;+
; NAME:
;     GET_AMPCAL_STRUCT
; PURPOSE:
;     Define structure necessary for holding reference amplitude calibration
;     information from the AMPCAL segment.
; CATEGORY:
;     OVRO APC DATA ANALYSIS
; CALLING SEQUENCE:
;     ampcal = get_ampcal_struct()
; INPUTS:
; OPTIONAL (KEYWORD) INPUT PARAMETERS:
; ROUTINES CALLED:
; OUTPUTS:
;     ampcal    an empty amplitude calibration structure
; COMMENTS:
; SIDE EFFECTS:
; RESTRICTIONS:
; MODIFICATION HISTORY:
;     Written 27-Jul-1999 by Dale E. Gary
;     20-Feb-2006  DG
;       Added a third index to FACTORS and RMS to account for both R and L
;       data--a result of all dishes having R and L.
;-
function get_ampcal_struct

   ; Define amplitude calibration structure
   ampcal = {ampcal, tlsi: get_tl_struct(), $ ; Time/Label structure for I measurements
                    tlsrl: get_tl_struct(), $ ; Time/Label structure for R/L meas.
                  factors:   fltarr(10,86,2), $ ; Amplitude factors for 10 feeds at 86 frq
                      rms:   fltarr(10,86,2)}   ; RMS error for 10 feeds at 86 frequencies

return,ampcal
end