scholarly journals On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A band and the quality of solar-induced chlorophyll fluorescence (SIF): comparison of SIF between GOSAT and OCO-2

2019 ◽  
Vol 12 (12) ◽  
pp. 6721-6735 ◽  
Author(s):  
Haruki Oshio ◽  
Yukio Yoshida ◽  
Tsuneo Matsunaga
Keyword(s):  
Chlorophyll Fluorescence ◽  
Spatial Scales ◽  
Bare Soil ◽  
Estimation Accuracy ◽  
Terrestrial Vegetation ◽  
Analogue Circuit ◽  
Zero Level ◽  
Global Carbon Budget ◽  
Photosynthetic Production

Abstract. Satellite remote sensing of solar-induced chlorophyll fluorescence (SIF) has attracted attention as a method for improving the estimation accuracy of the photosynthetic production of terrestrial vegetation in recent years. The Greenhouse gases Observing Satellite (GOSAT) has the ability to observe both SIF and the concentrations of CO2 and CH4 and thus is expected to contribute to the understanding of the global carbon budget. Evaluating artefact signals (e.g. zero-level offset caused by non-linearity in the analogue circuit in the case of GOSAT) is effective for inferring the instrument status and important for retrieving SIF from satellite measurements. Here we investigate the characteristics of the zero-level offset and the consistency of satellite-derived SIFs by comparing the derived SIF with the Orbiting Carbon Observatory-2 (OCO-2) SIF at multiple spatial scales (footprint to global). The zero-level offset was evaluated using filling-in signals over bare soil while investigating the criteria for identifying barren areas. An analysis of the temporal variation of the zero-level offset over a period of 9 years suggests that the radiometric sensitivity of the GOSAT spectrometer changed after switching the optics path selector in January 2015. The GOSAT SIF was highly consistent with the OCO-2 SIF, with a bias within 0.1 mW m−2 nm−1 sr−1 for most months and an inter-region bias of about 0.2 mW m−2 nm−1 sr−1. Our results agree with the previous comparisons and support the consistency among the present satellite SIF data, which is important for the utilization of those data.

scholarly journals On the zero-level offset in the GOSAT TANSO-FTS O<sub>2</sub> A-band and the quality of solar-induced chlorophyll fluorescence (SIF): Comparison of SIF between GOSAT and OCO-2

2019 ◽  
Author(s):  
Haruki Oshio ◽  
Yukio Yoshida ◽  
Tsuneo Matsunaga
Keyword(s):  
Chlorophyll Fluorescence ◽  
Spatial Scales ◽  
Small Variation ◽  
Bare Soil ◽  
Correction Method ◽  
Estimation Accuracy ◽  
Terrestrial Vegetation ◽  
Analogue Circuit ◽  
Zero Level ◽  
Offset Correction

Abstract. Satellite remote sensing of solar-induced chlorophyll fluorescence (SIF) has attracted attention as a method for improving the estimation accuracy of the photosynthetic production of terrestrial vegetation in recent years. The Greenhouse gases Observing SATellite (GOSAT) has the ability to observe both SIF and the concentrations of CO2 and CH4 and thus is expected to contribute to understanding of the global carbon budget. Evaluating artifact signals (e.g., zero-level offset caused by non-linearity in the analogue circuit in the case of GOSAT) is effective for inferring the instrument status and important for retrieving SIF from satellite measurements. Here we investigate the criteria for identifying vegetation-free areas to evaluate the zero-level offset and the offset correction method, while comparing the derived SIF with the Orbiting Carbon Observatory-2 (OCO-2) SIF at multiple spatial scales (footprint to global). The criteria were determined as a small variation in the radiance within the GOSAT instantaneous field of view for cloudy ocean scenes and a higher albedo in the 2.0 μm band than in the 1.6 μm band for bare soil scenes, which were slightly different from the previously used criteria. The GOSAT SIF that was most consistent with the OCO-2 SIF was obtained when the zero-level offset was evaluated from bare soil over the globe, with a bias of about 0.1 mW m−2 nm−1 sr−1. Our results agree with the previous comparisons and support the consistency among the present satellite SIF data, which is important for the utilization of those data. An analysis of the temporal variation of the zero-level offset over a period of 9 years suggests that the radiometric sensitivity of the GOSAT spectrometer changed after switching the optics path selector in January 2015.

