Landing System Research Articles

Rural land systems both support and hinder the Sustainable Development Goals across Europe

AbstractAchieving sustainable rural land systems, including farms and forestry, is essential to achieve the European Union’s goal of fair and healthy food systems while becoming climate-neutral and halting biodiversity loss. Here we quantitatively assess the environmental and socioeconomic sustainability of rural land systems in Europe using spatial hotspot analyses based on 15 environmental and 9 social sustainability indicators from the European Sustainable Development Goals and the Common Agricultural Policy. We find high subsidy support for under-performing sustainability areas and low sustainability performance in areas producing the most calories. However, we identified two brightspots with good environmental and socioeconomic performance (Nordics and Central Europe), and five dragspots hindering sustainability: the Balkans, the Lowlands, Northern Italy, Southern Italy and Malta, and Southern Spain. Redirecting support to reward social and environmental benefits from land use can help achieve sustainability goals.

The impact of national land supervision system on urban low-carbon transformation: evidence from China

The land system is a crucial factor influencing urban low-carbon sustainable development. However, previous research has paid little attention to the effects and mechanisms of the national land supervision system (NLSS) on urban low-carbon transformation (ULCT). This study uses China’s routine land inspection as a quasi-natural experiment and examines the impact of NLSS on ULCT using panel data from 283 Chinese cities between 2005 and 2016. The study finds that NLSS significantly promotes ULCT, with a series of robustness checks supporting this conclusion, showing a 1.95% improvement in carbon emission performance in cities under supervision. NLSS mainly facilitates ULCT by improving land use efficiency, upgrading the structural of the service sector, and promoting technological progress. Compared to eastern cities, southern cities, large cities, and non-resource-based cities, NLSS more effectively promotes low-carbon transformation in central and western, northern, small- and medium-sized, and resource-based cities. Additionally, in contrast to cities with high environmental awareness, high marketization levels, high financial development levels, and high fiscal pressure, NLSS more strongly promotes ULCT in cities with lower levels of these factors. Furthermore, NLSS exhibits a significant positive spatial spillover effect in promoting ULCT. In advancing ULCT, NLSS can be synergized with smart city pilot policies and innovative city pilot policies but has not shown synergies with low-carbon city pilot policies.

Spatiotemporal Differentiation of Land Ecological Security and Optimization Based on GeoSOS-FLUS Model: A Case Study of the Yellow River Delta in China Toward Sustainability

Land ecological security (LES) is a crucial issue pertaining to the sustainability of landscapes or land systems. Nevertheless, previous studies largely neglected the impacts of landscape structure on LES. This study, taking the Yellow River Delta (YRD) as the case area, analyzed the spatiotemporal differentiation patterns of regional LES in 19 counties (cities and districts) from 2000 to 2020 through the application of landscape metrics and employed GeoSOS-FLUS to forecast the landscape structure and corresponding land ecological security in 2030 under four different scenarios to advance sustainability. The results show that, first, landscape fragmentation and irregularity are decreasing, while aggregation and connectivity are increasing. The primary landscape change involves the transition from farmland to developed areas. Second, the LES index is rising. In 2020, about 73.68% of the research units reached level IV, while most were at level III. Third, it is projected that by 2030, the LES index will rise under all scenarios, exhibiting an eastward-declining gradient in its geographic distribution, with higher values prevailing in the eastern regions and gradually tapering off towards the west. It is expected that in the business-as-usual scenario, the proportion of LES reaching level V will be the highest. This study not only reveals the impact mechanism of the landscape structure on land ecological security but also provides an important basis for formulating scientific and rational land use planning and management strategies from the perspectives of sustainable land governance and sustainable land use.

Research on the Effectiveness of China's Rural Land Ownership Policy

The confirmation of rural land rights and the "separation of three rights" have opened the prelude to the deepening reform of China's agricultural land system, and are of great significance to the implementation of rural revitalization and agricultural security strategy in the new era. Based on existing literature studies, this paper summarizes and analyzes the effect of land ownership confirmation on farmers' income, land circulation, scale management, urbanization, rural governance and other aspects of China's rural land ownership confirmation. The research shows that land ownership confirmation can improve farmers' income, promote land circulation and scale management to a certain extent, but the effect is limited. The impact on urbanization and rural governance is still unclear.

