POSTER SESSION 3
15:30–17:30, Wednesday, September 16
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1399 | POSTER 63
RBRQUADRANTE PERFORMANCE IMPROVEMENTS FOR ARGO-CLASS PROFILING RADIOMETRY
The RBRquadrante is a four-channel narrow-band radiometer developed to meet the requirements of the BGC-Argo program for downwelling irradiance and PAR. An independent inter-comparison study by Xing et. al deemed the RBRquadrante suitable for BGC-ARGO; the accuracy, dark-offset, temperature sensitivity and pressure-stability shortcomings it identified were taken as avenues for improvement, the implementation of which we present here. Calibration accuracy was improved by modifying the optics to remove sensitivity to out-of-band radiation. Performance at low-light levels was ameliorated by improving the sensitivity of the sensor. The temperature dependence of the sensors was improved on three fronts: (1) components were changed to decrease the overall temperature sensitivity, (2) the dark-correction polynomial fit to temperature was increased to better capture its variability, and (3) a new firmware was released to expose data from an internal thermistor situated close to the optics, to enable end-users to develop a custom dark-temperature correction in post-processing, if desired. Combined, these improvements reduced calibration residuals by a factor 5 to 10. A new UV-transmissive diffuser was integrated, enabling the capability to measure irradiance at 380 nm, a wavelength required by BGC-Argo. The augmented performance of the RBRquadrante was validated in three ways: against an independent dataset and repeated temperature calibrations, in an independent calibration facility, and in-situ where the performance are compared to similar sensors. Finally, the recently-adopted models to computed PAR from downwelling irradiance at 380, 443, 490 and 555nm was tested and validated against direct PAR measurements.
Mathieu Dever, RBR, [email protected], https://orcid.org/0000-0002-4292-6368
Jon Taylor, RBR, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
