Control System Design and Implementation at Flexible, Distributed Offshore Sensor Test Sites in the Yangtze Estuary Area

Marine in situ testing is a necessary step for stereotyping newly developed marine sensors. The use of test sites in the Yangtze Estuary area, which has high turbidity and abundant nutrients, can effectively reduce the needed testing time owing to its harsh conditions. Five test stations were established, and a floating buoy and fixed test equipment were designed. A control system, including a sensor connection, data processor, video remote transmission, and corresponding control algorithm, was developed. The control system enabled the nondestructive monitoring of biological attachments and bidirectional, real-time communication between an upper server on land and the control system at the test sites. The dissolved oxygen(DO), temperature, and pH data of DOS600 and DPS600 sensors were compared with those of AP2000 sensors. Temperature recording using the DOS600 sensor was performed nearly as well as that of the AP2000 sensor. The mean DO values(standard deviations) were 8.414 mg L-1(2.068) and 6.896 mg L-1(1.235) for the DOS600 and AP2000 sensors, respectively, indicating that the DOS600 performance was unsatisfactory. The pH recording of the DPS600 was slightly worse than that of the AP2000 sensor. Experimental results showed that the DO value was more easily affected by the buoy movement of waves compared to the pH and temperature. Moreover, data fluctuations showed that the DO and pH parameters were more vulnerable to biofouling than temperature. Waves and biofouling create a harsh test environment, and the performance difference between the developed sensors and a standard sensor can be obtained in a short time period.

THE BRIEF INTRODUCTION OF CHANGCHUN JINGYUETAN OPEN REMOTE SENSING STUDY AND TEST SITE OF THE CHINESE ACADEMY OF SCIENCES

In 1979, the Changchun Jingyuetan Remote Sensing Study and Test Site (RSSTS)began its work, and it was formally established in 1985. The RSSTS is subordinated the Changchun Branch of Chinese Academy of Sciences and is supported by the Changchun Institute of Geography and Changchun Institute of Optics and Fine Machnics, Chinese Academy of Sciences. It is under the management of the Resource & Environment Bureau of Chinese Academy of Sciences and it is the study base of remote sensing basis and application tests in China. The RSSTS is situated in the Jingyuetan scenic spot of the suburbs of Changchun City, Jilin Province. It is located at 43°40′—43°50′N and 125°18′-125°18′E.

Depth Estimates of Buried Utility Systems Using the GPR Method: Studies at the IAG/USP Geophysics Test Site

Identifying underground utilities and predicting their depth are fundamental when it comes to civil engineering excavations, for example, to install or repair water, sewer, gas, electric systems and others. The accidental rupture of these systems can lead to unplanned repair costs, delays in completing the service, and risk injury or death of workers. One way to detect underground utilities is using the GPR-Ground Penetrating Radar geophysical method. To estimate depth, the travel time (two-way travel time) information provided by a radargram is used in conjunction with ground wave velocity, which depends on the dielectric constant of materials, where it is usually assumed to be constant for the area under investigation. This procedure provides satisfactory results in most cases. However, wrong depth estimates can result in damage to public utilities, rupturing pipes, cutting lines and so on. These cases occur mainly in areas that have a marked variation of water content and/or soil lithology, thus greater care is required to determine the depth of the targets. The present work demonstrates how the interval velocity of Dix (1955) can be applied in radargram to estimate the depth of underground utilities compared to the conventional technique of constant velocity applied to the same data set. To accomplish this, synthetic and real GPR data were used to verify the applicability of the interval velocity technique and to determine the accuracy of the depth estimates obtained. The studies were carried out at the IAG/USP test site, a controlled environment, where metallic drums are buried in known positions and depths allowing the comparison of real to estimated depths. Numerical studies were also carried out aiming to simulate the real environment with variation of dielectric constant in depth and to validate the results with real data. The results showed that the depths of the targets were estimated more accurately by means of the interval velocity technique in contrast to the constant velocity technique, minimizing the risks of accidents during excavation.

GPR Tomographic Imaging of Concrete Tubes and Steel/Plastic Tanks Buried in IAG/USP Geophysical Test Site, Brazil

