Ground-based Equipment Research Articles

Prediction the Level of the Electromagnetic Background Created by Constellations of Satellites Near the Earth’s Surface Using Registration Data

A technique has been proposed for predicting the average intensity of electromagnetic background created near the Earth’s surface by a constellation of communication satellites, taking into account the number of satellites in the constellation, the satellite total radiated power, parameters of its radiation in the main and side lobes, the orbit altitude and restrictions on the tilt angle of service of ground-based equipment. The results of the analysis of the dependence of the average electromagnetic background levels at the Earth’s surface on the number of satellites in the constellation under various scenarios for the implementation of information services for terrestrial subscriber terminals are presented, confirming the adequacy of the developed approach. It is concluded that the expected levels of electromagnetic background in the microwave range created by megaconstellations of low-orbit communication satellites are many orders of magnitude higher than the levels of electromagnetic background of natural origin, which significantly changes the physical characteristics of the habitat.

Design of an active wing-folding biomimetic flapping-wing air vehicle

In nature, birds and bats dynamically alter their wing shapes to suit various flight environments and tasks. This paper focuses on the design and validation of a biomimetic flapping-wing aerial vehicle, named FlexiWing, which features a unique mechanism for active wing deformation. This mechanism allows the wings to adjust their shapes flexibly in response to flight demands, significantly enhancing attitude control and maneuverability.’ ‘This study began with an in-depth exploration of biomimetic principles, focusing particularly on how birds and bats achieve precise control during flight through active wing deformation. Subsequently, we present a detailed account of the design and fabrication process of the active folding biomimetic flapping-wing aerial vehicle, including the design of mechanical mechanisms and material selection. Utilizing lightweight nylon materials and hollow carbon fiber rods, we successfully constructed a mechanically foldable wing structure. To achieve precise control over the aircraft’s movement, an embedded control system was designed, comprising an onboard embedded flight controller and ground-based equipment. The onboard controller uses a high-performance ESP32-C3 processor and a JY901 inertial measurement unit to acquire real-time attitude information of the aircraft. The control system incorporates Wi-Fi communication technology, enabling operators to send commands via a remote control or personal computer to manage flight modes and attitudes. Ultimately, a series of flight experiments were conducted to validate the performance of FlexiWing. The results demonstrate that FlexiWing exhibits remarkable maneuverability and stability, capable of achieving high-precision attitude control through active wing folding, making it adaptable to complex environments and tasks.’

Analysis of the Effect of Tilted Corner Cube Reflector Arrays on Lunar Laser Ranging

This paper primarily investigates the effect of the tilt of corner cube reflector (CCR) arrays on lunar laser ranging (LLR). A mathematical model was established to study the random errors caused by the tilt of the CCR arrays. The study found that, ideally, when the laser ranging pulse width is 10 picoseconds or less, it is possible to distinguish from which specific corner cubes within the CCR array each peak in the echo signal originates. Consequently, partial data from the echo can be extracted for signal processing, significantly reducing random errors and improving the single-shot precision of LLR. The distance obtained by extracting part of the echo can be reduced to the center position of the array, thereby providing multiple higher-precision ranging results from each measurement. This not only improves the precision of LLR but also increases the data volume. A simulation experiment based on the 1.2 m laser ranging system at Yunnan Observatories was conducted. By extracting one peak for signal processing, the single-shot precision improved from 32.24 mm to 2.52 mm, validating the theoretical analysis results. Finally, an experimental laser ranging system based on a 53 cm binocular telescope system was established for ground experiments. The experimental results indicated that the echo signal could identify the tilt state of the CCR array. By extracting the peak returned by the central CCR for signal processing, the ranging precision was greatly improved. Through theoretical analyses, simulation experiments, and ground experiments, a solution to reduce the random errors caused by the tilt of the CCR array was provided. This offers an approach to enhance the single-shot precision of future LLR and provides a reference for upgrading ground-based equipment at future laser ranging stations.

Influence of the relative position of the Parus-A ionosonde antennas on the results of oblique sounding

The article considers the issue of relevance of ground-based equipment for ionosphere sounding and investigates some parameters of the ionospheric network of Roshydromet, equipped with Russian ionosondes “Parus-A”. The analysis of antenna systems used in these ionosondes has been carried out. The peculiarities of the reception of oblique sounding signals depending on the mutual arrangement of the antennas have been analyzed. A proposal has been made to take these issues into account in the development of new domestic ionosondes.

