scholarly journals Constructing a New Inter-Calibration Method for DMSP-OLS and NPP-VIIRS Nighttime Light

2020 ◽  
Vol 12 (6) ◽  
pp. 937 ◽  
Author(s):  
Jinji Ma ◽  
Jinyu Guo ◽  
Safura Ahmad ◽  
Zhengqiang Li ◽  
Jin Hong
Keyword(s):  
Infrared Imaging ◽  
Dynamic Range ◽  
Calibration Method ◽  
Logistic Function ◽  
Coefficient Of Determination ◽  
Nighttime Light ◽  
Development Assessment ◽  
China Region

The anthropogenic nighttime light (NTL) data that are acquired by satellites can characterize the intensity of human activities on the ground. It has been widely used in urban development assessment, socioeconomic estimate, and other applications. However, currently, the two main sensors, Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) and Suomi National Polar-orbiting Partnership Satellite’s Visible Infrared Imaging Radiometer Suite (NPP-VIIRS), provide inconsistent data. Hence, the application of NTL for long-term analysis is hampered. This study constructed a new inter-calibration method for DMSP-OLS and NPP-VIIRS nighttime light to solve this problem. First, NTL data were processed to obtain vicarious site across China. By comparing different candidate models, it is discovered the Biphasic Dose Response (BiDoseResp) model, which is a weighted combination of sigmoid functions, can best perform the regression between DMSP-OLS and logarithmically transformed NPP-VIIRS. The coefficient of determination of BiDoseResp model reaches 0.967. It’s residual sum of squares is 6.136 × 10 5 , which is less than 6.199 × 10 5 of Logistic function. After obtaining the BiDoseResp-calibrated VIIRS (BDRVIIRS), we smoothed it by a filter with optimal parameters to maximize the consistency. The result shows that the consistency of NTL data is greatly enhanced after calibration. In 2013, the correlation coefficient between DMSP-OLS and original NPP-VIIRS data in the China region is only 0.621, while that reaches to 0.949 after calibration. Finally, a consistent NTL dataset of China from 1992 to 2018 was produced. When compared with the existing methods, our method is applicable to the full dynamic range of DMSP-OLS. Besides, it is more suitable for country or larger scale areas. It is expected that this method can greatly facilitate the development of research that is based on the historical NTL archive.

scholarly journals Evaluation of Pathologic Complete Response as a Surrogate for Long-Term Survival Outcomes in Triple-Negative Breast Cancer

2020 ◽  
Vol 18 (8) ◽  
pp. 1096-1104
Author(s):  
Min Huang ◽  
Joyce O’Shaughnessy ◽  
Jing Zhao ◽  
Amin Haiderali ◽  
Javier Cortes ◽  
...  
Keyword(s):  
Triple Negative ◽  
Pathologic Complete Response ◽  
Complete Response ◽  
Sensitivity Analyses ◽  
Coefficient Of Determination ◽  
Survival Outcomes ◽  
Term Survival ◽  
Long Term Survival

Background: Pathologic complete response (pCR) is a common efficacy endpoint in neoadjuvant therapy trials for triple-negative breast cancer (TNBC). Previous studies have shown that pCR is strongly associated with improved long-term survival outcomes, including event-free survival (EFS) and overall survival (OS). However, the trial-level associations between treatment effect on pCR and long-term survival outcomes are not well established. This study sought to evaluate these associations by incorporating more recent clinical trials in TNBC. Methods: A literature review identified published randomized controlled trials (RCTs) of neoadjuvant therapy for TNBC that reported results for both pCR and EFS/OS. Meta-regression models were performed to evaluate the association of treatment effect on pCR and EFS/OS. Sensitivity analyses were conducted to assess the impact of divergent study designs. Results: Ten comparisons from 8 RCTs (N=2,478 patients) were identified from the literature review. The log (odds ratio) of pCR was a significant predictor of the log (hazard ratio) of EFS (P=.003), with a coefficient of determination of 0.68 (95% CI, 0.41–0.95). There was a weaker association between pCR and OS (P=.18), with a coefficient of determination of 0.24 (95% CI, 0.01–0.77). Consistent results were found in the exploratory analysis and sensitivity analyses. Conclusions: This is the first study that has shown a trial-level association between pCR and survival outcomes in TNBC. By incorporating the most up-to-date RCTs, this study showed a significant trial-level association between pCR and EFS. A positive association between pCR and OS was also recorded.

scholarly journals China’s city-level carbon emissions during 1992–2017 based on the inter-calibration of nighttime light data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiandong Chen ◽  
Ming Gao ◽  
Shulei Cheng ◽  
Xin Liu ◽  
Wenxuan Hou ◽  
...  
Keyword(s):  
Carbon Emissions ◽  
Infrared Imaging ◽  
Carbon Intensity ◽  
Nighttime Light Data ◽  
Reduction Strategies ◽  
Nighttime Light ◽  
Novel Method ◽  
Data Source ◽  
Emission Reduction Strategies

