format

Data format

The raw data are in ascii format, in counts.  The data were calibrated to physical units  using the calibration data from Satlantic, Inc.

The resulting data are formatted in 11 tab-delimited columns, in the following order:

  1. day of year (1=Jan 1 1998)
  2. decimal time (GMT)
  3. Lu412 (uW/cm²/nm/sr)
  4. Lu443 (uW/cm²/nm/sr)
  5. Lu490 (uW/cm²/nm/sr)
  6. Lu510 (uW/cm²/nm/sr)
  7. Lu555 (uW/cm²/nm/sr)
  8. Lu670 (uW/cm²/nm/sr)
  9. Lu683 (uW/cm2/nm/sr)
  10. Ed490 (uW/cm²/nm)
  11. water temperature (°C)

The Ed and Lu data are the downwelling irradiance and upwelling radiance measurements respectively.  Note that local time (HST) is 10 hours behind GMT.

 

Calibration files

Calibrations of the TSRB sensors are made by Satlantic Inc.  The current calibration file is: TSRB008e.cal (Jun 2000).  The calibration file for data prior to June 2000 is TSRB008.cal  (Nov 1994).  (To download this file using Netscape (PC or UNIX), hold the shift key while you click.  For Netscape (Mac), hold down the mouse button and choose "Save this Link as ...".  For Internet Explorer, click with the right mouse button and choose "Save Target As ...".).

The calibration file contains the following information:
Rows 1-8: radiance and irradiance calibration data
     Column 1: center wavelength (nm)
     Column 2: dark counts (D)
     Column 3: calibration factor (F)
     Column 4: immersion correction (I)
Row 9: temperature correction coefficients (c0 ... c3)

The appropriate equation for converting raw (count) irradiance values to irradiance values in units of uW/cm^2/nm is:

Ed(calibrated) = [Ed(counts)-D] * F * I.

A similar relationship converts the measured radiances (counts) to units of
uW/cm^2/nm/sr.

The temperature calibration values consist of a list of four numbers (c0 ... c3). The temperature (in degrees C) is calculated as:

T(calibrated) = c0 + c1*T(counts) + c2*T(counts)2 + c3*T(counts)3.

Note that the data presented here have already been calibrated and do not need
to have these corrections applied. The calibration file is included here for
completeness.

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Webpage by Jasmine S. Bartlett, Oregon State University.