Satellite Verification Research Articles

Verification of satellite and model products against a dense rain gauge network for a severe flooding event in Kumasi, Ghana

AbstractFloods as a result of severe storms cause significant impacts on lives and properties. Therefore, timely and accurate forecasts of the storms will reduce the associated risks. In this study, we look at the characteristics of a storm on 28 June, 2018 in Kumasi from a rain gauge network and satellite data, and reanalysis data. The storm claimed at least 8 lives and displaced 293 people in Kumasi, Ghana. The ability of satellite and reanalysis data to capture the temporal variations of the storm was assessed using a high temporal resolution (accumulation per minute) rain gauge data. We employed the observation data from the Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa (DACCIWA) rain gauges to assess the storm's onset, duration, and cessation. Subsequently, the performance of the ERA5 reanalysis and Global Precipitation Measurement (GPM) satellite precipitation estimates in capturing the rainfall is assessed. Both GPM and the ERA5 had difficulty reproducing the hourly pattern of the rain. However, the GPM produced variability that is similar to the observed. Generally, the region of maximum rainfall was located in the southern parts of the study domain in ERA5, while GPM placed it in the northern parts. The study contributes a verification measure to improve weather forecasting in Ghana as part of the objectives of the GCRF African Science for Weather Information and Forecasting Techniques (SWIFT) project.

ОЦЕНОЧНЫЕ ПРИЗНАКИ ВИНОГРАДОПРИГОДНЫХ ЗЕМЕЛЬ ПО СПЕКТРАЛЬНЫМ ПАТТЕРНАМ

The purpose of the study is to determine the necessary set of estimated signs of vineyards with terroir properties based on the generalization of literary sources and the setting up of field experience in the application of spectral indices from satellite images. The use of spectral data on the state of soils, plants and the environment makes it possible to evaluate the growth force of bushes and the yield of vineyards by difference normalized indices. Spectral analysis of vineyards using satellite images allows obtaining data on the vegetative and moisture variability of vine plantations with a frequency of 2-7 days. The correct interpretation of spectral satellite images is possible when they are verified by ground studies of soil indicators, vegetation of bushes by phenophases, agricultural work performed in the aisle, soil, air and leaf moisture. In the future, verification of satellite and ground-based data will reduce the number of route-field surveys and laboratory tests. To solve this problem, spectral data from the public satellite platforms Sentinel-2 and Landsat-8 must be calibrated using ground samples from sample plots of vineyard lands with terroir properties, which are defined as spectral patterns (samples) of vineyards. The presence of a relationship between soil moisture, leaf area and yield makes it possible, on the basis of the normalized NDVI vegetation index and NDMI soil moisture, to determine the micro-sites of vine plantations of different productivity and quality of grape harvest. Microzoning of the area according to such parameters as physical and chemical composition, soil moisture, morphometry, exposure and slope slopes makes it possible to identify viticultural areas with terroir properties. Identification of the boundaries and areas of vineyards with terroir properties using spectral raster satellite images with vectorization of difference soil layers in a geographic information system allows you to quickly assess viable lands, the productivity of various areas of vineyards and optimize agricultural work in accordance with a precision approach in viticulture.

