scholarly journals Design and Analysis of a Next-Generation Wide Field-of-View Earth Radiation Budget Radiometer

2020 ◽  
Vol 12 (3) ◽  
pp. 425 ◽  
Author(s):  
Luca Schifano ◽  
Lien Smeesters ◽  
Thomas Geernaert ◽  
Francis Berghmans ◽  
Steven Dewitte
Keyword(s):  
Mechanical Design ◽  
Thermal Analyses ◽  
Field Of View ◽  
Radiation Budget ◽  
Radiative Energy ◽  
Wide Field ◽  
Expected Performance ◽  
Wide Field Of View ◽  
Earth Radiation Budget ◽  
Earth Radiation

Climate on Earth is determined by the Earth Radiation Budget (ERB), which quantifies the incoming and outgoing radiative energy fluxes. The ERB can be monitored by non-scanning wide field-of-view radiometers, or by scanning narrow field-of-view radiometers. We propose an enhanced design for the wide field-of-view radiometer, with as key features the use of a near-spherical cavity to obtain a uniform angular sensitivity and the integration of the shuttered electrical substitution principle, eliminating long term drifts of the radiometer and improving its time response. The target absolute accuracy is 1 W/m 2 and the target stability is 0.1 W/m 2 per decade for the measurement of the total outgoing Earth’s radiation. In order to increase the spatial resolution and to separate the total outgoing radiation into reflected Solar and emitted thermal radiation, we propose the joint use of the radiometer with wide field-of-view Shortwave (400–900 nm) and Longwave (8–14 μm) cameras. This paper presents the concept and design of the novel wide field-of-view radiometer, including simulations and analyses of its expected performance. We focus on mechanical design and the measurement characteristics based on optical and thermal analyses. In combination with the cameras, we obtain an estimated accuracy of 0.44 W/m 2 .

New in-flight calibration adjustment of the NIMBUS 6 and 7 Earth Radiation Budget wide field of view radiometers

1984 ◽  
Vol 89 (D4) ◽  
pp. 5057-5076 ◽  
Author(s):  
H. Lee Kyle ◽  
Frederick B. House ◽  
Philip E. Ardanuy ◽  
Herbert Jacobowitz ◽  
Robert H. Maschhoff ◽  
...  
Keyword(s):  
Field Of View ◽  
Radiation Budget ◽  
Wide Field ◽  
Wide Field Of View ◽  
Earth Radiation Budget ◽  
Earth Radiation

scholarly journals Numerical Focusing of a Wide Field-of-View Instrument for Monitoring the Planetary Energy Budget

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 17
Author(s):  
Anum Barki Ashraf ◽  
J. Robert Mahan ◽  
Kory J. Priestley ◽  
Mohan Shankar
Keyword(s):  
Field Of View ◽  
Radiation Budget ◽  
Wide Field ◽  
Optical Instruments ◽  
Wide Field Of View ◽  
Monitoring Applications ◽  
Earth Radiation Budget ◽  
Recovery Error ◽  
Ray Trace ◽  
Earth Radiation

Wide field-of-view optical instruments based on Ritchey-Crétien telescopes have been proposed to replace narrow field-of-view scanning instruments for Earth radiation budget monitoring applications. A disadvantage of such instruments is that they are subject to significant focal plane distortion. A novel numerical focusing scheme is proposed and demonstrated using a Monte Carlo ray-trace-based simulation of the performance of a candidate instrument. Results are presented which indicate that image recovery error can be significantly reduced using the proposed algorithm.