Food and land system transformations under different societal perspectives on sustainable development

Abstract The future of food and land systems is crucial for achieving multiple UN Sustainable Development Goals, given their essential role in providing adequate nutrition and their significant impact on Earth system processes. Despite widespread consensus on the need for transformation, discussed strategies vary widely, from technology-driven to sufficiency-focused approaches, emphasizing different agents of change and policy mixes. This study assesses the implications of a new generation of target-seeking scenarios incorporating such diverse sustainability perspectives. We apply two integrated assessment models to explore food and land futures under three whole-economy Sustainable Development Pathways (SDPs): Economy-driven Innovation, Resilient Communities, and Managing the Global Commons. Our assessment shows that all SDPs align sufficient food supply with progress towards planetary integrity, halting biodiversity loss, mitigating adverse impacts from irrigation, and significantly reducing nitrogen pollution. While all pathways comply with the Paris climate target, they diverge in the timing of climate mitigation efforts and focus on different greenhouse gases and emission sources. The Economy-driven Innovation pathway rapidly achieves net-negative CO2 emissions from the land system, whereas Resilient Communities and Managing the Global Commons significantly decrease agricultural non-CO2 emissions. Moreover, sustainability interventions attenuate trade-offs associated with narrowly focused mitigation pathways and reduce reliance on carbon dioxide removal strategies like re/afforestation and bioenergy with carbon capture and storage.

Evaluating potential landing sites for the Artemis III mission using a multi-criteria decision making approach

The selection of a landing site within the Artemis Exploration Zone (AEZ) involves multiple factors and presents a complex problem. This study evaluates potential landing sites for the Artemis III mission using a combination of Geographic Information Systems (GIS) and Multi-Criteria Decision Making (MCDM) methodologies, specifically the TOPSIS algorithm. By integrating topographic, illumination, and mineralogy data of the Moon, we assess 1247 locations that meet the Human Landing System (HLS) requirements within 13 candidate regions and Site 004 near the lunar south pole. Criteria considered include surface visibility, HLS-astronaut line of sight, Permanently Shadowed Regions (PSRs), sunlight exposure, direct communication with Earth, geological units, and mafic mineral abundance. Site DM2 (Nobile Rim 2), particularly the point at latitude 84°12’5.61”S (−84.20156°) and longitude 60°41’59.61”E (60.69989°), is the optimal location for landing. Sensitivity analysis confirms the robustness of our approach, validating the suitability of the best location despite the MCDM method employed and variations in criteria weightings to prioritize illumination and PSRs. This research demonstrates the applicability of GIS-MCDM techniques for lunar exploration and the potential benefits they can bring to the Artemis program.

Severe Convection at Burgas Airport: Case Study 17 September 2022

Convection monitoring and forecasting are crucial for air traffic management as they can lead to the development of intense thunderstorms and hazards such as severe turbulence and icing, lightning activity, microbursts and hail that affect aviation safety. The airport of Burgas is located in southeast Bulgaria on the Black Sea coast and occurrences of intense thunderstorms are mainly observed in the warm season between May and September. This work presents an analysis of severe convection over southeast Bulgaria on 17 September 2022. In the late afternoon, a gust front was formed that reached the Burgas airport with a wind speed exceeding 45 m/s, the record for the past 50 years, damaging the instrument landing system of the airport. To analyse the severe weather conditions, we combine state-of-the-art observations from satellite and radar with the upper-air sounding and surface. The studied period was dominated by the presence of a very unstable air mass over southeast Bulgaria ahead of the atmospheric front. As convection developed and moved east towards Burgas, it had four characteristics of severe deep convection, including gravitational waves at the overshooting cloud top, a cold U-shape, a flanking line and a cloud top temperature below −70 °C. The positive integrated water vapour (IWV) rate of change preceded the lightning activity peak by 30 min. Analysis of integrated vapour transport (IVT) gives higher values by a factor of two compared to climatology associated with the atmospheric river covering the eastern Mediterranean sea.

An estimation method for vision-based autonomous landing system for fixed wing aircraft

In this paper, we propose a vision-based estimation method for autonomous landing of fixed-wing aircraft for Advanced Air Mobility. The concept of autonomous flight with minimal human intervention has gained significant interest with a particular focus on autonomous landing. The goal is to overcome the limitations of existing instrument landing systems and reduce reliance on GNSS during aircraft landing. The proposed system leverages the following techniques for high-performance and real-time operations in various real-world environments and during all stages of landing. A deep learning segmentation model was directly learned, created, and used for robust runway recognition performance against environmental changes around the runway. Algorithms were designed to adapt to different flight stages considering the varying information offered by image data when the aircraft is in mid-air and on the ground. The relative lateral position from the aircraft to the runway was estimated using bird’s-eye-view conversion and inverse projection techniques instead of conventional perspective-n-point methods for reducing the recognition error occurring from the conversion between 2D image and 3D world. Finally, the mixed-precision technique was used for the segmentation model to improve inference speed and ensure real-time operation in real-world deployment. Estimation stability and reliability were improved by using a Kalman Filter to cope with sensor uncertainties caused by the real-world flight environment. Consequently, we show that the average error in the lateral position estimation by the proposed method is comparable to the accuracy of a single GNSS and demonstrate successful autonomous landing of our test aircraft with a set of flight tests.

