MOBY January 2005 Reprocessing

Revised April 8, 2016

This document describes how MOBY data are processed after January 2005 when these modifications were implemented.

Quality Checking

• New clear water “Kl” from Jim Mueller are now used to QC the measurements. The old deployments were reevaluated to determine if any days were now “good” based on the new lower “Kl” resulting in 147 days being changed from bad to good.
• A third flag was added to the quality checking flag, the data can now be marked "questionable". For old deployments a program will use the standard deviation and light level of the Es data to distinguish between "bad" and "questionable" data. Bad MOBY data will now be only those MOBY files which are cloud contaminated. Questionable data will be data which demonstrate a higher level of instability and are not cloud contaminated. In the current processing a person, not a program, will decide which data are questionable.
• Fibered Lu red spectrograph temperature correction
  • Adjust the Red SpectroGraph (RSG)• Lu data by regressing the pixels verse temperature to remove the temperature affect from the RSG data.
• System response (see table below)
• The pre- and post- deployment system response and wavelength calibrations were evaluated, the table below shows if the pre-cal, post-cal or mean of pre- and post- were used for each deployment and sensor. Also which version of the straylight correction is applied, if the thermal correction is applied and the state of the lamp calibrations. "BOL" means only the beginning of life lamp calibrations exist and "EOL" means the end of life calibrations have been evaluated and applied.
• Straylight correction
  • The SLC was based on the NIST characterization of MOBY using SIRCUS. SLC version 4.021 and 5.021 was used in this processing. But for deployments M249 and forward version 6 is used.
• Thermal Corrections (December 2002 MOS204cfg06)
  • Based on a thermal characterization of the spectrometer system, a correction is applied to the system response and in-water data. The correction is about 0.5% per degree.
• The times of the dark scan measurements are no longer included in the computation of the average time for Lu/Es/Ed.
• An additional form of the solar normalized water leaving radiance (Lwn2) has been included.
• The computational form is: Lwn2 = (Lw/Es).*(Fo), where Fo is the Thuillier (2003) solar spectrum. The earth-sun distance (Res) was removed from the calculation May 2012 and all deployments data were reprocessed.
• Other Current changes
  • Integration time of Lu blue spectrograph has changed to match the red spectrograph for deployment 25 forward.
  • The MODIS-2 satellite RSR's were updated

Key:

• BOL = Beginning of Life Lamp calibration done
• EOL = End of Life Lamp calibration done
• Lamp Pre/Post = BOL/BOL means both pre and post calibration lamp have only the Beginning of Life Lamp calibration done, EOL/BOL means the precals have the End of Life Lamp calibration done, etc. N/A means that calibration, pre or post, does not exist and so there is no lamp calibration to keep track of
• Pre = Pre-deployment system responses applied
• Post = Post-deployment system responses applied
• Mean = Pre and Post-deployment system responses averaged and applied
• 2Int = Blue and Red spectrographs are using difference integration time calibrations
• 1Int = Blue and Red spectrographs use the same integration time calibrations