hs6PROCESS_INTERACTIVE

Consistent with up to date protocols, hs6PROCESS_INTERACTIVE processes raw backscattering data as sampled in natural water bodies using HOBI Labs Hydroscat-6 (hs6). hs6PROCESS_SEABASS should is also designed to be compatible with Hydroscat-4 and 2.

This Matlab script processes backscattering coefficients, as sampled in natural water bodies using HOBI Labs Hydroscat-6 Backscattering Meter and Fluorometer (hs6). Consistent with up to date protocols, hs6PROCESS_INTERACTIVE processes raw backscattering data (engineering units) sampled in natural water bodies using hs6. hs6PROCESS_INTERACTIVE is also designed to be compatible with Hydroscat-4 (hs4) and Hydroscat-2 (hs2)] instrument variants. We point out however that the expectation for two fluorescence (fl) channels is hardcoded into the hs6PROCESS_SEABASS script. Thus (uncorrected) input hs6 data MUST contain two fl channels. Otherwise it may not work properly. The wavelengths of these hardcoded fl channels are as follows: 470 excitation/510 emission (channel 1) and 442 excitation/700 emission (channel 2). Nevertheless, if these wavelength values are incorrect, user should not worry. hs6PROCESS_SEABASS does not perform any processing steps on fl values that require knowing the correct fl wavelengths. This means that user can simply "correct" fl wavelengths in the output files after processing.

hs6PROCESS_INTERACTIVE uses up to date processing protocols (as of June 2019) to process backscattering coefficients, which it outputs as both individual as well as depth-binned spectra. All output data products are formatted as to be consistent with Hydrolight 5.0. User should run hs6PROCESS_INTERACTIVE AFTER running acsPROCESS_INTERACTIVE, if he/she wishes to perform Doxaran et al. (2016) sigma-correction.

Inputs: metadata_HeaderFile_hs6.txt - ascii file containing metadata required to process hs6 data

Outputs: Station_#bbp.mat - MAT/HDF5 file containing individual particulate backscattering (bbp) + fl spectra. No sigma correction applied. Station#_bbp_bin#_HE53.txt - Seabass-formatted ascii file(s) containing sigma-corrected and depth-binned bbp spectra, as well as depthb-binned fl spectra. One binned hs6 file (of equal bin size) is produced bin absorption file listed in metadata_HeaderFile_hs6.txt. These files are formatted for Hydrolight 5.0

Required Matlab Scripts and Functions: dataSNATCH5.m depthSELECTOR.m Doxarian_SIGMA.m hs6_binFUNCTION_HE53.m HS6_dataFLAGGER5.m HS6_fileREADER_MS.m lambda_INTERPOLATE.m metaData_Reader_hs6.m morel_Correction_pw.m

Program Description: hs6PROCESS_INTERACTIVE processes raw field-collected backscattering coefficients following a series of steps. It is outfitted to process raw data contained in Hydrosoft-output ascii (.dat) files. Hydrosoft is a free software package provided by HOBI Labs for preliminary processing of its optical oceanographic instrumentation. It uses the following steps:

1. Reads ascii data. Accepts uncorrected backscattering coefficients and uncorrected fluorescence.
2. Calculates particulate backscattering coefficients (bbp) a. Calculates wavelength-dependent backscattering coefficients of pure-water using methods devised by Morrel (1974) b. Subtracts pure-water backscattering coefficients from total (uncorrected) backscattering coefficients
3. Prompts user to select a subset of the cast for processing (unselected portions of the cast will be excluded from all subsequent steps)
4. QA/QC bbp data. bbp spectra are flagged and removed by user: a. user flags 'suspect' bbp spectra that may be contaminated b. user determines whether to remove previously-flagged bbp spectra. If an a spectrum is removed, its corresponding (paired) fl values are removed automatically.
5. Produces MAT/HDF5 file containing processed individual bbp spectra, corresponding fl values, as well as their depths and wavelengths
6. Depth-bins bbp and fl spectra. a. Sigma-correct bbp spectra according to Doxaran et al. (2016) using depth-binned absorption spectra measured with ac-s. A binned absorption spectrum is chosen for each bbp spectrum using nearest neighbor approach with respect to depth. b. bbp and fl are depth-binned at the same bin size as that of the the absorption spectra used to sigma-correct them
7. Produces Hydrolight-compatible ascii (.txt) file(s) containing depth-binned bbp and fl averages.

