Terrestrial Technology Research Articles

Potential of Low-Cost UAV Photogrammetry for Documenting Hard-to-Access Interior Spaces Through Building Openings

Unmanned aerial vehicles (UAVs) are primarily used in the field of cultural heritage for mapping the exteriors of larger objects and documenting the roofs and façades of tall structures that cannot be efficiently or feasibly measured using conventional terrestrial technologies and methods. However, due to the considerable diversity of cultural heritage, there are practical demands for the measurement of complex and inaccessible objects in interior spaces. This article focuses on the use of two different off-the-shelf UAVs for partial photogrammetric reconstruction of the attic of a mining house, which was only visible through a window in the gable wall. Data from both UAVs were compared with each other and with terrestrial laser scanning. Despite the lower quality of the results from the DJI Mini 4 Pro compared to the DJI Mavic 3 Enterprise, the results from both UAVs would still be suitable for documenting the interior attic spaces. However, a detailed analysis of the photogrammetric data indicates that, when selecting a UAV for this purpose, it is necessary to consider the limitations of the camera system, which may lead to a reduction in the geometric accuracy and completeness of the point clouds.

Time-Series Feature Selection for Solar Flare Forecasting

Solar flares are significant occurrences in solar physics, impacting space weather and terrestrial technologies. Accurate classification of solar flares is essential for predicting space weather and minimizing potential disruptions to communication, navigation, and power systems. This study addresses the challenge of selecting the most relevant features from multivariate time-series data, specifically focusing on solar flares. We employ methods such as Mutual Information (MI), Minimum Redundancy Maximum Relevance (mRMR), and Euclidean Distance to identify key features for classification. Recognizing the performance variability of different feature selection techniques, we introduce an ensemble approach to compute feature weights. By combining outputs from multiple methods, our ensemble method provides a more comprehensive understanding of the importance of features. Our results show that the ensemble approach significantly improves classification performance, achieving values 0.15 higher in True Skill Statistic (TSS) values compared to individual feature selection methods. Additionally, our method offers valuable insights into the underlying physical processes of solar flares, leading to more effective space weather forecasting and enhanced mitigation strategies for communication, navigation, and power system disruptions.

Progress and Perspective of Seafloor Regolith‐Sampling Robots for Ocean Exploration

ABSTRACTSeafloor exploration has significantly enriched our understanding of the marine environment, climate change, and the evolution of Earth. Seafloor sampling tools are instrumental in acquiring regolith samples for various investigations, including geological surveys and resource exploration. Detailed analysis of collected samples can uncover further hidden mysteries of the ocean. Over the past few decades, numerous research institutions have dedicated efforts to developing efficient seafloor regolith‐sampling robots (SRSRs). This paper provides a comprehensive overview of the progress and perspectives on SRSRs. First, the paper introduces the particularities of seafloor regolith sampling, including operation characteristics and sampling requirements. Second, current SRSRs are classified into seven categories based on different sampling methods, and their general characteristics are summarized. Subsequently, representative seafloor drilling and sampling robots (SDSRs) from around the world are introduced, with a focus on comparing mainstream sampling methods. Furthermore, the challenges and constraints in seafloor sampling, encompassing terrestrial technology and the marine environment, are analyzed and discussed in depth. The critical technologies involved in transitioning SRSRs from conceptualization to prototype development are detailed. Finally, important development trends of SRSRs are presented, including recent short‐term development goals and future long‐term development goals.

The OPS-SAT case: A data-centric competition for onboard satellite image classification

While novel artificial intelligence and machine learning techniques are evolving and disrupting established terrestrial technologies at an unprecedented speed, their adaptation onboard satellites is seemingly lagging. A major hindrance in this regard is the need for high-quality annotated data for training such systems, which makes the development process of machine learning solutions costly, time-consuming, and inefficient. This paper presents “the OPS-SAT case”, a novel data-centric competition that seeks to address these challenges. The powerful computational capabilities of the European Space Agency’s OPS-SAT satellite are utilized to showcase the design of machine learning systems for space by using only the small amount of available labeled data, relying on the widely adopted and freely available open-source software. The generation of a suitable dataset, design and evaluation of a public data-centric competition, and results of an onboard experimental campaign by using the competition winners’ machine learning model directly on OPS-SAT are detailed. The results indicate that adoption of open standards and deployment of advanced data augmentation techniques can retrieve meaningful onboard results comparatively quickly, simplifying and expediting an otherwise prolonged development period.

