5.1 Reading Low Dispersion Data

IUESIPS low dispersion merged spectrum (MELO) files may also be read using IUESPEC. Slit-integrated spectral data may be extracted from disk files, with options for applying the absolute calibration, correcting for camera sensitivity degradation (LWR only), and thermally induced sensitivity changes, as follows:

IUESPEC,'IMAGET',H,W,F,Q,start_wave,end_wave 

You may specify a wavelength range to which the data will be trimmed (the program will abort if a ``start_wave'' is entered without an ``end_wave'' for low dispersion data). For example, to access the MELO file for image SWP 11245 between 2400 Å and 3200 Å you could enter:

IUESPEC,'SWP11245LLG',H,W,F,Q,2400,3200

If the image was exposed in both apertures, then

IUESPEC,'SWP11245LLG',HL,WL,FL,QL

IUESPEC,'SWP11245LSM',HS,WS,FS,QS

would extract the large and small aperture data. You should note that we gave the output vectors different names to allow manipulation of data from both apertures, and we did not ask IUESPEC to trim the data. You may also specify the IMAGET and version number this way:

IUESPEC,'SWP11245LLG;1',H1,W1,F1,Q1