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Topic Review
Deep Learning for Remote Sensing Image Scene Classification
Scene classification in remote sensing images aims to categorize image scenes automatically into relevant classes like residential areas, cultivation land, forests, etc. The implementation of deep learning (DL) for scene classification is an emerging tendency, with an effort to achieve maximum accuracy.
  • 1.4K
  • 13 Oct 2023
Topic Review
Geographic Information System
Geographic information systems (GIS) are composed of software, hardware, data, administrators, and methods for processing and analyzing data.  Creating and sharing spatial data in digital form is not only good practice but is also regulated by specific legal acts. Currently created in map portals and the widely available General Geographic Object Databases offer a reliable, current, and continuous source of spatial information for the entire country, extremely helpful in the planning process at various levels of generalization. The database implemented into the Spatial Information System is its most important element and should constitute a complete and reliable representation of elements of the real world.  GIS systems allow us to formulate models in a structured and formal way to reflect both the current situation and forecast changes that will occur in space when certain conditions are met. The proposed methodology can be used in practical applications:• Preparing planning studies, both regarding spatial policy and local law, as well as in economic planning and shaping the structure of rural space (structure of ownership and structure of use).• The development of thematic spatial information systems related to planning studies and works shaping the rural space.• Reports submitted to EU authorities relating to the utilization of funds dedicated to rural development in the multiannual financial framework and modification of the implemented actions.• The use of renewable energy sources to improve Poland’s energy security.
  • 1.4K
  • 19 Jan 2021
Topic Review
Recent Advances in Dielectric Properties-Based Soil Water Content Measurements
Dielectric properties are crucial in understanding the behavior of water within soil, particularly the soil water content (SWC), as they measure a material’s ability to store an electric charge and are influenced by water and other minerals in the soil. However, a comprehensive review paper is needed that synthesizes the latest developments in this field, identifies the key challenges and limitations, and outlines future research directions. In addition, various factors, such as soil salinity, temperature, texture, probing space, installation gap, density, clay content, sampling volume, and environmental factors, influence the measurement of the dielectric permittivity of the soil. Therefore, this review aims to address the research gap by critically analyzing the current state-of-the-art dielectric properties-based methods for SWC measurements. The motivation for this review is the increasing importance of precise SWC data for various applications such as agriculture, environmental monitoring, and hydrological studies. We examine time domain reflectometry (TDR), frequency domain reflectometry (FDR), ground-penetrating radar (GPR), remote sensing (RS), and capacitance, which are accurate and cost-effective, enabling real-time water resource management and soil health understanding through measuring the travel time of electromagnetic waves in soil and the reflection coefficient of these waves. SWC can be estimated using various approaches, such as TDR, FDR, GPR, and microwave-based techniques. These methods are made possible by increasing the dielectric permittivity and loss factor with SWC. The available dielectric properties are further synthesized based on mathematical models relating apparent permittivity to water content, providing an updated understanding of their development, applications, and monitoring. It also analyzes recent mathematical calibration models, applications, algorithms, challenges, and trends in dielectric permittivity methods for estimating SWC.
  • 1.4K
  • 31 Oct 2024
Topic Review
Three-Dimensional Point Cloud Semantic Segmentation for Cultural Heritage
In the cultural heritage field, point clouds, as important raw data of geomatics, are not only three-dimensional (3D) spatial presentations of 3D objects but they also have the potential to gradually advance towards an intelligent data structure with scene understanding, autonomous cognition, and a decision-making ability. The approach of point cloud semantic segmentation as a preliminary stage can help to realize this advancement.
  • 1.4K
  • 09 Mar 2023
Topic Review
Machine Learning Model in HSI-AD
In the field of remote sensing, hyperspectral image (HSI) is a ground image collected by advanced sensor technology and imaging system mounted on satellites or other aircraft. Anomaly detection (AD) is a very important sub-branch in machine learning and has important applications in computer vision, data mining, and natural language processing (NLP). HSI-AD refers to the identification of pixels whose spectral characteristics in an image are significantly different from adjacent or global background pixels.
