In this chapter, we discuss normal generators for mapping class groups of surfaces. Especially, we focus on the relation between normal generation of a mapping class with its asymptotic translation lengths on the Teichmüller space and the curve graph of the underlying surface. We also discuss several open questions.
Steven Cunnington, Matilde Barberi-Squarotti, José Luis Bernal
et al.
Mapping the integrated 21cm emission line from dark matter-tracing neutral hydrogen gas is the primary science goal for MeerKLASS (MeerKAT's Large Area Synoptic Survey). Prior to the arrival of MeerKAT, this intensity mapping technique had only been tested on a couple of pre-existing single-dish radio telescopes with a handful of observational hours with which to make early pioneering detections. The 64-dish MeerKAT array, precursor to the Square Kilometre Array Observatory (SKAO), can scan the sky in auto-correlation mode and perform intensity mapping across large sky areas, presenting the exciting potential for a wide-sky (${\gtrsim}\,10{,}000\,{\rm deg}^2$) spectroscopic survey across redshift $0.4\,{<}\,z\,{<}\,1.45$. Validating the auto-correlation (or single-dish) mode of observation for a multi-dish array and developing the analysis pipeline with which to make unbiased measurements has presented major challenges to this endeavour. In this work, we overview the advances in the field that have facilitated a robust analysis framework for single-dish intensity mapping, and review some results that showcase its success using early MeerKLASS surveys. We demonstrate our control of foreground cleaning, signal loss and map regridding to deliver detections of cosmological clustering within the intensity maps through cross-correlation power spectrum measurements with overlapping galaxy surveys. Finally, we discuss the prospects for future MeerKLASS observations and forecast its potential, making our code publicly available: https://github.com/meerklass/MeerFish.
Line-intensity mapping (LIM) is an emerging cosmological technique that traces large-scale structure through the integrated spectral-line emission of unresolved sources. Reconstructing unbiased sky maps requires careful joint treatment of instrumental calibration and map-making, a task made challenging by time-varying receiver gains, thermal drifts, and correlated $1/f$ noise intrinsic to single-dish radio telescopes. We present a Bayesian framework for joint calibration and map-making using Gibbs sampling, giving access to the full joint posterior of calibration and sky map parameters. Our data model is grounded in the radiometer equation, capturing the coupling between noise level and system temperature without assuming a fixed noise amplitude. Gain and system temperature are estimated via an iterative generalised least squares (GLS) scheme, while absolute flux calibration is achieved either with external calibrators or via known signal injections such as noise diodes. We further introduce a $1/f$ noise model that avoids spurious periodic correlations arising from the common assumption of a diagonally structured noise covariance in the frequency domain. The workflow is implemented in an efficient software package using the Levinson algorithm and a polynomial emulator to reduce computational cost. Demonstrated on simulations representative of MeerKLASS single-dish observations, the framework generalises to other single-dish surveys and to cross-correlation and interferometric data.
El uso de puntos de control terrestres (GCP) es fundamental para calibrar con precisión el posicionamiento fotogramétrico en detección remota
con vehículos aéreos (UAV). Sin embargo, colocar manualmente el GCP durante la georreferenciación puede resultar costoso y
llevar mucho tiempo, especialmente en terrenos complejos, lo que potencialmente limita la eficiencia operativa y la eficacia del sistema.
Sin embargo, la integración de receptores de navegación modernos con software avanzado de imágenes en movimiento en tiempo real (RTK) ofrece
un potencial significativo para mejorar la precisión fotogramétrica cuando se utiliza con vehículos aéreos no tripulados. El propósito de este estudio fue evaluar
cómo varias variables de GCP afectan la precisión fotogramétrica en terrenos geográficamente desafiantes.
Si utiliza un vehículo aéreo no tripulado equipado con tecnología RTK avanzada respaldada por el Sistema de Navegación Global por Satélite (GNSS).
Se implementó el error cuadrático promedio (RMSE) de los puntos de control (CP) para evaluar la calidad de los medicamentos
en los escenarios propuestos. Las características indican que aumentar el número de GCP y garantizar una distribución uniforme
reduce significativamente el RMSE para los CP, observándose mejoras a partir de 3 GCP, contrariamente a estudios anteriores
que sugerían 1 GCP en el contexto de georreferenciación directa (DG). El análisis de los resultados sugiere un rango óptimo de 4 a 5
GCP, cuyo arroyo resulta consistentemente en el rango de decímetros.
