function norh_gt_freq, index, numerical=numerical

;+
; NAME:
;       norh_gt_freq
;
; PURPOSE:
;       Return the obseving frequancy 
;
; CALLING SEQUENCE:
;       freq=norh_gt_freq(index)
;
; INPUTS:
;       index: index structure
;
; HISTORY:
;       Writtern 1998-05-29 TY
;       Modified 2000-04-19 TY based on V. Grechnev's suggestion
;-


  out = index.norh.obs_freq

if keyword_set(numerical) then begin
  outstr=out
  out=fltarr(n_elements(outstr))
  whr=where((outstr eq '17GHz'),count)
  if (count ge 1) then out(whr)=1.7e10
  whr=where((outstr eq '34GHz'),count)
  if (count ge 1) then out(whr)=3.4e10
endif

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

return,out

end