AbstractAccurate, long-term, full-coverage carbon dioxide (CO2) data in units of prefecture-level cities are necessary for evaluations of CO2 emission reductions in China, which has become one of the world’s largest carbon-emitting countries. This study develops a novel method to match satellite-based Defense Meteorological Satellite Program’s Operational Landscan System (DMSP/OLS) and Suomi National Polar-orbiting Partnership’s Visible Infrared Imaging Radiometer Suite (NPP/VIIRS) nighttime light data, and estimates the CO2 emissions of 334 prefecture-level cities in China from 1992 to 2017. Results indicated that the eastern and coastal regions had higher carbon emissions, but their carbon intensity decreased more rapidly than other regions. Compared to previous studies, we provide the most extensive and long-term CO2 dataset to date, and these data will be of great value for further socioeconomic research. Specifically, this dataset provides a foundational data source for China’s future CO2 research and emission reduction strategies. Additionally, the methodology can be applied to other regions around the world.

scholarly journals S-NPP VIIRS Day Night Band On-Board Solar Diffuser Calibration Validation Using the Scheduled Lunar Collections

2021 ◽  
Vol 13 (6) ◽  
pp. 1093
Author(s):  
Taeyoung Choi ◽  
Changyong Cao
Keyword(s):  
Infrared Imaging ◽  
Dynamic Range ◽  
Spectral Response ◽  
High Gain ◽  
Radiometric Calibration ◽  
Calibration Source ◽  
Global Space ◽  
Long Term Trends ◽  
Calibration Coefficients

Similar to the Reflective Solar Band (RSB) calibration, Suomi-National Polar-orbiting Partnership (S-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) on-board calibration of Day Night Band (DNB) is based on the Solar Diffuser (SD) observations in the Low Gain State (LGS). DNB has a broad spectral response covering a wavelength range roughly from 500 nm to 900 nm with a large dynamic range from three different gain states called High Gain State (HGS), Mid Gain State (MGS), and LGS. The calibration of MGS and HGS is also dependent on the LGS gain estimation with the gain ratios for each gain state. Over the lifetime of S-NPP VIIRS operations, the LGS gains have been derived from the on-board SD observations since its launch in October 2011. In this study, the lifetime LGS gains are validated by the lunar calibration coefficients (defined as F-factors) using a lunar irradiance model called Global Space-based Inter-Calibration System (GSICS) Implementation of RObotic Lunar Observatory (ROLO) (GIRO). Using the moon as an independent on-orbit calibration source, the S-NPP VIIRS DNB on-board SD based radiometric calibration is validated by the lunar F-factors within two percent of the lunar F-factors in terms of the standard deviation in the long-term trends over nine years of the S-NPP VIIRS operation.

scholarly journals Cross-Sensor Nighttime Lights Image Calibration for DMSP/OLS and SNPP/VIIRS with Residual U-Net

2021 ◽  
Vol 13 (24) ◽  
pp. 5026
Author(s):  
Dmitry Nechaev ◽  
Mikhail Zhizhin ◽  
Alexey Poyda ◽  
Tilottama Ghosh ◽  
Feng-Chi Hsu ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Dynamic Range ◽  
Satellite System ◽  
Sensor Calibration ◽  
Environmental Light ◽  
Nighttime Lights ◽  
Military Conflicts ◽  
Highly Correlated ◽  
Polar Satellite

Remote sensing of nighttime lights (NTL) is widely used in socio-economic studies of economic growth, urbanization, stability of power grid, environmental light pollution, pandemics and military conflicts. Currently, NTL data are collected with two sensors: (1) Operational Line-scan System (OLS) onboard the satellites from the Defense Meteorology Satellite Program (DMSP) and (2) Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi NPP (SNPP) and NOAA-20 satellites from the Joint Polar Satellite System (JPSS). However, the nighttime images acquired by these two sensors are incompatible in spatial resolution and dynamic range. To address this problem, we propose a method for the cross-sensor calibration with residual U-net convolutional neural network (CNN). The CNN produces DMSP-like NTL composites from the VIIRS annual NTL composites. The pixel radiances predicted from VIIRS are highly correlated with NTL observed with OLS (0.96 < R2 < 0.99). The method can be used to extend long-term series of annual NTL after the end of DMSP mission or to cross-calibrate same year NTL from different satellites to study diurnal variations.

scholarly journals New optical sensor based on the immobilization of a triazene ligand in PVC membrane for Hg(II) ion

