Production Of Topographic Maps Research Articles

UAV based Topographical mapping and accuracy assessment of Orthophoto using GCP

For smaller locations, the traditional aerial photogrammetry techniques utilizing helicopters or airplanes are expensive and difficult. A new competitive strategy is necessary for quick spatial data collecting at a low cost and in a short amount of time for a developing nation like Nepal where geospatial data is in great demand. Currently, the UAV (Unmanned Aerial Vehicle) has become an alternative for different engineering applications, especially in surveying, one of these applications is for making a topographical map. This study demonstrates how this can be achieved using one of the evolving remote sensing technologies, Unmanned Aerial Vehicles (UAVs). Besides, this study also involves image processing and topographic map production using Pix4D and GIS environments. For this study,DJI Mavic Air-2 Advanced quadcopter collected about 207 images at a flying height of 80 m above the Kathmandu University area. An orthophoto of 2.4 cm GSD covering 127064 sq. Meter of area was produced. The RMSE of 5.37 cm in X and 3.32 cm in Y and 4.05cm in Z was achieved With appropriate checkpoints.The measurements in the orthophoto replicated the field measurements to an error of less than 0.5% of the actual dimensions.

Automatic Extraction and Placement of Building Point Vector Data from Aerial Imagery for the 1: 25 000 Topographic Map Production

Automatic Extraction and Placement of Building Point Vector Data from Aerial Imagery for the 1: 25 000 Topographic Map Production

Methods and experiments for collecting information and constructing models of bottom-layer contours in paddy fields

To realize intelligent, accurate, and efficient operation of paddy field machinery that drive the paddy field bottom-layer below the tillage layer, the paddy field bottom-layer contours must be known. However, surface measurement systems cannot directly measure paddy field bottom-layer contours, making it difficult to collect and digitally model. In this study, an agricultural machine without a shock-absorbing suspension on the rear axle was used as an acquisition platform. Combined with a global navigation satellite system (GNSS) and attitude and heading reference system (AHRS) positional measurement technology, a 1/4 single-degree-of-freedom model of the vehicle body collected bottom-layer contour information of paddy fields. Based on the Delaunay triangulation principle, a digital model of the bottom-layer contour was established based on the collected bottom-layer contour point set. Subsequently, the ray method, used to extract specific triangles containing predicted points, and the point-plane intersection principle, used to estimate the elevation of arbitrary points in the whole area of bottom-layer, were used. Straight line contour acquisition on concrete road slope, contour acquisition on the bottom-layer surface of a paddy field, and elevation estimation of arbitrary points in the whole area were performed as verification tests. The results indicate that, in the x, y, and z axes, the average errors of the cement slope profile collection were 0.86, 0.68, and 0.55 cm, respectively, with standard errors of 0.99, 0.78, and 0.67 cm, respectively. Further, the average errors of the bottom-layer contour collection of the paddy field were 1.57, 0.91, and 1.25 cm, respectively, with standard errors of 1.87, 1.01, and 1.55 cm, respectively. The average error of elevation estimation at any point in the whole area was 1.25 cm with a standard error of 1.49 cm. The presented method can continuously and accurately acquire bottom-layer contour information, construct a digital model of the bottom-layer contour, accurately predict the location coordinates of any point within the field, and provide a reference for the walking environment of intelligent farming machines and measurement methods for the production of high-precision topographic maps.

An Automatic Derivation Method for Creation of Complex Map Symbols in a Topographic Map

The topographic map plays a very important role in economic construction. In the process of drawing topographic maps, different symbols represent different ground objects, but the symbols representing complex ground objects are often complicated and difficult to create. Moreover, the creation process of complex map symbols can seriously affect the efficiency of topographic map production. Therefore, this paper proposes an automatic derivation method for creation of complex map symbols in a topographic map. The data used are new geographic entity data under the background of Chinese new fundamental surveying and mapping situation. Firstly, four derivation modes of complex map symbols are summarized, including feature-point mode, centroid mode, feature-line mode, and parallel-line mode; then, using the four modes singly or in combination, the complex map symbols of the topographic map are directly derived from the geographic entity data based on programming, and the topographic map cartographic result is obtained automatically. Finally, some topographic maps for Shanxi Province, China, is used for the validation of the creation of map symbols. The experimental results show that the proposed method can automatically derive the complex map symbols of the topographic map, greatly improving production efficiency and obtaining a good visualization effect. The proposed method is a new approach for a new situation and realizes the transformation and upgrading of fundamental surveying and mapping achievements.

