function norh_gt_efl, index

;+
; NAME:
;       norh_gt_efl
;
; PURPOSE:
;       Return the e-folding length of the dirty beam
;       in units of dirty-map pixel
;
; CALLING SEQUENCE:
;       efl=norh_gt_efl(index)
;
; INPUTS:
;       index: index structure
;
; HISTORY:
;       Writtern 1998-09-17 TY
;       Modified 2000-04-19 TY based on V. Grechnev's suggestion
;-


  out = index.norh.efl_in_pix_dty

if n_elements(index) eq 1 then out=out(0)

return,out

end