User Instructions:

1. Fill out metadata_HeaderFile_hs6.txt (as specified below)
2. Run hs6PROCESS_INTERACTIVE using Matlab command window.
3. Select appropriate metadata_HeaderFile_hs6.txt file when prompted.
4. Select subset of hs6 cast for processing a. Examine time-series plot of hs6 cast (appears automatically). Plot displays hs6 vertical position (depth) over time (spectrum index). b. To select subset of hs6 cast, enter "y" into command window c. Select cast subset by entering indices into command window. These can be entered individually (not recommended) or as an array, using a colon to separate beginning and end indices (recommended). Matlab's figure data cursor can help determine indices. d. Evaluate previously-selected cast subset(s) (highlighted in red). To select an additional cast subset enter repeat steps b-c. e. If satsified with previously-made selection(s) enter "n" into the command window. Re-confirm you are satisfied by entering "y" f. If unsatisfied with selections, enter "redo" or "exit" to start over.
5. Flag questionable bbp spetra for possible removal. a. Examine depth profiles of bbp channel. These channels are oriented vertically by depth index (as opposed to actual depth), with shallowest index on top. b. To create an acceptable range of bbp values, enter "y" into command window in response to message "Create ACS Limit?" To skip steps 5c-e, enter "n".** c. When prompted, use the command window to: enter an upper limit for bbp, press enter, enter a lower limit for bbp, and press enter. "0" is good lower limit because bbp is always positive. d. Your selected Limits are indicated on depth profile by black vertical lines. Enter "y" into command window to accept limits or "n" to try again. e. Any spectrum containing bbp values outside of user-selected range for channels 1-8 will be automatically flagged. A flagged spectrum is indicated by a row of white stars (one on each bbp channel). If satisfied with limits, enter "n" when "Create ACS limit? (y/n)" re-appears on command window. f. To flag a single spectrum enter "y" in response to "Flag additional hs6 readings? (y/n):" command window prompt. Enter "n" to skip this step completely. If "y" is entered, prompt will read "Enter depth of data you want to flag: ". Enter the index of the spectrum of interest into the command window. You then will be asked to confirm or reject your selection ("y" or "n") as you view it. Repeat as many times as necessary. Respond with "n" to "Flag additional hs6 readings? (y/n):" to stop flagging bbp specta. h. Enter "y" on command window in response to "Accept modified HS6 data? (y/n)". This piece of code is an artifact from a previous feature. However the coder (me) was too lazy to remove it, so please answer "y" so you don't mess anything up!
6. Evaluate flagged bbp spectra. You will now be asked to accept or reject your flagged bbp spectra. a. View your first flagged bbp spectrum in the subplot display. Flagged spectrum (red) will be plotted with all bbp spectra (blue) that fall within the 2 m depth bin (e.g. 0-2 m, 2-4 m, etc.) that encompasses it. Flagged c spectrum will also be ploted along with bbp spectra in the adjacent 2 m depth bin(s). Solid black lines represent mean +/- 3*sigma of the unflagged c spectrum within a bin. Subplots are also labeled with numerical depth (m) of flagged spectrum. b. Compare shape and magnitude of flagged bbp spectrum against unflagged spectra. b. In the command window, enter "keep" to retain and "discard" to remove spectrum from analysis. DO NOT SELECT "EDIT" c. Confirm your decision using "y" or "n" d. Repeat steps a-c with the remainder of flagged c spectra.

Filling out metadata_HeaderFile_hs6.txt: hs6PROCESS_SEABASS relies on a metadata header to process hs6 data. All information pertaining to the specific hs6 cast should be included in this header. A header template (metadata_HeaderFile_hs6.txt), indicating important fields, is provided in the hs6PROCESS_SEABASS repository on GitHub. When filling out this header file, the first three headers (indicating user instructions) should be left alone. Required information fields contain = signs. USER SHOULD ONLY ALTER TEXT APPEARING ON THE RIGHT HAND SIDE OF =. User should indicate unavailability of desired information with "NA". DO NOT DELETE ROWS! Below are fields contained in metadata_HeaderFile_hs6.txt and instructions on how to fill them out. Spaces should never be used in header fields; use underscore instead (_).

data_file_name=indicate name of ascii (.dat) file containing unprocessed hs6 data. This file is generated using HydroSoft software created by HOBI Labs to support their instrument platforms (e.g. HydroScat, a-Beta, c-Beta & Abyss-2) by converting raw signals to engineering units. Please note: When using HydroSoft to output .dat files, user should be sure NOT to apply pure-water correction; hs6PROCESS_SEABASS applies this step already. It is ok for user to output both sigma-corrected and uncorrected backscttering coefficients as hs6PROCESS_SEABASS can differentiate between them.

