HS-6 processing instructions

NOTE: In April 2010 the HS-6 underwent a calibration and wavelength change.

- The new wavelengths are: 420 442 470 510 589 700

- Original wavelengths were: 442 470 510 589 671 870

Processing HS6 is generally the same procedure as the AC-9. See AC-9 processing instructions for more detailed information. The "X" cast is not processed for the HS6.

Hydroscat files must be initially removed from the DH4, then processed through Hydrosoft software on a Windows PC (or via Virtual Machine on the Mac). Files from the DH4 will have a .LOG extension. Files processed through Hydrosoft will have a .DAT extension.

The optimum/traditional directory structure for HS6

    your_workspace/HYDROSCAT/pb#/
                  dat
                  final
                  from_DH4

Processing Steps:

1) Open Hydrosoft

2) Select Processing Tab, then select Process Raw Files.

3) Select appropriate calibration file from the OCEANCOLOR calibration directory and choose input/output directories.

Calibration files for the Wetlabs instruments can be found at: /home/oceancolor/CALIBRATIONS/Wetlabs/

4) Start MATLAB in the directory you want to process the files in and run process_hs6(pb#). Directory should be parent to those listed above.

5) Once finished running process_hs6(pb#), correct bb values from AC-9 a and b values by running sigmacorrect_bb(pb#) in same directory as processing takes place.

Sigmacorrect_bb.m needs to be updated to newest HS6 Kexp calibration coefficients (check line 139 of the script). Kexp coefficient values are found by opening the HS6.cal files and looking for "Kexp" under each channel. Channels are ordered from short to long wavelengths when Kexp values are entered in sigmacorrect_bb.

Sigma correction is an adjustment to improve the accuracy of backscattering measurements in highly-attenuating water. Some light that would otherwise be detected as backscattering is lost to attenuation in the water between the instrument and the detection volume, causing backscattering to be underestimated. The correction needs attenuation measurements Kbb = a + .4b where b = c-a from AC instrument.

6) Look at values after processing by running plot_bbp_final(pb###). When opening the file to look at, look in the "final" directory. Files are "ds_##"

plot_bbp_final