The Estimation of theoretical accuracy of mobile terrestrial LiDAR

Mobile Terrestrial LiDAR (Light Detecting And Ranging) (MTL) is a new technology adapted to increasing need of 3D geo-referenced data. The system requires an integration of laser scanners with other sensors of navigation such as GPS and INS and inertial measurement unit. This fusion allows direct georeferencing of point cloud data. As well as the practical accuracy, the theoretical accuracy of raw data also deals with the investors in the mobile mapping systems. This study evaluates the theoretical accuracy of point clouds produced by MTL system through the error propagation theory. The accuracy estimation implies a description of sensors integration, synchronization and calibration. In addition, this paper presents models of reference transformation. The results of this study show that the MTL data accuracy depends on several parameters. Among these parameters, the range is the most critical one.Le LiDAR Terrestre Mobile (LMT) est une nouvelle technologie adaptée au besoin croissant de données géoréférenciés 3D. Le système nécessite l'intégration des scanners laser avec d'autres capteurs de navigation tels que GPS et l’unité de mesure inertielle INS. Cette fusion permet le géoréférencement direct de nuages de points. Outre la précision pratique, la précision théorique des données brutes concerne également les investisseurs dans les systèmes de cartographie mobile. Cette étude évalue la précision théorique des nuages de points produits par le système à travers la théorie de propagation d'erreur. L'estimation de la précision implique une description de l'intégration, de la synchronisation et de la calibration des capteurs. En outre, cet article présente des modèles de transformation de référence. Les résultats de cette étude montrent que la précision des données LMT dépend de plusieurs paramètres. Parmi ces paramètres, nous retrouvons la distance système-objet qui est la plus influente

Study and evaluation of open source software in photogrammetry - MicMac and E-foto

De nos jours, nous parlons fréquemment de logiciels spécialisés de photogrammétrie fonctionnant sur des ordinateurs plus ou moins puissants. Ces logiciels sont de plus en plus commercialisés en grand nombre. Certes, les logiciels de photogrammétrie numérique ont facilité, par leur automatisation, la totalité du processus photogrammétrique où l’opérateur se contente seulement de la supervision en contrôlant les résultats. Mais, ces solutions restent toujours chères pour un grand nombre d’utilisateurs. C’est dans ce sens que les logiciels open source se sont de plus en plus développés et améliorés pour aboutir à la qualité fournie par les solutions payantes. Durant ce travail les deux solutions open source E-foto et MicMac ont été étudiées puis évaluées par rapport à des solutions payantes. Sur la base des résultats obtenus, nous avons conclu que les solutions libres E-foto et MicMac ont donné des résultats très satisfaisants par rapport aux logiciels payants, cette performance est plus remarquée chez la solution développée par l’Institut National de l’Information Géographique (IGN). Mots clés: Photogrammétrie, modélisation 3D, solution libre, MicMac, E-fotoNowadays, we frequently discuss photogrammetric software running on more or less powerful computers. These softwares are increasingly marketed in large numbers. Using automation digital photogrammetry softwares have admittedly made the entire photogrammetric process much easier, where the operator is only supervising and controlling the results. But these solutions are still expensive to a lot of users. In this sense, the open source softwares are being continuously developed and improved to achieve the quality provided by commercial solutions. This work aims to study and evaluate two open source solutions, E-foto and MicMac, compared to commercial solutions. Based on the obtained results, we concluded that the open source E-foto and MicMac gave very satisfactory results compared to the commercial softwares, this performance is more remarkable in the solution developed by the IGN. Keywords: Photogrammetry, 3D modeling, open source, MicMac, E-fot

