A generalisation of the least-squares method for the adjustment of free networks

Summary The system of normal equations for the adjustment of a free network is a singular one. Therefore, a number of coordinates has to be fixed according to the matrix. The mean square errors and the error ellipses of such an adjustment are dependent on this choice. This paper gives a simple, direct method for the adjustment of free networks, where no coordinates need to be fixed. This is done by minimizing not only the sum of the squares of the weighted errorsV ^T PV=minimun but also the Euclidean norm of the vectorX and of the covariance matrixQ X ^T X=minimum trace (Q)=minimum This last condition is crucial for geodetic problems of this type.     

Which variables are essential for renewable energies?

ABSTRACT

Essential Variables are defined as a minimal set of variables that explain the state of the system. They are crucial for predicting its developments, and support metrics that measure its evolution. The variables should be relevant to meet requirements of stakeholders and be technically and economically feasible for systematic observation. A definition of Essential Renewable Energies Variables is proposed linked with their identification in several domains in renewable energy using a bottom-up and user-driven approach, and spanning over several years of documented interaction with stakeholders. Lists of variables are proposed in hydropower, solar, wind, and marine energies. It does not comprise the variables relating to social and economic aspects supporting decision making in investment nor those relating to civil engineering that are needed to erect a plant or farm.     

Typography and the alphabet

Abstract

The alphabet is the best tool that humankind has for storing thoughts, ideas and instructions until they can be employed, acted upon or communicated to others. This paper presents a necessarily brief and selective summary of the development of the alphabet in Europe from pre-Christian days to the digital/laser technology in use today.     

Mapping Manchester: One Man's Contribution to City Centre Maps

Abstract

Experiments in the smoothing of contours produced by the ECU automated contouring system are described. The result is a flexible system within which the creative and interpretive skills of the cartographer can operate to produce a result which is acceptable quantitatively and qualitatively.     

A vector and raster graphic mapping tool on micro-computers

Abstract

The rapid development of physically-based hydrological information and modelling systems has necessitated enhanced data entry and display systems. A 'mapping tool' is developed for the manipulation and display of spatial information, which is a cost-efficient, self-contained utility system that is suitable for use on micro-computers. It has the ability to be integrated as part of any modelling or information system. Diverse applications using the 'mapping tool' are briefly described including resource management systems for planners, mass balance studies in urban catchments and data entry systems for physically based models.     

Digital world meets urban planet – new prospects for evidence-based urban studies arising from joint exploitation of big earth data,information technology and shared knowledge

ABSTRACT

The digital transformation taking place in all areas of life has led to a massive increase in digital data – in particular, related to the places where and the ways how we live. To facilitate an exploration of the new opportunities arising from this development the Urban Thematic Exploitation Platform (U-TEP) has been set-up. This enabling instrument represents a virtual environment that combines open access to multi-source data repositories with dedicated data processing, analysis and visualisation functionalities. Moreover, it includes mechanisms for the development and sharing of technology and knowledge. After an introduction of the underlying methodical concept, this paper introduces four selected use cases that were carried out on the basis of U-TEP: two technology-driven applications implemented by users from the remote sensing and software engineering community (generation of cloud-free mosaics, processing of drone data) and two examples related to concrete use scenarios defined by planners and decision makers (data analytics related to global urbanization, monitoring of regional land-use dynamics). The experiences from U-TEP’s pre-operations phase show that the system can effectively support the derivation of new data, facts and empirical evidence that helps scientists and decision-makers to implement improved strategies for sustainable urban development.     

The Representation of Topographic Information on Maps: The Depiction of Relief

Abstract

The development of water transport, particularly of dock provision, was a potent influence on the nature and structure of some British towns. The impact of this development has been recorded in the detailed mapping of water transport specifically and in the mapping of towns generally. The nature and extent of this mapping is analysed in order to assess the degree to which early maps can be used as sources for the history of urban water transport and its impact on the townscape.     