Arash Asgharivaskasi, Fritz Girke, Nikolay Atanasov
Autonomous exploration of unknown environments using a team of mobile robots demands distributed perception and planning strategies to enable efficient and scalable performance. Ideally, each robot should update its map and plan its motion not only relying on its own observations, but also considering the observations of its peers. Centralized solutions to multi-robot coordination are susceptible to central node failure and require a sophisticated communication infrastructure for reliable operation. Current decentralized active mapping methods consider simplistic robot models with linear-Gaussian observations and Euclidean robot states. In this work, we present a distributed multi-robot mapping and planning method, called Riemannian Optimization for Active Mapping (ROAM). We formulate an optimization problem over a graph with node variables belonging to a Riemannian manifold and a consensus constraint requiring feasible solutions to agree on the node variables. We develop a distributed Riemannian optimization algorithm that relies only on one-hop communication to solve the problem with consensus and optimality guarantees. We show that multi-robot active mapping can be achieved via two applications of our distributed Riemannian optimization over different manifolds: distributed estimation of a 3-D semantic map and distributed planning of SE(3) trajectories that minimize map uncertainty. We demonstrate the performance of ROAM in simulation and real-world experiments using a team of robots with RGB-D cameras.
This article extends the study of the dynamical properties of the symmetric McMillan map, emphasizing its utility in understanding and modeling complex nonlinear systems. Although the map features six parameters, we demonstrate that only two are irreducible: the linearized rotation number at the fixed point and a nonlinear parameter representing the ratio of terms in the biquadratic invariant. Through a detailed analysis, we classify regimes of stable motion, provide exact solutions to the mapping equations, and derive a canonical set of action-angle variables, offering analytical expressions for the rotation number and nonlinear tune shift. We further establish connections between general standard-form mappings and the symmetric McMillan map, using the area-preserving Hénon map and accelerator lattices with thin sextupole magnet as representative case studies. Our results show that, despite being a second-order approximation, the symmetric McMillan map provides a highly accurate depiction of dynamics across a wide range of system parameters, demonstrating its practical relevance in both theoretical and applied contexts.
The availability of a robust map-based localization system is essential for the operation of many autonomously navigating vehicles. Since uncertainty is an inevitable part of perception, it is beneficial for the robustness of the robot to consider it in typical downstream tasks of navigation stacks. In particular localization and mapping methods, which in modern systems often employ convolutional neural networks (CNNs) for perception tasks, require proper uncertainty estimates. In this work, we present uncertainty-aware Panoptic Localization and Mapping (uPLAM), which employs pixel-wise uncertainty estimates for panoptic CNNs as a bridge to fuse modern perception with classical probabilistic localization and mapping approaches. Beyond the perception, we introduce an uncertainty-based map aggregation technique to create accurate panoptic maps, containing surface semantics and landmark instances. Moreover, we provide cell-wise map uncertainties, and present a particle filter-based localization method that employs perception uncertainties. Extensive evaluations show that our proposed incorporation of uncertainties leads to more accurate maps with reliable uncertainty estimates and improved localization accuracy. Additionally, we present the Freiburg Panoptic Driving dataset for evaluating panoptic mapping and localization methods. We make our code and dataset available at: \url{http://uplam.cs.uni-freiburg.de}
Samuel M. Bateman, Ning Xu, H. Charles Zhao
et al.
Building and maintaining High-Definition (HD) maps represents a large barrier to autonomous vehicle deployment. This, along with advances in modern online map detection models, has sparked renewed interest in the online mapping problem. However, effectively predicting online maps at a high enough quality to enable safe, driverless deployments remains a significant challenge. Recent work on these models proposes training robust online mapping systems using low quality map priors with synthetic perturbations in an attempt to simulate out-of-date HD map priors. In this paper, we investigate how models trained on these synthetically perturbed map priors generalize to performance on deployment-scale, real world map changes. We present a large-scale experimental study to determine which synthetic perturbations are most useful in generalizing to real world HD map changes, evaluated using multiple years of real-world autonomous driving data. We show there is still a substantial sim2real gap between synthetic prior perturbations and observed real-world changes, which limits the utility of current prior-informed HD map prediction models.