Simulation of water-salt transport and balance in cultivated-wasteland system based on SWAP model in Hetao Irrigation District of China

Water and salt transport among different use type land is important to irrigation management in arid area. In this study, a typical irrigation unit including cultivated land and wasteland in Hetao Irrigation District of China was selected to explore water and salt transport between cultivated land and wasteland system. Soil water-salt dynamics, groundwater depth and salinity were observed within the period of crop growing and autumn irrigation period in 2018 and 2019. Calibrated SWAP model was used to simulate water and salt flux of cultivated land and wasteland during the crop growing period and autumn irrigation period. Furthermore, water-salt transport exchange capacity was calculated between cultivated land and wasteland system in study area. Groundwater was recharged by soil water and soil salt was leached in cultivated land during the crop growing period. Soil water was recharged by groundwater and soil salt was accumulated in saline wasteland during the crop growing period. During the crop growing period, the total leaching of soil salinity was 15.64 t·ha−1 in cultivated land. Soil salt accumulation was 2.03 t·ha−1 in saline wasteland. During the autumn irrigation period, the total leaching of soil salinity was 14.93 t·ha−1 in cultivated land. Total leaching of soil salinity was 1.56 t·ha−1 in saline wasteland. Overall, saline wasteland had an important role to receive salt from cultivated land and maintain salt dynamic balance in arid irrigation area with shallow groundwater.

The Impact of Climate-Related Security Risks on Community Values: Insights from Zambia’s Southern Province

Abstract This article explores the impact of climate-related security risks on community values and how that impact influences responses to the risks. Research and practice have paid little attention to how non-material and subjective conditions, especially values, mediate the climate-security nexus. We focused on the impact of land conflicts and food insecurity (as examples of climate-related security risks) on community values through a study of two rural communities in Zambia’s southern province using impact rating, focus-group discussions (FGD s), and interviews. Innovatively, we began by identifying community values and asking about the impact of climate security risks on community values instead of what ‘experts’ perceive or consider to be risks. We found that, firstly, participants from both communities perceived both land conflicts and food insecurity as having a strong to very strong influence on their values. Secondly, women perceive the impact of land conflicts and food insecurity on values to be greater than men do. Thirdly, the perception of the impact of climate-related security risks on values is prevalent among communities in Zambia’s southern province. The article concludes that values are crucial and central determinants in how communities interpret and respond to climate-related security risks, as well as how they engage with food, land, and water systems. It recommends that policymakers and practitioners integrate community values for effective and sustainable climate-related security risk policies and interventions.

Simulation and real-life implementation of UAV autonomous landing system based on object recognition and tracking for safe landing in uncertain environments.

The use of autonomous Unmanned Aerial Vehicles (UAVs) has been increasing, and the autonomy of these systems and their capabilities in dealing with uncertainties is crucial. Autonomous landing is pivotal for the success of an autonomous mission of UAVs. This paper presents an autonomous landing system for quadrotor UAVs with the ability to perform smooth landing even in undesirable conditions like obstruction by obstacles in and around the designated landing area and inability to identify or the absence of a visual marker establishing the designated landing area. We have integrated algorithms like version 5 of You Only Look Once (YOLOv5), DeepSORT, Euclidean distance transform, and Proportional-Integral-Derivative (PID) controller to strengthen the robustness of the overall system. While the YOLOv5 model is trained to identify the visual marker of the landing area and some common obstacles like people, cars, and trees, the DeepSORT algorithm keeps track of the identified objects. Similarly, using the detection of the identified objects and Euclidean distance transform, an open space without any obstacles to land could be identified if necessary. Finally, the PID controller generates appropriate movement values for the UAV using the visual cues of the target landing area and the obstacles. To warrant the validity of the overall system without risking the safety of the involved people, initial tests are performed, and a software-based simulation is performed before executing the tests in real life. A full-blown hardware system with an autonomous landing system is then built and tested in real life. The designed system is tested in various scenarios to verify the effectiveness of the system. The code is available at this repository: https://github.com/rnjbdya/Vision-based-UAV-autonomous-landing.

