National Topographic Database Research Articles

Automated Avalanche Terrain Exposure Scale (ATES) mapping – local validation and optimization in western Canada

Abstract. The Avalanche Terrain Exposure Scale (ATES) is a system for classifying mountainous terrain based on the degree of exposure to avalanche hazard. The intent of ATES is to improve backcountry recreationist's ability to make informed risk management decisions by simplifying their terrain analysis. Access to ATES has been largely limited to manually generated maps in high-use areas due to the cost and time to generate ATES maps. Automated ATES (AutoATES) is a chain of geospatial models which provides a path towards developing ATES maps on large spatial scales for relatively minimal cost compared to manual maps. This research validates and localizes AutoATES using two ATES benchmark maps which are based on independent ATES maps from three field experts. We compare the performance of AutoATES in two study areas with unique snow climate and terrain characteristics: Connaught Creek in Glacier National Park, British Columbia, Canada, and Bow Summit in Banff National Park, Alberta, Canada. Our results show that AutoATES aligns with the ATES benchmark maps in 74.5 % of the Connaught Creek study area and 84.4 % of the Bow Summit study area. This is comparable to independently developed manual ATES maps which on average align with the ATES benchmark maps in 76.1 % of Connaught Creek and 84.8 % of Bow Summit. We also compare a variety of DEM types (lidar, stereo photogrammetry, Canadian National Topographic Database) and resolutions (5–26 m) in Connaught Creek to investigate how input data type affects AutoATES performance. Overall, we find that DEM resolution and type are not strong indicators of accuracy for AutoATES, with a map accuracy of 74.5 % ± 1 % for all DEMs. This research demonstrates the efficacy of AutoATES compared to expert manual ATES mapping methods and provides a platform for large-scale development of ATES maps to assist backcountry recreationists in making more informed avalanche risk management decisions.

Topographic Base Map Update in Nepal: Overview, Accomplishments and Way Forward

The latest series of topographic base map of Nepal were prepared by Survey Department of Nepal during 1992-2001 A.D and preparation of their digital database namely National Topographic Database started in 1999 A.D. Understanding the utmost need of updating these maps and database, the department started update process in a rapid pace from fiscal year 2075/76 B.S based on ZiYuan-3 Survey and Mapping (ZY-3) satellite images with 2.1 m panchromatic and 5.8 m multispectral spatial resolution. The overall update procedure includes satellite image processing, feature update, field verification, field data compilation, finalization, map and database approval from Mapping Technical Subcommittee and finally map reproduction. The technical aspects of this whole process is based on standard specification document namely “Specifications for 1:25000 and 1:50000 Topographic Base Maps”. First level of update and field verification of all grid sheets covering Nepal was completed by fiscal year 2078/79 and is now in the phase of approval by Mapping Technical Subcommittee and reproduction. At the end of 2079 B.S, around 250 number of sheets have been approved and are made available by the department. With the completion of this update series, there are further opportunities to produce thematic data/maps as well as administrative maps of smaller scales. Furthermore, with the availability of higher resolution images through LiDAR, UAV and other resources, the department has opportunities to work on large scale mapping in coming days.

MAINTENANCE AND UPDATE NATIONAL TOPOGRAPHIC DATA BASE IN HIGH FREQENCY USING MODERN PROCEDURES AND TECHNIQUES

Abstract. The state of Israel is a small country, in terms of area, with one the higher population growth rate among all the OECD countries. Hence, each year more than 50,000 housing units built and more than 1,500 km roads constructed in average, each year along the last decade.The Survey of Israel )SOI( is a National Mapping and Cadastral agency (NMCA) that holds the responsibility to update, maintain and disseminate the National Topographic Data Base (NTDB) to all of the governmental offices and municipalities, to utilize, plan and promote the construction of the public needs.Today, the reality is dynamic and the changes occurs every day, therefore, the users expect that the existing database will portray the current reality as possible. In order to address the user's requirements for rapid updating rate, the Survey of Israel promote a new and modern initiatives, including:Promote the cooperation and working relationship with the municipalities to rapidly update the streets, address and POI’s.Data Fusion from different governmental and municipalities data sources.Developing change detection techniques to update the buildings and roads layers.Developing new frameworks for the manual inspection and QA/QC procedures.Developing automatic tools to update the height component via high resolution DSM and DTM (50cm GSD).Disseminate quarterly the NTDB products to the users.Develop a modern processes management system for the update and QA workflowIn this article, we will demonstrate the initiatives and techniques that improved our NTDB updating rate to less than a year and a half in a national average.