Application rate and hydraulic tips used in remotely piloted aircraft affect the phytosanitary products in coffee plant canopies

Most coffee (Coffea arabica) phytosanitary management techniques are performed using ground-based equipment, and remotely piloted aircraft are a recent alternative. Therefore, this study evaluates the effect of different application rates and hydraulic tips used for spreading phytosanitary products on coffee crops using a remotely piloted aircraft, assisted by artificial targets and dye tracing. The experiment was a 4 × 3 factorial randomized block design with four tips (XR 110-01, TT 110-01, AIXR 110-015, and TTJ60 110-02) and three application rates (8, 12, and 16 L ha-1). Hydrosensitive paper was used to analyze the droplet spectrum, and the Brilliant Blue tracer was used to detect spray deposition. The DJI Agras T20 remotely piloted aircraft was used to apply the phytosanitary product. Speed, flight height, and application range were maintained at 5.56 m s-1, 2 m, and 5 m, respectively. The flight direction was perpendicular to the crop planting lines. The application rate and hydraulic tip jointly controlled the accumulation of droplets on the target according to its position in the plant canopy. Therefore, remotely piloted aircraft can be used in coffee phytosanitary management, particularly to control targets that predominately occur in the upper third of the plant canopy.

3D cell culture model: From ground experiment to microgravity study.

Microgravity has been shown to induce many changes in cell growth and differentiation due to offloading the gravitational strain normally exerted on cells. Although many studies have used two-dimensional (2D) cell culture systems to investigate the effects of microgravity on cell growth, three-dimensional (3D) culture scaffolds can offer more direct indications of the modified cell response to microgravity-related dysregulations compared to 2D culture methods. Thus, knowledge of 3D cell culture is essential for better understanding the in vivo tissue function and physiological response under microgravity conditions. This review discusses the advances in 2D and 3D cell culture studies, particularly emphasizing the role of hydrogels, which can provide cells with a mimic in vivo environment to collect a more natural response. We also summarized recent studies about cell growth and differentiation under real microgravity or simulated microgravity conditions using ground-based equipment. Finally, we anticipate that hydrogel-based 3D culture models will play an essential role in constructing organoids, discovering the causes of microgravity-dependent molecular and cellular changes, improving space tissue regeneration, and developing innovative therapeutic strategies. Future research into the 3D culture in microgravity conditions could lead to valuable therapeutic applications in health and pharmaceuticals.

Refined mapping and kinematic trend assessment of potential landslides associated with large-scale land creation projects with multitemporal InSAR

Since 2012, a mega-project, “Mountain Excavation and City Construction” (MECC), has been underway on the Chinese Loess Plateau, aiming to create extra flat ground for urban growth. However, this large-scale land creation has led to dramatic changes in the local geological environment, forming a large number of engineered loess slopes. This study aims to map and assess the boundaries and stability of these potentially unstable engineered slopes (potential landslides). Based on spatio-temporal deformation patterns of landslides prior to failure, a novel interferometric synthetic aperture radar (InSAR)-based procedure for potential landslide mapping and stability evaluation was constructed in this study. The proposed procedure was employed to map and evaluate the potential landslides in the Yan’an New District (YND), the largest land-creation area in the Loess Plateau. First, the spatial locations and boundaries of the potential landslides were determined by combining optical image interpretation with differential deformation maps derived from Sentinel-1 small baseline subset InSAR (SBAS-InSAR) analysis. Then, the kinematic evolution trend of the mapped potential landslide was evaluated by quantitative analysis of the time-series displacements using an exponential model. Finally, the potential influencing factors and failure modes of the potential landslide were examined and discussed. The results indicate that the InSAR-derived differential deformation maps reflect the external boundary of the potential landslides well, and a total of 18 potential landslides are identified and mapped for the first time in the large-scale land-creation area of the YND. Over 82% of the coherent targets (CTs) within these potential landslides showed primary or steady creep during the InSAR observation period; however, tertiary creep was also observed on several slopes. Thus, it is crucial to utilize multitemporal InSAR and/or ground-based equipment for the continuous monitoring of engineered slopes in large-scale land-creation areas. The high correlation between spatiotemporal deformation patterns and environmental factors indicates that the activity of potential landslides is mainly controlled by the thickness of filling loess, while rainfall accelerates the displacement of slopes. These findings can contribute to the development of landslide disaster prevention and mitigation measures in the YND.