2017 ◽  
Vol 82 (3) ◽  
pp. 317-328
Author(s):  
Homa Shafiekhani ◽  
Fahimeh Nezam ◽  
Shahriyar Bahar
Keyword(s):  
Optical Sensor ◽  
Dynamic Range ◽  
Direct Determination ◽  
Pvc Membrane ◽  
Sensing Element ◽  
Wide Dynamic Range ◽  
Optode Membrane ◽  
Term Response

This paper describes the development and creation of a new sensitive optical sensor that is quite selective to Hg(II) ions in aqueous solution. The sensing element, the newly synthesized methyl 2-[3-(3-methylphenyl)-2-triazen- 1-yl]benzoate, incorporated into a plasticized poly(vinyl chloride) membrane, is able to determine Hg(II) ion with a high selectivity over a wide dynamic range from 5.0?115.1 ?g L-1 at pH 7.5 with a lower detection limit of 0.67 ?g L-1. The response of the optode membrane to Hg(II) was fully reversible and revealed a very good selectivity towards Hg(II) ion from a wide variety of other metal ions in solution. The overall performance characteristics of the sensor were evaluated and good reversibility, wide dynamic range, long life span, long-term response stability and high reproducibility were found. The proposed optical sensor gives proper results in applications including direct determination of the Hg(II) ion in real environmental samples.

Calibration Method of Cool Box Used for Measuring of Thermal Conductivity Coefficient

2016 ◽  
Vol 861 ◽  
pp. 335-342
Author(s):  
Petr Kurečka ◽  
Jiří Teslík
Keyword(s):  
Thermal Conductivity ◽  
Temperature Difference ◽  
Building Materials ◽  
Measurement Accuracy ◽  
Thermal Conductivity Coefficient ◽  
Calibration Method ◽  
Box Method ◽  
Natural Building

One of the methods used for determining of the thermal conductivity coefficient value of building materials is the Calibrated and Guarded Hot Box method. This method is based on the principle of measuring the heat flux density that passes through the test specimen at a temperature difference between warm and cool parts of the measuring box. For measuring of thermal conductivity coefficient is at the Faculty of Civil Engineering of VŠB-TUO used the Cool Box. Measuring in Cool Box uses the same principle of measuring as Calibrated and Guarded Hot Box. For creating temperature difference during the measurements at the Cool Box is not used heat, but cold. Measurement of the thermal conductivity coefficient by a Cool Box is very complex in terms of measurement accuracy. That the resulting values as accurate as possible, it is necessary to calibrate itself refrigerated cabinets and all sensors that are used for measurements. This paper describes the principles of calibration of Cool Box and other components, which are used for measuring the thermal conductivity coefficient of selected natural building materials. Determination of the thermal insulation properties of selected materials is part of a long-term research focused on conventional and unconventional natural building materials.

The Flexible Microtube Plasma as Post-Ionization Source for Cholesterol in nano-Electrospray Mass Spectrometry

2021 ◽  
Author(s):  
Daniel Foest ◽  
Alexander Knodel ◽  
Robert Ahrends ◽  
Cristina Coman ◽  
Joachim Franzke ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Dynamic Range ◽  
Standard Addition ◽  
Polar Compounds ◽  
Ionization Mass ◽  
Ionization Source ◽  
Long Term Stability ◽  
Novel Approach

Cholesterol serves as a biomarker in clinical- and life-sciences. The determination of abnormal levels can indicate several types of human diseases. However, the low polarity of free cholesterol makes it hardly accessible by (nano) electrospray ionization mass spectrometry (nESI-MS). As novel approach, the flexible microtube plasma (FμTP) for post-ionization allows the determination of low-polar compounds like cholesterol in combination with nESI-MS. Focusing on the analytical performance, the activated post-ionization leads to an increased cholesterol signal by a factor of 22. The repeatability and long-term stability could be successful evaluated by using a complex liver extract. Via the method of standard addition, a linear dynamic range of 1.7 orders of magnitude, a minimum detectability of 3.71 mg/L and a high accuracy (deviation: − 8.11 %) is demonstrated proofing the FμTP-nESI-MS as an excellent approach for a derivatization-free determination of cholesterol without the necessity of high-resolution Orbitrap devices or enhanced MS acquisition-methods.

scholarly journals Global Nighttime Light Change from 1992 to 2017: Brighter and More Uniform

2020 ◽  
Vol 12 (12) ◽  
pp. 4905
Author(s):  
Yunfeng Hu ◽  
Yunzhi Zhang
Keyword(s):  
United States ◽  
Infrared Imaging ◽  
Electricity Consumption ◽  
The United States ◽  
Added Value ◽  
Light Change ◽  
Nighttime Lights ◽  
Long Time ◽  
Nighttime Light

