Stationary Stations Research Articles

Application of Atmospheric Augmentation for PPP-RTK with Instantaneous Ambiguity Resolution in Kinematic Vehicle Positioning

The long convergence time and non-robust positioning accuracy are the main factors limiting the application of precision single-point positioning (PPP) in kinematic vehicle navigation. Therefore, a dual/triple-frequency multi-constellation PPP-RTK method with atmospheric augmentation is proposed to achieve cm-level reliable kinematic positioning. The performance was assessed using a set of static station and kinematic vehicle positioning experiments conducted in Wuhan. In the static experiments, instantaneous convergence within 1 s and centimeter-level positioning accuracy were achieved for PPP-RTK using dual-frequency observation. For the kinematic experiments, instantaneous convergence was also achieved for dual-frequency PPP-RTK in open areas, with RMS of 2.6 cm, 2.6 cm, and 7.5 cm in the north, east, and up directions, respectively, with accuracy similar to short-baseline real-time kinematic positioning (RTK). Horizontal positioning errors of less than 0.1 m and 3D positional errors of less than 0.2 m were 99.54% and 98.46%, respectively. Additionally, after the outage of GNSS and during satellite reduction in obstructed environments, faster reconvergence and greater accuracy stability were realized compared with PPP without atmospheric enhancement. Triple-frequency PPP-RTK was able to further enhance the robustness and accuracy of positioning, with RMS of 2.2 cm, 2.0 cm, and 7.3 cm, respectively. In summary, a performance similar to RTK was achieved based on dual-frequency PPP-RTK, demonstrating that PPP-RTK has the potential for lane-level navigation.

New Measuring and Data Transmission Equipment for Operational Oceanography at the Gelendgik Black Sea Test Site of Institute of Oceanology of the RAS

The design and principles of operation of the bottom multi-modem station MDS-II, located in the coastal zone (depth of location — 25 m) of the northeastern part of the Black Sea at the Gelendzhik Test Site of IO RAS are described. The station is connected to the coastal center by means of a bottom fiber-optic cable, through which power is supplied to the station, and online transmission of measurement data takes place. The station is an underwater server to which one can connect a measuring device and get a real-time access to it, as well as remotely control on its operation. The design of an automatic stationary station for vertical sounding (SSVS) of water column, which is also used at the Gelendzhik Test Site, is also described. This station is installed close to the MDS-II multi-modem station and is connected to one of its modems. The station consists of a bottom electric winch installed on the seabed and a floating module (probe) on a cable line wound around the winch drum. When the command ʺsoundingʺ is given, the cable unwinds and the floating module, equipped with temperature and pressure sensors, floats and measures the water temperature profile from the bottom layer to the sea surface. Then the cable is winding on a drum, and the floating module returns to the bottom layer. A prototype of a new SSVS is being developed, which will allow sounding of the water layer with a thickness of up to 100 m. It will be equipped with a multi-parameter probe that makes joint measurements of hydrophysical and bio-optical parameters.

Analysis of the dynamic response of a base isolated building during an earthquake with an intensity of 7 points on the MSK-64 scale