Определение статистических параметров флуктуаций коэффициента преломления ионосферы по данным радиолинии передачи информации космос-Земля

The study considers the problem of restoring the covariance function of fluctuations in the refractive index of the ionosphere based on the analysis of random changes in the frequency of the radio signal. To solve the problem, a trans-ionospheric signal of an information transmission radio line is used, radiated from a low-orbit spacecraft and received at a stationary receiving point. A method for estimating ionospheric parameters based on data from one typical communication session is described. To conduct a full-scale experiment, the signal emitted by the P-band radio transmitter of the on-board monitoring and control system of the Aist-2D spacecraft is used during a typical communication session. To receive the signal, ground-based equipment of a bistatic radar complex with a synthesized aperture of the P frequency band is used

Determination of statistical parameters of fluctuations in the refractive index of the ionosphere according to the data of the space-earth information transmission radio line

The study considers the problem of restoring the covariance function of fluctuations in the refractive index of the ionosphere based on the analysis of random changes in the frequency of the radio signal. To solve the problem, a trans-ionospheric signal of an information transmission radio line is used, radiated from a low-orbit spacecraft and received at a stationary receiving point. A method for estimating ionospheric parameters based on data from one typical communication session is described. To conduct a full-scale experiment, the signal emitted by the P-band radio transmitter of the on-board monitoring and control system of the Aist-2D spacecraft is used during a typical communication session. To receive the signal, ground-based equipment of a bistatic radar complex with a synthesized aperture of the P frequency band is used. Keywords: the ionosphere, fluctuations in the refractive index, the radio line of information transmission from the spacecraft, the scale of inhomogeneities and the dispersion of the electron density of the ionosphere.

Estimation of the synchronization error for spaced-apart ground points of satellite communication

A significant number of patents and publications in the open press show the intensity of the ongoing research to create new methods of synchronization and specialized ground-based equipment for frequency-time synchronization. The article considers the implementation of an autonomous synchronization system between ground-based satellite communication points, which is used in conditions of unfavorable reception or absence of signals from global navigation satellite systems. The paper presents studies on the assessment of the error of time synchronization of geographically separated ground points of satellite communications. The basics of constructing the receiving equipment of a radio engineering system are considered and the mutual correlation of the reference signal of the receiving equipment and the received input synchronization signal is calculated. The results of field tests of mutual synchronization equipment are presented, where the potential synchronization accuracy of equipment at ground objects with previously unknown coordinates was determined, while the synchronization equipment provided measurement of the signal propagation time from one ground object to another with the formation of universal time scales on points. The method of mutual synchronization of linked points is carried out by the duplex method at a frequency of 1065 MHz (request) and 625 MHz (response) by phase-code-manipulated signals with a base equal to 1023 and a duration of 0,1 ms.

Analysis of Electronic Warfare Capability of the People’s Liberation Army Strategic Support Force (PLASSF): Its Impacts and Implications on Korean Security

This paper analyzes the electronic warfare capabilities of the People’s Liberation Army Strategic Support Force (PLASSF), established in 2015 in China. Based on the investigation, this paper aims to examine the impacts of electronic warfare capabilities of PLASSF on South Korea as well as the implications for Korean security. The core mission of the PLASSF is to perform space, cyber, electronic, and psychological warfare. Under the Network Systems Department of the PLASSF, the units for electronic warfare operates ground-based equipment, (un) manned aircraft, and electronic warfare satellites. Based on this fact, this paper argues the impacts of the PLASSF’s electronic warfare capabilities are threefold: First, the PLASSF’s manned electronic aircraft allows them to collect the electronic intelligence regarding the major military equipment not only of the Korean military but of the U.S. Forces in Korea. Second, it is also expected that the PLASSF would conduct electronic warfare activities very close to the Korean Peninsula by utilizing its unmanned stealth electronic aircraft. Third, the PLASSF is highly likely to gather signals intelligence from space via electronic warfare satellites. In this regard, it is necessary for the Korean military to 1) develop a more concrete concept of electronic warfare; 2) explore the ways to refuse China’s electronic information collection; and 3) secure the electronic warfare countermeasure weapons system.