Digital transformation in topographic databases

Abstract. The increasingly widespread implementation of databases with geographical component, as well as the impregnation of geolocation culture, is driving a transformation in the storage, management and exploitation of geospatial information. Real-world elements go from being modeled as mere geometric representations, with just cartographic purposes, to be features with their own entity. Unique identifiers and lifecycle management are assigned to these features, allowing interactions between feature instances from different databases, that is, facilitating digital transformation and, therefore, increasing exponentially the exploitation possibilities.In this regard, the National Geographic Institute of Spain (IGN, by its Spanish acronym) have implemented several processes in its National Topographic Database, such as the connection with the cadastral information, in order to take advantage of its updates and give feedback to improve cadastral data; or the link with the information, in addresses form, provided from different public administration, that is processed to geolocate features in the topographic database. Likewise, work is being done in order to implement new processes that allow linking with other data sets.These processes, in addition to reusing information produced by different public administrations, constitute an advance towards the objective of geospatial information databases continuous updating.

PRODUCING AND VISUALIZING A COUNTRY-WIDE 3D DATA REPOSITORY IN FINLAND

Abstract. The amount and the quality of 3D spatial data are growing constantly, but the data is collected and stored in a distributed fashion by various data collecting organizations. This may lead to problems regarding interoperability, usability and availability of the data. Traditionally, national spatial data infrastructures have focused on 2D data, but recently there has been great progress towards introducing also 3D spatial data in governmental services. This paper studies the process of creating a country-wide 3D data repository in Finland and visualizing it for the public by using an open source map application. The 3D spatial data is collected and stored into one national topographic database that provides information for the whole society. The data quality control process is executed with an automated data quality module as a part of the import process to the database. The 3D spatial data is served from the database for the visualization via 3D service and the visualization is piloted in the National Geoportal.

Harmonizing National Topographic Data Using an Automated Quality Validation Process

Harmonizing National Topographic Data Using an Automated Quality Validation Process

Method of Elaboration of Detailed Existing Land Use (ELU) Map of Poland

Method of Elaboration of Detailed Existing Land Use (ELU) Map of Poland

SEMI AUTOMATED LAND COVER LAYER UPDATING PROCESS UTILIZING SPECTRAL ANALYSIS AND GIS DATA FUSION

Abstract. Technological improvements made in recent years of mass data gathering and analyzing, influenced the traditional methods of updating and forming of the national topographic database. It has brought a significant increase in the number of use cases and detailed geo information demands. Processes which its purpose is to alternate traditional data collection methods developed in many National Mapping and Cadaster Agencies. There has been significant progress in semi-automated methodologies aiming to facilitate updating of a topographic national geodatabase. Implementation of those is expected to allow a considerable reduction of updating costs and operation times. Our previous activity has focused on building automatic extraction (Keinan, Zilberstein et al, 2015). Before semiautomatic updating method, it was common that interpreter identification has to be as detailed as possible to hold most reliable database eventually. When using semi-automatic updating methodologies, the ability to insert human insights based knowledge is limited. Therefore, our motivations were to reduce the created gap by allowing end-users to add their data inputs to the basic geometric database. In this article, we will present a simple Land cover database updating method which combines insights extracted from the analyzed image, and a given spatial data of vector layers. The main stages of the advanced practice are multispectral image segmentation and supervised classification together with given vector data geometric fusion while maintaining the principle of low shape editorial work to be done. All coding was done utilizing open source software components.