LAND TENURE SYSTEMS’ ASSESSMENT EVALUATION: CASE STUDY OF COTE D’IVOIRE

In Cote d’Ivoire, as in many African countries, social tensions are frequently linked to a crisis of the rule of property law. These socio-legal conflicts are referred to by various names depending on their subject matter or the time and place in which they arise: law crises, the weakness of the State apparatus, the unsuitability and failure of institutions, and so on. However, in the majority of cases, these conflicts stem from a common phenomenon: weak land tenure security, or more precisely, land insecurity. The awareness of the magnitude of the problem of securing land tenure and its formalization through the "PAMOFOR" project (in which we participated as a research group and technical land operator), leads us to ask the following questions: How can we master the analysis of land governance and land tenure security in Côte d'Ivoire?  And what is its current state? Indeed, an assessment of land governance in Cote d’Ivoire is required. To accomplish this goal, the LGAF tool was used as the foundation of a highly participatory approach to systematically analyzing various aspects of land governance. The goal is to identify best practices and reach agreement on priority areas for land administration improvement. The analysis' findings enable stakeholders to address key governance gaps and develop a clear roadmap for improving land governance

Opportunities for the use of drone technology in forest ecosystems

Au cours de la dernière décennie, la technologie drone a suscité un grand intérêt et a été largement utilisée pour des applications civiles. Ainsi, les drones ont rapidement prouvé leurs efficiences dans les ressources naturelles, l’environnement, l’agriculture et la foresterie. Étant une plate-forme de télédétection, les drones ont le potentiel d'augmenter l'efficacité d'acquisition des données forestières en ayant des résolutions spatiale et temporelle beaucoup plus importantes que celles des autres techniques de télédétection. Dans cet article, nous présentons une synthèse des travaux de recherche portant sur l’utilisation de la technologie drone dans diverses applications forestières, dont la modélisation de la canopée forestière, l’évaluation des paramètres de l’inventaire forestier, le suivi de la santé des forêts et la discrimination des essences forestières. L’analyse de ces travaux a montré que l’utilisation de la technologie drone a concerné plusieurs aspects diversifiés, tandis que d’autres thématiques de recherche sont encore peu étudiées, notamment l’évaluation de la régénération naturelle, le suivi des projets de réhabilitation des écosystèmes naturels, l’étude des impacts des changements climatiques et des impacts anthropogènes sur un écosystème forestier. Le drone offre des opportunités d’utilisation de la technologie drone dans la gestion du domaine forestier Marocain, afin de remédier aux limites des techniques de télédétection utilisées actuellement en termes de résolution spatiale, de flexibilité du choix du temps d’acquisition des données et en terme du coût. Mots clés: Drone, Écosystème forestier, Inventaire forestier, Modélisation de la canopée forestière, Photogrammétrie, LidarOver the past decade, UAV technology has attracted a great deal of interest and has been widely used for civilian applications. UAVs have rapidly proven their efficiency in natural resources, the environment, agriculture and forestry. As a remote sensing platform, UAVs have the potential to increase the efficiency of forest data acquisition, having much higher spatial and temporal resolutions than other remote sensing techniques. In this paper, we present a synthesis of research on the use of UAV technology in various forestry applications, such as forest canopy modelling, forest inventory parameter assessment, forest health monitoring and forest species discrimination. The analysis of this research has shown that the use of UAV technology has concerned several diversified aspects, while other research themes are less studied, notably the assessment of natural regeneration, the monitoring of natural ecosystem rehabilitation projects, the study of climate and anthropogenic change impacts forest ecosystems. UAV technology is an opportunities for management of the Moroccan forest ecosystem, in order to overcome the limitations of the remote sensing techniques currently used, in terms of spatial resolution, flexibility in the choice of data acquisition time and in terms of cost. Keywords: UAV, Forest ecosystem, Forest inventory, Forest canopy modelling, Photogrammetry, Lida

