Each dataset is saved in a proprietary file format, consisting of 4 separate files:

.clm
Text header file with pixel dimensions, step size etc

.clw
List of wavelengths corresponding to the spectral channels. Given in nm, in binary form using single-precision (4-byte) floating point values.

.cld
The bulk of the data, given a spectrum at a time, starting at the top left pixel and moving right first. In other words, to access the data in order using nested loops, the inner loop would loop over wavelength, the middle one over columns and the outer one over rows. Stored in binary form as 16-bit unsigned integers.

.clb
This is the CCD background spectrum, which needs to be subtracted from each of the spectra in the .cld file. Stored as single-precision (4-byte) floating point values.