In this paper, the Ground Penetrating Radar (GPR) method was used to characterize concrete tubes and steel/plastic tanks buried in IAG/USP test site. The microwave tomography was used to improve the GPR images, aiming to retrieve the geometry of the targets. The numerical modeling studies also were done in order to predict the GPR results of the buried targets and to give more reliability to the results interpretation. The targets were installed in the first shallow geophysical test site of the Brazil located at Institute of Astronomy, Geophysics, and Atmospheric Science (IAG) of the University of S?o Paulo (USP). GPR profiles of 200 MHz (shielded bistatic antennas) were acquired along three lines containing concrete tubes and steel/plastic tanks buried in subsoil. The concrete tubes show a hyperbolic reflector for the top, and the vertical tube also presented a reflection on its bottom. The horizontal steel tanks were characterized by a strong GPR reflection on their top. The empty plastic tank shows a strong reflector for the top with normal polarity. On the other hand, the plastic tank filled with water shows a weaker reflector for its top characterized by the inverted polarity of GPR signal when compared with empty plastic tank. The plastic tank filled with water also went characterized by the strong reflection to its bottom, being a good indicative to interpret GPR data on target in subsoil with some types of fluid inside of tank. The results of polarity difference for the top of tank can be used as guide pattern to identify buried tank empty or filled with water. The application of microwave tomography to the GPR data permitted to determine the position and get a good identification of the edges of the targets studied. The numeric modeling presented a good accordance with real data reducing the ambiguities in interpretation of results. These results can be used as a reference, and they can be extrapolated for areas where there is no subsurface information.

Characteristics of the Variation of Cross Fault Short-Baseline and Short-Range Leveling in Western Yunnan Earthquake Test Site Before Lijiang M_S7.0 Earthquake

Results of analysis of variation of cross fault short-baseline and short-range leveling in Western Yunnan Earthquake Test Site (WYETS), results show that among five observation stations of cross fault short-baseline and short-range leveling in WYETS before the Lijiang MS7.0 Earthquake occurred in February 1996 only Yongsheng observation station (epicentral distance 82 km) located at Chenghai fault shows great variation about one year before the earthquake. And the nearest observation station, Lijiang (epicentral distance 42 km); presents great coseismic variation, but does not show obvious anomalous variation before the earthquake. There are no significant variations related to the earthquake at the other three observation stations. Two methods are used in analysis of the observed data and some valuable results have been obtained.

Assessing the Spatial Equality of COVID Testing Sites Maintaining Zero COVID Policy

Rapid and timely testing is essential to minimize the COVID-19 spread. Decision makers and policy planners need to determine the equal distribution and accessibility of testing sites. This study mainly examines the spatial equality of COVID-19 testing sites that maintain a zero COVID policy in Guangzhou City. The study has identified the spatial disparities of COVID testing sites, characteristics of testing locations, and accessibility. The study has obtained information on COVID testing sites in Guangzhou City and population data. Point pattern analyses, Euclidian distance and allocation, and network analyses are the main methods used to achieve the research objectives, and 1183 total COVID testing sites can be recognized in Guangzhou City. Results revealed that spatial disparities could be noticed over the study area. Testing locations of Guangzhou City are highly clustered. The most significant testing sites are located in Haizhu District, which has the third largest population. The highest population density can be identified in Yuexiu District. However, only 94 testing sites are located there. According to all the results, higher disparities can be identified, and a lack of testing sites is located in the north part of the study area. Some people in the northern part have to travel more than 10 km to reach a testing site. Finally, this paper suggests increasing the number of testing sites in the north and south parts of the study area and keeping the same distribution, considering the area, total population, and population density. This kind of research will be helpful to decision-makers in making proper decisions to maintain a zero COVID policy.

Quantitative Analysis of Seeing with Height and Time at Muztagh-Ata Site Based on ERA5 Database

Seeing is an important index to evaluate the quality of an astronomical site.To estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanalysis database(ERA5)is used.Seeing calculated from ERA5 is compared consistently with the Differential Image Motion Monitor seeing at the height of 12 m.Results show that seeing decays exponentially with height at the Muztagh-Ata site.Seeing decays the fastest in fall in 2021 and most slowly with height in summer.The seeing condition is better in fall than in summer.The median value of seeing at 12 m is 0.89 arcsec,the maximum value is1.21 arcsec in August and the minimum is 0.66 arcsec in October.The median value of seeing at 12 m is 0.72arcsec in the nighttime and 1.08 arcsec in the daytime.Seeing is a combination of annual and about biannual variations with the same phase as temperature and wind speed indicating that seeing variation with time is influenced by temperature and wind speed.The Richardson number Ri is used to analyze the atmospheric stability and the variations of seeing are consistent with Ri between layers.These quantitative results can provide an important reference for a telescopic observation strategy.

Method study and uncertainty analysis of calibration coefficients validation based on the Inner Mongolia test site

Calibration coefficients validation is the foundation for ascertaining the sensor performance and carrying out the quantitative application.Based on the analysis of the differences between the calibration and validation,two calibration coefficients validation methods were introduced in this paper.Taking the HJ-1A satellite CCD1 camera as an example,the uncertainties of calibration coefficients validation were analyzed.The calibration coefficients validation errors were simulated based on the measured data at an Inner Mongolia test site.The result showed that in the large view angle,the ground directional reflectance variation and the atmospheric path variation were the main error sources in calibration coefficients validation.The ground directional reflectance correction and atmospheric observation angle normalization should be carried out to improve the validation accuracy of calibration coefficients.

