function xyz2ned,param,loc

if n_elements(loc) eq 3 then begin
  loc=xyz2latlon(loc)
  loc=loc[0:1]
endif

if n_elements(loc) eq 2 then begin
  T=dblarr(3,3)
  T[0,0]=-sin(loc[0])*cos(loc[1])
  T[0,1]=-sin(loc[0])*sin(loc[1])
  T[0,2]=cos(loc[0])
  T[1,0]=-sin(loc[1])
  T[1,1]=cos(loc[1])
  T[1,2]=0
  T[2,0]=-cos(loc[0])*cos(loc[1])
  T[2,1]=-cos(loc[0])*sin(loc[1])
  T[2,2]=-sin(loc[0])
  T=invert(T,/double)
  dim=size(param)
  if (dim[0] eq 1) and (dim[1] eq 3) then begin
    output=T##param
  endif else begin
    if (dim[0] eq 2) and (dim[1] eq 3) and (dim[2] eq 3) then begin
      output=T##param##transpose(T)
    endif else output=0
  endelse
endif else output=0

return,output
end