ^s = l sin B.

The convergence of meridians in the plane of a geodetic projection or a cartographic projection is sometimes referred to as the Gauss convergence. It is the angle γ between the tangent to the representation of some meridian and the first coordinate axis—the axis of abscissae—of the given projection; this axis is usually a representation of the central meridian of the territory being mapped. In the case of conformal projections of the ellipsoid referred to isometric coordinates, γ is equal, except, perhaps, for the sign, to the argument of the derivative of the function of a complex variable that describes the projection under consideration. By disregarding infinitesimals of third and higher orders relative to l, the equation γ = γ^s is obtained.

The convergence of meridians must be known in order to carry out the numerical processing of the results of geodetic measurements and to solve various geodetic problems. On topographic maps the convergence can be defined as the angle of rotation of the kilometer grid of the map relative to the map’s margin.

REFERENCES

Krasovskii, F. N. Rukovodstvo po vysshei geodezii, part 2. Moscow, 1955.
Urmaev, N. A. Sferoidicheskaia geodeziia. Moscow, 1955.
Morozov, V. P. Kurs sferoidicheskoi geodezii. Moscow, 1969.

Mentioned in	?		Encyclopedia browser	?		Full browser	?
No references found			conventional current conventional design conventional door conventional grouping conventional memory conventional milling conventional mining conventional programming conventional spinning conventional sprinkler Conventionalism Conventionality convento converged network Convergence convergence circuit convergence coil convergence constant convergence control convergence electrode convergence factor convergence in measure convergence limit convergence line convergence magnet Convergence of Meridians convergence pressure convergence ratio Convergence Theory convergence zone Convergence Zones Convergence, Point of convergent convergent die convergent integral convergent precipitation convergent sequence convergent series Convergent Technologies Convergent Technologies Operating System convergent zone paths convergent-divergent nozzle converging lens converging mirror conversation piece conversational Conversational Algebraic Language conversational compiler Conversational LISP conversational mode Conversational Monitor System			Convergence Accommodation to Convergence Convergence Algorithm convergence circuit convergence coil convergence constant convergence control Convergence de luttes anti-autoritaires et anti-capitalistes Convergence des Luttes Anti-Capitalistes Convergence Diagnosis and Output Analysis convergence electrode convergence excess convergence excess convergence excess convergence factor convergence factor Convergence for Democracy convergence fusional reserve convergence fusional reserve convergence fusional reserve Convergence in Europe and the Process of Enlargement and Association Convergence in measure convergence insufficiency Convergence Internet Audiovisuel Numérique convergence limit convergence line convergence magnet Convergence Numérique Convergence of Audio/Video and Information Technology Convergence of Broadcast and Mobile Services Convergence of Meridians Convergence of Movements of the Peoples of the Americas Convergence of Organizations and Movements of Peoples of the Americas convergence pressure Convergence radius convergence ratio Convergence Santé Hôpital Convergence Set-Top Box Convergence Sublayer Convergence Sublayer - Protocol Data Unit Convergence Sublayer Indicator Convergence Sublayer Protocol Data Unit convergence technologies Convergence Technologies Professional Convergence Theory Convergence Transportation Electronics Association Convergence Virtual Machine Convergence zone Convergence zone Convergence zone Convergence zone Convergence zone Convergence zone convergence zones convergence zones convergence zones convergence zones convergence zones Convergence, Action, Jeunesse, Enfance, Femme convergence, cervical Convergence, Point of