Definition files are used by ECHOMOP to specify the structure of the sdfs used to store objects produced during the reduction.
Each of these objects is referred to internally by the package using a reference name. The definition file also contains translations of these reference names into actual path specifications within sdfs.
For instance; the object referred to as OBS_LINES internally is actually stored in the reduction file in the following object
MORE.ECHELLE.WAVE_FIT_1D.OBS_LINES[TUNE_MXRFLN,NUM_ORDERS]
All such objects can be freely moved around the reduction file merely by altering their specified paths.
The default definitions are likely to be adequate for most circumstances.
For more information see 'Redefining Object paths'.
Martin Clayton