Analysis on the development status of intelligent and connected vehicle test site

With the development of automobile intelligence and connectivity,Intelligent and Connected Vehicle(ICV)is an inevitable trend in the transformation and upgrading of the automotive industry.The maturity of any advanced technology is inseparable from a large number of test verifications,especially the research and application of automotive technology require a large number of reliable tests for evaluation and confirmation.Therefore,the ICV Test Site(ICVTS)will become a key deployment area.In this paper,we analyze the development status of ICVTS outside and within China,summarize the shortcomings of the existing test sites,and put forward some targeted suggestions,in an effort to guide the development and construction of ICVTS towards the path that seems to be most promising.

Site Test of Thermal Environment of Rammed Earth Construction in Anji County of China

The scientific evaluation on heat insulation and preservation capacity of rammed earth construction can provide an effective evidence for its superiority in preserving thermal environment of the construction. By taking an eco-hotel in Zhejiang Anji County as the research object, 33 test points have been set. The indoor and outdoor air temperature of eco-hotel and the surface temperature of building envelopes had been recorded by using data acquisition instrument, temperature transmitter and other equipments from January 27 to February 2 in 2007. Then, the data of a period had been selected for comparison and analysis and the results had been obtained as follows. In January when the temperature difference between day and night in Anji was not large, without particular thermal insulation measures and equipments, the indoor temperature of eco-hotel fluctuated very little, showing that rammed earth construction was of obvious capacity for heat preservation and insulation, that its heat stability was evident and that it could ensure excellent indoor thermal environment.

Site testing campaign for the Large Optical/infrared Telescope of China:general introduction of the Daocheng site

The Daocheng site is one of the three candidate sites for the Large Optical/infrared Telescope(LOT)of China.It was discovered by Yunnan Observatories during the survey of potential sites for the next-generation large-aperture solar telescopes of China.This paper describes the overview of the site,the observation platform and the monitor instrument.In addition,simple statistical results are presented(from November,2016 up to December,2017).Detailed data results can refer to the overview of LOT site testing and data analysis articles,which were published during the same period.

Site testing campaign for the Large Optical Telescope at the Ali site

The Large Optical/infrared Telescope(LOT)is a ground-based 12 m diameter telescope which is proposed to be built in western China.The site selection for LOT in China began in 2016,and Ali was listed as one of the three candidate sites.Remote studies and local surveys have been carried out for more than 15 years in western China,and the results show that Ali is a promising site with comprehensive quality in terms of atmospheric and supporting conditions.An overview of the site testing campaign at the Ali site from 2016 to 2019 is presented.After the two years of data collection,the overall median seeing value is found to be 1.17 arcsec,the observable nights are 81.71%and the good observable nights are 71.76%.The weather conditions as follows,the median night temperature value is-5.18℃,the median night relative humidity value is 41.25%,the median night atmospheric pressure value is 540.92 hPa,the median night wind speed value is 7.41 m s-1 and the mainly wind direction is southwestern(SW).The median night sky background value is 22.07 magV.We also discuss the wind speed at different locations on-site,the possibility of light pollution and the effect of wind speed on differential image motion monitor(DIMM)seeing measurements.

Investigation into dynamic response of regional sites to seismic waves using shaking table testing

This study addresses the changes in acceleration,pore water pressure and Fourier spectrums of different types of seismic waves with various amplitudes via large-scale shaking table tests from two sites:a sand-containing regional site and an all-clay site.Comparative analyses of the test results show that the pore water pressures in sand-soil layers of the regional site initially increase and then decrease as the amplitudes of the seismic accelerations increase.The actions of the vertical and vibrational seismic waves contribute to greater pore water pressures.The amplification coefficient of the sand-layer regional site becomes smaller as the seismic waves grow stronger,so that both sites are capable of filtering high frequencies and amplifying low frequencies of seismic waves.This is more apparent with the increase in the peak value of the acceleration,and the natural vibration frequencies of both sites decrease with the transmission of the seismic waves from the basement to the ground surface.The decreasing frequency value of the sand-containing regional site is smaller than that of the all-clay site.

Research and application of reanalysis data for radio astronomical site testing

Selecting a good site for ground-based astronomy is very important. Based on the ERA-Interim global reanalysis data, this paper studied the atmospheric conditions of the Qitai Telescope(QTT) site from the aspects of absolute humidity, mixing ratio and precipitable water vapor(PWV). Error estimations of meteorological parameters are also analyzed. These primary results show that the QTT site has obvious advantages in terms of conditions with much less atmospheric water vapor than two well-known existing sites with 100-meter-aperture radio telescopes in the world. In addition, due to the influence of atmospheric water vapor on radio observations, the atmospheric transmittance for each frequency band of the site are simulated, and the atmospheric opacity is also calculated as well as Planck radiation brightness. Based on these results, the effective observational time of different bands is further estimated.

