;+ ; ; NAME: ; ; stx_sum_pixel_data ; ; PURPOSE: ; ; Construct a summed STIX pixel data structure (i.e., sum the counts to form a 32x4 element matrix, ; normalize for livetime, incident area, lenght of the energy interval considered, and correct for grid transmission) ; ; CALLING SEQUENCE: ; ; pixel_data_summed = stx_sum_pixel_data(pixel_data) ; ; INPUTS: ; ; pixel_data: STIX pixel data structure to be summed ; ; KEYWORDS: ; ; sumcase: string indicating which pixels are summed. Options: ; - 'ALL': top row + bottom row + small pixels ; - 'TOP': top row pixels only ; - 'BOT': bottom row pixels only ; - 'TOP+BOT': top row + bottom row pixels ; - 'SMALL': small pixels only ; Default, 'TOP+BOT' ; ; ; subc_index: indices of the imaging detectors used. Default, indices of the subcollimators from 10 to 3. ; Used just for computing the total number of counts in the image ; ; silent: if set, no message is printed ; ; OUTPUTS: ; ; 'stx_pixel_data_summed' structure containing: ; ; - LIVE_TIME: 32-element array containing the live time of each detector in the considered time interval ; - TIME_RANGE: two-element STX_TIME array containg the start and the end of the selected time interval ; - ENERGY_RANGE: array containing the lower and the upper edge of the selected energy interval ; - COUNT_RATES: array 32x4 containing the value of the countrates A,B,C,D recorded by each subcollimator. ; Pixel measurements are summed (from 12 to 4) and countrates are normalized by live time, ; incident area and length of the energy interval considered (rates are then in counts s^-1 cm^-2 keV^-2). ; Optionally, they are corrected for the grid internal shadowing and transmission ; - COUNTS_RATES_ERROR: array 32x4 containing the errors associated with the countrates A,B,C,D recorded by each detector ; (compression errors and statistical errors are taken into account, no systematic errors are added) ; - TOT_COUNTS: total number of counts recorded by the imaging subcollimators selected by means of 'subc_index' ; - TOT_COUNTS_BKG: estimate of the total number of background counts recorded by the imaging subcollimators (selected with 'subc_index') ; in the considered time and energy interval ; - RCR: Rate Control Regime status during the flare measurement ; - SUMCASE: string indicating which pixels are summed (see above comment on 'sumcase' keyword for more details) ; - DETECTOR_MASKS: 32-element array containing information on the detectors used for the measurement ; (1 if the corresponding detector has been used, 0 otherwise) ; ; HISTORY: August 2022, Massa P., created ; October 2023, Massa P., fixed bug in the estimation of the total number of bkg counts ; January 2026, Massa P., removed 'xy_flare' entry as grid transmission correction is not applied anymore to the raw counts ; March 2026, Massa P., made it compatible with new ELUT correction ; ; CONTACT: ; paolo.massa@fhnw.ch ;- function stx_sum_pixel_data, pixel_data, subc_index=subc_index, sumcase=sumcase, silent=silent default, sumcase, 'TOP+BOT' default, silent, 0 ;; Imaging detectors default, subc_index, stx_label2ind(['10a','10b','10c','9a','9b','9c','8a','8b','8c','7a','7b','7c',$ '6a','6b','6c','5a','5b','5c','4a','4b','4c','3a','3b','3c']) ;;************** Sum counts, background counts and errors case sumcase of 'TOP': begin pixel_ind = [0] end 'BOT': begin pixel_ind = [1] end 'TOP+BOT': begin pixel_ind = [0,1] end 'ALL': begin pixel_ind = [0,1,2] end 'SMALL': begin pixel_ind = [2] end end ;; Check if 'sumcase' is compatible with pixel masks (i.e., if the selected pixels have been used) pixel_masks = reform(pixel_data.PIXEL_MASKS,4,3) if total(pixel_masks[*,pixel_ind]) lt 4.*n_elements(pixel_ind) then message, "Change 'sumcase': one of the selected pixels is not available" counts = reform(pixel_data.COUNTS, 32, 4, 3) ;; Compute total counts: saved in the pixel data structure tot_counts = total(counts[subc_index,*,pixel_ind]) counts = n_elements( pixel_ind ) eq 1 ? reform(counts[*, *, pixel_ind]) : $ total( counts[*, *, pixel_ind], 3 ) counts_error = reform(pixel_data.COUNTS_ERROR, 32, 4, 3) counts_error = n_elements( pixel_ind ) eq 1 ? reform(counts_error[*, *, pixel_ind]) : $ sqrt(total( counts_error[*, *, pixel_ind]^2, 3 )) ;;************** Livetime correction: units are counts s^-1 live_time = cmreplicate(pixel_data.LIVE_TIME, 4) live_time_error = cmreplicate(pixel_data.LIVE_TIME_ERROR, 4) count_rates = f_div(counts,live_time) counts_rates_error = abs(count_rates) * sqrt( f_div(counts_error,counts)^2. + f_div(live_time_error,live_time)^2. ) ;;************** Normalization per keV: units are counts s^-1 keV^-1 energy_range = pixel_data.ENERGY_RANGE count_rates = count_rates/(energy_range[1]-energy_range[0]) counts_rates_error = counts_rates_error/(energy_range[1]-energy_range[0]) ;;************** Normalization for effective area: units are counts s^-1 keV^-1 cm^-2 subc_str = stx_construct_subcollimator() eff_area = subc_str.det.pixel.area eff_area = reform(transpose(eff_area), 32, 4, 3) eff_area = n_elements( pixel_ind ) eq 1 ? reform(eff_area[*, *, pixel_ind]) : total(eff_area[*,*,pixel_ind], 3) count_rates = count_rates/eff_area counts_rates_error = counts_rates_error/eff_area ;;************** Fill in calibrated pixel data structure pixel_data_summed = stx_pixel_data_summed() pixel_data_summed.LIVE_TIME = pixel_data.LIVE_TIME pixel_data_summed.TIME_RANGE = pixel_data.TIME_RANGE pixel_data_summed.ENERGY_RANGE = pixel_data.ENERGY_RANGE pixel_data_summed.COUNT_RATES = count_rates pixel_data_summed.COUNTS_RATES_ERROR = counts_rates_error pixel_data_summed.TOT_COUNTS = pixel_data.tot_counts pixel_data_summed.TOT_COUNTS_BKG = pixel_data.tot_counts_bkg pixel_data_summed.RCR = pixel_data.RCR pixel_data_summed.SUMCASE = sumcase pixel_data_summed.DETECTOR_MASKS = pixel_data.DETECTOR_MASKS return, pixel_data_summed end