EarthCARE BBR detectors performance characterization

The Broadband Radiometer (BBR) is an instrument being developed for the ESA EarthCARE satellite. The BBR instrument objective is to provide measurements of the reflected short-wave (0.25-4.0 mu m) and emitted long-wave (4.0-50 mu m) TOA radiance over three along-track views (forward, nadir and backward). The instrument has three fixed telescopes, one for each view, each containing a broadband detector. Each detector consists of an uncooled focal plane array (FPA) hybridized with a readout integrated circuit (ROIC) and a proximity electronics circuit-card assembly (CCA) packaged in an aluminum base plate with cover. The detectors, based on INO's VOx microbolometer technology, are required to provide fast pixel response time (< 6 ms), uniform spectral response over the entire spectral range (achieved by the development of a gold black absorber), and low NEDT under the instrument operating conditions. The detectors development has now passed the critical design review (CDR) and various development units (among which the most recent is the engineering model (EM)) have been shown to meet the specification requirements. This paper first provides a description of the detector design, followed by its principles of operation. It further presents and discusses measurement and analysis results for the performance characterization of the engineering model in the context of the applicable requirements.