Digital Map Products Research Articles

ALTIMETRY ASSESSMENT OF ASTER GDEM v2 AND SRTM v3 DIGITAL ELEVATION MODELS: A CASE STUDY IN URBAN AREA OF BELO HORIZONTE, MG, BRAZIL

Abstract: This work is an altimetry evaluation study involving Digital Elevation Models ASTER GDEM version 2 and SRTM version 3. Both models are readily available free of charge, however as they are built from different remote sensing methods it is also expected that they present different data qualities. LIDAR data with 25 cm vertical accuracy were used as reference for assessment validation. The evaluation study, carried out in urbanized area, investigated the distribution of the residuals and the relationship between the observed errors with land slope classes. Remote sensing principles, quantitative statistical methods and the Cartographic Accuracy Standard of Digital Mapping Products (PEC-PCD) were considered. The results indicated strong positive linear correlation and the existence of a functional relationship between the evaluated models and the reference model. Residuals between -4.36 m and 3.11 m grouped 47.7% of samples corresponding to ASTER GDEM and 63.7% of samples corresponding to SRTM. In both evaluated models, Root Mean Square Error values increased with increasing of land slope. Considering 1: 50,000 mapping scale the PEC-PCD classification indicated class B standard for SRTM and class C for ASTER GDEM. In all analyzes, SRTM presented smaller altimetry errors compared to ASTER GDEM, except in areas with steep relief.

Uncertainty-guided sampling to improve digital soil maps

Digital soil mapping (DSM) products represent estimates of spatially distributed soil properties. These estimations comprise an element of uncertainty that is not evenly distributed over the area covered by DSM. If we quantify the uncertainty spatially explicit, this information can be used to improve the quality of DSM by optimizing the sampling design. This study follows a DSM approach using a Random Forest regression model, legacy soil samples, and terrain covariates to estimate topsoil silt and clay contents in a small catchment of 4.2km2 in the Three Gorges Reservoir Area, Central China. We aim (i) to introduce a method to derive spatial uncertainty, and (ii) to improve the initial DSM approaches by additional sampling that is guided by the spatial uncertainty. The proposed uncertainty measure is based on multiple realizations of individual and randomized decision tree models. We used the spatial uncertainty of the initial DSM approaches to stratify the study area and thereby to identify potential sampling areas of high uncertainties. Further, we tested how precisely available legacy samples cover the variability of the covariates within each potential sampling area to define the final sampling area and to apply a purposive sampling design. For the final Random Forest model calibration, we combined the legacy sample set with the additional samples. This uncertainty-driven DSM refinement was evaluated by comparing it to a second approach. In this second approach, the additional samples were replaced by a random sample set of the same size, obtained from the entire study area. For the comparative analysis, external, bootstrap-, and cross-validation was applied. The DSM approach using the uncertainty-driven refinement performed best. The averaged spatial uncertainty was reduced by 31% for silt and by 27% for clay compared to the initial DSM approach. Using external validation, the accuracy increased by the same proportions, while showing an overall accuracy of R2=0.59 for silt and R2=0.56 for clay.

Using quantile regression forest to estimate uncertainty of digital soil mapping products

Digital Soil Mapping (DSM) products are simplified representations of more complex and partially unknown patterns of soil variations. Therefore, any prediction of a soil property that can be derived from these products has an irreducible uncertainty that needs to be mapped. The objective of this study was to compare the most current DSM method – Regression Kriging (RK) – with a new approach derived from RandomForest – Quantile Regression Forest (QRF) – in regard to their ability of predicting the uncertainties of GlobalSoilMap soil property grids. The comparison was performed for three soil properties, pH, organic carbon and clay content at 5–15cm depth in a 27,236km2 Mediterranean French region with sparse sets of measured soil profiles (1/13.5km2) and for a set of environmental covariates characterizing the relief, climate, geology and land use of the region. Apart from classical performance indicators, comparisons involved accuracy plots and the visual examinations of the uncertainty maps provided by the two methods.The results obtained for the three soil properties showed that QRF provided more accurate and more interpretable predicted patterns of uncertainty than RK did, while having similar performances in predicting soil properties. The use of QRF in operational DSM is therefore recommended, especially when spatial sampling of soil observations are too sparse for applying RK.