Modélisation 3D des façades de bâtiments des anciennes Médina

Le LIDAR (Light Detecting and Ranging) terrestre statique est un outil de levé présentant actuellement une source de données 3D indispensable dans l’évaluation et la surveillance des bâtiments patrimoniaux. A travers des processus automatiques de modélisation 3D, la manipulation de cette source de données dans des outils de communication devient plus souple. Le processus de modélisation 3D impose des sous missions indispensables dont la segmentation. Une grande partie des approches de segmentation se focalisent sur l’emploi des composantes géométriques en exploitant la représentation mathématique d’une surface plane ou courbée. En raison de la complexité de l’architecture des façades, une segmentation utilisant uniquement l’aspect géométrique reste insuffisante. Ainsi, une nouvelle approche de segmentation est développée équilibrant les résultats de l’extraction des surfaces homogènes. Ceci, en se basant sur l’ensemble des composantes d’un nuage de points coloriés à savoir les composantes géométriques, les valeurs RGB et les intensités laser des détails constituant les façades des bâtiments des anciennes Médina. Le processus s’initialise par l’extraction des segments plans à l’aide de l’algorithme RANSAC. Le résultat fera l’objet d’une deuxième segmentation radiométrique basée sur l’introduction du critère de similarité couleur dans l’algorithme de croissance de région. Enfin une fusion de classes sera effectuée en fonction de la similarité de l’intensité laser.    The static terrestrial LIDAR is a tool of surveying which present a vital source of 3D data in the heritage buildings evaluation and monitoring. Through automated  3D modeling process, manipulating this data source in communication tools becomes more flexible. The 3D modeling process imposes on essential tasks including segmentation. Much of segmentation approaches focus on the use of geometric components by exploiting the mathematical representation of a plane or curved area. Due to the complexity of the facades architecture, segmentation using only the geometrical aspect is insufficient. Thus, a new segmentation approach is developed balancing the results of extracting homogeneous areas based on all colored point cloud components namely geometric data, the RGB values and intensities of facades details especially in old Medina building. The process consists of the planar segments extracting using the RANSAC algorithm. The result will be subject to radiometric segmentation through the introduction of color similarity criterion in the region growing algorithm and finally a fusion of classes based on the intensity’s similarity

La lasergrammétrie terrestre dans le domaine architectural et valorisation du patrimoine : Etude de cas au Maroc

La lasergrammétrie terrestre a des applications dans plusieurs domaines. L’architecture et la valorisation du patrimoine est l’un des domaines qui profitent de plus en plus des potentialités de cette technologie. Cependant, au niveau national, ces usages restent assez limités. Ceci est dû au manque d’expertise, surtout en ce qui concerne le post-traitement des données, au nombre limité de décideurs qui connaissent cette technologie et font appel à ses applications et aussi au coût élevé de cette technologie. Dans ce travail, nous présentons dans un premier temps un descriptif de la technologie. Ensuite, nous nous enchainons sur ses applications dans la préservation du patrimoine architectural à travers la réalisation de projets réels depuis l’acquisition jusqu’à la génération de différents produits dérivés. Nous avons réalisé deux projets de relevé de sites du patrimoine architectural national : le site de Chellah à Rabat et la grande mosquée Hassan II. Nous avons généré différents produits dérivés pour chaque site allant du nuage de points 3D, plans de façades, cartographie d’écart et SIG 3D. A travers ces deux projets, nous avons pu conclure que l’utilisation de la lasergrammétrie dans un projet architectural est très utile et rentable à condition de bien répondre à ses exigences et maitriser ses particularités et ses limites

The Estimation of theoretical accuracy of mobile terrestrial LiDAR

Mobile Terrestrial LiDAR (Light Detecting And Ranging) (MTL) is a new technology adapted to increasing need of 3D geo-referenced data. The system requires an integration of laser scanners with other sensors of navigation such as GPS and INS and inertial measurement unit. This fusion allows direct georeferencing of point cloud data. As well as the practical accuracy, the theoretical accuracy of raw data also deals with the investors in the mobile mapping systems. This study evaluates the theoretical accuracy of point clouds produced by MTL system through the error propagation theory. The accuracy estimation implies a description of sensors integration, synchronization and calibration. In addition, this paper presents models of reference transformation. The results of this study show that the MTL data accuracy depends on several parameters. Among these parameters, the range is the most critical one

Applied Deep Learning-Based Crop Yield Prediction: A Systematic Analysis of Current Developments and Potential Challenges