The geopotential to (14, 14) from a combination of satellite and gravimetric data

A set of2261 5°×5° mean anomalies were used alone and with satellite determined harmonic coefficients of the Smithsonian' Institution to determine the geopotential expansion to various degrees. The basic adjustment was carried out by comparing a terrestrial anomaly to an anomaly determined from an assumed set of coefficients. The (14, 14) solution was found to agree within ±3 m of a detailed geoid in the United States computed using1°×1° anomalies for an inner area and satellite determined anomalies in an outer area. Additional comparisons were made to the input anomaly field to consider the accuracy of various harmonic coefficient solutions. A by-product of this investigation was a new γ_E=978.0463 gals in the Potsdam system or978.0326 gals in an absolute system if −13.7 mgals is taken as the Potsdam correction. Combining this value of γ_E withf=1/298.25, KM=3.9860122·10 ²² cm ³ /sec ² , the consistent equatorial radius was found to be6378143 m.     

SURVEYING FROM AIR PHOTOGRAPHS FIXED BY REMOTE RADAR CONTROL*

Abstract

During the last thirty years, developments in the taking of air photographs (and of mapping from them) have been progressive until, under present day conditions, no programme of topographical mapping for economic development can be satisfactorily undertaken without using them.     

A bevy of area-preserving transforms for map projection designers

ABSTRACT

Sometimes map projection designers need to create equal-area projections to best fill the projections’ purposes. However, unlike for conformal projections, few transformations have been described that can be applied to equal-area projections to develop new equal-area projections. Here, I survey area-preserving transformations, giving examples of their applications and proposing an efficient way of deploying an equal-area system for raster-based Web mapping. Together, these transformations provide a toolbox for the map projection designer working in the area-preserving domain.     

Geographic Reality Versus Imagination in Taiwan’s Historical Maps

Abstract

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During the past 400?years, Taiwan has experienced the dominance of various political regimes, which allowed the development of a diversity of cartographic styles for academic comparison. A detailed analysis of historical maps across centuries demonstrates that this contested island has been illustrated with a blending of reality, misconception and imagination. This paper narrates how maps reveal political rulers’ conscious and unconscious perceptions of this island. We call attention to the abundant cartographic materials in existence and suggest that they can be fascinating materials for the study of the contested colonial histories of this island in various disciplines.     

Sonifying data uncertainty with sound dimensions

ABSTRACT

The communication of data uncertainty is a crucial problem in data science, information visualization, and geographic information science (GIScience). Effective ways to communicate the uncertainty of data enables data consumers to interpret the data as intended by the producer, reducing the possibilities of misinterpretation. In this article, we report on an empirical investigation of how sound can be used to convey information about data uncertainty in an intuitive way. To answer the research question How intuitive are sound dimensions to communicate uncertainty? we carry out a cognitive experiment, where participants were asked to interpret the certainty/uncertainty level in two sounds A and B (N = 33). We produce sound stimuli by varying sound dimensions, including loudness, duration, location, pitch, register, attack, decay, rate of change, noise, timbre, clarity, order, and harmony. In the stimuli, both synthetic and natural sounds are used to allow comparison. The experiment results identify three sound dimensions (loudness, order, and clarity) as significantly more intuitive to communicate uncertainty, providing guidelines for sonification and information visualization practitioners.     

A goal-based approach to the identification of essential transformation variables in support of the implementation of the 2030 agenda for sustainable development

ABSTRACT

The United Nations' 2030 Agenda for Sustainable Development sets seventeen Sustainable Development Goals (SDGs) to be achieved by 2030. Earth observation are needed that can support the development and validation of transformation policies to make progress towards the SDGs. A participatory and inclusive goal-based approach (GBA) is introduced that links societal goals, targets and indicators to Essential Transformation Variables (ETVs) of the human and non-human environment. The GBA is complementary to the widely used expert-based approach. The GBA is applied to the SDGs at the goal, target and indicator levels. The high-level conceptual model used for the SDGs is humanity embedded in the Earth's life-support system (ELSS). At the goal level, very few of the SDGs are directly focusing on the ELSS and its physiology. Most of the SDG Targets focus on transformations in society and the built environment. Having targets that explicitly focus on the physiology of the ELSS would be important for sustainability. Most of the current indicator measure the built environment and the embedded social fabric. Sustainable development requires a functioning ELSS, and to ensure this, complementary indicators that bring environmental aspects to the monitoring of SDG targets are needed.     

Map design for children

Abstract

The development of graphicacy in children has been a laudible and long standing aim of geographical education. The interaction between children and maps in a variety of circumstances is examined and the abilities of children to create their own maps are outlined. The conclusions from such studies can lead to recommendations for map design for children. In particular, the cognitive and graphic processes must be understood and applied.     