The Application of Terrestrial LiDAR for Geohazard Mapping, Monitoring and Modelling in the British Geological Survey

Geomatics is the discipline of electronically gathering, storing, processing, and delivering spatially related digital information; it continues to be one of the fastest expanding global markets, driven by technology. The British Geological Survey (BGS) geomatics capabilities have been utilized in a variety of scientific studies such as the monitoring of actively growing volcanic lava domes and rapidly retreating glaciers; coastal erosion and platform evolution; inland and coastal landslide modelling; mapping of geological structures and fault boundaries; rock stability and subsidence feature analysis, and geo-conservation. In 2000, the BGS became the first organization outside the mining industry to use Terrestrial LiDAR Scanning (TLS) as a tool for measuring change; paired with a Global Navigation Satellite System (GNSS), BGS were able to measure, monitor, and model geomorphological features of landslides in the United Kingdom (UK) digitally. Many technologies are used by the BGS to monitor the earth, employed on satellites, airplanes, drones, and ground-based equipment, in both research and commercial settings to carry out mapping, monitoring, and modelling of earth surfaces and processes. Outside BGS, these technologies are used for close-range, high-accuracy applications such as bridge and dam monitoring, crime and accident scene analysis, forest canopy and biomass measurements and military applications.

Evaluation of the effectiveness of the combined use of radio interference equipment on unmanned aerial vehicles and ground-based radio reconnaissance equipment

Evaluation of the effectiveness of the combined use of radio interference equipment on unmanned aerial vehicles and ground-based radio reconnaissance equipment

The Use of UAVs to Save People in the Mountains: Tasks, Problems, Perspective

The actual problem of organizing and conducting rescue operations in the mountains is considered. The achievements associated with the following factors were noted: the active development of UAVs of various designs, masses, and equipment; development of new information systems, including sensors, communication systems; the emergence of new image processing algorithms and other types of data based on artificial intelligence methods. It was emphasized that a fundamentally new achievement that opens up broad prospects is an integrated approach to the use of rescue equipment, including ground-based mobile equipment, UAVs of various types, global navigation and mobile communications, and professional rescuers. Problems were identified that are associated with the difficulties of the task, including a complex mountainous terrain, snow cover, avalanches, strong winds, low temperatures, immobility and even lack of communication with the victims. The article considers the problem of low temperatures, which leads to icing, which gives rise to an uncontrolled change in the properties of the control object UAVs, difficulties in the functioning of control elements, and distortion of the sensors. Based on the methods of artificial intelligence, including modern methods of detecting damage, a comparative analysis of different approaches was carried out and a predominant approach was drawn, which allows a high degree of certainty to detect problems of UAV icing and timely change of control system settings.

Cyber-physical system for control the heat and mass transfer in the oil reservoir and producing pumping well

A special cyber-physical system is developed to control transient heat and mass transfer during the commissioning of the unified oil production complex consisted of oil reservoir, producing well equipped with electric submersible centrifugal pump, well production tree and ground-based control station. Two main elements of cyber-physical system are following: – computer simulator of heat and mass transfer in virtual oil production complex based on mathematical and numerical models of such processes along with simultaneous visualization of computational results; – portable imitation hardware of real ground-based equipment which is realized as 3D-printed plastic model consisted of control elements (pipeline valves, drossel chamber, ground-based control station) and recording devices (manometers, level indicator, liquid sampler and control station itself). Mechanisms of these elements are replaced by Arduino microchips to simulate the operation of real devices. An important feature of the cyber-physical system is the data exchange and interaction between oil production computer simulator and microcontroller software. Data transfer is going through the COM-ports of computer and microcontroller. The simulator sends calculated working characteristics of oil production complex to the memory of microcontroller, which not only analyzes incoming data but also displays it on the recording devices and forms necessary control parameters, which are sent back to simulator and affect the further behavior of the whole complex. Different elements of the CPS provides the possibility to control and visualize the commissioning of the oil production complex under consideration and the whole system is oriented to simulate the real technological actions performing by specialists in oil production.

Non-Coaxial 24-Speed Shaft-Planetary Gearbox

The article presents the results of the analysis of existing designs of non-coaxial planetary gearboxes, their advantages and disadvantages. The invention is related to transport machinery area, transmission of transport vehicles, land transport systems, including motor vehicles, tractor-trailers, construction and road machines, tractors and ground-based equipment for special purposes. The design and kinematic scheme of a non-coaxial multiple-speed shaft-planetary gearbox, type 24R10, are presented. The work describes the operation of a non-coaxial multiple-speed shaft-planetary gearbox, type 24R10 (24 direct gears and 10 reverse gears), as well as gear ratios for each gear. A technical and economic assessment of the non-coaxial multiple-speed shaft-planetary gearbox, such as 24R10, is given. It is shown that the task is solved by compacting the layout of the multiple-speed gearbox and the planetary mechanism both in gear and summing modes, as the torque enters two links and is removed from the third one. The research proves that the design of a non-coaxial multiple-speed shaft-planetary gearbox, type 24R10, provides an improvement in the layout and operational characteristics of the gearbox and, accordingly, the operational capabilities of the vehicle.

