Investigating the Potential Accuracy of Spaceborne Solar-Induced Chlorophyll Fluorescence Retrieval for 12 Capable Satellites Based on Simulation Data

Remote sensing of solar-induced chlorophyll fluorescence (SIF) has been widely investigated with satellites/sensors covering the spectral range of SIF emission with fine spectral resolutions (SRs). The potential precision of SIF retrievals is limited by instruments’ spectral specifications. Here, the influence of spectral characteristics (SR, signal-to-noise ratio (SNR), and spectral coverage) on data-driven SIF retrieval was assessed using simulations, and the SIF retrieval capability of the obsolete, in-orbit, and planned satellites was evaluated from the spectral perspective. As a result, the 757–759- and 735–758-nm fitting windows (FWs) were found to be optimal for far-red SIF retrieval on satellites with fine (< 0.1 nm) and moderate (0.1–0.5 nm) SR. The 682–697-nm FW was found to perform better for red SIF retrievals. For far-red SIF retrievals, Orbiting Carbon Observatory 2 (OCO-2) and TanSat were found to have the best SIF retrieval performance, with a root-mean-square-error (RMSE
$^{\ast}$
) of lower than 0. 25 mW
$\cdot \,\,\text{m}^{-2}\,\,\cdot $
sr
$^{-1}\,\,\cdot $
nm-1, followed by satellites with moderate SRs (0.1–0.5 nm) such as CO2 monitoring (CO2M), TROPOspheric Monitoring Instrument (TROPOMI), and Global Ozone Monitoring Experiment 2 (GOME-2) (RMSE
$^{\ast} < 0.5$
mW
$\cdot \,\,\text{m}^{-2}\,\,\cdot $
sr
$^{-1}\,\,\cdot $
nm-1). The high SNR of SCanning Imaging Absorption Spectro Meter for Atmospheric CHartographY (SCIAMACHY) did not improve the far-red SIF retrieval greatly (RMSE
$^{\ast} =0.47$
mW
$\cdot \,\,\text{m}^{-2}\,\,\cdot $
sr
$^{-1}\,\,\cdot $
nm-1) but obtained a low RMSE
$^{\ast} $
at the red band (0.43 mW
$\cdot \,\,\text{m}^{-2}\,\,\cdot $
sr
$^{-1}\,\,\cdot $
nm-1). The highest red SIF retrieval potential was found on TROPOMI, with an RMSE
$^{\ast} $
of 0.41 mW
$\cdot \,\,\text{m}^{-2}\,\,\cdot $
sr
$^{-1}\,\,\cdot $
nm-1. Tropospheric Emissions Monitoring of Pollution (TEMPO) and FLuorescence Explorer (FLEX) gave poor performance (RMSE
$^{\ast} >0.9$
mW
$\cdot \,\,\text{m}^{-2}\,\,\cdot $
sr
$^{-1}\,\,\cdot $
nm-1) with their current spectral specifications. Improvement of the spectral characteristics is still needed to obtain precise SIF retrievals.