ОЦЕНОЧНЫЕ ПРИЗНАКИ ВИНОГРАДОПРИГОДНЫХ ЗЕМЕЛЬ ПО СПЕКТРАЛЬНЫМ ПАТТЕРНАМ

The purpose of the study is to determine the necessary set of estimated signs of vineyards with terroir properties based on the generalization of literary sources and the setting up of field experience in the application of spectral indices from satellite images. The use of spectral data on the state of soils, plants and the environment makes it possible to evaluate the growth force of bushes and the yield of vineyards by difference normalized indices. Spectral analysis of vineyards using satellite images allows obtaining data on the vegetative and moisture variability of vine plantations with a frequency of 2-7 days. The correct interpretation of spectral satellite images is possible when they are verified by ground studies of soil indicators, vegetation of bushes by phenophases, agricultural work performed in the aisle, soil, air and leaf moisture. In the future, verification of satellite and ground-based data will reduce the number of route-field surveys and laboratory tests. To solve this problem, spectral data from the public satellite platforms Sentinel-2 and Landsat-8 must be calibrated using ground samples from sample plots of vineyard lands with terroir properties, which are defined as spectral patterns (samples) of vineyards. The presence of a relationship between soil moisture, leaf area and yield makes it possible, on the basis of the normalized NDVI vegetation index and NDMI soil moisture, to determine the micro-sites of vine plantations of different productivity and quality of grape harvest. Microzoning of the area according to such parameters as physical and chemical composition, soil moisture, morphometry, exposure and slope slopes makes it possible to identify viticultural areas with terroir properties. Identification of the boundaries and areas of vineyards with terroir properties using spectral raster satellite images with vectorization of difference soil layers in a geographic information system allows you to quickly assess viable lands, the productivity of various areas of vineyards and optimize agricultural work in accordance with a precision approach in viticulture.

Dynamic verification of satellite systems using Ilities

The research outlines the design for an ‘ilities tool’ to assist small satellite verification. Prior literature commonly requests for ilities to be built-in to small satellite systems to prevent failure. Test standards are reviewed to define critical ilities. Definitions are then used to develop calculations that system designers can automate with a software tool . Previous failure data are used to predict the reliability of a future small satellite system. Bayesian estimation is applied to a qualitative NASA database of 219 small satellite (0.001–180 kg) failures from 2000 to 2016 to generate eight failure categories. A communication system (47%) or the attitude control (16%) failure are most likely to occur. A failure in the communication system has a low chance of survivability (16%). A failure within the attitude control system is expected to end with partial mission success (54%). The research suggests that an ilities tool can contribute to dynamically aiding verification. Such a tool will complement small satellite verification methods currently described by testing standards.

Mutually assured surveillance at risk: Anti-satellite weapons and cold war arms control

ABSTRACT In the early 1970s, Moscow and Washington had established a satellite verification regime to monitor arms control treaty compliance. Satellites had become a primary source of transparency and stability in superpower relations. Yet by the end of the 1970s, both the United States and the USSR were developing anti-satellite (ASAT) weapons that could destroy observation satellites. This article uses recently declassified archival documents to show that Jimmy Carter pushed for ASAT limits due to his broader arms control agenda, whereas Ronald Reagan rejected ASAT arms control primarily because of its potential impact on the Strategic Defense Initiative.

Satellite verification of ultra-low emission reduction effect of coal-fired power plants

In this paper, satellite data from five isolated power plants were used to explore the change local emissions levels belonged to the vicinity of the power plant before and after ultra-low emissions (ULE) retrofitted. Sulphur dioxide (SO2) and nitrogen dioxide (NO2) observations from Ozone monitoring Instrument (OMI) satellite data were used to evaluate the emission changes of the power plants retrofitted by ULE technology. Meanwhile, the actual emission reduction effect of isolated power plants was evaluated by the OMI data. It was observed that the isolated power plants have shown obvious point source characteristics. The average annual SO2 emission reduction ratio of SZ, ZD, JJ, ND and BD power plants after ultra-low transformation is 43.7%, 56.9%, 29.0%, 34.6% and 26.8%, respectively, compared with that before the transformation, while the corresponding PBL-SO2 column concentration reduction ratio is 27.0%, 14.3%, 15.6%, 26.6% and 4.2%, respectively. The average annual NOx emission reduction ratio of the power plants after ultra-low transformation is 44.7%,79.3%,29.0%,73.2% and 29.8%, respectively, compared with that before the transformation, while the corresponding NO2 column concentration reduction ratio is 7.0%,27.2%,25.7%,8.9% and 5.6%, respectively. The trend of emission reduction before and after the ULE retrofitted of SO2 and NO2 column concentration by satellite observation is consistent with the calculated trend of emission reduction. Satellite observations have confirmed the emission reduction effect of ULE technology.

