A high dynamic radiation measurement instrument: the Bolometric Oscillation Sensor (BOS)

Abstract

Abstract. The Bolometric Oscillation Sensor (BOS) is a broadband radiation measurement instrument onboard the PICARD satellite that was active between 2010 and 2014. The main detector is a thermistor attached black coated surface, which was permanently exposed to space without any optical and aperture accessories. The temperature measurements are used within a transfer function to determine variations in incoming solar irradiance as well as the terrestrial radiation. In the present article, the measurement principle of the BOS and its transfer function are presented. The performance of the instrument is discussed based on laboratory experiments and space observations from the PICARD satellite. The comparison of the short-term variation of total solar irradiance (TSI) with absolute radiometers such as VIRGO/SOHO and TIM/SORCE over the same period of time suggests that the BOS is a relatively much simpler but very effective sensor for monitoring electromagnetic radiation variations from visible to infrared wavelengths.

Interannual variation of global net radiation flux as measured from space

“…The PICARD‐BOS has a hemispherical field of view [ Zhu et al , ]. It is designed to be sensitive to the relative change of received net flux, rather than to the absolute level of each individual flux component.…”

“…The PICARD‐BOS was operated between July 2010 and March 2014. The details on the working principle of the instrument and data reduction of measurements could be found in Zhu et al []. Total solar irradiance data (TSI) registered by the PREcision MOnitoring Sensor (PREMOS), on the same PICARD platform [ Schmutz et al , ] was also included in the analysis to calibrate the absolute level of the direct solar radiation measured by PICARD‐BOS.…”

“…Global coverage is reached after two days of data acquisition. The original PICARD‐BOS observational drift resulted from the degradation of paint on the sensor (Figure a) is modeled using a linear regression function [ Zhu et al , ]. The total amount of radiation (TAR; Figure b) is calculated after the instrument drift correction as the sum of aforementioned radiation fluxes: where f tar is the total amount of radiation, f s is the solar radiation, f r is the reflected solar radiation, f t is the reemitted thermal radiation, and t is time.…”

“…The ascending and descending node times were 6 A.M. and 6 P.M., respectively. The broadband bolometric oscillation sensor (BOS) operated as a part of the payload of PICARD [Zhu et al, 2015]. It has continuously measured the total amount of radiation (TAR) including the direct solar where f tar is the total amount of radiation, f s is the solar radiation, f r is the reflected solar radiation, f t is the reemitted thermal radiation, and t is time.…”

Remote sensing of earth’s energy budget: synthesis and review

“…There are also multiple broadband sensors abroad geostationary satellites such as the Geostationary Earth Radiation Budget (GERB) sensors, carried by Meteosat-8 launched in 2002, and Meteosat-9, launched in 2007(Brindley and Russell 2017, and the broadband bolometric oscillation sensor (BOS) operated as a part of the payload of PICARD between June 2010 and March 2014 (Zhu et al 2015). In addition to conventional geostationary satellites, the Deep Space Climate Observatory (DSCOVR) satellite, placed at the neutral gravity point between the Earth and the Sun (Lagrange point 1), has been offering high temporal observations (15-60 min) of the sunlit side of the Earth since 2015.…”