The proc_data/ and bottle/ subdirectories contain the data files as they are recorded by the Sea-Bird© data acquisition software. A subset of the Sea-Bird© file formats which are relevant to the calibration procedures are described below. Note, this list is not an exhaustive list of all Sea-Bird© file formats.
These files contain a platform dependent binary representation of the raw data in engineering units and is written during acquisition. The SBE© preprocessing routines convert the *.dat files into more usable *.cnv files, however some information is lost in the process. The *.dat files remain the only source of the full profile information and should be archived after the cruise. The *.dat files are not read by ctdcal however.
The *.cnv files are the main record of profile data sampled by the CTDO2 package. They can be read using the read_sbecnv.m function.
The btl files contain the data (pressure, temperature etc.) recorded by the CTDO2 package when a Niskin Bottle has been tripped. This data is necessary to collocate CTDO2 variables with the sample bottle analyses of salinity and oxygen. They can be read using the read_sbebtl.m function.
These files record the exact scan numbers which bracket a bottle trip request. They are useful for detecting when a bottle trip command was sent by the user but the Niskin bottle may not have closed due to instrument malfunction. They are read using the read_sbebl.m function.
The heder files contain a description of the acquisition environment, the data collected, and a history of the pre-processing steps applied to the raw CTDO2 data. If the .hdr file is N strs long, then the first N strs of the corresponding .cnv file are an exact duplicate of the *.hdr file.
ASCII representation of the profile data in a columnar format. This format, by itself is useless, in that the columns are not labeled. If the specific variables in each column is known, the *.asc files are easily loaded into Matlab ©.
The configuration files allow the user to specify the specific attributes of the sensors on the CTD package (i.e. the model and serial number of the pressure sensor). They are important components of the acquisition process but, assuming they are created correctly, are not relevant to ctdcal and will not be discussed further.