Estimating in-use steel stock of civil engineering and building in China by nighttime light image

China is dramatically changing due to rapid development in recent years. This can be observed from the change in landscapes, which most resulted from new or replaced constructions. The floor area of residential and commercial construction had increased fourfold from 1990 to 2005, and its speed does not show any sign of slowing down. The construction will also drive the demand of steel, which comprises half of the total national consumption. However, there were not many studies aiming to quantify the construction steel stock in China, which was mainly due to lack of statistical data. In order to overcome this obstacle, we proposed a methodology to estimate sub-national steel stock using nighttime light image. As a result, we found out that the Beijing municipality possesses the most construction steel stock. Most construction steel stock exists on the eastern coast, and is most concentrated in the Beijing municipality, the Tianjin municipality, the Shanghai municipality, and the Guangdong province

Effect of Blood Pressure Control on Long-Term Risk of End-Stage Renal Disease and Death Among Subgroups of Patients With Chronic Kidney Disease.

Background Our objective was to explore the effect of intensive blood pressure (BP) control on kidney and death outcomes among subgroups of patients with chronic kidney disease divided by baseline proteinuria, glomerular filtration rate, age, and body mass index. Methods and Results We included 840 MDRD (Modification of Diet in Renal Disease) trial and 1067 AASK (African American Study of Kidney Disease and Hypertension) participants. We used Cox models to examine whether the association between intensive BP control and risk of end-stage renal disease (ESRD) or death is modified by baseline proteinuria (≥0.44 versus <0.44 g/g), glomerular filtration rate (≥30 versus <30 mL/min per 1.73 m2), age (≥40 versus <40 years), or body mass index (≥30 versus <30 kg/m2). The median follow-up was 14.9 years. Strict (versus usual) BP control was protective against ESRD (hazard ratio [HR]ESRD, 0.77; 95% CI, 0.64-0.92) among those with proteinuria ≥0.44 g/g but not proteinuria <0.44 g/g. Strict (versus usual) BP control was protective against death (HRdeath, 0.73; 95% CI, 0.59-0.92) among those with glomerular filtration rate <30 mL/min per 1.73 m2 but not glomerular filtration rate ≥30 mL/min per 1.73 m2 (HRdeath, 0.98; 95% CI, 0.84-1.15). Strict (versus usual) BP control was protective against ESRD among those ≥40 years (HRESRD, 0.82; 95% CI, 0.71-0.94) but not <40 years. Strict (versus usual) BP control was also protective against ESRD among those with body mass index ≥30 kg/m2 (HRESRD, 0.75; 95% CI, 0.61-0.92) but not body mass index <30 kg/m2. Conclusions The ESRD and all-cause mortality benefits of intensive BP lowering may not be uniform across all subgroups of patients with chronic kidney disease. But intensive BP lowering was not associated with increased risk of ESRD or death among any subgroups that we examined

What is so great about nighttime VIIRS data for the detection and characterization of combustion sources?

The Suomi National Polar Partnership (SNPP) is a satellite operated jointly by the United States National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA).  The primary imaging sensor on SNPP is the Visible Infrared Imaging Radiometer Suite (VIIRS).  Among imaging meteorological satellite sensors the VIIRS is unique in collecting visible, near-infrared and short-wave infrared spectral radiances at night.  With sunlight eliminated, these spectral bands make it possible to observe the radiant emissions from gas flares, biomass burning, industrial sites and volcanoes worldwide every 24 hours.  With multispectral detections it is possible to model the blackbody emission curve (also known as a Planck curve), which can then be used to estimate the temperature of the source, size of the source (m2), radiative heat intensity (W/m2), radiant heat (MW).  This is a substantial advance over satellite fire products based on detection in a single spectral band. 

Methods Used For the 2006 Radiance Lights

The Operational Linescan System (OLS) flown on the Defense Meteorological Satellite Program (DMSP) satellites, has a unique capability to record low light imaging data at night worldwide. These data are archived at the National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC).  The useful data record stretches back to 1992 and is ongoing. The OLS visible band detector observes radiances about one million times dimmer than most other Earth observing satellites. The sensor is typically operated in a high gain setting to enable the detection of moonlit clouds. However, with six bit quantization and limited dynamic range, the recorded data are saturated in the bright cores of urban centers. A limited set of observations have been obtained at low lunar illumination were obtained where the gain of the detector was set significantly lower than its typical operational setting (sometimes by a factor of 100). By combining these sparse data acquired at low gain settings with the operational data acquired at high gain settings, we have produced a global nighttime lights product for 2006 with no sensor saturation.  This product can be related to radiances based on the pre-flights sensor calibration

Using the Short-Wave Infrared for Nocturnal Detection of Combustion Sources in VIIRS Data

