As an example let us create a master flat frame by combining all calibration flat field associated to a science frame. As an example we take the science frame susi0100.bdf. Suppose the association table contains 4 flat field associated with susi0100.bdf. To do these into the master flat field we enter:
COMBINE/CCD FF susi0100
The command will first go the association table and select all rows that have the science frame susi0100.bdf in the column :SC. From this subtable it will store all frames in the column :FF in a temporary MIDAS catalogue called susi0100_ff.cat. This catalogue will be used as input for the final combining. Since we didn't specify the output frame name, the default naming convention will be used: the output flat will be susi0100_ff.bdf. The output on the screen and stored in the MIDAS log file will look like ( VERBOSE=YES):
Combining FLAT frames: Input=susi0100_ff.cat; output=susi0100_ff.bdf
Statistics of frame no. 0:
area [@60,@10:@1070,@1020] of frame
minimum, maximum: 5.560000e+02 8.654000e+03
mean, standard_deviation: 6.101316e+03 1.913127e+02
Statistics of frame no. 1:
area [@60,@10:@1070,@1020] of frame
minimum, maximum: 8.390000e+02 1.276900e+04
mean, standard_deviation: 8.313817e+03 2.569877e+02
Statistics of frame no. 2:
area [@60,@10:@1070,@1020] of frame
minimum, maximum: 4.220000e+02 1.046500e+04
mean, standard_deviation: 5.622723e+03 1.722370e+02
Method=avsigclip, low= 0.00, high= 0.00
lowclip= 3.00, highclip= 3.00
frame # Ncomb Exp_time Mode Scale Offset Weight
susi0142.bdf 1 1.00 571.878 1.093 -0 0.333
susi0140.bdf 1 5.00 862.392 0.725 -0 0.333
susi0143.bdf 1 5.00 441.692 1.416 -0 0.333
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Statistics of output frame susi0100_ff :
area [@60,@10:@1070,@1020] of frame
minimum, maximum: 6.045866e+02 1.023942e+04
mean, standard_deviation: 6.886717e+03 2.060752e+02
Ncomb Exp_time Mean Mode N_undef
susi0100_ff 3 3.933 6886.72 623.478 0
Undefined pixels, set to `null value' (= 0.000000)
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