subroutine da_set_merc(proj) !-------------------------------------------------------------------------- ! Purpose: Sets up the remaining basic elements for the mercator projection !-------------------------------------------------------------------------- implicit none type(proj_info), intent(inout) :: proj real :: clain if (trace_use) call da_trace_entry("da_set_merc") ! Preliminary variables clain = COS(rad_per_deg*proj%truelat1) proj%dlon = proj%dx / (earth_radius_m * clain) ! Compute distance from equator to origin, and store in the ! proj%rsw tag. proj%rsw = 0.0 if (proj%lat1 .NE. 0.0) then proj%rsw = (alog(tan(0.5*((proj%lat1+90.)*rad_per_deg))))/proj%dlon end if if (trace_use) call da_trace_exit("da_set_merc") end subroutine da_set_merc