Digital Photogrammetric Workstation Research Articles

IMPROVED METHODOLOGIES FOR THE REVISION OF A TRADITIONAL TOPOGRAPHIC MAP SERIES

Abstract. Conventional topographic maps are still important for many applications, such as land planning, but require frequent updates, which involve high costs and are not easy to accomplish. There are however many advances in Photogrammetry that are not always exploited to their full potential in a real map production environment. The traditional process involves aerial triangulation with ground control points, stereo restitution in digital photogrammetric workstations and field completion. The process is very time-consuming and expensive and map update is many times not done with the frequency required by users.This paper describes the implementation of an improved methodology for very frequent revision of the Portuguese map series of scale 1:25,000 making use of conventional digital aerial photography, which now is acquired on a regular basis for all the country. Vector features are digitised in monoscopic mode, in a GIS environment, over true orthophotos. These can be produced in a largely automated manner, using direct georeferencing data, and with minimal ground control only for vertical adjustments. Revision time and cost can be significantly reduced, keeping acceptable accuracy standards. That will satisfy the users that require the traditional high standards of the topographic map series for land panning.Additionally, for the task of field data collection of information that cannot be obtained from aerial photographs, a method is being applied to make use of video data collected in the field along roads with action cameras, with GPS. Operators can confirm or identify attributes of objects along, or near roads, such as power lines.

An Optimal Image–Selection Algorithm for Large-Scale Stereoscopic Mapping of UAV Images

Recently, the mapping industry has been focusing on the possibility of large-scale mapping from unmanned aerial vehicles (UAVs) owing to advantages such as easy operation and cost reduction. In order to produce large-scale maps from UAV images, it is important to obtain precise orientation parameters as well as analyzing the sharpness of they themselves measured through image analysis. For this, various techniques have been developed and are included in most of the commercial UAV image processing software. For mapping, it is equally important to select images that can cover a region of interest (ROI) with the fewest possible images. Otherwise, to map the ROI, one may have to handle too many images, and commercial software does not provide information needed to select images, nor does it explicitly explain how to select images for mapping. For these reasons, stereo mapping of UAV images in particular is time consuming and costly. In order to solve these problems, this study proposes a method to select images intelligently. We can select a minimum number of image pairs to cover the ROI with the fewest possible images. We can also select optimal image pairs to cover the ROI with the most accurate stereo pairs. We group images by strips and generate the initial image pairs. We then apply an intelligent scheme to iteratively select optimal image pairs from the start to the end of an image strip. According to the results of the experiment, the number of images selected is greatly reduced by applying the proposed optimal image–composition algorithm. The selected image pairs produce a dense 3D point cloud over the ROI without any holes. For stereoscopic plotting, the selected image pairs were map the ROI successfully on a digital photogrammetric workstation (DPW) and a digital map covering the ROI is generated. The proposed method should contribute to time and cost reductions in UAV mapping.

GIS-Based Estimation of Potential Solar Energy on Flat Roofs in Maadi, Cairo, using True Ortho World View Image and Digital Surface Model