Fine scale population density data and its application in risk assessment

ABSTRACTPopulation density is one of the key parameters for assessing the magnitude of population exposed to risk, and the better quality data we have, the better the assessment of risk. The aim of this study is to elaborate a high-resolution spatially distributed population density grid, which estimates population at the commune scale with a reliability of over 90%. The novelty of the approach is population density estimation in a regular European grid, based on buildings vector data collected in the national topographic database. Using abductive reasoning in combination with statistics and spatial analysis, the authors extract approximate information about a population from the large-scale topographic data. Moreover, linking the obtained population data with the cadastral data – by unique building identifier – allows for regular, quick and census survey-independent updates of the population surface. A shortcoming of the approach is the issue of the possible existence of two houses per family, which leads to an overestimation of population. However, in the study area it affected only two of the total 14 communes by 7%–9%.

Redistribution population data across a regular spatial grid according to buildings characteristics

Abstract Population data are generally provided by state census organisations at the predefined census enumeration units. However, these datasets very are often required at userdefined spatial units that differ from the census output levels. A number of population estimation techniques have been developed to address these problems. This article is one of those attempts aimed at improving county level population estimates by using spatial disaggregation models with support of buildings characteristic, derived from national topographic database, and average area of a flat. The experimental gridded population surface was created for Opatów county, sparsely populated rural region located in Central Poland. The method relies on geolocation of population counts in buildings, taking into account the building volume and structural building type and then aggregation the people total in 1 km quadrilateral grid. The overall quality of population distribution surface expressed by the mean of RMSE equals 9 persons, and the MAE equals 0.01. We also discovered that nearly 20% of total county area is unpopulated and 80% of people lived on 33% of the county territory.

REINVENTING THE NATIONAL TOPOGRAPHIC DATABASE

The National Land Survey (NLS) has had a digital topographic database (TDB) since 1992. Many of its features are based on the Basic Map created by M. Kajamaa in 1947, mapping first completed in 1977. The basis for the renewal of the TDB begun by investigating the value of the TDB, a study made by the Aalto University in 2014 and a study on the new TDB system 2030 published by the Ministry of Agriculture in 2015. As a result of these studies the NLS set up a programme for creating a new National Topographic Database (NTDB) in beginning of 2015. First new version should be available in 2019. The new NTDB has following key features: 1) it is based on processes where data is naturally maintained, 2) it is quality managed, 3) it has persistent Ids, 4) it supports 3D, 4D, 5) it is based on standards. <br><br> The technical architecture is based on interoperable modules. A website for following the development of the NTDB can be accessed for more information: <a href="http://kmtk.maanmittauslaitos.fi/"target="_blank">http://kmtk.maanmittauslaitos.fi/</a>.

REINVENTING THE NATIONAL TOPOGRAPHIC DATABASE

Abstract. The National Land Survey (NLS) has had a digital topographic database (TDB) since 1992. Many of its features are based on the Basic Map created by M. Kajamaa in 1947, mapping first completed in 1977. The basis for the renewal of the TDB begun by investigating the value of the TDB, a study made by the Aalto University in 2014 and a study on the new TDB system 2030 published by the Ministry of Agriculture in 2015. As a result of these studies the NLS set up a programme for creating a new National Topographic Database (NTDB) in beginning of 2015. First new version should be available in 2019. The new NTDB has following key features: 1) it is based on processes where data is naturally maintained, 2) it is quality managed, 3) it has persistent Ids, 4) it supports 3D, 4D, 5) it is based on standards. The technical architecture is based on interoperable modules. A website for following the development of the NTDB can be accessed for more information: http://kmtk.maanmittauslaitos.fi/.

