3.1  Which data windows are available ?

lw = gt_wlimits(qlds, /short) 
Window        Label         Band    Xmin   Xmax    Wmin      Wmax

  0       O_4_554_51        NIS2    344    368    553.13    555.93
  1       HE_1_584_33       NIS2    599    623    582.94    585.75
  2       O_3_599_60        NIS2    729    753    598.17    600.99
  3       MG_9_368_07       NIS1    850    874    367.22    368.91
  4       MG_10_624_94      NIS2    945    969    623.52    626.34
  5       O_5_629_73        NIS2    986   1010    628.34    631.16

The Xmin Xmax numbers give the detector start and stop pixels for each data window. The wavelengths are calculated using an average pixel-wavelength conversion applicable to the date of observation. The table above also shows that the data windows are 25 pixels wide.

To put the data of the first window into an array:

data = gt_windata(qlds,0)

help,data
DATA            FLOAT     = Array[25, 10, 73]

The wavelength dimension has 25 pixels, 10 exposures were taken by stepping in SolarX, and only 73 pixels along the slit (SolarY) were telemetred.

In general, the variable data will then be a data array with from 2 to 4 dimensions. The dimensions are always in the order (Wavelength , SolarX, SolarY, Time). The fourth dimension (Time) is only added where the observation sits at the same SolarX location and takes repeated exposures. In that case the SolarX dimension is retained, but only has one element.

3.1.1  Timings for each slit exposure

If you are interested in comparing actual timings for the events as seen by different instruments, you need to get the starting time for each of the exposures (i.e. slit positions):

time_start=gt_start(QLDS,/exposure,/truncate)