The Determinants of Entrepreneurship Development in Spatial Systems

2017 ◽  
Vol 13 ◽  
pp. 8-24
Author(s):  
Zbigniew Zioło
Keyword(s):  
Spatial Scales ◽  
Institutional Barriers ◽  
Entrepreneurship Development ◽  
Continental Scale ◽  
Spatial Systems ◽  
Business Conditions ◽  
Mutual Relations ◽  
Growth Shape ◽  
Strategic Goal

The processes of technological  progress create new opportunities for economic, social and cultural growth, shape new relations between economic  entities and their environment,  and influence changes in the determinants  of entrepreneurship development.  These processes vary significantly in certain geographic locations, characterised by an enormous  diversity of natural, social, economic and cultural structures. As a consequence, this creates different opportunities  and different conditions for the development of entrepreneurship in certain spatial scales, from the continental scale, through national and regional to local scales. The article presents complex conditions  for the development of entrepreneurship, highlights its limitations resulting from institutional  barriers, and the importance of knowing the mechanisms of mutual relations between spatial systems and the influence of control instruments. The quality of central and local government authorities is of particular significance here, which do not always properly use the mechanisms of rational business support. A serious barrier to the development of entrepreneurship is the low quality of social capital, manifested in a lack of trust in institutional authorities and reluctance to engage in entrepreneurship and business development. The conclusions point out that further research should be developed that will take into account changing business conditions, with a defined strategic goal of raising the quality and standard of living, international competitiveness of the country and products in different market categories.

scholarly journals Synergetic Use of Sentinel-1 and Sentinel-2 Data for Soil Moisture Mapping at Plot Scale

2018 ◽  
Vol 10 (8) ◽  
pp. 1285 ◽  
Author(s):  
Reza Attarzadeh ◽  
Jalal Amini ◽  
Claudia Notarnicola ◽  
Felix Greifeneder
Keyword(s):  
Soil Moisture ◽  
Optical Data ◽  
Estimation Accuracy ◽  
Support Vector ◽  
Practical Applications ◽  
Initial Stage ◽  
Object Based ◽  
Single Polarization ◽  
Selection Of

This paper presents an approach for retrieval of soil moisture content (SMC) by coupling single polarization C-band synthetic aperture radar (SAR) and optical data at the plot scale in vegetated areas. The study was carried out at five different sites with dominant vegetation cover located in Kenya. In the initial stage of the process, different features are extracted from single polarization mode (VV polarization) SAR and optical data. Subsequently, proper selection of the relevant features is conducted on the extracted features. An advanced state-of-the-art machine learning regression approach, the support vector regression (SVR) technique, is used to retrieve soil moisture. This paper takes a new look at soil moisture retrieval in vegetated areas considering the needs of practical applications. In this context, we tried to work at the object level instead of the pixel level. Accordingly, a group of pixels (an image object) represents the reality of the land cover at the plot scale. Three approaches, a pixel-based approach, an object-based approach, and a combination of pixel- and object-based approaches, were used to estimate soil moisture. The results show that the combined approach outperforms the other approaches in terms of estimation accuracy (4.94% and 0.89 compared to 6.41% and 0.62 in terms of root mean square error (RMSE) and R2), flexibility on retrieving the level of soil moisture, and better quality of visual representation of the SMC map.

Effects of gibberellic acid and prohexadione-calcium on growth, chlorophyll fluorescence and quality of okra plant

2007 ◽  
Vol 51 (3) ◽  
pp. 575-578 ◽  
Author(s):  
I. Ilias ◽  
G. Ouzounidou ◽  
A. Giannakoula ◽  
P. Papadopoulou
Keyword(s):  
Chlorophyll Fluorescence ◽  
Gibberellic Acid ◽  
Prohexadione Calcium

scholarly journals The Value of Citizen Science in Increasing Our Knowledge of Under-Sampled Biodiversity: An Overview of Public Documentation of Auchenorrhyncha and the Hoppers of North Carolina

2021 ◽  
Vol 9 ◽  
Author(s):  
Kyle D. Kittelberger ◽  
Solomon V. Hendrix ◽  
Çağan Hakkı Şekercioğlu
Keyword(s):  
North Carolina ◽  
Citizen Science ◽  
Spatial Scales ◽  
The United States ◽  
Undescribed Species ◽  
The Past ◽  
Global Biodiversity ◽  
Temporal And Spatial

Due to the increasing popularity of websites specializing in nature documentation, there has been a surge in the number of people enthusiastic about observing and documenting nature over the past 2 decades. These citizen scientists are recording biodiversity on unprecedented temporal and spatial scales, rendering data of tremendous value to the scientific community. In this study, we investigate the role of citizen science in increasing knowledge of global biodiversity through the examination of notable contributions to the understanding of the insect suborder Auchenorrhyncha, also known as true hoppers, in North America. We have compiled a comprehensive summary of citizen science contributions—published and unpublished—to the understanding of hopper diversity, finding over fifty previously unpublished country and state records as well as dozens of undescribed and potentially undescribed species. We compare citizen science contributions to those published in the literature as well as specimen records in collections in the United States and Canada, illuminating the fact that the copious data afforded by citizen science contributions are underutilized. We also introduce the website Hoppers of North Carolina, a revolutionary new benchmark for tracking hopper diversity, disseminating knowledge from the literature, and incorporating citizen science. Finally, we provide a series of recommendations for both the entomological community and citizen science platforms on how best to approach, utilize, and increase the quality of sightings from the general public.