Series cartográficas y base de datos de información geográfica producidas en España

Las tareas de elaboración o actualización de la cartografía nacional de un país deben iniciarse con el análisis pormenorizado de las opciones disponibles, y aprovechar la experiencia y conocimientos adquiridos por otros productores en la elaboración de sus mapas, tanto en técnica como en estética. En el Instituto Geográfico Nacional se dispone de una amplia variedad de productos cartográficos básicos y derivados cubriendo una gran variedad de escalas y productos que van desde 1:25.000 hasta escalas muy pequeñas como 1:8.000.000. En algunas series se dispone de una dualidad entre la base de datos de Información Geográfica y la versión mapa o cartográfica de la misma. De esta forma, se conserva una resolución aproximadamente mitad en la base de datos, es decir BTN25 (Base Topográfica Nacional 1:25.000) tiene una resolución 1:10.000 (aproximadamente) como fuente principal de MTN25 (Mapa Topográfico Nacional), y BTN100 (Base Topográfica Nacional 1:100.000) con una resolución 1:100.000 que es el soporte fundamental del Mapa Provincial 1:200.000. Sin embargo, debido a los ciclos de vida de escalas pequeñas, por ejemplo 1:1.000.000, es necesario realizar en ellas actuaciones más frecuentes que en escalas grandes que deben ser aprovechadas en la medida de lo posible en estas escalas, aunque sea generalmente solo a nivel semántico.Revista Ciencias Espaciales, Volumen 8, Número 1 Primavera, 2015; 491-508

CREATION OF A HIGH-RESOLUTION PRODUCT CLC2006_BACKDATING BY A BACKWARD LOOK FROM THE DIGITAL LAND COVER MODEL DLM-DE2009 TO 2006 - A CONTRIBUTION TO THE GERMAN CORINE LAND COVER 2012 PROJECT WITHIN A BOTTOM-UP APPROACH

Abstract. For the update 2012 of CORINE Land Cover, in Germany a new approach has been developed in order to profit from the higher accuracies of the national topographic database. In agreement between the Federal Environment Agency (UBA) and the Federal Agency for Cartography and Geodesy (BKG), CLC2012 has been derived from an updated digital landscape model DLM-DE, which is based on the Official Topographical Cartographic Information System ATKIS of the land survey authorities. The DLM-DE 2009 created by the BKG served as the base for the update 2012 in the national and EU context, both under the responsibility of the BKG. In addition to the updated CLC2012, a second product, the layer "CLC_Change" (2006-2012) was also requested by the European Environment Agency. The objective of the project part of DLR-DFD was to contribute the primary change areas from 2006 to 2009 in the phase of method change using the refined 2009 geometry of the DLM-DE 2009 for a retrospective view back to 2006. A semiautomatic approach was developed for this task, with an important role of AWiFS time series data of 2005 / 2006 in the context of separation between grassland – arable land. Other valuable datasets for the project were already available GMES land monitoring products of 2006 like the soil sealing layer 2006. The paper describes the developed method and discusses exemplary results of the CORINE backdating project part.

THE IRANIAN NATIONAL GEODATA REVISION STRATEGY AND REALIZATION BASED ON GEODATABASE

Abstract. In recent years, using of spatial database for storing and managing spatial data has become a hot topic in the field of GIS. Accordingly National Cartographic Center of Iran (NCC) produces – from time to time – some spatial data which is usually included in some databases. One of the NCC major projects was designing National Topographic Database (NTDB). NCC decided to create National Topographic Database of the entire country-based on 1:25000 coverage maps. The standard of NTDB was published in 1994 and its database was created at the same time. In NTDB geometric data was stored in MicroStation design format (DGN) which each feature has a link to its attribute data (stored in Microsoft Access file). Also NTDB file was produced in a sheet-wise mode and then stored in a file-based style. Besides map compilation, revision of existing maps has already been started. Key problems of NCC are revision strategy, NTDB file-based style storage and operator challenges (NCC operators are almost preferred to edit and revise geometry data in CAD environments). A GeoDatabase solution for national Geodata, based on NTDB map files and operators' revision preferences, is introduced and released herein. The proposed solution extends the traditional methods to have a seamless spatial database which it can be revised in CAD and GIS environment, simultaneously. The proposed system is the common data framework to create a central data repository for spatial data storage and management.