Developing a procedure to produce large-scale topographic maps of open-pit mines using rotary wing unmanned aerial vehicles

Recently, the rapid development of unmanned aerial vehicle (UAV) has led to increasingly popular applications of this technology in the field of surveying and mapping. This article presents the result of developing a procedure to produce large-scale topographic maps for open-pit mines in Vietnam in which unmanned aerial vehicles (UAV) are used to collect data. With the goal of creating a procedure that ensures accuracy, safety, and efficiency for the production of topographic maps, the theories and official regulations for measuring and editing topographic maps in general and in mines in particular, as well as using drones in Vietnam have been applied. The procedure is specifically developed for the vertical takeoff and landing (rotary) UAVs. Experiments consisting of the flight altitude calculation, determining the appropriate take-off position, and image acquisition were conducted at two open-pit mines, namely Dong Da Mai coal mine and Long Son quarry to verify the procedure. The digital surface models (DSM) and orthophotos are generated from the acquired photos, georeferenced to the VN-2000 coordinate system using ground control points (GCP), and evaluated with checkpoints. In addition, the experiment included the investigation of the various combination of GCP networks to determine the optimal GCP number for each case. Experimental results show that the procedure is logical, correct, straightforward, safe, and effective. UAV resulted products, such as orthophotos, DSM, and topographic maps were accurate and met the requirements of all the national standards.

Detecting topographic database changes and updating 1:25.000 scale maps population class by changes

ABSTRACT For rapid production of spatial data and topographic maps, map production systems should be transformed into a dynamic structure. Topographic map production system in Turkey, cartographic operations for each map are repeated in the same way, regardless of the amount of data updated in the geographic database. The implementation of similar actions on maps with very few changes is not time and cost effective. In this study, changes were determined by comparing the current and previous data from TOPODB and the resulting changes were integrated into the population class of 1:25.000 scale topographic maps in a third less time.

Suitability of Open Street Map (OSM) for 1:50,000 Topographic Map

Open-source data is open for anyone and everyone for access, modification, reuse, and sharing for particular application. Open-source data is compiled from various sources using public user collaboration. Open street map is one of open-source vector provider. The suitability study of the use of open-source data for the production of topographic maps of various scales is important as a new approach. The importance of the feasibility study of the use of open-source data can help improve the efficiency of the production of mapping products. Many methods of producing topographic maps of various scales use various state -of -the -art technologies for fast and efficient map production. The objective of the study is to check the planimetric accuracy and feature geometry of open-source vector datasets. Conventional methodologies for the production of multi -scale topographic maps are time consuming and involve high costs. Therefore, open-source data is an alternative source for the production of topographic maps of various scales. This data source shows the potential use for generation of multiple data layers such as roads, points, places, waterways, railways, natural, buildings and land use. The planimetric accuracy of open-source vector data is ranging from 2-5 m. The overlay analysis between reference dataset and open-source data show the similarity geometry for 1:50,000 map scale. This method shows a high level of suitability for the efficient updating of topographic data and the production of topographic maps for 1:50,000 map scale.

Smartphone Distance Measurement Application Using Image Processing Methods

This study introduces a new method to measure the distance of an object from an observer location using image processing methods by utilizing smartphone camera technology. This study involved the development of an application for distance measurement where users can measure the distance of an object using their smartphone. For this study, the basic image processing method was used to determine the proportional width of the object marker which then be used to derive the distance to the object. The application has been successfully developed where the distance from the smartphone to the object marker can be obtained with an accuracy of +/-0.05 meters for distances of less than 3 meters. However, further research needs to be conducted to enhance the application modules for better distance measurement accuracy. This study indicated that the development of smartphone applications using image processing methods has great potential to be applied in various distance measurement applications in the near future, especially in data collection activities for the production of small-scale topographic maps or for land surveying applications.