Verification of satellite ozone/temperature profile products and ozone effective height/temperature over Kunming, China

Ozonesonde data from November 2013 to April 2015 over Kunming, China are used to verify ozone and temperature profile retrievals from two spaceborne instruments, the version 4.2 product from the Microwave Limb Sounder (MLS) on the NASA Aura satellite and the version 6.0 product from the Atmospheric Infrared Sounder (AIRS) on the NASA Aqua satellite. We calculated and compared the ozone effective height Heff and effective temperature Teff, which are two important parameters in ground-based total ozone retrieval through the use of various profile datasets. This is used to verify the accuracy of the operative values (Heff(0) = 23 km, Teff(0) = −46.3 °C (or −45 °C)) from the World Meteorological Organization. The results show that the deviation of MLS and AIRS ozone profiles from ozone sounding data has significant oscillation and scatter in the upper troposphere and lower stratosphere. The average difference of MLS at 82.5 hPa is (80.5 ± 65.1) %, and that of AIRS at 70 and 100 hPa are (105.6 ± 74.9) % and (107.0 ± 67.8) %, respectively. The two satellite temperature profiles have differences within ±3 °C and can effectively describe the vertical distribution and variation of temperature. When calculating the Heff and Teff, upper stratospheric data missing from the sounding data must be filled in by the satellite profile data; otherwise the calculated results will show large errors of 3.2 km and 3.3 °C. The Heff and Teff at Kunming are respectively 24.36 to 25.51 km and −48.3 to −43.6 °C. The operational Heff and Teff used at Kunming ozone observation station clearly do not conform to the actual situation and must be corrected.

基于实验测量与OCS仿真计算的卫星光学散射特性对比验证

基于实验测量与OCS仿真计算的卫星光学散射特性对比验证

HELIOS, a nadir-looking sea ice monitoring camera

We present the prototype of a simplified photogrammetric system (HELicopter-borne Ice Observation System, HELIOS) and demonstrate how it can be used to document ground-based and airborne sea ice surveys. The aerial unit consists of a nadir-looking digital camera mounted on a gimbal, a GPS receiver and a computer. It is of low-cost and weight and is designed such that it withstands low temperatures, operates autonomously and fits to any standard helicopter skid. The accuracy of the georeferenced photographs is about ± 15 m for a flight height of 85 m, flight speed of 130 km/h and a GPS sampling rate of 4 Hz. Systematic errors arise from the GPS-based determination of the camera position, the pointing accuracy of the gimbal, and the camera alignment in flight direction. Because most sea ice mapping projects require lesser accuracies than conventional mapping standards (e.g. ≤ 0.5 m for a map scale of 1:600, ASPRS (1994)), HELIOS offers a broad range of applications. This includes the photogrammetric documentation of experimental sites as well as the verification of satellite-, and model-based estimates of sea ice and snow cover properties. Images taken simultaneously with other airborne observations provide a valuable tool to assess the accuracy of those measurements.

Verifying greenhouse gas emissions of Annex I parties: Methods we have and methods we want

Despite the hopeful prediction in the New York Times story, we are very far from being able to use satellites to verify compliance with the Kyoto Protocol’s caps on greenhouse gas emissions of Annex I states. The problem is not only one of insufficiently developed or installed technology. “Satellite verification” would also mean changing the current system of reporting-and-review of state emissions, opening it up to independent scrutiny, and making it less forgiving of state evasiveness and ambiguity about emissions than it is now. Some states will be interested in this proposal and others will not. In any event, the current MRV system, built on bottom-up state reporting, will remain the dominant framework of international GHG emissions knowledge for the foreseeable future. To safeguard its own credibility, it must progressively be strengthened. In this article I outline the existing verification regime’s main shortcomings and argue that the most efficient way around them is to incorporate into the current MRV system top-down (satellite and surface) measurements, resolved by modeling software at the state level, and produced by independent scientific experts in cooperation with the UNFCCC.

