The PACE Mission carries three instruments: Ocean Color Instrument (OCI), Spectro-polarimeter for Planetary Exploration one (SPEXone), and Hyper-Angular Rainbow Polarimeter 2 (HARP2). The lasted information on relative spectral response (RSR) and signal to noise (SNR) is provided here for each sensor.
The OCI instrument is highly configurable with respect to spectral sampling across the blue and red hyperspectral focal plane arrays (FPAs). The baseline on-orbit configuration is employed for standard earth-viewing science data collection, and includes 119 spectral bands on the blue FPA, and 163 spectral bands on the red FPA. The latest on-orbit RSR are version 1.1.1, and were derived from flight unit testing with RSR measurements sampled at 1 nm for most wavelengths and 0.1 nm at selected wavelengths. In-band RSRs below 900 nm without 0.1-nm coverage were modeled by combining all available measurements with component level optical throughput measurements. The results were interpolated to a common 0.1-nm wavelength grid. The spectral band centers and widths, a table of the RSRs, and a table of SNR model coefficients for each band, as derived from the prelaunch measurements, are provided here for the OCI baseline configuration.
Note that OCI has two bands (near 1250 nm and 1615 nm) that are provided in both standard gain and high gain. Standard gain is provided before high gain in the tables above. Also note that the spectral band centers overlap near 600nm, at the transition between the blue and red FPA. With respect to the RSRs, occasional negative RSR values can be observed, and are due to either measurement noise (typically less than 1e-6) or electronic crosstalk.