무인항공기를 활용한 농촌 지역자원의 물리적 환경변화 분석연구 - 홍성군 갈산면 지역자원을 중심으로 -

Recently, the use of unmanned aerial vehicles (UAVs) is increasing in the field of land information acquisition and terrain exploration through high-altitude aerial photography. High-altitude aerial photography is suitable for large-scale geographic information collection, but has the disadvantage that it is difficult to accurately collect small-scale geographic information. Therefore, this study used low-altitude UAV to monitor changes in small rural spaces around rural resources, and the results are as follows. First, the low-altitude aerial imagery had a very high spatial resolution, so it was effective in reading and analyzing topographic features. Second, an area with a large number of aerial images and a complex topography had a large amount of point clouds to be extracted, and the number of point clouds affects the three-dimensional quality of rural space. Third, 3D mapping technology using point cloud is effective for monitoring rural space and rural resources because it enables observation and comparison of parts that cannot be read from general aerial images. In this study, the possibility of rural space analysis of low-altitude UAV was verified through aerial photography and analysis, and the effect of 3D mapping on rural space monitoring was visually analyzed. If data acquired by low-altitude UAV are used in various forms such as GIS analysis and topographic map production it is expected to be used as basic data for rural planning to maintain and preserve the rural environment.

A Key Numbering Solution for 1:25,000 Topographic Maps

ABSTRACT The automatic placement of map labels in graphically dense areas is one of the challenging problems in modern cartography. Creation of the annotation layer still requires human interaction and automation of this process has significant potential for reducing the time required for map production. In this paper, we present a software technique for the key numbering process that we applied to approximately 20% of the 1:25,000 topographic maps of Turkey. The results were compared with those obtained from the traditional manual method. The consistency of the results is above 90%, achieving time savings of 70%, which indicates an substantial improvement in topographic map production.

Online digital archive of aerial photographs (1935–1941) of Ethiopia

AbstractThe archive of aerial photographs, dating 1935–1941 and covering parts of north and central of Ethiopia, is one of the few archives with pre‐1960 remotely sensed data in Africa. It allows adding 30 years of time depth for geographical studies, in contrast to the commonly known oldest imagery dating to 1964, sometimes 1958. These photographs were originally acquired by the Italian military forces, to obtain raw material for warfare purposes and the production of topographic maps. To make the archive accessible, it has been scanned and georeferenced. Procedures used in georeferencing and digitally archiving are detailed in this paper, as well as our experiences with orthorectification and use of the photosets in scientific research. This data set of aerial photographs of Ethiopia in the 1930s has been availed to the wider scientific community through the Pangaea website http://doi.org/10.1594/PANGAEA.920077 (Nyssen et al., 2020, Aerial photographs of Ethiopia 1935–1941) Additionally, a web interface (http://www.ethiopia1935.ugent.be/) allows scientists visualizing the location of relocated photographs, and to select and freely order scenes of interest.

La necesidad de un mapa para la provincia La institucionalización del conocimiento cartográfico y catastral durante el siglo XIX en la Provincia de Buenos Aires

Este artículo busca poner en valor la actividad del Departamento Topográfico como productor y recopilador del saber territorial durante el siglo XIX en la provincia de Buenos Aires. Buscamos demostrar que, desde su establecimiento en 1824 y con diferentes nombres, el Departamento pasa de ser una institución central para la conformación del Estado, concentrando múltiples funciones, a ser una sección técnica dentro una estructura más amplia como fue el Ministerio de Obras Públicas de la Provincia de Buenos Aires. Mediante el análisis de esta repartición, buscamos demostrar la íntima relación que existía entre la producción de mapas topográficos y catastro durante el siglo XIX, cuando los medios y las técnicas disponibles obligaron a la unión de esfuerzos. Ello fue posible gracias a la estandarización de los trabajos, a la redacción de instrucciones, en suma, a una normalización de las prácticas que tiene su origen en el estado rivadaviano y se prolonga durante todo el siglo.

Unmanned Aerial Vehicle-based Digital Topographic Map Production and Flood Flow Analysis

Unmanned Aerial Vehicle-based Digital Topographic Map Production and Flood Flow Analysis

TOPOGRAPHIC MAPPING OF THE MOON IN THE 21ST CENTURY: FROM HECTOMETER TO MILLIMETER SCALES

Abstract. This paper presents a review of lunar topographic mapping in the two decades of the 21st century, including descriptions of lunar exploration missions, relevant payloads and data, mapping techniques, as well as global and regional mapping products. Various lunar photogrammetric mapping techniques such as construction of geometric models of lunar orbital images, block adjustments, shape from shading, co-registration of lunar orbital image and elevation data have been developed to process lunar orbital images and generate mapping products. Global topographic products at hectometer and decameter scales have been produced from orbital images and/or laser altimeter data. Regional topographic maps of the landing sites and other sites of interest have been generated at meter-scale using the sub-meter to meter resolution orbital images. Detailed local topographic products at centimeter to millimeter scales of the landing sites and rover traverse areas have been produced using descent images acquired by the landers and stereo images acquired by the rovers. These multiple-scale topographic mapping products have been extensively used to support various science applications, as well as engineering applications such as surface operations of the rovers.