Introduction. The problem is considered and the relevance of studying the behavior of buildings and structures with seismic isolation systems using lead rubber bearing under real seismic impact, as well as assessing their technical condition after the earthquake, is emphasized. The experience of studying the behavior of base isolated buildings under real seismic impact abroad and in Russia is given.
 Materials and methods. The dynamic parameters seismic isolation of a reinforced concrete building using lead rubber bearing are investigated. Registration of seismic vibrations of the building was performed by a stationary station for dynamic monitoring. The results of processing the records were obtained based on the interpretation of monitoring data, including harmonic analysis, determination of the power spectral density, as well as the application of wavelet transform methods.
 Results. The results of dynamic monitoring of a base isolated building of a sea terminal located in Petropavlovsk-Kamchatsky city during an earthquake of 04/03/2023 with a magnitude of Mw =6.6 and an intensity at the site of the building equal to 7 points on the MSK-64 scale are presented. An analysis of the response and dynamic parameters of the building was performed, as well as a visual inspection of structures, as well as the building's seismic isolation systems.
 Conclusions. Analysis of the dynamic monitoring results made it possible to identify the natural vibration frequencies of the building, as well as to trace their changes during seismic impact. The maximum displacements of the building indicate minor shear deformations of the lead rubber bearing corresponding to the zone of their elastic operation. Both the rigidity of lead rubber bearing and the dynamic parameters of the building (frequencies (periods) of natural vibrations and the logarithmic damping decrement of the building) change depending on the intensity of the seismic impact and the shear deformation of the bearings, respectively. After the earthquake, widespread cracks and peeling of the plaster wall were observed with partial exposure of the layer of insulating material in the zone of filling with elastic elements the gaps between the strapping beams of the seismic isolation system and the structures of the building partitions at the level of the seismic isolating layer, which did not affect the operational reliability of the building. The study presented in this article shows that with the help of dynamic monitoring of buildings and structures, one can get a more complete and detailed understanding of their dynamic behavior, identify damage in the structural system of a building, and detect their undesirable or specific reactions that could not be taken into account when designing.

A Power-Aware Method for IoT Networks with Mobile Stations and Dynamic Power Management Strategy

The Internet of Things (IoT) plays a critical role in the digitalization of numerous industries, enabling increased automation, connectivity, and data collection in areas such as manufacturing, healthcare, transportation, and smart cities. This paper introduces a power-aware method for IoT networks using mobile stations and a dynamic power management strategy. The proposed method aims to improve power consumption and total packets received compared to the static-station balanced data traffic method. The proposed method uses a mobile station to dynamically adapt its transmission power based on the network conditions and the strength of the received signal. Furthermore, a dynamic power management strategy is employed to further decrease the power usage of the network by adjusting the power state of each station and IoT node according to its level of activity, data traffic, and communication requirements. Simulation results showed that the proposed method reduced power consumption by up to 64%, increased total packets received by 72%, and, as a result, increased network coverage and lifetime compared to the balanced data traffic method with static stations. This method can be employed in various IoT applications to improve power efficiency and increase network reliability.

Analysis of neutron monitor count rates and timing distributions from latitude surveys

Neutron monitors continuously record the hadronic part of secondary atmospheric radiation on the ground, which originates from primary cosmic rays. In Thailand, we developed a mobile neutron monitor housed inside a standard-size shipping container named “Changvan.” It contains three neutron-sensitive proportional counters set up in the typical NM64 layout. However, the central counter doesn’t have the lead producer, leading us to refer to it as a “semi-leaded” neutron monitor. We examined cosmic ray spectral variations on two latitude surveys during 2018-2019 and 2019-2020. This work examines the ratio of count rates between leaded and unleaded setups, which shows notable variation based on geomagnetic cutoff rigidity, suggesting a sensitivity to the cosmic ray spectrum. This measurement could be implemented at stationary stations. The unleaded counter, shielded by the reflector with a higher count from nearby lead, may have advantages over a bare one. Furthermore, we explore alternative techniques to identify spectral changes in Galactic cosmic rays using Changvan data. We analyze using time delay histograms to determine the leader fraction (L) of neutrons that are not preceded by another neutron from the same primary cosmic ray. We also examine other parameters, including the alpha (α) parameter and pulse rate (PR), which can be compared with count rates (CR). Our findings indicate that the ratios of L and α are not significantly affected by geomagnetic cutoff rigidity. In contrast, CR and PR exhibit significant dependency and show opposite trends.

