C+
C NAME:
C	Mk_D2V
C PURPOSE:
C	Make a velocity map at the density map surface if there is none available
C CATEGORY:
C	Data processing
C CALLING SEQUENCE:
	subroutine Mk_D2V(NN,DD,VV,D1AU,RR)
C INPUTS:
C	DD(N)		real		Density map
C	N		integer		# data points
C	D1AU		real		1 AU density
C	RR		real		Velocity map reference height
C OUTPUTS:
C	VV(N)		real		Velocity map
C CALLS:
C	BadR4
C PROCEDURE:
C	Bad values (indicated by BadR4()) are not processed
C MODIFICATION HISTORY:
C	NOV, 1995 B. Jackson (STEL,UCSD)
C	AUG-2003, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
C	    Made NN a read-only variable.
C-
	    integer	NN
	    real	DD(*)		! Density map
	    real	VV(*)		! Velocity map
	    real	D1AU
	    real	RR

	real	V0		/400./	! Standard velocity

	Bad = BadR4()

	D = 0.0				! Determine average density
	N = 0
	do I=1,NN
	    if (DD(I) .ne. Bad) then
		D = D+DD(I)
		N = N+1
	    end if
	end do
	D  = D/N
	V0 = V0*sqrt(D)

	do I=1,NN			! Make velocity map
	    if (DD(I) .eq. Bad) then
		VV(I) = Bad
	    else
		VV(I) = V0/sqrt(DD(I))
	    end if		
	end do

	return
	end