This research is concerned with the use of remotely sensed data in the estimation of the solar energy potentiality of the flat roofs in El Maadi District, Cairo. A solar radiation model was applied using a digital surface model (DSM) generated from two Worldview stereo satellite images using the digital photogrammetric workstation (Leica Photogrammetric Suite) LPS. The procedures included applying orientation with Rational Polynomial Coefficients (RPC) with and without GCPs, tie point measurements, aerial triangulation, automatic DSM and editing, true ortho-rectification. The accuracy of the DSM has been assessed and reported for both methods. The ortho-rectification, of stereo satellite images has been performed. A PAN true ortho-images with 0.5 m resolution resulted from applying orientation with rational polynomial coefficients (RPCs) refined with four accurate differential ground control points (DGCPs) and a high accurate DSM derived from stereo images were generated. Two classification methods were conducted (SVM and ANN) on the true ortho-image. First method without utilizing texture, the second utilizing texture features of Grey Level Co-occurrence Matrix (GLCM) as inputs. The SVM of the ortho-image and texture features overall accuracy was 93.4%, kappa coefficient was 0.92 and ANN of ortho-image and texture features overall accuracy of 91.2% and kappa coefficient was 0.90. Using the generated DSM as input, the area solar radiation model in ESRI ArcGIS was run. The model resulted in an annual total radiation grid for year 2015 which was converted to average daily radiation in kilowatt hour/square meters per day. A sample of 265 buildings footprints was extracted from the classification and used for the estimation. Assuming that 50% roof areas are available for solar Photovoltaic (PV), 12% PV grid conversion efficiency and 0.6 performance ratio and using ESRI zonal statistics tool, the technical potentiality for solar PV electricity generation for the sample buildings was calculated, classified into five classes and mapped.

Remote measurement methods for 3-D modeling purposes using BAE Systems’ Software

Abstract Efficient, accurate data collection from imagery is the key to an economical generation of useful geospatial products. Incremental developments of traditional geospatial data collection and the arrival of new image data sources cause new software packages to be created and existing ones to be adjusted to enable such data to be processed. In the past, BAE Systems’ digital photogrammetric workstation, SOCET SET®, met fin de siècle expectations in data processing and feature extraction. Its successor, SOCET GXP®, addresses today’s photogrammetric requirements and new data sources. SOCET GXP is an advanced workstation for mapping and photogrammetric tasks, with automated functionality for triangulation, Digital Elevation Model (DEM) extraction, orthorectification and mosaicking, feature extraction and creation of 3-D models with texturing. BAE Systems continues to add sensor models to accommodate new image sources, in response to customer demand. New capabilities added in the latest version of SOCET GXP facilitate modeling, visualization and analysis of 3-D features.

COMPARATIVE ASSESSMENT OF VERY HIGH RESOLUTION SATELLITE AND AERIAL ORTHOIMAGERY

Abstract. This paper aims to assess the accuracy and radiometric quality of orthorectified high resolution satellite imagery from Pleiades-1B satellites through a comparative evaluation of their quantitative and qualitative properties. A Pleiades-B1 stereopair of high resolution images taken in 2013, two adjacent GeoEye-1 stereopairs from 2011 and aerial orthomosaic (LSO) provided by NCMA S.A (Hellenic Cadastre) from 2007 have been used for the comparison tests. As control dataset orthomosaic from aerial imagery provided also by NCMA S.A (0.25m GSD) from 2012 was selected. The process for DSM and orthoimage production was performed using commercial digital photogrammetric workstations. The two resulting orthoimages and the aerial orthomosaic (LSO) were relatively and absolutely evaluated for their quantitative and qualitative properties. Test measurements were performed using the same check points in order to establish their accuracy both as far as the single point coordinates as well as their distances are concerned. Check points were distributed according to JRC Guidelines for Best Practice and Quality Checking of Ortho Imagery and NSSDA standards while areas with different terrain relief and land cover were also included. The tests performed were based also on JRC and NSSDA accuracy standards. Finally, tests were carried out in order to assess the radiometric quality of the orthoimagery. The results are presented with a statistical analysis and they are evaluated in order to present the merits and demerits of the imaging sensors involved for orthoimage production. The results also serve for a critical approach for the usability and cost efficiency of satellite imagery for the production of Large Scale Orthophotos.