In-cabin and outdoor environmental monitoring in vehicular scenarios with distributed computing

Accurate environmental monitoring is becoming the basis for assuring sustainable development in administrations at different levels, including cities and industry as key actors. However, current techniques rely on static stations that may not be representative of larger areas, for the case of outdoor scenarios, or even not considering indoor spaces where people can remain for long periods. This is the case of vehicles. The COVID-19 pandemic has remarked the importance of measuring air quality indoors, for instance. With the aim of solving this two-fold issue, this work proposes an in-cabin and outdoor air pollution monitoring system to assure healthy conditions when travelling, driving and operating vehicles, and to analyse the evolution of environmental parameters in cities. This effort is carried out exploiting distributed computing with micro-services, betting for an on-board hardware solution provided with sensors for measuring particulate matter, CO, CO2, NO2, O3, temperature and humidity. While basic data pre-processing is carried out in this acquisition unit, edge processing is performed on a single board computer aboard and intermediary communication nodes in the network path from the vehicle to the cloud. Vehicle connectivity is provided by 4G cellular and Low-Power Wide-Area (LPWAN) networks. Global environmental perception is acquired by cloud-based software powered by machine learning and time series analysis. The whole solution has been validated and tested in the city of Cartagena (Spain), with good performance in terms of data collection, communication links and service offered.

STCM: A spatio-temporal calibration model for low-cost air monitoring sensors

Air pollution is one of the most common health-threatening factors, potentially causing millions of deaths every year. Static stations typically collect air pollution data by utilizing a small number of costly and high-quality sensors and numerous low-cost micro stations. However, data collected from micro stations usually suffers from large noise and thus calibration would be necessary for operating good air pollution governance. Point-to-point models and sequence-to-point models have the potential limitations of either failing to mine latent patterns embedded in historical time series or ignoring spatial dependency within a certain region. To address these issues, we propose a novel method called Spatio-Temporal Calibration Model (STCM) based on dual encoders. STCM consists of long-term encoder, short-term encoder, and decoder modules. The long-term encoder encodes historical reference data via GRU and extracts the trend, periodicity, and adjacency of the target pollutant through a temporal attention mechanism. The short-term encoder then reflects real-time conditions through a spatial attention mechanism, quantifying dynamic station-wise correlations between micro stations and the static station. The decoder ultimately integrates outputs of dual encoders and generates calibration results of all micro stations. STCM has been experimentally justified by comparing against nine baseline methods based on two real-world datasets.

An Embedded Crowdsensing Unit for Mobile Urban Pollution Monitoring

Crowdsensing using mobile sensors to gather environmental data is gaining momentum, given its potential to better reflect the status of larger areas than static stations. Crowdsensing using personal or vehicle devices can offer a flexible solution in smart city scenarios. Apart from regular bikes and mopeds, mobility devices such as e-scooters are sustainable and eco-friendly mobility solutions in urban settings, while at the same time they can offer a flexible mobile crowdsensing platform for environmental perception. However, new hardware designs for onboard units are necessary to cover dimension and power constraints at the same time that proper communications and air pollution sensors are integrated. The unit presented here covers these requirements with a hardware/software platform provided with low-power wide area network (LPWAN) communications, sensors for particulate matter (PM <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> ), NO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> , CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> , 0 <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> , noise, and weather, and software-based management of peripherals and sensors to reduce power consumption. It involves a fully functional design that has been implemented, together with a proper LPWAN network deployment and a data collection back-end, and has been evaluated on e-scooters in terms of both communications capabilities and functionality for monitoring air and noise pollution in the city of Cartagena, Spain.

Analysis of the nonstationarity characteristics and future trends of flood extremes in the Dongting Lake Basin

Study regionDongting Lake Basin of China. Study focusThis study aimed to analyze the nonstationary characteristics and future trends of flood extremes in the Dongting Lake Basin. The spatiotemporal variations in the flood extremes that occurred over the past 60 years were explored using the trend-free prewhitening-MK (TFPW-MK) method, the nonstationary characteristics of flood extremes were detected using the Pettitt test, and the nonstationarity analysis was performed using the GAMLSS model. Furthermore, a combination of TFPW-MK and the Hurst exponent was employed to predict the future trends in flood extremes. New hydrological insights for the region(1) Evident variations were observed in the flood extremes from most hydrometric stations. Among the 10 stations with a decreasing extreme trend, seven exhibited evident decreases. Such decreases probably result from the impact of water conservancy projects. Among the remaining six stations with an increasing extreme trend, two exhibited evident increases. Such increases probably result from the effect of highly extreme precipitation. (2) Flood extremes from most (9 of 16) stations showed nonstationarity. The lognormal distribution was the optimal distribution of extreme values for nonstationary stations, whereas the Gamma distribution was the optimal distribution of extreme values for stationary stations. Despite the preferable fitting efficiency of the GAMLSS model, its simulation performance for nonstationary stations that showed significant trends must be improved. (3) The flood extremes of the 14 stations will maintain existing trends in the future. The Xiangtan Station exhibited anti-persistence and might show a decreasing trend in the future, whereas Shimen Station did not show persistence.