Libera and Continuity of the Earth Radiation Budget Climate Data Record

2021 ◽  
Author(s):  
Peter Pilewskie ◽  
Maria Hakuba ◽  
Keyword(s):  
Rapid Development ◽  
Radiation Budget ◽  
Radiative Energy ◽  
Wide Field ◽  
Climate Data ◽  
The Earth ◽  
Data Record ◽  
Earth Radiation Budget ◽  
Climate Data Record ◽  
Earth Radiation

<p>The NASA Libera Mission, named for the daughter of Ceres in Roman mythology, will provide continuity of the Clouds and the Earth’s Radiant Energy System (CERES) Earth radiation budget (ERB) observations from space. Libera’s  attributes enable a seamless extension of the ERB climate data record. Libera will acquire integrated radiance over the CERES FM6-heritage broad spectral bands in the shortwave (0.3 to 5 μm), longwave (5 to 50 μm) and total (0.3 to beyond 100 μm) and adds a split-shortwave band (0.7 to 5 μm) to provide deeper insight into shortwave energy deposition. Libera leverages advanced detector technologies using vertically aligned black-carbon nanotubes with closed-loop electrical substitution radiometry to achieve radiometric uncertainty of approximately 0.2%. Libera will also employ a wide field-of-view camera to provide scene context and explore pathways for separating future ERB missions from complex imagers.</p><p>The Libera science objectives associated with continuity and extension of the ERB data record are to identify and quantify processes responsible for ERB variability on various time scales. Beyond data continuity, Libera’s new and enhanced observational capabilities will advance our understanding of spatiotemporal variations of radiative energy flow in the visible and and near-infrared spectral regions. They will also enable the rapid development of angular distribution models to facilitate near-IR and visible radiance-to-irradiance conversion.</p>

scholarly journals Radiation budget estimates over Africa and surrounding oceans: inter-annual comparisons

2007 ◽  
Vol 7 (10) ◽  
pp. 2617-2629 ◽  
Author(s):  
A. Ben Rehouma ◽  
M. Viollier ◽  
M. Desbois
Keyword(s):  
Field Of View ◽  
Radiation Budget ◽  
Wide Field ◽  
Narrow Strip ◽  
Annual Variations ◽  
Wide Field Of View ◽  
Low Cloud ◽  
Net Flux ◽  
The Impact ◽  
Local Anomalies

Abstract. Three independent datasets of Radiation Budget at the top of the atmosphere (TOA) spanning two decades are compared: the Scanner Narrow Field of View data (from ERBE, ScaRaB, and CERES instruments, 1985–2005), the ERBS Nonscanner Wide Field of View data (1985–1998) and the simulated broadband fluxes from the International Satellite Cloud Climatology Project (ISCCP-FD, 1983–2004). The analysis concerns the shortwave (SW) reflected flux, the longwave (LW) emitted flux and the net flux at the Top Of the Atmosphere (TOA) over Africa and the surrounding oceans (45° S–45° N/60° W–60° E), a region particularly impacted by climate variability. For each month, local anomalies are computed with reference to the average over this large region, and their differences between the 2002–2005 and 1985–1989 periods are analysed. These anomalies are, for a large part, independent on the general observed trends (about 2.5 W m−2 per decade), which may be affected by possible calibration drifts. Although the regional flux anomalies can be related to calibration through the scene identification and the choice of the anisotropy correction, this effect is limited if the calibration drifts remains reasonable. Large inter-annual variations are observed locally. Over a part of the South East Atlantic (35°–10° S/10° W–10° E), including the marine low cloud area off Angola, there is a decrease of the yearly means of net flux estimated to 2.2, 3 and 6 W m−2 respectively for the Scanner, Nonscanner and ISCPP-FD data. Over a narrow strip of the Sahel Zone, the net flux increases by about 5 W m−2. We believe that these observations are real. They could be due to the impact of calibration drift but only if the drifts were significant (>4%) and correlated between the datasets, which is highly improbable.

scholarly journals Global Daytime Mean Shortwave Flux Consistency Under Varying EPIC Viewing Geometries