Using georadar systems for mapping underground utility networks

Abstract The transport infrastructure development in big cities leads to design underground road passages for fluidity of traffic. Under these conditions it is necessary to divert the underground utilities routes. Also, the construction of new metro sections is an alternative to public transport from the surface. New modern office and residential buildings, as well as new commercial complexes, require new underground utility projects. In these circumstances, design studies require investigations about underground utility networks, in order to avoid the damage in execution operations of new construction foundations works. These investigations allow the design of metro lines and metro station avoiding major waterways, sewers, gas or electric cables, or design first the deviation project for these underground utility networks. Georadar systems together with advanced positioning surveying, assisted by specialized software, allow fast mapping, non-destructive and precise, very useful to designers for types of construction mentioned above. This system becomes a necessity in terms of urban agglomerations in growing today [6]. This article refers to modern systems Ground Penetrating Radar (GPR), to software for taking over of field information and to post-processing software that lead to obtaining 3D georeferenced digital map products, integrated into a GIS [1].

La breve y triste historia de la geología en Uruguay

Se describen las etapas que pueden reconocerse en los ciento ocho años en los que se desarrollaron conocimientos geológicos científicos en Uruguay. La Facultad de Agronomía fue la única institución que mantuvo actividad geológica durante todo el período, aunque con distinta intensidad. Se reconocen 5 periodos bien definidos: Periodo 1907-1948, el Dr. Karl Walther en facultad de Agronomía y geólogos contratados por el Instituto de Geología creado en 1912; Walther produjo desde 1909 hasta 1948 cincuenta artículos científicos y reconoció los principales rasgos geológicos del Uruguay. Periodo 1954-1959, con el Profesor Juan Goñi y un equipo de 6 docentes. Periodo 1959-1973, se normalizan los trabajos en la Facultad de Agronomía llegando a formarse un equipo de 15 docentes, cuya meta era la cartografía geológica. Período1974-1984, la Dictadura interviene la Universidad y en 1978 se crea la Licenciatura de Geología en Facultad de Ciencias y en 1983 egresan los primeros geólogos, con limitado nivel científico. Período1985-2015, resurge Agronomía, se realizan post-grados en el extranjero y la Geología se desarrolla a un nivel aceptable, con cursos de post-grados, cursos de minería y producción de cartas digitales a varias escalas. Se concluye que la Facultad de Agronomía fue el principal motor de los estudios geológicos en Uruguay, porque desde su creación en 1907 hasta la fecha siempre tuvo un grupo de trabajo en geología básica.

PRECISE ORTHO IMAGERY AS THE SOURCE FOR AUTHORITATIVE AIRPORT MAPPING

As the aviation industry moves from paper maps and charts to the digital cockpit and electronic flight bag, producers of these products need current and accurate data to ensure flight safety. FAA (Federal Aviation Administration) and ICAO (International Civil Aviation Organization) require certified suppliers to follow a defined protocol to produce authoritative map data for the aerodrome. Typical airport maps have been produced to meet 5 m accuracy requirements. The new digital aviation world is moving to 1 m accuracy maps to provide better situational awareness on the aerodrome. The commercial availability of 0.5 m satellite imagery combined with accurate ground control is enabling the production of avionics certified .85 m orthophotos of airports around the globe. CompassData maintains an archive of over 400+ airports as source data to support producers of 1 m certified Aerodrome Mapping Database (AMDB) critical to flight safety and automated situational awareness. CompassData is a DO200A certified supplier of authoritative orthoimagery and attendees will learn how to utilize current airport imagery to build digital aviation mapping products.