Electrically conducting polymers and composites for applications in space exploration

AbstractPushing the boundaries of space exploration and settlement requires innovative materials that are multi‐functional, reusable, and tolerant of the extreme hazards in space environments. Polymers represent an interesting class of materials for these applications due to their range of properties, low density, and ease of manufacturing. Electrically conductive materials based on polymers and other organic materials can be beneficial for safety purposes or for integrating advanced functions, such as dust mitigation and non‐destructive evaluation. Given the unique demands of the space industry, emerging materials developed for space may not appear in conventional forums. Conversely, many investigators focus on polymers and composites for other applications and may not realize the suitability of their material for space. This review provides an informational bridge between experts from conventional polymer fields and more space‐focused research groups. First, a brief history of polymer material integration from Apollo to Artemis is used as a context for their increasing importance to space exploration. Next, a polymer and composite materials‐focused summary of space hazards is discussed for different space environments. Finally, different space applications suitable for electrically conductive polymers and composites are discussed in the context of enabling space exploration and developing new terrestrial technology.

Mars In Situ Resource Utilization (ISRU) with Focus on Atmospheric Processing for Near-Term Application—A Historical Review and Appraisal

The inspirational paper by Ash, Dowler, and Varsi in 1978, proposing to utilize in situ resources on Mars (ISRU) rather than bringing them from Earth, originated the field of Mars ISRU that has been the subject of research ever since. In this paper, we reviewed significant research reported on Mars ISRU since 1978 and reported briefly on accomplishments. We found that prior to 2014, progress on small tasks was sporadic and intermittent, always at low Technology Readiness Level (TRL). In 2014, the National Aeronautics and Space Administration (NASA) took a bold, imaginative, unprecedented step to fund a major project in Mars ISRU: the so-called “MOXIE” (Mars Oxygen In Situ Experiment), in which an oxygen production plant based on solid oxide electrolysis (SOEC) was developed, and finally demonstrated on Mars in 2022 and 2023. While MOXIE leaves behind it a wealth of accomplishments, there remains the need to close remaining gaps with additional laboratory and field work. Solid-oxide electrochemical cell (SOEC) technology has become a major area of worldwide investment for terrestrial energy and CO2 control. There is a very strong overlap between this terrestrial technology and Mars ISRU. NASA has already leveraged the terrestrial development work via MOXIE. NASA can leverage further advances with a comparatively small investment beyond 2023. Because NASA is engaged in a major program to return humans to the Moon, NASA’s focus is on lunar ISRU. Unfortunately, the mission impact and return on investment for lunar ISRU does not compare to that for Mars ISRU. NASA’s concept for Mars ISRU is futuristic, involving autonomous mining, transporting, and processing large amounts of Mars regolith. This might well occur long after initial human landings which could better profit in the near-term from MOXIE technology. By continuing further development of SOEC technology beyond MOXIE, while leveraging large investments in terrestrial applications, NASA can develop the Mars ISRU appropriate to nearer term human missions at modest investment. The goal of this paper is to place the relatively mature MOXIE technology advance and solid oxide electrolysis in general in perspective to the historical evolution of low TRL Mars ISRU technology.

UWB and MB-OFDM for Lunar Rover Navigation and Communication

This paper presents a comprehensive study of ultra-wideband (UWB) and multi-band orthogonal frequency-division multiplexing (MB-OFDM) technologies for lunar rover navigation and communication in challenging terrains. Lunar missions pose unique challenges, such as signal propagation in the lunar environment, terrain elevation, and rover movement constraints. To address these challenges, we propose a hybrid communication and navigation system that leverages UWB technology for high-precision positioning and MB-OFDM for robust and high-throughput communication. We develop a realistic simulation framework that incorporates terrain elevation, obstacles, and rover movement constraints, along with a simple fading model for communication. Simulation results demonstrate the effectiveness of the proposed system in navigating lunar rovers to their target locations while maintaining reliable communication links with a lunar lander. A novel approach based on game theory for rover navigation is also presented. The study provides valuable insights into the design and optimization of communication and navigation systems for future lunar missions, paving the way for seamless integration of advanced terrestrial technologies in extraterrestrial environments.