In Situ Measurements of Plankton Biorhythms Using Submersible Holographic Camera

The paper presents a diagnostic complex for plankton studies using the miniDHC (digital holographic camera). Its capabilities to study the rhythmic processes in plankton ecosystems were demonstrated using the natural testing in Lake Baikal in summer. The results of in situ measurements of plankton to detect the synchronization of collective biological rhythms with medium parameters are presented and interpreted. The most significant rhythms in terms of the correlation of their parameters with medium factors are identified. The study shows that the correlation with water temperature at the mooring site has the greatest significance and reliability. The results are verified with biodiversity data obtained by the traditional mesh method. The experience and results of the study can be used for the construction of a stationary station to monitor the ecological state of the water area through the digitalization of plankton behavior.

The Multi-Type Demands Oriented Framework for Flex-Route Transit Design

Flex-route transit is regarded as the feasible solution to provide flexible service for various demands. To improve the service of flex-route transit, this paper proposes a design framework with the input of multi-type demands. Firstly, according to the multi-feature-based classification method, static stations and dynamic stations are divided by hierarchical clustering algorithm based on historical demands. Secondly, in the two-stage planning method, an offline plan is generated by multi-route design model and route-design-oriented genetic algorithm based on the classified stations and the flexible combination of reserved demands and regular travel patterns. Then, an online plan is adjusted by route modification model and greedy algorithm based on the offline plan and real-time demands. Numerical experiments demonstrate the applicability of flex-route transit in the realistic road network and show that flex-route transit can transport demands more effectively and save nearly 40% of cost compared with traditional transit.

Unmanned Aerial System-Based Data Ferrying over a Sensor Node Station Network in Maize.

Agriculture is considered a hotspot for wireless sensor network (WSN) facilities as they could potentially contribute towards improving on-farm management and food crop yields. This study proposes six designs of unmanned aerial system (UAS)-enabled data ferries with the intent of communicating with stationary sensor node stations in maize. Based on selection criteria and constraints, a proposed UAS data ferrying design was shortlisted from which a field experiment was conducted for two growing seasons to investigate the adoptability of the selected design along with an established WSN system. A data ferry platform comprised of a transceiver radio, a mini-laptop, and a battery was constructed and mounted on the UAS. Real-time monitoring of soil and temperature parameters was enabled through the node stations with data retrieved by the UAS data ferrying. The design was validated by establishing communication at different heights (31 m, 61 m, and 122 m) and lateral distances (0 m, 38 m, and 76 m) from the node stations. The communication success rate (CSR) was higher at a height of 31 m and within a lateral distance of 38 m from the node station. Lower communication was accredited to potential interference from the maize canopy and water losses from the maize canopy.

Respiratory risks caused by atmospheric air pollution and respiratory morbidity among residents of Omsk