PRECISE ORTHO IMAGERY AS THE SOURCE FOR AUTHORITATIVE AIRPORT MAPPING

Abstract. As the aviation industry moves from paper maps and charts to the digital cockpit and electronic flight bag, producers of these products need current and accurate data to ensure flight safety. FAA (Federal Aviation Administration) and ICAO (International Civil Aviation Organization) require certified suppliers to follow a defined protocol to produce authoritative map data for the aerodrome. Typical airport maps have been produced to meet 5 m accuracy requirements. The new digital aviation world is moving to 1 m accuracy maps to provide better situational awareness on the aerodrome. The commercial availability of 0.5 m satellite imagery combined with accurate ground control is enabling the production of avionics certified .85 m orthophotos of airports around the globe. CompassData maintains an archive of over 400+ airports as source data to support producers of 1 m certified Aerodrome Mapping Database (AMDB) critical to flight safety and automated situational awareness. CompassData is a DO200A certified supplier of authoritative orthoimagery and attendees will learn how to utilize current airport imagery to build digital aviation mapping products.

PHOTOGRAMMETRIC PROCESSING OF APOLLO 15 METRIC CAMERA OBLIQUE IMAGES

The integrated photogrammetric mapping system flown on the last three Apollo lunar missions (15, 16, and 17) in the early 1970s incorporated a Metric (mapping) Camera, a high-resolution Panoramic Camera, and a star camera and laser altimeter to provide support data. In an ongoing collaboration, the U.S. Geological Survey’s Astrogeology Science Center, the Intelligent Robotics Group of the NASA Ames Research Center, and Arizona State University are working to achieve the most complete cartographic development of Apollo mapping system data into versatile digital map products. These will enable a variety of scientific/engineering uses of the data including mission planning, geologic mapping, geophysical process modelling, slope dependent correction of spectral data, and change detection. Here we describe efforts to control the oblique images acquired from the Apollo 15 Metric Camera.

PHOTOGRAMMETRIC PROCESSING OF APOLLO 15 METRIC CAMERA OBLIQUE IMAGES

Abstract. The integrated photogrammetric mapping system flown on the last three Apollo lunar missions (15, 16, and 17) in the early 1970s incorporated a Metric (mapping) Camera, a high-resolution Panoramic Camera, and a star camera and laser altimeter to provide support data. In an ongoing collaboration, the U.S. Geological Survey’s Astrogeology Science Center, the Intelligent Robotics Group of the NASA Ames Research Center, and Arizona State University are working to achieve the most complete cartographic development of Apollo mapping system data into versatile digital map products. These will enable a variety of scientific/engineering uses of the data including mission planning, geologic mapping, geophysical process modelling, slope dependent correction of spectral data, and change detection. Here we describe efforts to control the oblique images acquired from the Apollo 15 Metric Camera.

SGM-based seamline determination for urban orthophoto mosaicking

Mosaicking is a key step in the production of digital orthophoto maps (DOMs), especially for large-scale urban orthophotos. During this step, manual intervention is commonly involved to avoid the case where the seamline crosses obvious objects (e.g., buildings), which causes geometric discontinuities on the DOMs. How to guide the seamline to avoid crossing obvious objects has become a popular topic in the field of photogrammetry and remote sensing. Thus, a new semi-global matching (SGM)-based method to guide seamline determination is proposed for urban orthophoto mosaicking in this study, which can greatly eliminate geometric discontinuities. The approximate epipolar geometry of the orthophoto pairs is first derived and proven, and the approximate epipolar image pair is then generated by rotating the two orthorectified images according to the parallax direction. A SGM algorithm is applied to their overlaps to obtain the corresponding pixel-wise disparity. According to a predefined disparity threshold, the overlap area is identified as the obstacle and non-obstacle areas. For the non-obstacle regions, Hilditch thinning algorithm is used to obtain the skeleton line, followed by Dijkstra’s algorithm to search for the optimal path on the skeleton network as the seamline between two orthophotos. A whole seamline network is constructed based on the strip information recorded in flight. In the experimental section, the approximate epipolar geometric theory of the orthophoto is first analyzed and verified, and the effectiveness of the proposed method is then validated by comparing its results with the results of the geometry-based, OrthoVista, and orthoimage elevation synchronous model (OESM)-based methods.