In recent years the role of preventive
archaeological investigations - and
consequently that of archaeologists
-in territorial and urban transformation
became more and more important;
On the other hand, the time
allocated to archaeological investigation
is often severely compressed:
so, it is essential to exercise targeted
and effective action and, even more
so, to have in-depth knowledge of
the context on which the project
impacts. The National Geoportal for
Archaeology is a useful tool, making
archaeological data available for
consultation and free reuse. Its usefulness
is growing every day, thanks
to recent provisions that provide for
the use of the GNA as a standard for
the delivery of minimum data for all
archaeological investigations.
We introduce an infinite group action on partition functions of WK type, meaning of the type of the partition function $Z^{\rm WK}$ in the famous result of Witten and Kontsevich expressing the partition function of $ψ$-class integrals on the compactified moduli space $\overline{\mathcal{M}}_{g,n}$ as a $τ$-function for the Korteweg--de Vries hierarchy. Specifically, the group which acts is the group $\mathcal{G}$ of formal power series of one variable $\varphi(V)=V+O(V^2)$, with group law given by composition, acting in a suitable way on the infinite tuple of variables of the partition functions. In particular, any $\varphi \in \mathcal{G}$ sends the Witten--Kontsevich (WK) partition function $Z^{\rm WK}$ to a new partition function $Z^\varphi$, which we call the WK mapping partition function associated to $\varphi$. We show that the genus zero part of $\log Z^\varphi$ is independent of $\varphi$ and give an explicit recursive description for its higher genus parts (loop equation), and as applications of this obtain relationships of the $ψ$-class integrals to Gaussian Unitary Ensemble and generalized Brézin--Gross--Witten correlators. In a different direction, we use $Z^\varphi$ to construct a new integrable hierarchy, which we call the WK mapping hierarchy associated to $\varphi$. We show that this hierarchy is a bihamiltonian perturbation of the Riemann--Hopf hierarchy possessing a $τ$-structure, and prove that it is a universal object for all such perturbations. Similarly, for any $\varphi\in\mathcal{G}$, we define the Hodge mapping partition function associated to $\varphi$, prove that it is integrable, and study its role in hamiltonian perturbations of the Riemann--Hopf hierarchy possessing a $τ$-structure. Finally, we establish a generalized Hodge--WK correspondence relating different Hodge mapping partition functions.
We consider a new type of mappings in metric spaces which can be characterized as mappings contracting perimeters of triangles. It is shown that such mappings are continuous. The fixed-point theorem for such mappings is proved and the classical Banach fixed-point theorem is obtained like a simple corollary. An example of a mapping contractive perimeters of triangles which is not a contraction mapping is constructed.
Deep learning-based methods have been extensively explored for automatic building mapping from high-resolution remote sensing images over recent years. While most building mapping models produce vector polygons of buildings for geographic and mapping systems, dominant methods typically decompose polygonal building extraction in some sub-problems, including segmentation, polygonization, and regularization, leading to complex inference procedures, low accuracy, and poor generalization. In this paper, we propose a simple and novel building mapping method with Hierarchical Transformers, called HiT, improving polygonal building mapping quality from high-resolution remote sensing images. HiT builds on a two-stage detection architecture by adding a polygon head parallel to classification and bounding box regression heads. HiT simultaneously outputs building bounding boxes and vector polygons, which is fully end-to-end trainable. The polygon head formulates a building polygon as serialized vertices with the bidirectional characteristic, a simple and elegant polygon representation avoiding the start or end vertex hypothesis. Under this new perspective, the polygon head adopts a transformer encoder-decoder architecture to predict serialized vertices supervised by the designed bidirectional polygon loss. Furthermore, a hierarchical attention mechanism combined with convolution operation is introduced in the encoder of the polygon head, providing more geometric structures of building polygons at vertex and edge levels. Comprehensive experiments on two benchmarks (the CrowdAI and Inria datasets) demonstrate that our method achieves a new state-of-the-art in terms of instance segmentation and polygonal metrics compared with state-of-the-art methods. Moreover, qualitative results verify the superiority and effectiveness of our model under complex scenes.
Abstract. Scientific-methodical approaches to the development of working land management projects to improve the condition of unproductive lands are proposed.
The state policy of land protection envisages the principle of rational nature management on all categories of land, in the event of land disturbance, it envisages their restoration (earthing, reclamation). However, only a small part of the fertile topsoil is used to improve agricultural land.
