“A convergência meridiana é utilizada para transformar o azimute verdadeiro, determinando por via astronômica, em azimute plano (norte de quadrícula) e vice-versa.O azimute plano é utilizado, em geodésia, no cálculo do transporte de coordenadas planas sistema UTM (E,N).

Em topografia de minas, para locação da área em campo, o azimute verdadeiro é determinado, a partir do azimute plano por técnica GNSS.”

http://www.amiranet.com.br/files/produtos/sumario_2097.pdf


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Note added at 1 hr (2012-02-15 13:25:22 GMT)
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“The grid azimuth is defined as the angle measured in the horizontal plane between the grid
meridian (which is parallel to the central meridian of a plane rectangular coordinate system,
for example state plane or UTM) of P1 and the vertical plane spanned by the normal to P1
and P2. This is very similar to the definition of the geodetic azimuth. It is possible to convert between geodetic azimuth and grid azimuth by applying the mapping angle (also known as
convergence) and possibly the T-t correction (also known as the second term correction or
the curvature correction).”

http://www.terrasurv.com/azimuths.pdf

“Then from the above point by a line drawn 340° 30' grid azimuth for a distance of 600 metres.”

http://www.assembly.nl.ca/legislation/sr/annualregs/CNR1996/...