Overview of the Cumulus Humilis Aerosol Processing Study

The primary goal of the Cumulus Humilis Aerosol Processing Study (CHAPS) was to characterize and contrast freshly emitted aerosols below, within, and above fields of cumuli, and to study changes to the cloud microphysical structure within these same cloud fields in the vicinity of Oklahoma City during June 2007. CHAPS is one of few studies that have had an aerosol mass spectrometer (AMS) sampling downstream of a counterflow virtual impactor (CVI) inlet on an aircraft, allowing the examination of the chemical composition of activated aerosols within the cumuli. The results from CHAPS provide insights into changes in the aerosol chemical and optical properties as aerosols move through shallow cumuli downwind of a moderately sized city. Three instrument platforms were employed during CHAPS, including the U.S. Department of Energy Gulfstream-1 aircraft, which was equipped for in situ sampling of aerosol optical and chemical properties; the NASA Langley King Air B200, which carried the downward-looking NASA Langley High Spectral Resolution Lidar (HSRL) to measure profiles of aerosol backscatter, extinction, and depolarization between the King Air and the surface; and a surface site equipped for continuous in situ measurements of aerosol optical properties, profiles of aerosol backscatter, and meteorological conditions, including total sky cover and thermodynamic profiles of the atmosphere. In spite of record precipitation over central Oklahoma, a total of 8 research flights were made by the G-l and 18 by the B200, including special satellite verification flights timed to coincide with NASA satellite A-Train overpasses.

Long-Term Observation of Asian Dust in Changchun and Kagoshima

Monitoring of Asian dust at two stations in Changchun, Jilin Province in northeast China, and Kagoshima, southwest Japan, is discussed. In Changchun, interval records were made with digital and video cameras from 18 March 2003. In Kagoshima, a web camera system to monitor volcanic clouds has been working since December 2000, which also provides data for studies of dust. A heavy dust episode on 11 November 2002, affecting both stations, was detected using 11 and 12 μm channels of NOAA/AVHRR. We observed dust in Changchun on 26 March, 7, 14–16 April, 1–2, 8, 10, 19 May, 8, 23 June, and 12 July in 2003. The observed images corresponded well to NOAA/AVHRR imagery and with 8.6, 11 and 12 μm Terra/MODIS results, although conditions were too cloudy for satellite verification in some cases.

Design and Development of an Advanced Real-Time Satellite Simulator

An advanced real-time satellite simulator (ARTSS) has been developed to support the ground operations activities of the ETRI satellite control system, such as testing of the system facilities, validation of flight control procedures, verification of satellite commands as well as training of the ground operators. The design of ARTSS is based on the top-down approach and makes use of a modular programming to ensure flexibility in modification and expansion of the system. Graphics-based monitoring and control facilities enhance the satellite simulation environment. The software spacecraft model in ARTSS simulates the characteristics of a geostationary communication satellite using a momentum bias three-axis stabilization control technique. The system can be also interfaced with a hardware payload subsystem such as Ku-band communication transponder to enhance the simulator capability. Therefore, ARTSS is a high fidelity satellite simulation tool that can be used on low-cost desk top computers. In this paper, we describe the design features, the simulation models and the real-time operating functions of the simulator.

Platform Harvest sea level measurement comparisons

Three in situ water level measurement systems have been installed on Platform Harvest in support of the TOPEX/Poseidon Satellite Verification Experiment. Each of the systems have fundamentally different instrument configurations, which provides a unique simultaneous set of measurements in a deep water‐exposed near‐shore environment. Each of the sensor “zeros”; have also been referenced to the same datum as a requirement of the experiment; thus absolute differences can be analyzed. Straightforward, simple comparisons of the systems are presented for TOPEX/Poseidon cycles 2 through 30. The systems are shown to agree well both in the mean and in frequency content. Nontidal sea level residuals are shown to be highly correlated to atmospheric pressure.