Legal Issues Pertaining to High Altitude Platform Station Implementation in Indonesia as an Archipelagic State

Information is a necessity for the interests of government, the economy, social culture, as well as defense and security in the era of industrial revolution 4.0. Since 1976, the Indonesian government has been working on developing a satellite communication system starting with the Palapa A1 Satellite, followed by its subsequent generations. However, this system has limitations, particularly in providing coverage to rural areas in Indonesia. To address this issue, the government has started the procurement of the Wahana Dirgantara Super or High-Altitude Platform Station (HAPS) in Indonesia. HAPS are stations positioned at altitudes of 20 to 50 km above the Earth's surface. Given Indonesia's geographical location, HAPS is seen as the most suitable solution as it utilizes non-ground terrestrial technology to improve information and communication technology coverage in rural areas. However, the location on which the HAPS is positioned might trigger new issues, particularly with regard to state sovereignty and disruption of flight traffic. The operation of HAPS also needs further consideration so that the protection of personal data in Indonesia will not be disrupted. This article employs normative juridical research as a methodology. The research collected and analyzed primary sources in the form of law, regulation, and policy at the national and regional levels, as well as secondary sources that are available in textbooks, journal articles, and website content. This article aims to explain the development of HAPS regulations based on international law and national law and to examine the legal issues related to the procurement of HAPS in Indonesia . At the end, this article suggests that it is necessary to regulate HAPS in Indonesia with reference to aviation safety, security, and liability issues as well as maintaining state sovereignty and ensuring personal data protection.

Achievable Capacity of Geostationary-Ground Optical Links

We estimate the capacity of optical links at telecom wavelengths built upon existing terrestrial technologies. We study the impact of molecular absorption while varying the modulation scheme and compare the result with the ultimate capacity achievable in void. We then investigate the impact of atmospheric turbulence and evaluate how much capacity we recover with current mitigation techniques such as adaptive optics, and data coding coupled with delay diversity or data interleaving. We conclude by evaluating the achievable capacity in the presence of molecular absorption and atmospheric turbulence.

Future Technologies for Train Communication: The Role of LEO HTS Satellites in the Adaptable Communication System.

The railway sector has been characterized by important innovations regarding digital technologies for train-to-ground communications. The actual GSM-R system is considered an obsolescent technology expected to be dismissed by 2030. The future communication systems in the rail sectors, such as Adaptable Communication Systems (ACS) and Future Railway Mobile Communication Systems (FRMCS), can manage different bearers as 4G/5G terrestrial technologies and satellites. In this environment, the new High Throughput Satellite (HTS) Low-Earth Orbit (LEO) constellations promise very interesting performances from data rate and coverage points of view. The paper analyzes the LEO constellations of Starlink and OneWeb using public data. The Rome-Florence railway line is considered for simulations. The results evidence the LEO satellite can provide interesting performance in terms of visibility, service connectivity, and traffic capacities (up to 1 Gbps). This feature enables the LEO to fully manage a high amount of data, especially in the railway scenarios of the next years when video data applications will be more present.

On the first probe to transit between two interstellar civilizations

AbstractIf a space-faring civilization embarks on a program to send probes to interstellar destinations, the first probe to arrive at such a destination is not likely to be one of the earliest probes, but one of much more advanced capability. This conclusion is based on a scenario in which an extraterrestrial civilization (ETC) embarks upon an interstellar program during which it launches increasingly sophisticated probes whose departure speed increases as a function of time throughout the program. Two back-of-the-envelope models are considered: one in which the launch velocity of an outgoing vehicle increases linearly with the time of launch, and a second in which the increase is exponential with launch date. In this paper consideration is directed to an hypothesized probe arriving within the Solar System from a non-terrestrial civilization. Within the above scenarios, a first-encounter probe will be one that was launched well after the initiation of an interstellar program by an ETC. Consequently, such a probe would be the product of a relatively advanced phase of that ETC's technology. The more distant the site from which an ETC is launching probes, the greater will be the technology gap between a first-encounter probe and terrestrial technology. One possible ramification may pertain to interpreting the nature of Unidentified Aerial Phenomena (UAP). Are flight characteristics of any UAP singular enough as to be consistent with an origin from a distant ETC?

Effects of Simulated Solar Wind on Polymethyl Methacrylate Thin Film.

Space exploration missions are currently becoming more frequent, due to the ambition for space colonization in sight of strengthening terrestrial technologies and extracting new raw materials and/or resources. In this field, the study of the materials’ behaviour when exposed to space conditions is fundamental for enabling the use of currently existing materials or the development of new materials suitable for application in extra-terrestrial environments. In particular, the versatility of polymers renders them suitable for advanced applications, but the effects of space radiation on these materials are not yet fully understood. Here, to shed light on the effects of simulated solar wind on a polymeric material, polymethyl methacrylate (PMMA) was produced through radical bulk polymerization. The PMMA in the form of a thin film was subjected to proton beam bombardment at different fluences and in a high vacuum environment, with structural changes monitored through real-time FT-IR analysis. The structure of the residual material was investigated through MALDI-TOF mass spectrometry and 1H-NMR spectroscopy. The collected data allowed us to hypothesize the structural modifications of the PMMA and the related mechanisms.