Estimation of the mean tree height of forest stands by photogrammetric measurement using digital aerial images of high spatial resolution

Tree height is one of the more fundamental measurements in forest inventories. In addition to classical field measurements, tree height may be estimated by remote sensing methods, such as by photogrammetric measurements of aerial images. Since it has been found and generally accepted that the extraction of forest and tree data from classical analogue aerial photographs has certain limitations, especially in the densely canopied forests, the usefulness of photogrammetric-based forest inventory in many countries remains a controversial issue. Therefore, this paper focuses on investigating the possibility of applying digital photogrammetric method to estimate mean stand height. Photogrammetric stereo-measurements of tree height were conducted on colour infrared images of high spatial resolution (ground sample distance – GSD – of 30 cm and 10 cm) using a digital photogrammetric workstation. The height of each tree within 183 sample plots (14 subcompartments) were calculated as the difference between the tree top elevations determined with the aerial images and the corresponding tree bottom elevations determined from the digital terrain model. To compare the photogrammetric- and field-estimated mean stand heights, the mean plot heights were calculated for both photogrammetric and field estimates of tree heights. Repeated measurements using ANOVA testing did not reveal a statistically significant difference (p > 0.05) between the field-estimated and photogrammetric-estimated mean stand heights using the 30 cm and 10 cm GSD digital aerial images. Deviations of the mean stand heights estimated using the images of both spatial resolutions were similar to the field-estimated heights. Using the 30 cm images the deviations of the photogrammetrically estimated mean stand height amounted to 0.35 m (1.59%) on average, whereas using the 10 cm images the deviations amounted to 0.31 m (1.41%) compared to the field estimation. Therefore, it can be concluded that the 30 cm GSD aerial images allow for the photogrammetric measurement of mean stand heights with accuracy similar to 10 cm GSD aerial images. In addition, 30 cm GSD aerial images are more favourable financially since the same area of interest could be covered with a considerably smaller number of images than of the 10 cm GSD aerial images.

Фотограмметрические технологии геоинформационного моделирования наводнений (на примере г. Крымск)

Abstract: The flood zones and consequences of the flood in Krymsk (July, 2012) for the local population were modeled on the base of GIS-technologies and photogrammetric tools of satellite images processing. Modelling results are compared with actual consequences. Advanced analytical toolbox of GIS software and an efficiency of creating accurate digital elevation models via digital photogrammetric workstations allow – to create reliable platform for modeling flood zones and predicting consequences of floods.

Modeling of binocular stereo vision for remote coordinate measurement and fast calibration

This research is intended for a super-size 3 dimensional scaling events sensing and positioning system based on binocular stereo vision. A model for computing the coordinates of targets in the physical world coordinate system is proposed and simulated. Constitution of a reference point for remote coordinate measurement is made for this purpose on condition that coordinates of both digital photogrammetric workstations are given, with the knowledge of the distance between the two workstations and the angles between optical axes of cameras and the base line connecting the workstations. A calibration method is presented. Applications of the results could be found in airport surface surveillance and runway incursion monitoring. Position data obtained in real time for aircraft and vehicles on the airport surface could be presented to an Advanced Surface Movement Guidance and Control System (A-SMGCS).

Development of a methodological approach for the accurate measurement of slope changes due to landslides, using digital photogrammetry

This paper presents a method for studying recent landscape evolution due to mass movements. The method presented employs digital photogrammetric techniques, combined with global positioning system (GPS) measurements, to analyse landslide features depicted in aerial images taken by ad hoc and historical flights. The method was applied and validated in a 7 -km2 area, located on a south-facing slope of a tributary of the Pas River (Cantabrian Range, Spain). In this area many landslide deposits and features are present, dated from 120,000 years BP to the present. The method starts with the design and carrying out of an ad hoc flight to take 1:5,000 photographs to be used as a reference, using different aircraft devices to control the position and geometry of the photograms. Different ground control points (GCPs) were measured using GPS techniques to support the geomorphological and photogrammetric work. Reference and historical photograms were digitised in a photogrammetric scanner and the digital images and GCPs were incorporated into a digital photogrammetric workstation to generate the reference digital stereo models by aerotriangulation. The models generated have a precision of 21 cm for the reference images and 33 cm for the historical images. The obtained landslide maps were compared with traditional geomorphological maps and an increased precision in the volume and area measurements was confirmed. Backward crown displacements show rates for the last 15 years of 15 mm year−1. Mass involved in landslide mobility rates in recent landslides are 440 tons.