RADIOACTIVITY LEVEL OF RESIDENTIAL AREAS AROUND XINJIANG NUCLEAR TESTING SITE AND ESTIMATED POPULATION DOSE

Results are reported on a research for the radioactive level in the investigation region and the control region around the Xinjiang Nuclear Testing Site from 1982 to 1987. There are no significant differences on the land γ radiation level, nor in the radioactive level in the soil, food and water between the two regions. The distribution and transfer of 90Sr, 137Cs and Pu in various kinds of soil are also discussed. It is estimated that the effective dose equivalent of radiation, undergone by the residents around the Testing Site is only 2.9% of that of natural radiation taken yearly by people in normal areas.

New Explorations of Laboratory and On-site Testing of Broadband Seismographs in China

According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's key parameters and other concerning technical specifications are well described in guide documents(China Earthquake Administration, 2017). This includes seismometer sensitivity, linearity and clip levels based on the shake table test, as well as the seismometer natural period, damping constant based on electrical calibration(Wang Guangfu,1986; Ple?inger A.,1993) and instrumental self-noise collocation estimation(Holcomb L.G., 1989; Sleeman R. et al., 2006). However, with the development of seismic observation technology, many new requirements for the performance evaluation of seismographs have been put forward, and new testing items and methods have emerged.

Site Testing at the Gaomeigu Village

The work on the site testing at the Gaomeigu village Lijiang county in the northwest of Yunnan Province, was started in 1994 after the completion of the investigation on optical/infrared astronomical observatory site resources over Yunnan Province. The observation of the astro climate conditons has been made for more than two years. The major results are given as follows: The photometrical nights are 75, the half photometrical nights 39, the spectroscopic nights 99 5. the average of the temperature difference during night is 3 2℃, the average of the winding speed 3 6m/s, the precipitable water vapor at night is 13.0mm in the raining season and 4.3mm in the dry season respectively. The seeing measurement was made by a three subaperture DIMM. 20486 sets data obtained for 294 nights. The average of the Fried parameter is 15.53cm (FWHM=0.″71). The micro temperature sensors were used to determine the atmospheric turbulence distribution near the ground from 6 5cm to 27m. The typical value is about 0.″11 at night. The sky brightness and the extinction coefficient in B.V. colors was measured by a photometer. The means of the sky brightness B=22 m 34/◇″ and V=21 m.54/◇″. The extinction coefficients K′ v=0.135 and K′ bv =0.298.

Numerical simulation of the behaviors of test square for prehistoric earthen sites during archaeological excavation

During the process of archaeological excavation in the regions of Southeast China, collapse of test square usually occurs due to poor site-specific conditions. In this paper, the fast Lagrangian analysis of continua in three dimensions（FLAC3D） is employed to reveal the behaviors of test square. Taking the archaeological works in Liangzhu prehistoric earthen sites as the research background, the paper first introduces the geological setting, excavation procedure and monitoring scheme of the studied test square. Then, the deformation of four sides of the test square is modeled using FLAC3D. By comparison, it shows that the numerical results are consistent with the results from field monitoring. The result suggests that the numerical simulation can be effectively applied to representing the actual behaviors of the test square,which is helpful for determination of excavation scheme and stability evaluation of the test square during archaeological excavation.

SiteTesting with IRA-935 Hygrometer and Statistical Analyses

A brief description of infrared IRA-935 water vapour measuring instrument is presented and integrated vertical water vapour content W 0 in the atmosphere at Gaomeigu and Fenghuangshan sites and precision analyses are given in the paper. The daily variation and distributions of W 0 in a whole year and monthly average W 0 measurements at these two sites are discussed in more detail. The statistical results of the observational data in the whole year are also analysed and discussed.

The AIMS Site Survey

This paper reports site survey results for the Infrared System for the Accurate Measurement of Solar Magnetic Field, especially in Saishiteng Mountain, Qinghai, China. Since 2017, we have installed a weather station,spectrometers for precipitable water vapor, and Solar Differential Image Motion Monitor, and have carried out observations on weather elements, precipitable water vapor, and daytime seeing conditions for more than one year in almost all candidates. At Mt. Saishiteng, the median value of daytime precipitable water vapor is 5.25 mm and its median value in winter season is 2.1 mm. The median value of the Fried parameter of daytime seeing observation at Saishiteng Mountain is 3.42 cm. Its solar direct radiation data show that solar average observable time is 446 minutes per day and premium time is 401 minutes per day in 2019 August.