ArgoCanada / medsrtqc

An experimental container for Argo Canada realtime quality control code
https://argocanada.github.io/medsrtqc/
MIT License
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Conversion from BETA_BACKSCATTERINGxxx to BBPxxx #10

Closed cgrdn closed 2 years ago

cgrdn commented 2 years ago

Raw data from the backscattering meter (BETA_BACKSCATTERINGxxx) are transmitted as counts.

The equation to convert from counts to backscatter is:

BBPxxx = 2\pi\chi[(BETA_BACKSCATTERINGxxx - DARK_BACKSCATTERINGxxx)*SCALE_BACKSCATTERINGxxx - BETASWxxx]

where:

\chi: conversion factor depending on sensor angle, provided in Argo reference table

BETASWxxx is the contribution to the Volume Scattering Function (VSF) by pure seawater at xxx nanometers wavelength. Code to calculate this based on Zhang et al. (2009) provided here: http://doi.org/10.17882/42916

The coefficients should be included in PREDEPLOYMENTCALIB***, ex:

PREDEPLOYMENT_CALIB_EQUATION="BBP700=2pichi((BETA_BACKSCATTERING700-DARK_BACKSCATTERING700_O)SCALE_BACKSCATTERING700-BETASW700)" PREDEPLOYMENT_CALIB_COEFFICIENT="DARK_BACKSCATTERING700=71, DARK_BACKSCATTERING700_O=80, SCALE_BACKSCATTERING700=0.008, chi=1.076, BETASW700 (contribution of pure sea water) is calculated at 124°" PREDEPLOYMENT_CALIB_COMMENT="Sullivan et al., 2013, Zhang et al., 2009, BETASW700 is the contribution by the pure seawater at 700nm, requiring temperature, salinity and using a depolarization of 0.039, its default value. the script can be found at http://doi.org/10.17882/42916.