ASSESSMENT OF ULTRACAMD PERFORMANCE IN AN ARID ENVIRONMENT – CASE STUDY IN LIBYA

Abstract. Large format digital aerial cameras are now in widespread commercial operation. Despite the advantages of the new cameras over their traditional film counterparts, systematic image errors have been observed in all existing large format digital cameras. Organizations such as the USGS and EuroSDR have therefore focused efforts on calibration, validation and certification of digital camera systems. However, to-date, few studies have assessed the effects of extreme temperature and humidity variations on these camera systems, and the potential for self-calibration in this respect. This research addresses these issues through investigation of the UltraCamD, with test data acquired over a range of climatic zones in Libya. This presentation will report the preliminary results of self-calibration using a bundle block adjustment for an UltraCamD system, based upon aerial data acquired for two test sites during a single field campaign. The datasets were flown at two different flying heights and incorporate differing block geometries. A SOCET SET (v5.4.1) digital photogrammetric workstation was used to triangulate the imagery with investigation of different tie point densities. Following this, a self-calibrating bundle block adjustment was performed using the BLUH software provided by the University of Hannover. Initial testing investigated the influence of tie point density and different coordinate systems and datums on the bundle adjustment results. Further testing was then performed within BLUH in order to determine the optimal set of additional parameters, compensating for systematic image errors and impact upon object space coordinates of independent check points and ground control points.

COMPARISON BETWEEN DIGITAL PHOTOGRAMMETRIC SYSTEMS

The usage of Digital Photogrammetric Systems leads to increasing the mapping capabilities and efficiency through a full automation or in some cases half automation of mapping procedures. The digital image processing has possibility to improve the photogrammetric mapping implementation concerning the functionality and performance results relation. The goal of research is to investigate the functionality, flexibility and efficiency of two Digital Photogrammetric Mapping Systems for 3D surface modelling from aerial photographs. The experimental photogrammetric measurements have been carried out using DDPS software (Photogrammetric Package for Digital Aerial Photographs) as well as DPW (Digital Photogrammetric Workstation) LISA FOTO. The results of comparison between these two photogrammetric software show capabilities and possibilities for getting best results in digital photogrammetric processing. The analysis demonstrates that DDPS does not fulfil fully a typical workflow in digital photogrammetric mapping. However, the digital surface modelling is more efficient in time‐consuming. There is no doubt that DPW LISA FOTO together with image processing module LISA BASIC have more priorities, potentials and leads to wide applications. Despite this fact, DPW work is more complicated than DDPS in such aspects as stereo model creation, interpretation capabilities etc. The best digital photogrammetric mapping work flow could be achieved when integrating these two systems for getting a more efficient and highest productivity.

ANALYSIS OF THE EFFECTS OF IMAGE QUALITY ON DIGITAL MAP GENERATION FROM SATELLITE IMAGES

Abstract. High resolution satellite images are widely used to produce and update a digital map since they became widely available. It is well known that the accuracy of digital map produced from satellite images is decided largely by the accuracy of geometric modelling. However digital maps are made by a series of photogrammetric workflow. Therefore the accuracy of digital maps are also affected by the quality of satellite images, such as image interpretability. For satellite images, parameters such as Modulation Transfer Function(MTF), Signal to Noise Ratio(SNR) and Ground Sampling Distance(GSD) are used to present images quality. Our previous research stressed that such quality parameters may not represent the quality of image products such as digital maps and that parameters for image interpretability such as Ground Resolved Distance(GRD) and National Imagery Interpretability Rating Scale(NIIRS) need to be considered. In this study, we analyzed the effects of the image quality on accuracy of digital maps produced by satellite images. QuickBird, IKONOS and KOMPSAT-2 imagery were used to analyze as they have similar GSDs. We measured various image quality parameters mentioned above from these images. Then we produced digital maps from the images using a digital photogrammetric workstation. We analyzed the accuracy of the digital maps in terms of their location accuracy and their level of details. Then we compared the correlation between various image quality parameters and the accuracy of digital maps. The results of this study showed that GRD and NIIRS were more critical for map production then GSD, MTF or SNR.

