grivation, grid declination, total correction sum of magnetic deviation and grid convergence, i.e. the difference between the grid north and magnetic north
grivation, grid declination, total correction sum of magnetic deviation and grid convergence, i.e. the difference between the grid north and magnetic north
grivation, grid declination, total correction sum of magnetic deviation and grid convergence, i.e. the difference between the grid north and magnetic north
grivation, grid declination, total correction sum of magnetic deviation and grid convergence, i.e. the difference between the grid north and magnetic north
grivation, grid declination, total correction sum of magnetic deviation and grid convergence, i.e. the difference between the grid north and magnetic north