  • 1.4K
  • 05 May 2022
Topic Review
BDS-3 Integrity Concept
Compared to the BeiDou regional navigation satellite system (BDS-2), the BeiDou global navigation satellite system (BDS-3) carried out a brand new integrity concept design and construction work, which defines and achieves the integrity functions for major civil open services (OS) signals such as B1C, B2a, and B1I. The integrity definition and calculation method of BDS-3 are introduced. The fault tree model for satellite signal-in-space (SIS) is used, to decompose and obtain the integrity risk bottom events. In response to the weakness in the space and ground segments of the system, a variety of integrity monitoring measures have been taken. On this basis, the design values for the new B1C/B2a signal and the original B1I signal are proposed, which are 0.9 × 10−5 and 0.8 × 10−5, respectively. The hybrid alarming mechanism of BDS-3, which has both the ground alarming approach and the satellite alarming approach, is explained. At last, an integrity risk analysis and verification work were carried out using the operating data of the system in 2019. The results show that the actual operation of the system is consistent with the conceptual design, which satisfies the integrity performance promised by BDS-3 in the ICAO SAPRs.
  • 1.4K
  • 24 Nov 2021
Topic Review
Application of Vegetation Indices beyond Vegetation Monitoring
Vegetation indices (VIs) have long been a crucial tool for monitoring plant growth and health, assessing the impact of environmental factors on vegetation, and supporting decision-making processes in agriculture and forestry. Traditionally, these mathematical formulations, leveraging the spectral response of plants to sunlight, have been instrumental in assessing vegetation health. However, emerging research suggests some unconventional applications that extend the scope of VIs.
  • 1.3K
  • 08 Aug 2023
Topic Review
Remote Sensing Land Surface Temperature-Based ET Algorithms
Evapotranspiration (ET) is a process that includes evaporation from the surface, such as open water bodies, soil and vegetation, and transpiration as the water released mostly by the plant leaves transported from the root system. ET is a key factor in the hydrological cycle, since it describes the mechanism and energy needed to transport the liquid water stored in the soil-watershed-canopy system to the atmosphere, converted into water vapour.  Remote sensing technology is a globally consistent and economically feasible means to estimate ET values at regional and meso-scales on the Earth’s surface, since the approach directly links surface radiances and the components of the surface energy balance. Over the past, combined use of satellite remote sensing data from optical and thermal infrared sensors has provided substantial progress in the estimation of ET. Based on the concept of surface energy balance and net radiation, most remote sensing models have estimated ET for application studies such as water consumption, water resources planning and management over watersheds or modeling ecological processes and analyzing biophysical characteristics of landscape.
  • 1.3K
  • 02 Aug 2022
Topic Review
Laser-Induced Breakdown Spectroscopy for Food Quality Evaluation
Laser-induced Breakdown Spectroscopy (LIBS) is becoming an increasingly popular analytical technique for characterizing and identifying various products; its multi-element analysis, fast response, remote sensing, and sample preparation is minimal or nonexistent, and low running costs can significantly accelerate the analysis of foods with medicinal properties (FMPs). 
  • 1.3K
  • 28 Jul 2022
Topic Review
Thundercloud Features in Different Regions
A comparison of thundercloud characteristics in different regions of the world was conducted. The clouds studied developed in India, China and in two regions of Russia. Several field projects were discussed. Cloud characteristics were measured by weather radars, the SEVERI instrument installed on board of the Meteosat satellite, and lightning detection systems. The statistical characteristics of the clouds were tabulated from radar scans and correlated with lightning observations. Thunderclouds in India differ significantly from those observed in other regions. The relationships among lightning strike frequency, supercooled cloud volume, and precipitation intensity were analyzed. In most cases, high correlation was observed between lightning strike frequency and supercooled volume. 
  • 1.3K
  • 23 Aug 2021
Topic Review
Reconstruction of Remotely Sensed LST
Land surface temperature (LST) is an important environmental parameter in climate change, urban heat islands, drought, public health, and other fields. Thermal infrared (TIR) remote sensing is the main method used to obtain LST information over large spatial scales. However, cloud cover results in many data gaps in remotely sensed LST datasets, greatly limiting their practical applications. Many studies have sought to fill these data gaps and reconstruct cloud-free LST datasets over the last few decades. This paper reviews the progress of LST reconstruction research. A bibliometric analysis is conducted to provide a brief overview of the papers published in this field. The existing reconstruction algorithms can be grouped into five categories: spatial gap-filling methods, temporal gap-filling methods, spatiotemporal gap-filling methods, multi-source fusion-based gap-filling methods, and surface energy balance-based gap-filling methods. The principles, advantages, and limitations of these methods are described and discussed. The applications of these methods are also outlined. In addition, the validation of filled LST values’ cloudy pixels is an important concern in LST reconstruction. The different validation methods applied for reconstructed LST datasets are also reviewed herein. Finally, prospects for future developments in LST reconstruction are provided.