Introduction. Contaminants emitted into atmospheric air and tropical to respiratory organs form maximum non-carcinogenic risks in Omsk. Respiratory risk levels over the past 12 years have not dropped below the "high risk" level and ranged from 9.4 to 20 in different years of observation. "Clean Air" Federal project, which is being implemented in Omsk, should be successful not only in terms of reducing harmful emissions, but also contribute to a sustainable reduction in the incidence rate. The study aims to determine the list of pollutants affecting the actual levels of respiratory morbidity of the Omsk population, with the establishment of intracity risk areas. Materials and methods. The study used social-hygienic monitoring data: results of laboratory studies of atmospheric air at stationary stations of Roshydromet, respiratory disease incidence of the Omsk population by age groups for the period 2009-2020. Population health risks were assessed according to health risk assessment methodology applied in case of exposure to chemicals (Guide R 2.1.10.1920-04). Correlation and two-factor variance analyses were used to assess the association between respiratory risks and respiratory disease incidence. Results. Long-term increase in the incidence of chronic bronchitis and asthma in adults and adolescents, unstable rates of asthma in children and dysfunctional health indicators in children under 1 year of age may indicate adverse effects of air-polluting chemicals. High levels of respiratory hazards in Omsk are formed mainly by suspended substances, formaldehyde, carbon (black), hydrogen chloride. The negative impact of these pollutants on the health of Omsk residents was confirmed by spatiotemporal positive connections in the system "respiratory risks - respiratory diseases". Microdistricts with the highest levels of respiratory risks and morbidity of respiratory diseases in children 0-14 years old have been identified on the territory of the city. Conclusion. A list of pollutants emitted in the atmospheric air, affecting the actual levels of respiratory morbidity of the population of Omsk, has been established. Intracity areas of respiratory risk and increased incidence of respiratory diseases in children have been identified. Risk mitigation measures are proposed.

Longitudinal assessment of personal air pollution clouds in ten home and office environments.

Elevated exposure to indoor air pollution is associated with negative human health and well-being outcomes. Inhalation exposure studies commonly rely on stationary monitors in combination with human time-activity patterns; however, this method is susceptible to exposure misclassification. We tracked ten participants during five consecutive workdays with stationary air pollutant monitors at their homes and offices, and wearable personal monitors. Real-time measures of size-resolved particulate matter (within range 0.3-10μm) and CO2 , and integrated samples of PM10 , VOCs, and aldehydes were collected. The PM10 cloud magnitude (excess of PM10 beyond stationary room concentration) was detected for all participants in homes and offices. The PM10 cloud magnitude ranged within 5-37μg/m3 and was the most discernible in the coarse particle size fraction. Particles associated with "Urban mix," "Traffic," and "Human activities" sources contributed the most to PM10 exposures. The personal CO2 clouds were detected for participants with the SEMs in their living rooms and private or low-occupancy offices. The stationary monitors placed in bedrooms were better predictors of personal PM10 and CO2 exposures. An overall of 33VOCs and aldehydes were detected in both microenvironments, with the majority exhibiting high correlation between personal and stationary stations.

COMPARATIVE ANALYSIS OF TECHNICAL CHARACTERISTICS OF CHARGING STATIONS OF ELECTRIC VEHICLES

The article analyzes and compares charging stations for electric vehicles and their components. The analysis of charging modes of electric vehicles showed that four internationally standardized modes are used, three of which use alternating current with single-phase and three-phase switching and only one – direct current. When charging on direct current, the fastest charging is provided. There are four standardized cases of connecting charging stations to electric vehicles. Three cases of cable connection can be used on alternating current, only the third case – on direct current, and the fourth case – when wirelessly charging an electric car. Analysis of the principles of use of charging stations showed that they classify portable, wall, and stationary stations. National standards introduce road signs for electric vehicles, and a European standard establishes harmonized identifiers for the power supply of electric vehicles. There are some standardized protocols for the interaction of the charging station and the control server, which are designed to optimize energy resources and energy production systems. A comparison of existing types of connectors for charging electric vehicles has shown that the standardized interface between the charging station and the electric vehicle remains one of the most acute problems. Recommendations on approaches to metrological support of charging stations are formulated. The issue of international and regional standardization of electricity meters of direct current for use in charging stations remains relevant. International standards are transformed into relevant European standards without changes. However, in some cases, it is necessary to develop a special European standard, in particular for meters of active electrical energy of the direct current.