The camera and the geomorphologist

The methods we use to produce geomorphic data are deeply interwoven with the geomorphic questions we choose to ask, and with the geomorphic theories we construct. Authors have described major changes in the history of geomorphology in terms of theoretical shifts and/or social-cultural changes, but it seems clear that shifts in methodological practices also can produce deep changes in geomorphology as a whole. The camera has had a long, illustrious, and complex history as a geomorphic tool, and as such is useful for assessing larger geomorphological concerns and themes. The camera is also a symbol of the ongoing revolution in geomorphology from a data-poor to a data-rich subject; this revolution is built upon many methodological changes, and it has had many side-effects. The interrelated history of cameras and fluvial geomorphology provides an illuminating case study in past and present changes in the geomorphic sciences. Some past geomorphic practices, such as using photos as descriptive evidence for verifying geomorphic theory, remain as important approaches today. Other camera-based practices have dwindled to some degree, such as the production of large-area topographic maps through traditional aerial-photogrammetry, which have been overtaken by alternative methods such as Lidar and interferometric radar. And newer camera-based techniques, such as structure from motion photogrammetry, are at the heart of the recent democratization of geomorphic data. As the modern data revolution progresses, it is important to ask questions such as “who has been part of the data revolution, and what have been their motivations?” and “have winners and losers been produced as part of the data revolution?” Not all effects of the data revolution have been completely positive; many geomorphologists feel overwhelmed by big data expectations and methodological concerns. From a philosophy of science perspective, the moves toward population-like geomorphic data have strained “normal” inductive inference procedures, and recent research has brought to light inferential alternatives such as advanced data mining and the hypothetico-deductive approach. Even so, most current analytical techniques appear to be lagging behind the newly-introduced big data, producing “new wine in old bottles”: new data for old analyses. Beyond pure geomorphic research, the camera and its derivatives are also part of profound shifts in educational and outreach expectations and practices. Clearly, the data revolution in geomorphology is still in its infancy, and much of that revolution has been wrought by the humble camera.

Proposta de metodologia para generalização cartográfica para mapeamento topográfico de áreas urbanas

La generalización cartográfica consiste en la preservación de las características de los elementos representados en una carta topográfica cuando su escala es reducida, de forma que la información pueda ser comprendida fácilmente por el usuario; en otras palabras, es un proceso de adaptación cuantitativo y cualitativo. La elabora- ción de cartas topográficas en diferentes escalas a través de generalización es reali- zada en varios países, haciendo más eficiente la producción y actualización del mapeo base. Dentro del contexto de generalización, este trabajo tiene como objetivo definir una metodología para la representación de edificaciones, límites de propie- dades y vías en escala 1:5.000, por generalización de cartas topográficas en escala 1:2.000. Esto fue realizado por medio de un análisis de las clases de los elementos presentes en la escala reducida, así como de la identificación de los problemas de representación, y de la definición y aplicación de los operadores de generalización cartográfica. Los resultados se alcanzaron utilizando el software ArcMap y los operadores de generalización: eliminación, simplificación y amalgamado, de acuer- do con cada problema de representación detectado. La generalización manual es un proceso subjetivo e intuitivo, por esta razón el resultado depende de los operadores de generalización y del grado de aplicación de los mismos, siendo estos factores consecuencia de las decisiones tomadas por el cartógrafo.

Accuracy assessment using different UAV image overlaps

Unmanned aerial vehicle images are considered an important tool in close-range photogrammetry for topographic map production and 3D modelling using structure-from-motion approaches. The effect of overlap percentage in vertical and integrated vertical and oblique images on accuracy is evaluated. Analysis showed that the accuracy of the photogrammetric products (e.g., digital surface model and orthoimagery) is increased with the increased overlap percentage in vertical images. The accuracy is better when oblique images are integrated into vertical images than when only vertical images are used even with the same number of images. Furthermore, the building façade is constructed, but the building suffers from noise. Increasing the number of integrated vertical and oblique images improves the accuracy of the products and provides considerable precision to 3D modelling. This study showed that the improved result is due to the increased redundancy in image matching and optimised parameters of interior orientation through self-calibration. The images are processed using Pix4D software.