Steep terrain forest operations – challenges, technology development, current implementation, and future opportunities

ABSTRACTWhile modern fully mechanized ground-based systems are a default option for safe and productive harvesting, they have always been limited by terrain factors such as slope, soil strength, and roughness. There is a limit with regard to the physical feasibility of operating machines on steep slopes because both the weight and also the force from the momentum created during traction loss can affect stability. A huge interest to improve traction of harvesting machines when operating on steep slopes is arising. One way to improve traction and stability on steep slopes is through assisting harvesting machines by winch and cable to anchor locations such as tree stumps or stationary equipment. This technology offers potential for improving the safety, productivity, and efficiency of a harvesting operation, as well as for improving machine mobility and reducing soil disturbance through the reduction of slip. With the exponential development of such technology, an integrated approach must be developed for conducting productive and injury-free mechanical harvesting operations on steep slopes that draws on the skills and accountabilities of the working team. Beyond a certain physical threshold, the only feasible and achievable solution providing some “intelligent behavior” to machines and systems would be the role of mechatronics application. One of the most relevant points could be the possibility to introduce the concept of “teleoperation” using unmanned ground vehicles. Combining teleoperation with winch-assist technology would provide a platform for extending the range of ground-based equipment to previously infeasible terrain conditions.

Streamside management zone effectiveness for water temperature control in Western Montana

ABSTRACTAn important function of Streamside Management Zones (SMZs) retained during harvest operations is shading for temperature control. SMZ width and allowable timber removal varies by state. In Montana, an SMZ law requires that timber be retained within 15.2 m of streams, with a steep-slope ground-based equipment exclusion area that can extend up to 30.5 m. The amount of timber removal in the SMZ is a function of pre-harvest tree size and stocking, with removals of 0–30% typical. The effectiveness of SMZs for stream temperature control in Montana has not been previously evaluated. Between 1999 and 2004, half-hourly stream temperature data were collected at 30 operational harvest sites bordering perennial fish-bearing streams in western Montana. Temperature data were collected at the upper and lower boundary of the harvest, for a minimum of one summer before and after harvest. Covariate data were collected to describe the harvest, and fish data collected to evaluate biological response that may be associated with temperature changes. Response measures were analyzed using a linear mixed effects model. The model structure was based on the experimental design and included terms for year, position, harvest-state, and a position × harvest-state interaction, with the latter term used to estimate the impact of harvest on stream temperature. Results found no significant harvest effect for the six evaluated temperature metrics, with estimates between –0.1 and 0.04°C. Fish population and biomass also had no significant harvest effect. These results suggest that operational SMZs being retained in Montana are protective of water temperature.

Characteristics of the Ground-Based User Equipment of Satellite Radio Navigation System Employing Pseudolites in Noisy Environments

This article discusses the joint functioning of satellite radio navigation systems and their augmentations in the form of pseudolite networks under radio interference of various natures and intensities. The achievable precision in determining the coordinates of the object in noisy environments using and considering the estimates of the signal power level of navigational satellites, pseudolites and interference, is an indicator of the effectiveness of such joint systems. The paper refines the model of undisturbed motion of navigation satellites in terms of determining the geocentric coordinates of pseudolites (PL). A model for determining the signal levels of navigation satellites and pseudolites at the input of user equipment (UE) of satellite radio navigation systems (SRNS) was constructed. The algorithm was refined for calculating the mean square error (MSE) to determine coordinates when sharing signals of pseudolites and navigational satellites (NS) in noisy environments. The method was developed and the energy and precision characteristics of SRNS UE operated by NS and PL signals in noisy environments were determined.

An effective approach to identify the mass properties of a satellite attitude dynamics simulator

A satellite attitude dynamics simulator (SADS) is a low-cost, ground-based equipment for laboratory simulation of the space environment as satellite weightless, sun and magnetic field simulation as well as implementation of diverse attitude determination and control algorithms. Precise estimation of mass properties plays a significant role in guidance and control algorithms application. The objective of this paper is mass properties identification includes moment of inertia tensor and centre of mass position of a three-degrees-of-freedom SADS at the Space Research Laboratory. This paper investigates the well-known methods to estimate mass properties, i.e. Batch Least Squares and Classical Kalman Filter and presents an innovative approach using the Classical Levenberg–Marquardt (CLM) to solve this major problem. In order to verify the proposed technique, a MATLAB® SIMULINK® model of the SADS is employed. The experimental results indicate that the parameter estimation process using CLM technique is more accurate and reliable than other methods.