scholarly journals Highly sampled measurements in a controlled atmosphere at the Biosphere 2 Landscape Evolution Observatory

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jorge Arevalo ◽  
Xubin Zeng ◽  
Matej Durcik ◽  
Michael Sibayan ◽  
Luke Pangle ◽  
...  
Keyword(s):  
Landscape Evolution ◽  
Spatial Scales ◽  
Bare Soil ◽  
Biosphere 2 ◽  
University Of Arizona ◽  
Relative Water ◽  
Sampled Measurements ◽  
Temporal And Spatial ◽  
The University ◽  
Temperature Water

Abstract Land-atmosphere interactions at different temporal and spatial scales are important for our understanding of the Earth system and its modeling. The Landscape Evolution Observatory (LEO) at Biosphere 2, managed by the University of Arizona, hosts three nearly identical artificial bare-soil hillslopes with dimensions of 11 × 30 m2 (1 m depth) in a controlled and highly monitored environment within three large greenhouses. These facilities provide a unique opportunity to explore these interactions. The dataset presented here is a subset of the measurements in each LEO’s hillslopes, from 1 July 2015 to 30 June 2019 every 15 minutes, consisting of temperature, water content and heat flux of the soil (at 5 cm depth) for 12 co-located points; temperature, relative humidity and wind speed above ground at 5 locations and 5 different heights ranging from 0.25 m to 9–10 m; 3D wind at 1 location; the four components of radiation at 2 locations; spatially aggregated precipitation rates, total subsurface discharge, and relative water storage; and the measurements from a weather station outside the greenhouses.

scholarly journals The Solar-Induced Chlorophyll Fluorescence Imaging Spectrometer (SIFIS) Onboard the First Terrestrial Ecosystem Carbon Inventory Satellite (TECIS-1): Specifications and Prospects

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 815 ◽  
Author(s):  
Shanshan Du ◽  
Liangyun Liu ◽  
Xinjie Liu ◽  
Xinwei Zhang ◽  
Xianlian Gao ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Signal To Noise Ratio ◽  
Simulated Data ◽  
Terrestrial Ecosystem ◽  
Global Scale ◽  
Terrestrial Vegetation ◽  
Atmospheric Transmission ◽  
Imaging Spectrometer ◽  
Ecosystem Carbon ◽  
Carbon Inventory

The global monitoring of solar-induced chlorophyll fluorescence (SIF) using satellite-based observations provides a new way of monitoring the status of terrestrial vegetation photosynthesis on a global scale. Several global SIF products that make use of atmospheric satellite data have been successfully developed in recent decades. The Terrestrial Ecosystem Carbon Inventory Satellite (TECIS-1), the first Chinese terrestrial ecosystem carbon inventory satellite, which is due to be launched in 2021, will carry an imaging spectrometer specifically designed for SIF monitoring. Here, we use an extensive set of simulated data derived from the MODerate resolution atmospheric TRANsmission 5 (MODTRAN 5) and Soil Canopy Observation Photosynthesis and Energy (SCOPE) models to evaluate and optimize the specifications of the SIF Imaging Spectrometer (SIFIS) onboard TECIS for accurate SIF retrievals. The wide spectral range of 670−780 nm was recommended to obtain the SIF at both the red and far-red bands. The results illustrate that the combination of a spectral resolution (SR) of 0.1 nm and a signal-to-noise ratio (SNR) of 127 performs better than an SR of 0.3 nm and SNR of 322 or an SR of 0.5 nm and SNR of 472 nm. The resulting SIF retrievals have a root-mean-squared (RMS) diff* value of 0.15 mW m−2 sr−1 nm−1 at the far-red band and 0.43 mW m−2 sr−1 nm−1 at the red band. This compares with 0.20 and 0.26 mW m−2 sr−1 nm−1 at the far-red band and 0.62 and 1.30 mW m−2 sr−1 nm−1 at the red band for the other two configurations described above. Given an SR of 0.3 nm, the increase in the SNR can also improve the SIF retrieval at both bands. If the SNR is improved to 450, the RMS diff* will be 0.17 mW m−2 sr−1 nm−1 at the far-red band and 0.47 mW m−2 sr−1 nm−1 at the red band. Therefore, the SIFIS onboard TECIS-1 will provide another set of observations dedicated to monitoring SIF at the global scale, which will benefit investigations of terrestrial vegetation photosynthesis from space.

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