Imperfection of land system in agriculture, possible consequences and the ways to correct them

Significant transformations occurred during the land reform by January 1999. The monopoly of state ownership over land was abolished, and reorganizations of collective and state farms were carried out, alongside the privatization of land. Since 2002, the turnover of agricultural land has been regulated by Federal Law No. 101-FZ of July 24, 2002, "On the Turnover of Agricultural Land." Ownership, use, and disposal of land plots that are in shared ownership can only be carried out in accordance with the decisions of the participants in the shared ownership. However, the procedure for allocating land plots against the shares of land is lengthy, costly, and prone to corruption. Imperfect land legislation and incompetence in the courts hinder the completion of land transformations. This article discusses the issues of shared land ownership related to multi-contour land plots and methods to overcome these challenges.

Exploring an adaptive management model for “status-optimization-regulation” of mining city in transition: A case study of Huangshi, China

Mining cities face the challenges of ecological transformation and sustainable development after mineral depletion. Thus, ecological space optimization and adaptive management are pivotal after ecological restoration project, but easily neglected. Taking Huangshi in Hubei Province as an example, a top-down adaptive management model for regional mining ecological space integrating status-optimization-regulation (SOR) was established based on land system resilience (LSR) evaluation, circuit theory, complex network model and community discovery algorithm. The results showed that i) As the LSR increased, the land use structure shifted from non-ecological zones to forest and cropland, indicating that balancing agriculture and forest protection was crucial for increasing LSR in Huangshi. i) The ecological networks (ENs) of Huangshi had an irregular fishnet pattern, with densely intricate corridors in the south and broader, sparser ones in the north, and numerous ecological barriers near the mining area. Furthermore, the distribution of ecological sources and corridors displayed complementarity and hierarchy. iii) The optimized ENs exhibited higher connectivity and efficiency under disturbance, reducing corridor redundancy and migration costs. iv) The ENs clusters were classified into five types based on ecological connectivity: ecological buffer zone, priority restoration zone, moderate restoration zone, natural restoration zone, and moderate development zone, and tailored ecological regulatory strategies were proposed. The findings provide practice-oriented guidance for the sustainable development of mining cities, and offer a direct approach to support conscious, clear, and coherent adaptive management of ecological restoration in rapidly changing environments.

Optimizing Space Exploration: A Comprehensive Analysis of AI Integration in Rocket Launch and Landing Systems

Optimizing Space Exploration: A Comprehensive Analysis of AI Integration in Rocket Launch and Landing Systems

Optimizing Space Exploration: A Comprehensive Analysis of AI Integration in Rocket Launch and Landing Systems

Optimizing Space Exploration: A Comprehensive Analysis of AI Integration in Rocket Launch and Landing Systems

Research on Precise Landing of Rotor UAV Based on Multi-Sensor Fusion

With the rapid development of drone technology, the autonomous landing of drones has become a current research hotspot. This article introduces an autonomous drone landing system based on multi-sensor fusion. The system combines GPS, IMU, visual sensors, LiDAR, and other sensor data through Kalman filtering to achieve data fusion and improve the positioning accuracy and stability of the drone during landing.

Integrating Resilience Theory Into a Cultivated Land System: Empirical Insights From China's Key Grain‐Producing Regions

ABSTRACTExploring cultivated land use and conservation from a resilience perspective is crucial to address regional food security concerns. This article first examines the theoretical applicability of resilience in the context of cultivated land use systems and subsequently introduces a specific concept of cultivated land system resilience (CLSR). Focusing on the middle reaches of the Yangtze River, a major grain‐producing area in China, the study constructs a measurement system that encompasses five dimensions: endowment of production, socioeconomic factors, scale structure, ecological pressure, and food security. This system is used to evaluate the spatio‐temporal evolution and influencing mechanisms of CLSR in the region from 2001 to 2020. The results indicate that the level of CLSR increased by 7.2% overall and exhibits a distinct spatial pattern, with high‐value areas expanding from the center to the surrounding regions. Furthermore, CLSR shows a positive spatial correlation with rising levels of agglomeration. The spatial heterogeneity of CLSR is influenced by the interaction of various factors, resulting in a partially nonlinear two‐factor enhancement. The influence of each factor varies between different time periods, shifting from ecological pressure to scale structure, ultimately affecting food security. Thus, the resilience perspective offers greater explanatory power to identify key vulnerabilities in the regional cropland system. This approach can improve the efficient allocation of cropland resources and promote sustainable and healthy development at the regional level.