Approach to optimizing charging infrastructure of autonomous trolleybuses for urban routes

P u r p o s e s. When designing a system of urban electric transport that charges while driving, including autonomous trolleybuses with batteries of increased capacity, it is important to optimize the charging infrastructure for a fleet of such vehicles. The charging infrastructure of the dedicated routes consists of overhead wire sections along the routes and stationary charging stations of a given type at the terminal stops of the routes. It is designed to ensure the movement of trolleybuses and restore the charge of their batteries, consumed in the sections of autonomous running.The aim of the study is to create models and methods for developing cost-effective solutions for charging infrastructure, ensuring the functioning of the autonomous trolleybus fleet, respecting a number of specific conditions. Conditions include ensuring a specified range of autonomous trolleybus running at a given rate of energy consumption on routes, a guaranteed service life of their batteries, as well as preventing the discharge of batteries below a critical level under various operating modes during their service life.M e t ho d s. Methods of set theory, graph theory and linear approximation are used.Re s u l t s. A mathematical model has been developed for the optimization problem of the charging infrastructure of the autonomous trolleybus fleet. The total reduced annual costs for the charging infrastructure are selected as the objective function. The model is formulated as a mathematical programming problem with a quadratic objective function and linear constraints.Co n c l u s i o n. To solve the formulated problem of mathematical programming, standard solvers such as IBM ILOG CPLEX can be used, as well as, taking into account its computational complexity, the heuristic method of "swarm of particles". The solution to the problem is to select the configuration of the location of the overhead wire sections on the routes and the durations of charging the trolleybuses at the terminal stops, which determine the corresponding number of stationary charging stations at these stops.

ANALYSIS OF THE RESULTS OF AIR QUALITY MONITORING IN THE AREA OF THE CITY OF ZENICA

According to the World Health Organization (WHO), air pollution is the largest single environmental risk to public health. According to the latest estimate of this organization, 9 out of 10 people on the planet breathe polluted air. The development of industry in the relatively small Zenica valley reflected on air quality in the city of Zenica. The problem of high air pollution due to emissions of pollutants from industrial sources, traffic, and individual furnaces, burning of environmentally unsuitable fuels containing high sulfur and ash content has been present in the City of Zenica for a long time. In addition, the low wind speed during the year, which ranges up to 1.5 m/s, with unfavorable temperature inversions, causes the concentrations of pollutants in the air to reach alarmingly high values in a short period. In the wider area of the City of Zenica, air quality has been monitored since 1978 in the network of stationary stations. The paper presents results of air quality monitoring which are analyzed at the Institute Kemal Kapetanovic in Zenica for the sampling period from 01.01.2019. to 31.12.2020. years. Air quality monitoring included sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matter (PM10) at three locations in the wider area of the city of Zenica. In the wider area of the City of Zenica, air quality has been monitored since 1978 in the network of stationary stations. The paper presents the processed results of air quality monitoring which are analyzed at the Institute Kemal Kapetanovic in Zenica for the sampling period from 01.01.2019 to 31.12.2020. The measured concentrations of pollutants in the ambient air indicate that during the heating season, i.e. the winter months, the air quality in the urban and suburban areas of the city of Zenica is very poor. The data show that the highest hourly concentration of sulfur dioxide was recorded in December at the measuring station AMS Tetovo in the amount of 1100.59 µg/m3, which is located in the settlement next to the metallurgical facilities of the industrial zone Zenica.

Assessment of the quality of atmospheric air in woodlands of natural areas based on the intensity analysis of the process of dry deposition of impurities on an artificial underlying surface

Abstract To assess the quality of atmospheric air, the authors propose to apply the process of dry deposition of impurities on an artificial underlying surface that binds impurities in contact with it. The mass of these impurities is calculated upon laboratory exposure, after being transferred to an aqueous solution. The ease of absorber fabrication and the low cost facilitate the monitoring of air pollution at various points in woodlands, where the stationary stations for air-pollution-monitoring are very difficult and costly to arrange. A large number of control points makes it possible to identify forest areas with the highest levels of air pollution. A dynamic air-quality study at one of the monitoring points is necessary and sufficient to determine the concentration of impurities. The authors surveyed an urban forest using the proposed method, and the survey results confirmed that areas with an elevated concentration of airborne nitrogen dioxide exist within the woodland. This can lead to soil eutrophication and changes in forest biodiversity at the species and ecosystem levels.