Nighttime light images record the brightness of the Earth surface, indicating the scope and intensity of human activities. However, there are few studies on the long-term changes in global nighttime lights. In this paper, the authors constructed a long time series (1992~2017) nighttime light dataset combining the Defense Meteorological Satellites Program/Operational Linescan System (DMSP-OLS) and the Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) data sources and observed the following: (1) Global nighttime lights have become brighter. The global nighttime brightness in 2017 was 2.2 times that of 1992. Approximately 40.3% of the lighted area was significantly brightened, and an area of 1.3 × 107 km2 transitioned from an unlighted area to a lighted area. (2) Approximately 85.7% of the nighttime light increase occurred in the low-brightness zone (LBZ). Therefore, global brightness has become more uniform than before. (3) China, India, and the United States have led the global lighting trend. The increase in Chinese nighttime lights is the largest, with an average annual growth of 6.48%, followed by the light growth in India, while the United States has the largest brightened area. (4) The changes in nighttime lights in developing countries (e.g., China and India) are closely and positively related to their electricity consumption, industrial added value and gross domestic product (GDP). The shift of the LBZ center from Asia to Africa indicates the intercontinental transition of poverty.

Microarcsecond Astrometry with MCAO Using a Diffractive Mask

2012 ◽  
Vol 8 (S293) ◽  
pp. 369-374
Author(s):  
S. Mark Ammons ◽  
Eduardo A. Bendek ◽  
Olivier Guyon ◽  
Bruce Macintosh ◽  
Dmitry Savransky
Keyword(s):  
Adaptive Optics ◽  
Dynamic Range ◽  
Dynamic Distortion ◽  
Phase Errors ◽  
Reference Grid ◽  
Host Stars ◽  
Stellar Density

AbstractWe present a new ground-based technique to detect or follow-up long-period, potentially habitable exoplanets via precise relative astrometry of host stars using Multi-Conjugate Adaptive Optics (MCAO) on 8 meter telescopes equipped with diffractive masks. MCAO improves relative astrometry both by cancellation of high-altitude atmospheric layers, which induce dynamic focal-plane distortions, and the improvement of centroiding precision with sharper PSFs. However, mass determination of habitable exoplanets requires multi-year reference grid stability of ~1–10 μas or nanometer-level stability on the long-term average of out-of-pupil phase errors, which is difficult to achieve with MCAO (e.g., Meyer et al. 2011). The diffractive pupil technique calibrates dynamic distortion via extended diffraction spikes generated by a dotted primary mirror, which are referenced against a grid of background stars (Guyon et al. 2012). The diffractive grid provides three benefits to relative astrometry: (1) increased dynamic range, permitting observation of V < 10 stars without saturation; (2) calibration of dynamic distortion; and (3) a spectrum of the target star, which can be used to calibrate the magnitude of differential atmospheric refraction to the microarcsecond level. A diffractive 8-meter telescope with diffraction-limited MCAO in K-band reaches < 3–5 μas relative astrometric error per coordinate perpendicular to the zenith vector in one hour on a bright target star in fields of moderate stellar density (~10–40 stars arcmin−2). We present preliminary on-sky results of a test of the diffractive mask on the Nickel telescope at Lick Observatory.

scholarly journals Potentiality of Using Luojia 1-01 Nighttime Light Imagery to Investigate Artificial Light Pollution

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2900 ◽  
Author(s):  
Wei Jiang ◽  
Guojin He ◽  
Tengfei Long ◽  
Hongxiang Guo ◽  
Ranyu Yin ◽  
...  
Keyword(s):  
Infrared Imaging ◽  
Dynamic Range ◽  
Light Pollution ◽  
Artificial Light ◽  
Radiometric Calibration ◽  
Urban Core ◽  
Total Light ◽  
Successful Launch ◽  
Nighttime Light ◽  
Nighttime Light Imagery

The successful launch of Luojia 1-01 complements the existing nighttime light data with a high spatial resolution of 130 m. This paper is the first study to assess the potential of using Luojia 1-01 nighttime light imagery for investigating artificial light pollution. Eight Luojia 1-01 images were selected to conduct geometric correction. Then, the ability of Luojia 1-01 to detect artificial light pollution was assessed from three aspects, including the comparison between Luojia 1-01 and the Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS), the source of artificial light pollution and the patterns of urban light pollution. Moreover, the advantages and limitations of Luojia 1-01 were discussed. The results showed the following: (1) Luojia 1-01 can detect a higher dynamic range and capture the finer spatial details of artificial nighttime light. (2) The averages of the artificial light brightness were different between various land use types. The brightness of the artificial light pollution of airports, streets, and commercial services is high, while dark areas include farmland and rivers. (3) The light pollution patterns of four cities decreased away from the urban core and the total light pollution is highly related to the economic development. Our findings confirm that Luojia 1-01 can be effectively used to investigate artificial light pollution. Some limitations of Luojia 1-01, including its spectral range, radiometric calibration and the effects of clouds and moonlight, should be researched in future studies.

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