Restoration of Territories of a County Surrounded by Other Counties in the Late Joseon Period through Use of the GIS Method

Digital map making method can contribute to restoring the late Joseon period’s elaborate local administrative map on the basis of literature materials such as a record on the total number of the late Joseon’s houses and population called ‘Hogu-chongsu’. The restoration of the late Joseon’s local administrative map also visually shows us highly accurate and detailed information on territories of a county surrounded by other counties called ‘Wolgyeongji’ in that period. The visual restoration of the Joseon local administrative units through digital map making method unearthed the existing theory that Joseon’s Wolgyeongji completely disappeared in the year of 1906 is wrong. In reality, through this restoration work it is proved that some Wolgyeongji existed until the year of 1914 when the Japanese colonial government reorganized the local administrative units. Detailed information on the late Joseon’s Wolgyeongji was obtained by converting administrative boundary lines of the late Joseon period’s counties and townships into the form of digital historical geographic information layers. If the digital historical geographic information layers are accumulated through various research projects and the layers are shared among related scholars, study on areas which was not able to attempt by traditional method of reading existing literature materials will be available. The digitalized restoration of the late Joseon’s Wolgyeongji introduced in this article can be a meaningful example of new historical study methodology. The production of digital historical geographic map using geographic information system techniques should be accompanied by long-term and continuous financial supports by public research institutes.

Adoption the basis of spatial analysis and geographic information systems (GIS) techniques to development oil industry projects

It is recognized today that human lives the information age, which ischaracterized by the multiplicity of its data and the complexity of its aspects andthe most important thing is characterized by "information" that will determine theprogress of the people, the more able countries to devise ways to protect theinformation and how to make the best use of them whenever it is an indication ofits progress and its ability to face obstacles to development and the informationsources are diverse and interrelated up to the level of complexity that they can beanalyzed and dealt with the existence of developed computer systems, that storedand processed the information .And because maps are also considered sources ofinformation which use in management and project planning, and being animportant means of connecting ideas and planning them so it necessitated the needfor the emergence of advanced systems have the ability to draw and designschemes and production of digital maps. With possibility of linking information(metadata) with the real location on the Earth's surface, called the (spatial data).The emergence of these systems are scientific leap on the in geographic scienceespecially spatial data that has accumulated over the centuries and resulted in ahuge amount of data and information. These systems added a lot in the field ofbuilding spatial database which can updating and help in treating maps accuratelyand effectively combines the advantages of the two systems (information systemsand systems of digital maps), which was named "GIS" systems which electronic NO.10digital competent to enter, store and retrieve, analyze data . And connect themwith large areas of maps that can not be saved on security on the paper. The data issaved with maps in a coherent manner so as to facilitate the user to display the datawith maps and several methods as well as a calculation processing to extract theresults and reports in a few time and effort and use them in decision-making whichhelps to speed the study and analysis the information and support decision-makersin a number of important decisions concerning projects which requires accuracyand speed.

Application of legacy soil data in digital soil mapping for the elaboration of novel, countrywide maps of soil conditions

The main objective of the DOSoReMI.hu (Digital, Optimized, Soil Related Maps and Information in Hungary) project is to significantly extend the potential, how demands on spatial soil related information could be satisfied in Hungary. Although a great amount of soil information is available due to former mappings and surveys, there are more and more frequently emerging discrepancies between the available and the expected data. The gaps are planned to be filled with optimized digital soil mapping (DSM) products heavily based on legacy soil data, which still represent a valuable treasure of soil information at the present time. The paper presents three approaches for the application of Hungarian legacy soil data in object oriented digital soil mapping.

Development of a Digital Accident Hotspot Map for ADAS Applications Using Geospatial Methods in GIS

Digital maps have a large potential to support safety-related Advanced Driver Assistance Systems (ADAS) by providing detailed road and environment information. However, one critical attribute – road accident hotspot – is not available from existing digital maps, and is also difficult to derive from practical surveying. This paper provides a Geographical Information Systems (GIS)-based approach for the production of digital hotspot maps, based on a historical accident dataset and geospatial methods in a GIS. In this approach, firstly the Kernel Density Estimation (KDE) method was used to identify hotspot distribution; secondly the Percent Volume Contour (PVC) method was coupled with KDE to extract hotspot patterns; and finally the map layers of hotspot patterns were integrated with classical navigation maps. Following a description for geospatial hotspot production, the derivation of hotspot property data is also discussed. In order to prove this approach, a small-area case study was carried out in the City Centre of Nottingham. The presented results demonstrate that this approach is useful and effective for solving the hotspot creation problem for ADAS, but other future works will be required to improve data effectiveness.

