;+ ; FUNCTION get_sd_ave ; ; :Description: ; Obtain a tplot variable-type structure storing a time series of the values ; averaged over the given latitude/longitude range. ; ; :PARAMTERS: ; vn : a tplot variable the values in which are to be averaged ; ; :KEYWORD: ; latrng: the geographical latitude range for which the given values are averaged ; lonrng: the geographical longitude range for averaging ; maglat: Set this keyword if you give the latrng in magnetic latitude ; new_vn: Set a string to create a new tplot variable containing the averaged values ; ; :EXAMPLES: ; erg_load_sdfit, site='hok',/get ; dat = get_sd_ave( 'sd_hok_vlos_1', latrng=[60,70], lonrng=[140,170] ; ; :Author: ; Tomo Hori (E-mail: horit@stelab.nagoya-u.ac.jp) ; ; :HISTORY: ; 2011/07/03: Created ; ; $LastChangedBy: jwl $ ; $LastChangedDate: 2014-02-10 16:54:11 -0800 (Mon, 10 Feb 2014) $ ; $LastChangedRevision: 14265 $ ; $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/projects/erg/ground/radar/superdarn/get_sd_ave.pro $ ;- FUNCTION get_sd_ave, vn, latrng=latrng, lonrng=lonrng, maglat=maglat, new_vn=new_vn ;Check the arguments and keywords npar = n_params() if npar ne 1 then return, !values.f_nan if (tnames(vn[0])) eq '' then return, !values.f_nan if n_elements(latrng) ne 2 or n_elements(lonrng) ne 2 then return, !values.f_nan is_maglat = keyword_set(maglat) ;Initialize the AACGM environment if is_maglat then begin sd_init ;aacgmloadcoef, 2005 endif ;Obtain parts of the variable name prefix = strmid(vn, 0,7) ;e.g., 'sd_hok_' suf = strmid(vn,0,1,/reverse) ; e.g., '0' azmno_vn = prefix+'azim_no_'+suf ptbl_vn = prefix+ 'position_tbl_'+suf ctbl_vn = prefix+ 'positioncnt_tbl_'+suf ;Get variable values get_timespan, tr ;Time range get_data, vn, data=d, lim=vn_lim vn_v = d.v & vn_time = d.x get_data, azmno_vn, data=d azmno = d.y get_data, ctbl_vn, data= d lontbl = reform(d.y[0,*,*,0]) lattbl = reform(d.y[0,*,*,1]) scan_str = get_scan_struc_arr(vn) scant = scan_str.x scan = scan_str.y ;If maglat is set, use the AACGM lat table if is_maglat then begin glat = lattbl & glon = lontbl alt = glat & alt[*] = 400. ;[km] aacgmconvcoord, glat,glon,alt, mlat,mlon,err, /TO_AACGM lattbl = mlat endif idx = where( lattbl ge latrng[0] and lattbl le latrng[1] $ and lontbl ge lonrng[0] and lontbl le lonrng[1] ) ;if idx[0] eq -1 then return, !values.f_nan val = fltarr(n_elements(scant)) for i=0L, n_elements(scant)-1 do begin tmpscan = reform(scan[i,*,*]) if idx[0] ne -1 then val[i] = mean( tmpscan[idx], /nan ) $ else val[i] = !values.f_nan endfor ;Save as a tplot variable if keyword_set(new_vn) then begin if (size(new_vn))[1] eq 7 then begin store_data, new_vn, data={x:scant, y:val}, $ lim={ytitle:vn_lim.ytitle, yrange:vn_lim.zrange, constant:0 } endif endif ;Return the data structure containing the average values return, {x:scant, y:val} end