The ground-based continuous hyperspectral remote sensing technique presents a unique opportunity to advance terrestrial ecosystem monitoring.Accurate retrieval of solar-induced chlorophyll fluorescence(SIF)relies heav...The ground-based continuous hyperspectral remote sensing technique presents a unique opportunity to advance terrestrial ecosystem monitoring.Accurate retrieval of solar-induced chlorophyll fluorescence(SIF)relies heavily on commercially available spectrometers with high spectral resolution(SR).However,high-SR spectrometers are resource-intensive and challenging to maintain,limiting their widespread deployment at observational sites.Here,we explored an alternative low-configuration and low-cost spectrometer for SIF retrieval at 2 sites cultivated with wheat and rice.The results revealed the strong correlations between irradiance and radiance measurements in the selected SIF bands from the high-and low-configuration spectrometers(R^(2)>0.90,average root mean square error<8.95 mW m^(−2) nm^(−1) sr^(−1),relative root mean square error<7%).Far-red SIF retrieved from both spectrometers exhibited marked correlations at both half-hourly and daily averaged scales(R^(2)>0.90).Additionally,we utilized simulated data to examine the impact of SR and signal-to-noise ratio(SNR)on the far-red SIF retrieval from both high-and low-configuration spectrometers.Strong correlations(R^(2)>0.80)were found between the simulated data with SNR≥300 and SR<2 nm.Furthermore,we investigated the relationships between crop gross primary productivity(GPP)and far-red SIF from both types of spectrometers and their ability to identify crop growth stages.SIF from both types of spectrometers exhibited high correlations with GPP(R^(2)>0.70).The dates of various wheat-specific growth stages observed using the low-configuration spectrometer were consistent with those identified by the high-configuration spectrometer,with less than a 3-d differences for wheat.Our study confirms the capabilities of the low-configuration spectrometers for far-red SIF retrievals and promotes their deployment over large-scale ground observation networks,potentially advancing the large development of low-cost ground-based SIF measurements.展开更多
基金the National Natural Science Foundation of China(42125105)the National Key Research and Development Program of China(2022YFF1301900)the Nanjing University Integrated Research Platform of the Ministry of Education-Top Talents Program(090414380033).
文摘The ground-based continuous hyperspectral remote sensing technique presents a unique opportunity to advance terrestrial ecosystem monitoring.Accurate retrieval of solar-induced chlorophyll fluorescence(SIF)relies heavily on commercially available spectrometers with high spectral resolution(SR).However,high-SR spectrometers are resource-intensive and challenging to maintain,limiting their widespread deployment at observational sites.Here,we explored an alternative low-configuration and low-cost spectrometer for SIF retrieval at 2 sites cultivated with wheat and rice.The results revealed the strong correlations between irradiance and radiance measurements in the selected SIF bands from the high-and low-configuration spectrometers(R^(2)>0.90,average root mean square error<8.95 mW m^(−2) nm^(−1) sr^(−1),relative root mean square error<7%).Far-red SIF retrieved from both spectrometers exhibited marked correlations at both half-hourly and daily averaged scales(R^(2)>0.90).Additionally,we utilized simulated data to examine the impact of SR and signal-to-noise ratio(SNR)on the far-red SIF retrieval from both high-and low-configuration spectrometers.Strong correlations(R^(2)>0.80)were found between the simulated data with SNR≥300 and SR<2 nm.Furthermore,we investigated the relationships between crop gross primary productivity(GPP)and far-red SIF from both types of spectrometers and their ability to identify crop growth stages.SIF from both types of spectrometers exhibited high correlations with GPP(R^(2)>0.70).The dates of various wheat-specific growth stages observed using the low-configuration spectrometer were consistent with those identified by the high-configuration spectrometer,with less than a 3-d differences for wheat.Our study confirms the capabilities of the low-configuration spectrometers for far-red SIF retrievals and promotes their deployment over large-scale ground observation networks,potentially advancing the large development of low-cost ground-based SIF measurements.