Detecting the Sun’s active region using image processing techniques

The term ‘space weather’ refers to adverse conditions on the Sun that could affect the structures of spaceor terrestrial technology and risk human health or life. Flares produce effects that span the electromagneticspectrum. During a flash, they emit x-rays and ultraviolet radiation, resulting in extremely high temperatures.The purpose of this work is to create a new algorithm for the identification of solar flares and activeregions of the Sun, thus minimizing harm to spacecraft operations in orbit. An algorithm was developedfor the automatic detection of active regions of the Sun (sunspots, solar flares), based on methods of imageenhancement, segmentation, pattern recognition and mathematical morphology. The sun’s surface alsodisplays visible sunspots located in regions of the Sun that are magnetically active and whose number isan indication of the Sun’s magnetic activity. In tracking and predicting solar activity, the identification andclassification of sunspots are useful techniques. The main objective of this paper is to detect sunspots usingimages from the Solar Dynamics Observatory. Key words: solar flares, sunspots, active region.

Space-Based Global Maritime Surveillance. Part I: Satellite Technologies

Maritime surveillance (MS) is crucial for search and rescue operations, fishery monitoring, pollution control, law enforcement, migration monitoring, and national security policies. Since the early days of seafaring, MS has been a critical task for providing security in human coexistence. Several generations of sensors providing detailed maritime information have become available for large offshore areas in real time: maritime radar sensors in the 1950s and the automatic identification system (AIS) in the 1990s among them. However, ground-based maritime radars and AIS data do not always provide a comprehensive and seamless coverage of the entire maritime space. Therefore, the exploitation of space-based sensor technologies installed on satellites orbiting around the earth, such as satellite AIS data, synthetic aperture radar, optical sensors, and global navigation satellite systems reflectometry, becomes crucial for MS and to complement the existing terrestrial technologies. In the first part of this work, we provide an overview of the main available space-based sensors technologies and present the advantages and limitations of each technology in the scope of MS. The second part, related to artificial intelligence, signal processing, and data fusion techniques, is provided in a companion paper, titled: "Space-Based Global Maritime Surveillance. Part II: Artificial Intelligence and Data Fusion Techniques".

Disentangling LiDAR Contribution in Modelling Species–Habitat Structure Relationships in Terrestrial Ecosystems Worldwide. A Systematic Review and Future Directions

Global biodiversity is threatened by unprecedented and increasing anthropogenic pressures, including habitat loss and fragmentation. LiDAR can become a decisive technology by providing accurate information about the linkages between biodiversity and ecosystem structure. Here, we review the current use of LiDAR metrics in ecological studies regarding birds, mammals, reptiles, amphibians, invertebrates, bryophytes, lichens, and fungi (BLF). We quantify the types of research (ecosystem and LiDAR sources) and describe the LiDAR platforms and data that are currently available. We also categorize and harmonize LiDAR metrics into five LiDAR morphological traits (canopy cover, height and vertical distribution, understory and shrubland, and topographic traits) and quantify their current use and effectiveness across taxonomic groups and ecosystems. The literature review returned 173 papers that met our criteria. Europe and North America held most of the studies, and birds were the most studied group, whereas temperate forest was by far the most represented ecosystem. Globally, canopy height was the most used LiDAR trait, especially in forest ecosystems, whereas canopy cover and terrain topography traits performed better in those ecosystems where they were mapped. Understory structure and shrubland traits together with terrain topography showed high effectiveness for less studied groups such as BLF and invertebrates and in open landscapes. Our results show how LiDAR technology has greatly contributed to habitat mapping, including organisms poorly studied until recently, such as BLF. Finally, we discuss the forthcoming opportunities for biodiversity mapping with different LiDAR platforms in combination with spectral information. We advocate (i) for the integration of spaceborne LiDAR data with the already available airborne (airplane, drones) and terrestrial technology, and (ii) the coupling of it with multispectral/hyperspectral information, which will allow for the exploration and analyses of new species and ecosystems.