ОПТОЕЛЕКТРОННИЙ АПАРАТНО-ПРОГРАМНИЙ МОНОМОДУЛЬНИЙ ДАТЧИК МЕТЕОРОЛОГІЧНОЇ ДАЛЬНОСТІ ВИДИМОСТІ ТА ПРОЗОРОСТІ АТМОСФЕРИ З АВТОМАТИЧНОЮ КОРЕКЦІЄЮ ВПЛИВУ ЗОВНІШНЬОГО ЗАБРУДНЕННЯ ОПТИЧНИХ СИСТЕМ

A model sample of a monomodular hardware-software optoelectronic sensor of k-factor, meteorological range of visibility and atmosphere transparency with high technical and operational characteristics of small -sized execution is developed and created. The combination in the algorithm of functioning of the developed hardware-software methods of sensor creation provided increase of accuracy and invariance of results of measurement concerning external background illumination and self-testing with automatic correction of pollution effect of optical windows of the sensor. Continuous monitoring of the degree of contamination of optical windows provides an opportunity in case of detection of exceeding the permissible level of pollution to provide the operator with information about the need for preventive work. The proposed method of automatic correction of contamination of optical windows either completely eliminates or significantly increases the time interval of their mechanical cleaning operations, which reduces labour costs for maintenance of the sensor. The analysis of technical capabilities of the nodes of the model sample of the sensor allowed to estimate its basic meteorological parameters: the k-factor – (0.17÷1.11∙10-4) m-1, the meteorological visibility – (18÷27∙103 ) m and the atmosphere transparency per 1 km of the layer – (0÷0.895). The developed meteorological sensor can be used as a basic remote-controlled instrument for measuring meteorological parameters of the state of the atmosphere at the hydrometeorological stations of the country, mobile meteorological stations, stationary meteorological stations of road and air services to ensure guaranteed safety of workers.

Stability Analysis of Position Datum for Real-Time GPS/BDS/INS Positioning in a Platform System with Multiple Moving Devices

The rapid development of unmanned aerial vehicles (UAVs) in recent years has promoted their application in various fields, such as precise agriculture, formation flight, etc. In these applications, the accurate and reliable real-time position and attitude determination between each moving device in the same platform system are the key issue for safe and effective cooperative works. In traditional ways, static reference stations should be set up near the platform to keep the stable position datum of the platform system. In this paper, we abandoned the static stations and expected to achieve stable position datums with the platform system itself. To achieve this goal, we proposed an improved method based on both the Global Positioning System (GPS)/Beidou Navigation Satellite System (BDS) data and the inertial navigation system (INS) data to obtain precise positions of the moving devices. The time-differenced carrier phase (TDCP) was used to get the position variations and update the positions over time, and then, the INS data was integrated to further improve the accuracy and reliability of the updated positions; thus, this method is denoted as the TDCP/INS method. To evaluate the performance of this method and compare it with the traditional single-point positioning (SPP) method and the Kalman filtered SPP (KFSPP) method, a field vehicle experiment was conducted, and the position results achieved from these three methods were compared with those from the tightly combined real-time kinematic positioning (RTK)/INS method, where centimeter-level accuracy was obtained and regarded as the reference. The quantitative analysis where the position variations were evaluated and the qualitative analysis where the vehicle trajectories in three typical urban driving scenarios were discussed were both made for the three methods. The numerical results showed that the accuracy of the position variations from the SPP, KSPP, and TDCP methods was at the meter level, while that from the TDCP/INS method improved to the centimeter level, and the accuracies were 1.9 cm, 2.9 cm, and 3.1 cm in the east, north, and upward directions. The trajectory results also demonstrated a perfect consistency of the driving positions between the TDCP/INS method and the reference. As a contrast, the trajectories from the SPP and KFSPP methods had frequent jumps or sways when the vehicle drove along a large, curved road, turned at a crossroad, and passed under an urban viaduct.