An Assessment of the Altimetric Information Derived from Spaceborne SAR (RADARSAT-1, SRTM3) and Optical (ASTER) Data for Cartographic Application in the Amazon Region.

Difficulties in acquiring a complete aerial photography coverage on a regular basis in the Brazilian Amazon due to adverse environmental conditions affect the quality of the national topographic database. As a consequence, topographic information is still poor, and when available needs to be up-dated or re-mapped. In this research, altimetric information derived from RADARSAT-1 (Fine and Standard modes), SRTM3 (3 arc-seconds) and ASTER (band 3N-3B) was evaluated for topographic mapping in two sites located in the region: Serra dos Carajás (mountainous relief) and Tapajós National Forest (flat terrain). The quality of the information produced from Digital Elevation Models (DEMs) was evaluated regarding field altimetric measurements. Precise topographic field information acquired from Differential Global Positioning System (DGPS) was used as Ground Control Points (GCPs) for the modeling of the stereoscopic DEMs (RADARSAT-1, ASTER) and as Independent Check Points (ICPs) for the calculation of accuracies of the products. The accuracies were estimated by comparison of the DEMs values and real elevation values given by ICPs. The analysis was performed following two approaches: (1) the use of Root Mean Square Error (RMSE) for the overall classification of the DEMs considering the Brazilian Map Accuracy Standards (PEC) limits and, (2) calculations of trend analysis and accuracy based on a methodology that takes into account computed discrepancies and standard deviations. The investigation has shown that for flat relief, the altimetric accuracy of SRTM3 and Fine RADARSAT-1 DEMs fulfilled the PEC requirements for 1:100,000 A Class Map. However, for mountainous terrain, only the altimetry of SRTM3 and ASTER fulfilled these requirements. In addition, the performance of ASTER was slightly superior to SRTM3. However it is important to consider the difficulties in the acquisition of good stereo-pairs with optical data in the Amazon and the additional cost (GCPs) to produce ASTER DEMs. Despite showing systematic errors, the findings justify the usage of SRTM3 as a primary elevation source for semi-detailed topographic mapping in the region. It is suggested a combination of altimetry derived for SRTM3 and planimetry extracted from high-resolution SAR (ALOS/PALSAR, TerraSAR-X, RADARSAT-2) or if available optical data for semi-detailed topographic mapping programs in the Brazilian Amazon, where terrain information is seldom available or presents low quality.