Night-time images from the SNPP satellite VIIRS scanning radiometer in visible and infrared spectral bands provide invaluable data for detection and characterization of natural and technological combustion sources on the surface of the Earth, such as forest fires, gas flares, steel mills or active volcanoes. The presence of sub-pixel hot infrared (IR) emission sources can be readily detected at night in 1.6 micron near-infrared M10 channel. Their temperature and radiant heat intensity can be estimated by fitting of the Planck black-body spectral curve to the observed radiances of VIIRS infrared M-channels out to 4 um. VIIRS instrument is sensitive to the IR sources over a wide range of temperatures. This method can discriminate low temperature sources such as volcanoes and forest fires from the high temperature gas flares with 300 m average location error. The processing includes correction for panoramic “bow-tie” effect and filtering of the false detections resulting from sensor bombardment by the cosmic rays, especially at the aurora rings and at the South Atlantic anomaly. False detections can be largely removed by correlating of the observed bright spots in M10 channel with other infrared and the visible day-night band. NGDC NOAA provides global daily detection products for thousands of IR sources as KMZ vector maps and as CSV tables

Why VIIRS data are superior to DMSP for mapping nighttime lights

For more than forty years the U.S. Air Force Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) has been the only satellite system collecting global low-light imaging data.  A series of twenty-four DMSP satellites have collected low-light imaging data.  The design of the OLS has not changed significantly since satellite F-4 flew in the late 1970’s and OLS data have relatively coarse spatial resolution, limited dynamic range, and lack in-flight calibration.  In 2011 NASA and NOAA launched the Suomi National Polar Partnership (SNPP) satellite carrying the first Visible Infrared Imaging Radiometer Suite (VIIRS)  instrument.  The VIIRS collects low light imaging data and has several improvements  over the OLS’ capabilities.  In this paper we contrast the nighttime low light imaging collection capabilities of these two systems and compare their data products

Annual Time Series of Global VIIRS Nighttime Lights Derived from Monthly Averages: 2012 to 2019

A consistently processed annual global nighttime lights time series (2012–2019) was produced using monthly cloud-free radiance averages made from low light imaging day/night band (DNB) data collected by the NASA/NOAA Visible Infrared Imaging Radiometer Suite (VIIRS). The processing steps are modified from the original methods developed to produce annual nighttime lights products from nightly data. Only two years of VIIRS nighttime lights (VNL) were produced with the V.1 methods: 2015 and 2016. Here we report on methods used to produce a V.2 VNL time series from the monthly averages with filtering to remove extraneous features such as biomass burning, aurora, and background. In this case, outlier removal is achieved with a twelve-month median, which discards high and low radiance outliers, thus isolating the background to a narrow range of radiances under 1 nW/cm2/sr. Background areas with no detectable lighting are further isolated using a statistical measure of texture, 3 × 3 data range (DR). The DR threshold for zeroing out background rises as the number of cloud-free observations falls. The V.2 method extends the temporal leverage in the noise filtering by developing the DR threshold from a multiyear maximum DR and a multiyear percent cloud-free grid. Additional noise filtering is achieved by zeroing out grid cells that have low average radiances (\u3c0.6 nW/cm2/sr) and detection in only one or two years out of eight. The spatial extent and average radiance levels are compared for the V.1 and V.2 2015 VNL. For the vast majority of grid cells, the average radiances are nearly the same in the two products. However, the V.2 product has more areas of dim lighting detected. The key advantages of the V.2 time series include consistent processing and threshold levels across all years, thus optimizing the set for change detection analyses

Indicators of Electric Power Instability from Satellite Observed Nighttime Lights

Electric power services are fundamental to prosperity and economic development. Disruptions in the electricity power service can range from minutes to days. Such events are common in many developing economies, where the power generation and delivery infrastructure is often insufficient to meet demand and operational challenges. Yet, despite the large impacts, poor data availability has meant that relatively little is known about the spatial and temporal patterns of electric power reliability. Here, we explore the expressions of electric power instability recorded in temporal profiles of satellite observed surface lighting collected by the Visible Infrared Imaging Radiometer Suite (VIIRS) low light imaging day/night band (DNB). The nightly temporal profiles span from 2012 through to mid-2020 and contain more than 3000 observations, each from a total of 16 test sites from Africa, Asia, and North America. We present our findings in terms of various novel indicators. The preprocessing steps included radiometric adjustments designed to reduce variance due to the view angle and lunar illumination differences. The residual variance after the radiometric adjustments suggests the presence of a previously unidentified source of variability in the DNB observations of surface lighting. We believe that the short dwell time of the DNB pixel collections results in the vast under-sampling of the alternating current lighting flicker cycles. We tested 12 separate indices and looked for evidence of power instability. The key characteristic of lights in cities with developing electric power services is that they are quite dim, typically 5 to 10 times dimmer for the same population level as in Organization for Economic Co-operation and Development (OECD) countries. In fact, the radiances for developing cities are just slightly above the detection limit, in the range of 1 to 10 nanowatts. The clearest indicator for power loss is the percent outage. Indicators for supply adequacy include the radiance per person and the percent of population with detectable lights. The best indicator for load-shedding is annual cycling, which was found in more than half of the grid cells in two Northern India cities. Cities with frequent upward or downward radiance spikes can have anomalously high levels of variance, skew, and kurtosis. A final observation is that, barring war or catastrophic events, the year-on-year changes in lighting are quite small. Most cities are either largely stable over time, or are gradually increasing in indices such as the mean, variance, and lift, indicating a trajectory that proceeds across multiple years