Use of Multiple Gauges and Microwave Attenuation of Precipitation for Satellite Verification

In this paper both a microwave attenuation measurement along a horizontal line and multiple point gauge measurements are analyzed as possible ground-truth designs to validate satellite precipitation retrieval algorithms at the field of view spatial level (typically about 20 km). The design consists of comparing a sequence of pairs of contemporaneous measurements taken from the ground and from space. The authors examine theoretically the variance of expected differences between the two systems. The line average measurement leads to a smaller mean-square error compared to the case of a single point gauge, since some of the small-scale variability of the rain field is smoothed away by the line integration. The multiple point gauge measurements also give smaller mean-square error than that of a single point gauge. The centroid of the line and point gauge configurations are considered to be located randomly inside the field of view for different overpasses. A space-time spectral formalism is used with a noise-forced diffusive rain field to find the mean-square error. By considering instantaneous ground and satellite measurement pairs over about 50 visits when raining, we can reduce the expected error to approximately 10% of the standard deviation of climatological variability. This is considered to be a useful level of tolerance for identifying biases in the retrieval algorithms. It is found that the multiple point gauges (especially two gauges) are the economical ground-truth design compared to the microwave attenuation based on the mean-square error comparison. The major finding of this study is that a significant improvement over the point gauge is obtained by adding a single additional piece of information; adding more gauges or extending the line of attenuation is not an important improvement.

JERS-1/ERS-1 verification program and future verification program

From now on, data sets made by combining data from various multiple satellite sensors are increasingly important. JERS-1(Japanese Earth Resources Satellite-1) which has SAR (Synthetic Aperture Radar) and OPS (OPtical Sensor) will be launched by H-I rocket from Tanegashima Space Center, NASDA and ERS-1(European Remote Sensing Satellite-1) which has several sensors mainly for ocean monitoring will be also launched early in 1991. NASDA is planning to conduct JERS-1/ERS-1 Verification Program and will prepare for future satellite verification program such as ADEOS(ADvanced Earth Observing Satellite), TRMM (Tropical Rainfall Measuring Mission) and JPOP(Japanese Polar Plarform. In this paper, outline of JERS-1/ERS-1 verification program and future verification program will be presented.

Radiometric calibration of satellite sensors in the visible and near infrared: History and outlook

Documentation for radiometric calibration of visible and near infrared sensors viewing the earth has been quite limited in the past. Recent quantitative use of satellite radiometry suggests the need for better information concerning instrumentation, estimation of atmospheric effects, and ground verification of satellite measured radiances. An example from the thermal infrared spectral region illustrates that analysis algorithms provide the link between satellite-derived results and the required accuracy of satellite calibration.

Some Current Issues in Verification Technology

The success of substantive arms control negotiations can depend critically on the credibility of the arrangements for monitoring compliance with any putative treaty. This paper discusses some current issues in the technology of verification which are of relevance to the control science community. In particular, the current state of the art in satellite inspection is surveyed, and some suggestions for fruitful research are made. It appears that there is a need for civilian research into some aspects of satellite verification technology such as the resolution of sensors and in the processing of signals for improved reliability of observation

Electrical Injection Simulation of SGEMP

Increasing attention has been given to the problem of predicting the response of satellites to the system-generated electromagnetic pulse (SGEMP). This paper presents results of the first SGEMP electrical injection simulation experiments on the SKYNET satellite and compares them with pretest predictions. The important advantages offered by the electrical injection techniques are reviewed in light of the experimental findings. Latest advances in the state-of-the-art of injection pulsers, wide-bandwidth current probes and voltage probes, and dielectric transmission systems (dielectric waveguides and fiber optics) are highlighted. The significance of the results lies in the conclusion that electrical simulation techniques may provide the satellite community with a non-destructive, believable test method for satellite verification.