Towards sustainable topographic mapping

Abstract. “Everything happens somewhere”, a popular phrase nowadays to emphasize the importance of good and reliable geographic information. National Spatial Data Infrastructures (NSDI) are popping up in many countries in the world as governments realize that a wealth of geo-data is produced, but that this data is not known or available to other organizations. An NSDI channels this information to the users. Availability of geo-information and efficiency in the production are the key drivers.Another big driver is the Sustainable Development Goals (SDG). To monitor the development of the progress of the SDG’s, a wealth of statistical information on economic, social and environmental phenomena is collected. All this data is referring to a specific place on earth. Therefore, good and reliable geo-information is critical for the development of the SDG’s of a country.Topographic maps describe the land that belongs to a country, its sovereign territory. But they are also used for orientation, for the defense of your country, as a time stamp of how your country looks like at a specific moment in time, and many other applications. Topographic maps are therefore an indispensable asset in an NSDI. They link thematic information of any kind to a specific location. It is this location that is the linking pin to many other sources of information.However, the reality of today is that many developing countries lack any up-to-date topographic maps. They have to rely on old maps, often produced more than 40 years ago; there is no money or, more importantly, no expertise available to update these maps. In other cases, they rely on online mapping sources like Google Maps, OpenStreetMap, etc. These are good, but consistency in quality is an issue.Some countries already have topographic maps, but these date back from colonial times, and were not updated ever since. Others produce specific map series but are depending on the availability of reliable source material, like aerial photos and satellite imagery, purchased by the government. Or in some cases they have to organize partnerships with other national institutions to be able to purchase the necessary photo’s or imagery. Regular maintenance of these maps is then often a real issue.In general, every country has its own development stage, but when it comes to topographic mapping, it can be classified into 4 stages:1. No topographic map available2. Out of date analogue topographic map available3. Digital, but out of date topographic map available4. Digital and recent topographic map availableThis paper describes these different stages of official map production that exist in countries around the world, each stage with its own characteristics, timeframe, roadmap and needs. It is not focusing on the technology but concentrates on the institutional aspects of topographic map production and what could be done to develop the production processes into sustainable work procedures.

Comparison of Two Polynomial Geoid Models of GNSS/Leveling Geoid Development for Orthometric Heights in FCT, Abuja

Ellipsoidal heights from GNSS require geoid model for conversion to orthometric height. The geoid model could be global, regional or local. The lack of national geoid model in Nigeria makes development of local geoid very critical to local applications in place of integrated global geoid models. This study compares two polynomial geoid models for terrain representation in the FCT, Abuja. Nine coefficients were used to model the FCT surface for geoid interpolation and orthometric height modeling. Model A involved the use of the 2-D (x, y) positions while model B used 3-D (x, y, ) where = ( – ) the difference in average ellipsoidal height ( ) and each point’s ellipsoidal height ( ). The term is based on the assumption that the geoid varies with topography and may hence possibly lead to some improvements in accuracy of orthometric height determination. DGPS observations were carried out to determine ellipsoid heights. Least squares adjustment was performed to compute the coefficients of the models. Model A achieved standard deviation of σ = 11 cm while Model B achieved σ = 13cm. Though, Model B has a term that included highly accurate ellipsoidal height differences ( ), it has not resulted into any accuracy improvement over the model A. Model A based on 2-D positions is hence the better of the two models. The t-test and hypothesis test at 95% confidence limit, however, showed that the two models did not differ significantly. Model A having lower standard deviation is recommended with GNSS determined ellipsoidal heights to determine orthometric heights within the FCT. This becomes an easy alternative to conventional spirit leveling technique for production of topographical maps, cadastral surveys, and engineering/environmental applications.

Nineteenth-Century Ottoman Topographic Mapping of the Balkans

ABSTRACTIn this paper, we analyse the nineteenth-century Ottoman cartographic activities and map production in the European parts of their empire. Already weakened by centuries of wars, the Ottoman Empire, in its late phase of territorial regression, had to find a way to compensate the absence of its own mapping activities. That especially came to the fore when the interest of the Ottoman administration in the mapping of the European part of its empire was stimulated by the requirements of its military operations during the Russo-Turkish Wars, as well as by the consequent geopolitical changes that occurred with the independence of certain parts of the empire (Greece, Wallachia and Moldavia, Serbia, Montenegro, and Bulgaria). The solution was found in translating European, mostly Austrian and Russian, topographic maps into the Ottoman Turkish language. This practice resulted in the production of topographic maps that met the military needs of the Ottoman army, but also in a gradual transfer of the Western science and cartographic practice to the Ottoman culture.