Excavation is a complex of removal, transportation, and application of a fertile layer of soil and potentially fertile rocks on unproductive lands and disturbed lands for the purpose of their improvement. Landfilling in rural areas, by its very nature, is a nature protection measure that is performed in a complex of land management works, which have an investment character and are aimed at preserving the natural environment and increasing the productivity of agricultural land. In market conditions, the concept of "earthing" has been expanded and includes the removal of fertile soil and potentially fertile rocks during the construction of reservoirs, development of quarries, construction work with the excavation of fertile soil and their application not only to unproductive lands in agricultural enterprises, but also in organization of green industrial zones (for greening the territory of the object), liquidation of the consequences of industrial accidents.
In these cases, soils with a certain fertility potential are a commodity that has a market demand and a certain value. The economic effect of measures in the working project of land management must be calculated using the discount method, which takes into account both the outflow of money (investments) and the inflow that occurs due to the increase in land productivity.
Key words: grounding, working project of land management, disturbed lands, soil protection, fertile soil layer, low-productivity land, land management documentation, land management, management, land use.
The article focuses on the characterization of waterlogged quarries: their emergence, functioning and legal aspects of use; the issues of state registration of land plots occupied by waterlogged quarries are considered. The article substantiates the composition of cadastral works required for registration of a real estate object with the State cadastral register, and reviews the methods and regulatory requirements for the accuracy of determining the boundaries of land plots. It is recommended to carry out cadastral works taking into account and controlling the ecological and sanitary-epidemiological condition of a waterlogged quarry, which will provide the necessary information to public authorities, local self-government bodies, individuals and legal entities in the course of regulation and management of land relations for the organization of rational use and protection of land plots occupied by waterlogged quarries.
GEOmedia interviews Gian Bartolomeo Siletto, geologist, official representative for the Spatial Data Infrastructure (IDT) of Regione Piemonte.
Conversation with Umberto Trivelloni, Head of the IDT of the Veneto Region, Delio Brentan, P.M. for the IT part of the IDT, and Andrea Semenzato Analyst GIS Engineering Ingegneria Informatica S.p.A
V. M. Eshrokov, A. A. Cherkasov, R. K. Makhmudov
et al.
Introduction. A traditional for geography study of the spatial and planning organization features of the territory has recently acquired a “new life” in strategic and territorial planning documents. At the same time, the formation of urban and municipal districts with the abolition of village councils lead to the fact that the most important link in strategic and territorial planning at the level of settlements “falls out”. Approbation of traditional geographic methods of spatial analysis in the context of urban development of the territory is the main goal of the study.Materials and research methods. The basis of the work was a variety of data and materials: state and municipal statistics (official), cadastral registration, strategic and territorial planning documents, materials of sociological surveys and a field survey results of cities and towns that are part of the Stavropol Territory. Using the methods of systemic geoinformation analysis, a structural model of the urban development of the Stavropol Territory containing a geodatabase and cartographic bases of various scales was created.The results of the study and their discussion. The study was carried out on different scales: the Stavropol Territory, macro-settlement areas, the main urban agglomerations of the Stavropol Territory (Stavropol and Caucasian Mineral Waters (CMW), individual municipalities). A general characteristic of the spatial planning organization of the Stavropol Territory is given, an analysis of its individual elements is made: linear (planning axes), nodal (planning centers and nodes), areal (planning zones), current trends in the development of the entire system and individual elements have been established and characterized. Five types of spatial planning zones in the territory of the region have been identified. A structural model of urban development of the territory has been developed using the methods of geoinformation analysis and mapping. The main trends in the spatial planning organization of the territory are determined – concentration and polarization. The main problems of the spatial development of the region are identified and characterized.Conclusions. For the purposes of strategic and territorial planning of the Stavropol Territory, an analysis of the features of the spatial planning organization of the territory makes it possible to determine the territorial potentials in the form of areas and points of growth. Internal differences in the spatial and planning development of the Stavropol Territory show significant intra-regional differentiation with a high degree of geographical contrast and polarization of the territory. The asymmetry of regional development is manifested in the shift of socio-economic and urban centers of gravity in the western and southern directions - towards the main agglomerations of the region - Stavropol and CMW. The proposed structural model of urban development shows the need to take into account the role and potential of grassroots rural settlements, which are actually “erased” under the new municipal reform and the formation of large urban and municipal districts.
The foreign experience in the organization of management systems is analyzed, the principles of the use of land resources applicable to the conditions of the Republic of Belarus are considered. The main requirements for cadastral data in the land information systems of the EU countries are summarized.