Monitoring of SPEXone

The NASA PACE (Plankton Aerosol and Ocean Ecosystems) satellite, launched on February 8, 2024, has three science instruments: (i) Ocean Color Instrument (OCI), (ii) Hyper-Angular Rainbow Polarimeter 2 (HARP2) and (iii) SPEXone multi-angle spectrometer. The PACE mission has a minimum duration of three years, with orbit maintenance capabilities for 10 years.

SPEXone is a compact multi-angle channeled spectropolarimeter with five viewing angles and hyperspectral imaging of a ~100 km swath with a spatial resolution of 4.6 x 5.4 km in the along track and across-track directions and a spatial oversampling ratio of 2. SPEXone has a spectral range from 385 to 770 nm and a spectral resolution slightly below 2 nm. High accuracy polarimetry is achieved by implementation of the dual-beam snapshot spectral polarization modulation concept, yielding two complementary spectrally modulated hyperspectral images of the same scene from which both radiance and state of linear polarization can be extracted.

The automated in-flight monitoring of the SPEXone instrument include in-orbit stability of the thermal subsystem, the optics, and the detector. The results of the in-flight monitoring are presented on separate web-pages, see the links listed in the table of content.