2021 ◽  
Vol 2 ◽  
Author(s):  
Wenying Su ◽  
Lusheng Liang ◽  
David P. Duda ◽  
Konstantin Khlopenkov ◽  
Mandana M. Thieman
Keyword(s):  
Radiant Energy ◽  
Energy System ◽  
Field Of View ◽  
Radiation Budget ◽  
Distribution Models ◽  
The Earth ◽  
Imaging Camera ◽  
Earth Radiation Budget ◽  
Mean Square Errors ◽  
Earth Radiation

One of the most crucial tasks of measuring top-of-atmosphere (TOA) radiative flux is to understand the relationships between radiances and fluxes, particularly for the reflected shortwave (SW) fluxes. The radiance-to-flux conversion is accomplished by constructing angular distribution models (ADMs). This conversion depends on solar-viewing geometries as well as the scene types within the field of view. To date, the most comprehensive observation-based ADMs are developed using the Clouds and the Earth’s Radiant Energy System (CERES) observations. These ADMs are used to derive TOA SW fluxes from CERES and other Earth radiation budget instruments which observe the Earth mostly from side-scattering angles. The Earth Polychromatic Imaging Camera (EPIC) onboard Deep Space Climate Observatory observes the Earth at the Lagrange-1 point in the near-backscattering directions and offers a testbed for the CERES ADMs. As the EPIC relative azimuth angles change from 168◦ to 178◦, the global daytime mean SW radiances can increase by as much as 10% though no notable cloud changes are observed. The global daytime mean SW fluxes derived after considering the radiance anisotropies at relative azimuth angles of 168◦ and 178◦ show much smaller differences (<1%), indicating increases in EPIC SW radiances are due mostly to changes in viewing geometries. Furthermore, annual global daytime mean SW fluxes from EPIC agree with the CERES equivalents to within 0.5 Wm−2 with root-mean-square errors less than 3.0 Wm−2. Consistency between SW fluxes from EPIC and CERES inverted from very different viewing geometries indicates that the CERES ADMs accurately quantify the radiance anisotropy and can be used for flux inversion from different viewing perspectives.

scholarly journals Radiation budget estimates over Africa and surrounding oceans: inter-annual comparisons

2006 ◽  
Vol 6 (6) ◽  
pp. 13139-13163
Author(s):  
A. Ben Rehouma ◽  
M. Viollier ◽  
M. Desbois
Keyword(s):  
Field Of View ◽  
Radiation Budget ◽  
Wide Field ◽  
Narrow Strip ◽  
Annual Variations ◽  
Wide Field Of View ◽  
Low Cloud ◽  
Net Flux ◽  
Local Anomalies ◽  
Yearly Means

Abstract. Three independent datasets of Radiation Budget at the top of the atmosphere (TOA) spanning two decades are compared: the Scanner Narrow Field of View data (from ERBE, ScaRaB, and CERES instruments, 1985–2005), the ERBS Nonscanner Wide Field of View data (1985–1998) and the simulated broadband fluxes from the International Satellite Cloud Climatology Project (ISCCP-FD, 1983–2004). The analysis concerns the shortwave (SW) reflected flux, the longwave (LW) emitted flux and the net flux at the Top Of the Atmosphere (TOA) over Africa and the surrounding oceans (45° S–45° N/60° W–60° E), a region particularly impacted by climate variability. For each month, local anomalies are computed with reference to the average over this large region, and their differences between the 2002–2005 and 1985–1989 periods are analysed. These anomalies are relative values and are mostly independent on the absolute observed trends (about 2.5 Wm−2 per decade) which may be affected by possible calibration drifts. Large inter-annual variations are observed locally. Over a part of the South East Atlantic (35°–10° S/10° W–10° E), including the marine low cloud area off Angola, there is a decrease of the yearly means of net flux estimated to 2.2, 3 and 6 Wm−2 respectively for the Scanner, Nonscanner and ISCPP-FD data. Over a narrow strip of the Sahel Zone, the net flux increases by about 5 Wm−2.

Sign in / Sign up

Export Citation Format

Share Document