Integrated Satellite–Terrestrial Connectivity for Autonomous Ships: Survey and Future Research Directions

An autonomous vessel uses multiple different radio technologies such as satellites, mobile networks and dedicated narrowband systems, to connect to other ships, services, and the remote operations center (ROC). In-ship communication is mainly implemented with wired technologies but also wireless links can be used. In this survey paper, we provide a short overview of autonomous and remote-controlled systems. This paper reviews 5G-related standardization in the maritime domain, covering main use cases and both the role of autonomous ships and that of people onboard. We discuss the concept of a connectivity manager, an intelligent entity that manages complex set of technologies, integrating satellite and terrestrial technologies together, ensuring robust in-ship connections and ship-to-outside connections in any environment. This survey paper describes the architecture and functionalities of connectivity management required for an autonomous ship to be able to operate globally. As a specific case example, we have implemented a research environment consisting of ship simulators with connectivity components. Our simulation results on the effects of delays to collision avoidance confirm the role of reliable connectivity for safety. Finally, we outline future research directions for autonomous ship connectivity research, providing ideas for further work.

Next‐generation global satellite system with mega‐constellations

SummaryMega satellite constellations in low earth orbit (LEO) will provide complete global coverage; rapidly enhance overall capacity, even for unserved areas; and improve the quality of service (QoS) possible with lower signal propagation delays. Complemented by medium earth orbit (MEO) and geostationary earth orbit (GEO) satellites and terrestrial network components under a hybrid communications architecture, these constellations will enable universal 5G service across the world while supporting diverse 5G use cases. With an unobstructed line‐of‐sight visibility of approximately 3 min, a typical LEO satellite requires efficient user terminal (UT), satellite, gateway, and intersatellite link handovers. A comprehensive mobility design for mega‐constellations involves cost‐effective space and ground phased‐array antennas for responsive and seamless tracking. An end‐to‐end multilayer protocol architecture spanning space and terrestrial technologies can be used to analyze and ensure QoS and mobility. A scalable routing and traffic engineering design based on software‐defined networking adequately handles continuous variability in network topology, differentiated user demands, and traffic transport in both temporal and spatial dimensions. The space‐based networks involving mega‐constellations will be better integrated with their terrestrial counterparts by fully leveraging the multilayer 5G framework, which is the foundational feature of our hybrid architecture.

Electrochemical Approaches to “Living off the Land” in Space

The incredible expense of sending resources out of Earth’s gravity well to space predicates that systems for long-term space operations rely on resources already available in space for energy and materials. Such in-situ resource utilization (ISRU) can harness ubiquitous solar energy and its conversion to electricity. As such, electrochemistry has been recognized as a critical path for converting low-value compounds and materials in space into valuable products such as fuel, oxygen, structural materials, and functional materials/devices to support proposed space operations. Recent advances in electrolysis for splitting water and CO2 and in systems for reducing oxides provide promise for advancing ISRU. As demonstrated by the successful MOXIE development to provide a small-scale CO2 electrolysis unit to Mars, development of robust autonomous electrochemical systems for near-term ISRU presents unique challenges. Nonetheless, the potential rewards of such development for space operation as well as terrestrial technology deployment can be enormous.

An investigation on effect of EDL on heat transfer of micro heat pipe with square and triangular cross section

Electronic industries have always been trying to improve the efficiency of electronic devices with small dimensions through thermal management of this equipment, thus increasing the use of small thermal sinks. In this study micro heat pipes with triangular and square cross sections have been manufactured and tested. One of the main objectives is to obtain an understanding of micro heat pipes and their role in energy transmission with electrical double layer (EDL). Micro heat pipes are highly efficient heat transfer devices, which use the continuous evaporation/condensation of a suitable working fluid for two-phase heat transport in a closed system. Since the latent heat of vaporization is very large, heat pipes transport heat at small temperature difference, with high rates. Because of variety of advantage features these devices have found a number of applications both in space and terrestrial technologies. The theory of operation micro heat pipes with EDL is described and the micro heat pipe has been studied. The temperature distribution have achieved through five thermocouples installed on the body. Water and different solution mixture of water and ethanol have used to investigate effect of the electric double layer heat transfer. It was noticed that the electric double layer of ionized fluid has caused reduction of heat transfer.

Closure to “Evaluation of Terrestrial and Mobile Scanner Technologies for Part-Built Information Modeling” by Samad M. E. Sepasgozar, Perry Forsythe, and Sara Shirowzhan

Closure to “Evaluation of Terrestrial and Mobile Scanner Technologies for Part-Built Information Modeling” by Samad M. E. Sepasgozar, Perry Forsythe, and Sara Shirowzhan