Fundamental aspects of access control for geospatial data

Abstract

In recent years, geographical information systems have been employed in a wide variety of application domains, and as a result many research efforts are being devoted to those upcoming problems. Geospatial data security, especially access control, has attracted increased research interests within the academic community. The tendency towards sharing and interoperability of geospatial data and applications makes it common to acquire and integrate geospatial data from multiple organisations to accomplish a complex task. Meanwhile, many organisations have the requirement for securing access to possessed sensitive or proprietary geospatial data. In this heterogeneous and distributed environment, consistent access control functionality is crucial to promote controlled accessibility. As an extension of general access control mechanisms in the IT domain, the mechanism for geospatial data access control has its own requirements and characteristics of granularity and geospatial logic. In this paper, we address several fundamental aspects concerning the design and implementation of an access control system for geospatial data, including the classification, requirements, authorisation models, storage structures and management approaches for authorisation rules, matching and decision-making algorithms between authorisation rules and access requests, and its policy enforcement mechanisms. This paper also presents a system framework for realising access control functionality for geospatial data, and explain access control procedures in detail.     

Ability to detect and locate gross errors on DEM matching algorithm

Abstract

Digital elevation model (DEM) matching techniques have been extended to DEM deformation detection by substituting a robust estimator for the least squares estimator, in which terrain changes are treated as gross errors. However, all existing methods only emphasise their deformation detecting ability, and neglect another important aspect: only when the gross error can be detected and located, can this system be useful. This paper employs the gross error judgement matrix as a tool to make an in-depth analysis of this problem. The theoretical analyses and experimental results show that observations in the DEM matching algorithm in real applications have the ability to detect and locate gross errors. Therefore, treating the terrain changes as gross errors is theoretically feasible, allowing real DEM deformations to be detected by employing a surface matching technique.     

Assessment and planning for integrated river basin management using remote sensing,SWAT model and morphometric analysis (case study: Kaddam river basin,India)

Abstract

River basin assessment is crucial for water management and to address the watershed issues. So, an integrated river basin management and assessment model using morphometric assessment, remote sensing, GIS and SWAT model was envisaged and applied to Kaddam river basin, Telangana state, India. Morphometric results showed high drainage density ranging from 2.19 to 5.5?km²/km, with elongated fan shape having elongation ratio of 0.60–0.75 with sparse vegetation and high relief. Land use change assessment showed that 265.26?km² of forest land is converted into irrigated land and has increased sediment yields in watersheds. The calibration (r ²?=?0.74, NSE?=?0.84) and validation (r ²?=?0.72, NSE?=?0.84) of SWAT model showed that simulated and observed results were in agreement and in recommended ranges. The SWAT simulations were used to compute mean annual water and sediment yield from 1997 to 2012, along with morphometric results to categorize critical watersheds and conservation structures were proposed accordingly.     

Free and open source software for geospatial applications (FOSS4G) to support Future Earth

ABSTRACT

The development, integration, and distribution of the information and spatial data infrastructure (i.e. Digital Earth; DE) necessary to support the vision and goals of Future Earth (FE) will occur in a distributed fashion, in very diverse technological, institutional, socio-cultural, and economic contexts around the world. This complex context and ambitious goals require bringing to bear not only the best minds, but also the best science and technologies available. Free and Open Source Software for Geospatial Applications (FOSS4G) offers mature, capable and reliable software to contribute to the creation of this infrastructure. In this paper we point to a selected set of some of the most mature and reliable FOSS4G solutions that can be used to develop the functionality required as part of DE and FE. We provide examples of large-scale, sophisticated, mission-critical applications of each software to illustrate their power and capabilities in systems where they perform roles or functionality similar to the ones they could perform as part of DE and FE. We provide information and resources to assist the readers in carrying out their own assessments to select the best FOSS4G solutions for their particular contexts and system development needs.     

Digital Map Generalization at the Age of Enlightenment: a Review of the First Forty Years

Abstract

From 1966 to 2006, digital map generalization has undergone a 40-year development. This paper provides an examination of the development in the first 40 years and an outlook. Emphasis is on theoretical and technical developments.     

Korea: A Cartographic History

Abstract