Knowledge co-production for identifying indicators and prioritising solutions for food and land system sustainability in Australia

Achieving sustainable Australian food and land systems requires the rapid implementation and scaling up of a broad suite of solutions to meet the Sustainable Development Goals (SDGs). Decision-making frameworks are needed to identify suitable indicators and prioritise solutions at national scales to inform sustainability transitions. Using a knowledge co-production framework, we convened 150 stakeholders from 100 + organisations to identify 18 nationally relevant indicators that aligned with critical SDGs describing a sustainable food and land system for Australia, in addition to 78 key solutions (supply- and demand-side) to enable progress against these indicators. We then asked subject matter experts to code the impact of each solution on each indicator using an adapted interaction mapping method accounting for uncertainty. The solution category ‘Protecting and restoring nature’, which included solutions targeting conservation and restoration, showed the highest potential for capturing synergies and avoiding trade-offs across multiple indicators. This category exhibited 34.6% of total major synergies, supporting the achievement of clean water and sanitation (SDG6), economic growth (SDG12), life under water (SDG14), and life on land (SDG15). The solution category ‘Carbon sequestration’, which included technological and biological carbon dioxide removal solutions, had the highest number of trade-offs with individual sustainability indicators (42.3%), particularly those relating to zero hunger (SDG2), wellbeing (SDG3), SDG6, SDG14, and SDG15. Our framework can be used to inform future research investment, support the prioritisation of solutions for quantitative modelling, and inform discussions with stakeholders and policymakers for transforming national-scale food and land systems in alignment with the SDGs.

Four-stage cascaded adaptive sliding mode control for automatic carrier landing with airwake disturbances and uncertainties

ObjectiveThis paper addresses the carrier landing affected by airwake, parametric uncertainties, and carrier deck motion, its main target being the design of a novel sliding mode based automatic carrier landing system to obtain accurate tracking of the reference trajectory, robustness in terms of disturbances and uncertainties, as well as excellent touchdown accuracy. ApproachFor an aircraft nonlinear dynamics, written under a four-stage cascaded strict feedback form, the design of the novel landing control architecture involves the design of a guidance subsystem, robust sliding mode controllers (for the control of the heading angle, attitude angles, and angular rates), an approach power compensation system, adaptive control laws suppressing the uncertainties and disturbances, a Kalman filter for deck motion prediction, a block computing the reference trajectory, a tracking differentiator block for deck motion compensation, and first-order command filters. Main resultsThe software validation process proves the effectiveness of the sliding mode based control scheme and the suppression of the uncertainties and disturbances. Also, the comparison between the performances of the sliding mode control based carrier landing system and the ones associated to other automatic carrier landing systems shows the superiority of the sliding mode based control scheme, as well as its better touchdown accuracy and landing success rate. SignificanceThis study innovatively transforms the general carrier landing problem into a time-varying tracking control problem for cascaded strict feedback dynamics with disturbances and uncertainties. The new designed automatic carrier landing system is the first control architecture in the literature employing the sliding mode control augmented by adaptive control laws for carrier landing, subjected to airwake, deck motion, and uncertainties.

The Changing Morphology of Global Precipitation Systems during the Last Two Decades

Abstract The morphology of global precipitation systems can enhance our comprehension of precipitation patterns and the underlying physical processes. However, several unresolved issues remain in the existing studies of precipitation system morphology. This study employs Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM) (IMERG)-derived precipitation system dataset to investigate the climatological and changing characteristics of global precipitation system morphology from 2001 to 2022. The results show that precipitation systems with larger scales tend to be more flattened in morphology, while no clear differences in morphological characteristics are observed across systems with different intensities. In terms of geographic distributions, a notable land–sea contrast is observed, with land systems more circular than those over oceans. Due to the impact of the Coriolis force, the orientation distribution of precipitation systems shows obvious hemispherical contrast. Precipitation systems over tropical regions are more regular in shape and more likely to be organized convective systems. During the period of 2001–22, there is a significant trend of global precipitation systems becoming more flattened and are more likely to manifest as organized convective systems. Our results also indicate that the precipitation system morphology is under combined influence of subtropical highs, lateral stretching influences of wind, and the organizing effects of moisture transport and convergence. Moreover, the increasing flattening of precipitation systems could be attributed to enhanced atmospheric stability which constrains vertical expansion and increased moisture availability which favors wider horizontal extension. This study could provide new insights into precipitation changes under global warming.