data_file_name=pathway for aforementioned HydroSoft-generated ac-s .dat file (data_file_name). This pathway should include the folder in which sits, and should be ended using "/" or "" for mac and pc respectively.

affiliations=name of company or research institution with which investigators are affiliated.

investigators=lists of investigators. Multiple names should be separated by commas and "_" should be used in place of spaces.

contact=email of principle investigator

experiment=name of experiment or field campaign

station=field station number

latitude=latitude of field station. This should be indicated in decimal form. DO NOT format in minutes or seconds. Do not include Roman letters. South should be indicated with a negative sign.

longitude=longitude of field station. This should be indicated in decimal form. DO NOT format in minutes or seconds. Do not include Roman letters. West should be indicated with a negative sign.

documents=additional documents user wishes to submit to SeaBASS. DO NOT INDICATE kudelalab_HS6_readme.pdf. This is printed automatically in output files.

water_depth=bottom depth of the field station in meters. Numerals only. Do not include units.

calibration_file=name of original factory-supplied HOBI Labs calibration file. This file contains instrument-specific coefficients used to convert raw signals (measured by hs6) into engineering units. Although this file is not used by hs6PROCESS_INTERACTIVE, the user was too lazy to remove it from the code. Therefore, its still necessary to run hs6PROCESS_INTERACTIVE.

date(yyyymmdd)=indicate date on which ha6 was deployed.

kexp_vals=wavelength-dependent constants (kexp) used to calculate sigma coefficients of attenutation, Kbb, (see HydroSoft user manual or kudelalab_HS6_readme.pdf for details). These coefficients are instrument-specific and can be found inside the factory-supplied calibration file (header field=calibration_file). They should be listed in the same order as wavelengths of backscattering coefficients appear in the header of the HydroSoft-generated .dat file containing the unprocessed hs6 data (header field=data_file_name). In the event that instrument-specific Kexp_vals are unavailable for a particular Hydroscat, the constant 0.14 can be used for all wavelengths. In the event that it's used, this value should still be listed one time for each backscattering channel (e.g. 6 times for hs6).

apg_bin_files=binned ac-s measured absorption files with which to sigma-correct bbp spectra. These files must be formatted for Hydrolight 5.0 and would ideally contain data measured at the same time and location as hs6. DO NOT specify depth bin sizes in the metadata header file. hs6PROCESS_SEABASS bins hs6 data according to the bin sizes used in absorpiton files listed in hte header field. To prevent hs6PROCESS_SEABASS from depth-binning bbp and fl data, place "NA" after the = sign (e.g. apg_bin_files=NA).

apg_bin_path=pathway for apg_bin_files. This pathway must be the same for all binned absorption files should more than one be listed.

Metadata Header File Example: hs-6 metadata template Template contains information necessary for the processing of hs-6 data files (.dat) output using the HOBI Labs software program HydroSoft. Use commas to separate names of investigators and files, but DO NOT leave ANY spaces between words. If a space is unavoidable, use an underscore between words (like_this). Unknown or unavailable information should be indicated with NA. Latitude and longitude should be in decimal degrees and water depth should be in meters. Do not include units of measurement. These will be added later by the program.

DO NOT ALTER HEADER FIELDS####

data_file_name=COAST18.dat data_file_path=/Users/JBausell/Documents/acs_data/ affiliations=UC_Santa_Cruz investigators=Jesse_T_Bausell,_Easter_B_Bunny,Kris_B_Kringle contact=kudela@ucsc.edu experiment=COAST station=18 latitude=36.8972 longitude=-121.8859 documents=NA water_depth=24 calibration_files=HS990216_v3.ca date(yyyymmdd)=20181025 kexp_vals=[0.1450003,0.14499998,0.14200014,0.1439971,0.145993,0.147154] apg_bin_files=COAST_18_ac-s_bin_0.5.txt,COAST_18_ac-s_bin_1.txt,COAST_18_ac-s_bin_2.txt apg_bin_path=/Users/JBausell/Documents/acs_data/

Bibliography:

Doxaran, D., E. Leymarie, B. Nechad, A. Dogliotti, K. Ruddick, P. Gernex, and E. Knaeps, Improved correction methods for field measurements of particulate light backscattering in turbid waters. Optics express, 2016. 24: p. 3615-3637.

Morel, A, Optical Aspects of Oceanography. in Optical Aspects of Oceanography, M. G. Jerlov, and E. S. Nielsen, eds. (Academic Press Inc, 1977).