ISO 19157 standard application in technological process of the production of digital topographic maps

Standardization in the field of geographical information related to the definition of the system of collection, preparation, storage, maintenance, presentation and sharing of geographic information. Quality information of available spatial data are vital in the process of selecting a dataset where data value is directly related to its quality. Users of spatial data can choose data from multiple datasets. Therefore. It is necessary to compare the quality of datasets and determine which best meet customer requirements. Digital topographic maps for its visuality, brevity and easy of use have a big advantage over other spatial datasets and is therefore fully justified request for the development of the system of determining, evaluating and impart their quality. The main objective of this paper is to describe the possibilities of application of ISO 19157 'Geographic information - Data quality' standard in technological process of the production of digital topographic maps.

INSPIRE Geology Data Model Implementation in Digital Geological Map Production in Portugal: A Preliminary Approach

This work describes the implementation of the INSPIRE Geology data model (INSPIRE GE) for digital geological map production at the Portuguese Laboratory of Energy and Geology (LNEG). The process of harmonising geological mapping data involves the restructuring of the LNEG’s current data model into the extended INSPIRE GE, which aims a more efficient, interoperable and harmonized management data structure. The methodology, which is compliant with the Portuguese geology requirements, was applied to the Rosario antiform, a geological structure located in the Iberian Pyrite Belt. Three maps were produced: (i) a geologic map representing the geological units organized according to their spatial distribution and age; (ii) a lithologic map representing the most important rock types; and (iii) an age map representing the lower boundary age of the geological units. This study improves current LNEG's data structuring and geological map production flow. It also shows that the INSPIRE GE implementation is feasible and that it constitutes the first step toward data harmonization and interoperability in LNEG geological mapping activities.

GIS-based production of digital soil map for Nigeria

Soil, a valuable natural resource can be said to play a part across the range of human existence and its knowledge is fundamental to its utilization and management. Soil maps provide a means of gaining understanding about the soil, but limitations in accuracy, revision and mode of presentation– relating to graphics or digits–of such maps seem to stimulate lack of soil data in many places. However, much of the human activity has been treated with significant uncertainties, and many environmental processes relating to soil are poorly understood. Digital soil mapping seems to hold a strong prospect for addressing these challenges, with an interesting flexibility for utilizing many recent technologies. The present study proposes a digital soil map for Nigeria, and other thematicmaps based on soil properties, using geographic information system (GIS) technology. Existing graphical soil maps are the primary data sources. Although, the study is specific to making improved soil data available for the study area, the results tend to support the assumption that significantprospects are held by digital soil mapping in enhancing the knowledge of soil and its provision for a range of human activities.Key words: Soil, Soil maps, Digital soil map, GIS, Soil Database, Soil thematic maps, Query.

Production of Digital Map for the Sources of Pollution in Nassiriya Marshes by Using “GIS”

Production of Digital Map for the Sources of Pollution in Nassiriya Marshes by Using “GIS”

Design and Implementation of Digital Map Products Contributing GIS Perspective based on Cloud Computing

In this paper, we describe an augmented reality system for defense technologies and present a novel approach to a Collaboration Interaction Model (CIM) combining context-aware and mobile augmented reality devices. This model is aware of a user's context through user-centric integration and inference of contextual information in geo- cloud space. Based on the user's context, the model filters the content relevant to the user and overlays the filtered content over the associated physical entities. In addition, CIM generates the community according to the relationship between the entities and enables a user to selectively share personalized content with other mobile users.

A current perspective on Australian woody vegetation maps and implications for small remnant patches

Digital map products are routinely used by land managers and policy makers for environmental decision-making. This paper assesses the ability of such products to detect woody vegetation, particularly remnant patches which serve as critical landscape structures. Comparisons are made between two map products (NCAS and a SPOT-based classification) and a high spatial resolution reference dataset, across contrasting landscapes. Spatial analysis and statistical association tests are used to determine the ability of these map products to produce accurate measurements of woody vegetation. It is demonstrated that landscape structure is fundamental in determining the fitness-for-use and function of the digital map products.