  • 1.3K
  • 24 Nov 2021
Topic Review
Explore Mars by Unmanned Aerial Vehicle
The technology of Unmanned Aerial Vehicles (UAVs) has tremendous potential to support various successful space mission solutions. In general, different techniques for observing space objects are available, such as telescopes, probes, and flying spacecraft, orbiters, landers, and rovers. However, a detailed analysis has been carried out due to the benefits of UAVs relative to other planetary exploration techniques. A prototype UAV has been successfully simulated to fly on Mars’ surface. 
  • 1.3K
  • 24 Jan 2022
Topic Review
Unmanned Aerial Vehicles in Forest Health Monitoring
Unmanned aerial vehicles (UAVs) are platforms that have been increasingly used over the last decade to collect data for forest insect pest and disease (FIPD) monitoring. These machines provide flexibility, cost efficiency, and a high temporal and spatial resolution of remotely sensed data. 
  • 1.3K
  • 28 Jul 2022
Topic Review
Estimate Soil Organic Carbon from Remote Sensing
Monitoring soil organic carbon (SOC) typically assumes conducting a labor-intensive soil sampling campaign, followed by laboratory testing, which is both expensive and impractical for generating useful, spatially continuous data products. 
  • 1.2K
  • 27 Feb 2024
Topic Review
Classification of Farmland Vegetation
The classification and identification of farmland vegetation includes classification based on vegetation index, spectral bands, multi-source data fusion, artificial intelligence learning, and drone remote sensing.
  • 1.2K
  • 21 Jan 2022
Topic Review
Determination of Leaf Inclination Angle through Remote Sensing
The leaf inclination angle (LIA), defined as the leaf or needle inclination angle to the horizontal plane, is vital in radiative transfer, precipitation interception, evapotranspiration, photosynthesis, and hydrological processes. The remote sensing methods to estimate LIA are mainly based on the empirical, radiative transfer model, and gap fraction methods. More advanced inversion strategies and validation studies are necessary to improve the robustness of LIA remote sensing estimation.
  • 1.2K
  • 10 Mar 2023
Topic Review
Process-oriented mining method for marine abnormal variation
Marine anomaly variations (MAVs) refers to an abnormal decrease or increase of marine environmental parameters, which covers a specified spatial domain and lasts for a specified temporal duration, e.g., the monthly mean variation of sea surface temperature and the seasonal variation of sea surface height. These variations have evolution properties from production through development to death, which plays a significant role on exploring the evolution mechanism of marine environment and the mechanism. As few considering temporal evolution relationship, traditional spatiotemporal mining methods have great challenges in analyzing these MAVs. Thus, this paper takes the process semantics of MAVs to design the process-oriented mining workflow, and to explore the spatiotemporal patterns of MAVs.
  • 1.2K
  • 29 Oct 2020
Topic Review
Digital Elevation Models
Digital Elevation Models (DEMs) of planet Mars are crucial for many remote sensing applications and for landing site characterization of rover missions. Shape from Shading (SfS) is known to work well as a complementary method to greatly enhance the quality of photogrammetrically obtained DEMs of planetary surfaces with respect to the effective resolution and the overall accuracy.
  • 1.2K
  • 21 Jun 2022
Topic Review
Earth Observation for Sustainable Infrastructure
Infrastructure is a fundamental sector for sustainable development and Earth observation has great potentials for sustainable infrastructure development (SID). However, implementations of the timely, large–scale and multi–source Earth observation are still limited in satisfying the huge global requirements of SID. This review demonstrates that Earth observation has great potentials for sustainable infrastructure development. EOSI can benefit about 85% of infrastructure influenced SDGs and 61% of all SDGs, but Earth observation has been implemented in only 15% of infrastructure influenced SDG targets, and 70% of the infrastructure influenced targets that can be directly or indirectly derived from Earth observation data have not been included in current SDG indicators.
  • 1.2K
  • 21 Apr 2021
Topic Review
AeroVironment Global Observer
The AeroVironment Global Observer is a concept for a high-altitude, long endurance unmanned aerial vehicle, designed by AeroVironment (AV) to operate as a stratospheric geosynchronous satellite system with regional coverage. Two Global Observer aircraft, each flying for up to a week at an altitude of 55,000 to 65,000 feet (17,000 to 20,000 m), could alternate coverage over any area on the earth, providing a platform for communications relays, remote sensing, or long-term surveillance. In addition to flying above weather and above other conventional aircraft, operation at this altitude permits communications and sensor payloads on the aircraft to service an area on the surface of the earth up to 600 miles (970 km) in diameter, equivalent to more than 280,000 square miles (730,000 km2) of coverage. Global Observer may offer greater flexibility than a satellite and longer duration than conventional manned and unmanned aircraft.
  • 1.2K
  • 20 Nov 2022
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