The calibrated optical drifter data files are in the following format:

Column 1: decimal day of year since Jan 1 1993 (1.5 = noon on Jan 1 1993) (GMT)
Column 2: latitude (^oN)
Column 3: longitude (^oE)
Column 4: sea surface temperature (^oC)
Column 5: Ed(490) (uW/cm²/nm)
Column 6: Lu(412) (uW/cm²/nm/sr)
Column 7: Lu(443) (uW/cm²/nm/sr)
Column 8: Lu(490) (uW/cm²/nm/sr)
Column 9: Lu(510) (uW/cm²/nm/sr)
Column 10: Lu(555) (uW/cm²/nm/sr)
Column 11: Lu(670) (uW/cm²/nm/sr)
Column 12: Lu(683) (uW/cm²/nm/sr)

The calibration files for the optical drifters have the following format:

Column 1: center wavelength (nm)
Column 2: calibration factor (F)
Column 3: immersion correction (Im)

The first seven lines of each calibration file refer to the radiance sensors.  The final row refers to the irradiance sensor.

The appropriate equation for converting raw (count) radiance values to radiance values in units of uW/cm²/nm/sr is:

Lu(calibrated) = Lu(counts) * F * Im.

A similar equation yields the calibrated irradiance values.

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

Webpage by Jasmine S. Bartlett, Oregon State University.