Satellite land cover mapping of Canada's forests

Canada is a large country, approaching a billion hectares in size. With over 400 million hectares (Mha) of forested land that contribute $32.6 billion (Can$37 billion) to the trade balance, Canada is determined to be a good steward of this renewable resource. Ensuring effective resource management requires current and reliable forest information. In support of national and international reporting requirements, the Canadian Forest Service (http://www.cfs.nrcan.gc.ca), in partnershipwith the Canadian Space Agency (http://www.space.gc.ca/asc/ index.html), is using space-based technologies to monitor the country’s forests through an initiative called Earth Observation for Sustainable Development of forests (EOSD) (http://eosd.cfs.nrcan.gc.ca). EOSD is an important data source in the new plot-based National Forest Inventory (NFI) (http://nfi.cfs.nrcan.gc.ca) and the National Forest Carbon Accounting Framework (http://carbon.cfs.nrcan.gc.ca). TheNational Forest Information System (NFIS) (http://nfis.org) will be used to integrate and synthesize applicable data and products. In this communication we summarize the EOSD Land Cover program and provide interested readers links to websites for additional detail. The initiative’s overall goal is a land covermap of Canada’s forested ecozones based on Landsat satellite data.1 A goal for 2006 is to complete a land cover map representing circa 2000 forested area conditions. Using single scenes of Landsat data to produce land cover information is not uncommon. However, combining several, or even hundreds, of scenes to develop a large-area land cover map is relatively uncommon. To encompass Canada’s forested ecozones, approximately 800Mha must be mapped, requiring over 475 images. The EOSD classification scheme applied to the Landsat data merges the numerous spectral clusters found with a K-means hyperclustering algorithm into a smaller number of meaningful groupings labeled to conform with a closed 21-class legend. The EOSD legend was developed to fit with NFI’s hierarchical classification. Additional information on the methods and legend are available online (http://eosd.cfs.nrcan.gc.ca/cover/ legend e.html). EOSD land cover products—based on the National Topographic System (NTS) map sheet framework of the National Topographic Database—are available for download on a 1:250,000 NTS map sheet basis. Each map sheet represents an area of approximately 14,850km2. The products are available in a Paletted GeoTiff format, with a disabled tiff world file, and Federal Geographic Data Committee-compliant metadata. Final products are resampled to a 25m spatial resolution. As a single tile may be composed of a number of images, ESRI shape files provide source image information and actual mosaic lines. To date, approximately 225 of the 610 NTS sheets that cover Canada’s forested ecozones are complete and availablefor download. While under final developments, data may be accessed through the NFISwebsite, and via the SAFORAHportal (System of Agents for Forest Observation Research with Automation Hierarchies) accessible from the Land Cover Implementation area of the EOSD website (http://eosd.cfs.nrcan.gc.ca/cover/ index e.html). A protocol for addressing the accuracy of the national EOSD product based upon a stratified random sample has been proposed and is being tested.3 By mapping the forested areas of Canada, EOSD will contribute toward meeting its national and international reporting requirements related to climate change and sustainable forest management. This task will require the support and concerted effort of many partners to complete. Cooperation and communication both within and between various levels of government provides an opportunity to share resources and work towards common objectives. Products

Automatic road change detection and GIS updating from high spatial remotely-sensed imagery

This paper presents a framework for road network change detection in order to update the Canadian National Topographic DataBase (NTDB). The methodology has been developed on the basis of road extraction from IRS-pan images (with a 5.8 m spatial resolution) by using a wavelet approach. The feature matching and conflation techniques are used to road change detection and updating. Elementary experiments have showed that the proposed framework could be used for developing an operational road database updating system.

RADARSAT-2 stereoscopy and polarimetry for 3D mapping

Based on research studies over the last 20 years with different satellite synthetic aperture radar (SAR) sensors, a short review of elevation modelling, digital terrain model (DTM) generation, and three-dimensional (3D) cartographic feature extraction using stereoscopic and polarimetric methods is given. The results of these research studies were used to evaluate the potential of RADARSAT-2 and three of its new characteristics for mapping applications: ultra-fine mode, better orbit knowledge, and polarimetry. Stereoscopy and polarimetry can be used to improve the DTM generation when compared with RADARSAT-1. In the best case, 5-m accuracy (68% confidence level) can be expected in moderate topography. Three-dimensional feature extraction using stereoscopic ultra-fine mode data can meet the National Topographic Database standard (better than 10-m positioning, 90% confidence level). Polarimetry with two images from crossing orbits (quasi-orthogonal in the north) can also be used for DTM generation depending on the topographic and land-cover conditions. The major drawback is the complex scattering models over forest or agricultural lands with C-band SAR data. In short term, the method can be applied in bare surfaces. All these forecast improvements should be confirmed with real data.

A New Geographic Information Framework for Great Britain

The knowledge economy, enabled by easier and faster electronic processing, has brought geography to the fore in the minds of a wide variety of users, from politicians, government, and the commercial sector and to the citizen. This appears to be a make or break moment for national mapping agencies involved in mapping and geography. Geographic information, more than mapping, is now in demand. This information needs to fulfill specific roles and needs for the people who use it, often by integrating with all kinds of existing information, such as client inventories, property information, and consumer services for “where is my nearest?” The Ordnance Survey (OS) embarked on a program to redevelop the existing National Topographic Database in the late 1990s and this is now being transformed with the release of the OS MasterMap based on the Digital National Framework, which is a conceptual model and standards for integrating geographic information. There are several parallels with The National Map being