The Profiling Reflectance Radiometer (PRR) is an optical instrument designed to make profiles of downwelling irradiance and upwelling radiance through the upper 200 m of the water column.  Simultaneous to these profile measurements (using the PRR 600), reference downwelling irradiance measurements are also made at the sea surface using a sister instrument (the PRR 610).  The data from this reference instrument can then be used to normalize the profiled measurements to the incident irradiance. 

The PRR instruments used in this study have sensors at wavebands with the following center wavelengths:

412, 443, 490, 510, 555, and 665 nm.

Each of these wavebands have bandpasses of approximately 10 nm.  In addition to these bands, the PRR600 used also measures PAR (400-700 nm), natural fluorescence, temperature and depth, and the PRR610 also measures PAR.  Tilt and roll sensors were added to the PRR600 in September 1998.  The sampling frequency is approximately 2-3 Hz.

Further information regarding this instrument can be found at the home page for Biospherical Instruments Inc., the instrument manufacturer. 

Webpage by Jasmine S. Nahorniak, Oregon State University.