Agriculture is essential for global income, poverty reduction, and food security, with crop yield being a crucial measure in this field. Traditional crop yield prediction methods, reliant on subjective assessments such as farmers’ experiences, tend to be error-prone and lack precision across vast farming areas, especially in data-scarce regions. Recent advancements in data collection, notably through high-resolution sensors and the use of deep learning (DL), have significantly increased the accuracy and breadth of agricultural data, providing better support for policymakers and administrators. In our study, we conduct a systematic literature review to explore the application of DL in crop yield forecasting, underscoring its growing significance in enhancing yield predictions. Our approach enabled us to identify 92 relevant studies across four major scientific databases: the Directory of Open Access Journals (DOAJ), the Institute of Electrical and Electronics Engineers (IEEE), the Multidisciplinary Digital Publishing Institute (MDPI), and ScienceDirect. These studies, all empirical research published in the last eight years, met stringent selection criteria, including empirical validity, methodological clarity, and a minimum quality score, ensuring their rigorous research standards and relevance. Our in-depth analysis of these papers aimed to synthesize insights on the crops studied, DL models utilized, key input data types, and the specific challenges and prerequisites for accurate DL-based yield forecasting. Our findings reveal that convolutional neural networks and Long Short-Term Memory are the dominant deep learning architectures in crop yield prediction, with a focus on cereals like wheat (Triticum aestivum) and corn (Zea mays). Many studies leverage satellite imagery, but there is a growing trend towards using Unmanned Aerial Vehicles (UAVs) for data collection. Our review synthesizes global research, suggests future directions, and highlights key studies, acknowledging that results may vary across different databases and emphasizing the need for continual updates due to the evolving nature of the field

LAND TENURE SYSTEMS’ ASSESSMENT EVALUATION: CASE STUDY OF COTE D’IVOIRE

In Cote d’Ivoire, as in many African countries, social tensions are frequently linked to a crisis of the rule of property law. These socio-legal conflicts are referred to by various names depending on their subject matter or the time and place in which they arise: law crises, the weakness of the State apparatus, the unsuitability and failure of institutions, and so on. However, in the majority of cases, these conflicts stem from a common phenomenon: weak land tenure security, or more precisely, land insecurity. The awareness of the magnitude of the problem of securing land tenure and its formalization through the "PAMOFOR" project (in which we participated as a research group and technical land operator), leads us to ask the following questions: How can we master the analysis of land governance and land tenure security in Côte d'Ivoire? And what is its current state? Indeed, an assessment of land governance in Cote d’Ivoire is required. To accomplish this goal, the LGAF tool was used as the foundation of a highly participatory approach to systematically analyzing various aspects of land governance. The goal is to identify best practices and reach agreement on priority areas for land administration improvement. The analysis' findings enable stakeholders to address key governance gaps and develop a clear roadmap for improving land governance

Biomass and Carbon Stock Quantification in Cork Oak Forest of Maamora Using a New Approach Based on the Combination of Aerial Laser Scanning Carried by Unmanned Aerial Vehicle and Terrestrial Laser Scanning Data

The Mediterranean forests, particularly Cork oak (Quercus suber L., 1927), make a major contribution to the fight against climate change through Carbon sequestration. Hence, there is a great interest in the accurate quantification of biomass and carbon stock. In this context, this study aims at assessing the performance of a new approach, based on the combination of Unmanned aerial vehicle airborne Aerial laser scanning (ALS-UAV) and Terrestrial laser scanning (TLS) data, in the determination of dendrometric parameters (Circumference at 1.30 m and Tree Height), and consequently the estimation of biomass and carbon stock, considering field data as reference. This study takes the Maamora forest in Morocco as an example of a Mediterranean Cork oak forest. The methodology consists of collecting data at three levels: the entire area level for an ALS-UAV scan, the plot and tree levels for TLS surveys, as well as field data collection. Afterwards, dendrometric parameters (Circumference at 1.30 m and the Tree height) were estimated using individual tree segmentation and biomass; the carbon stock (aboveground, belowground, and total) was estimated using allometric equations. The comparison of the estimated dendrometric parameters with those measured in the field shows a strong relationship, with a Pearson coefficient of 0.86 and 0.83, a correlation coefficient (R2) of 0.81 and 0.71, and a Root mean square error (RMSE) of 1.84 cm and 0.47 m, respectively. Concerning the biomass and carbon stock estimation, the proposed approach gives a satisfactory accuracy, with a Pearson coefficient of 0.77, an R2 of 0.83, and an RMSE of 36.40 kg for biomass and 20.24 kg for carbon stock