Digital Photogrammetry – State of the Art and Potential for Application in Forest Management in Croatia

Background and purpose: The main goal of this paper is to inform forestry community about the latest developments in digital photogrammetry, as well as to present its possible application in forest management. For this purpose, the current state of technological development of the main tools of digital photogrammetry (digital aerophotogrammetric cameras and digital photogrammetric workstations) has been presented. Furthermore, two adjusted methods of manual digital photogrammetry for application in forest management, namely: method for strata delineation (i.e. creation of forest management division), and method for measuring stand structure elements have been developed and presented here. Material and methods: Research was carried out on the selected part of multi-aged, privately owned forest of ''Donja Kupcina - Pisarovina'' management unit which includes 6 compartments and 24 subcompartments and covers total area of 480 ha. After conducted aerial survey of research area, acquired digital images were processed, and digital terrain model and digital elevation model were derived. Digital aerial images of ground sample distance of 10 cm, topographical maps, digital terrain model and digital elevation model, as well as the digital photogrammetric workstations with appropriate software (PHOTOMOD, Global Mapper) were used for developing methods for strata delineation and stand structure elements estimation. Developments of both methods were carried out in the stereomodel of colour infrared digital aerial images in PHOTOMOD StereoDraw module. Additional data processing was conducted in ArcGIS 9.1. (for strata delineation) and in Global Mapper (for stand structure elements estimation) software. Discussion and conclusions: This research has showed that PHOTOMOD Lite and Global Mapper software packages in combination with the used materials (digital aerial images, digital elevation model) and digital photogrammetric workstation completely satisfy the needs for strata delineation and stand structure measurements. The PHOTOMOD software enables simple creation of projects of digital images, easy manipulation of multiple digital images, and many other features that facilitate photogrammetric measurement and photo-interpretation, but its free version PHOTOMOD Lite has limited capabilities in terms of number of images and quantity of vector data that can be processed. If digital images of high spatial resolution are used (e.g. 30 cm or better), as was the case in this research, stereo- effect experienced by the operator and the quality of photo-interpretation are very good. That enables clear determination of vegetation types and as well as single tree species, more accurate pinpointing of tree tops and more accurate delineation of tree crowns. As long as automatic procedures are not available, digital photogrammetry has to rely on manual methods. Allometric relation between variables measured with photogrammetric method and desired variables need to be developed. An attempt to address this issue, at least in part, is made within the ongoing project 'Application of digital photogrammetry in practical forest management'.

Graphic study and geovisualization of the old windmills of La Mancha (Spain)

In Spain, one can find geographical diversity and unique sites of great significance and cultural heritage. Many of the nation’s treasured places, however, have deteriorated or have even disappeared. What is left, then, should be studied and documented both graphically and infographically. It is important to preserve and document Spain’s unique locations, especially those related to vernacular heritage, to transhumance and visual impact assessment in many national infrastructures projects. Windmills are important examples of agro-industrial heritage and are sometimes found in the beds of streams and rivers but can also be found high in the hills. Their presence is constant throughout the Iberian Peninsula. These mills are no longer in use due to technological advances and the emergence of new grinding systems. The aim of this study was to present a specific methodology for the documentation of windmills, to create a graphical representation using computer graphics, as well as to disseminate knowledge of this agro-industrial heritage. This research has integrated graphic materials, including freehand sketches, photographs, digital orthophotos, computer graphics and multimedia in the creation of a specific methodology based on cutting-edge technology such as a digital photogrammetric workstation (DPW), global navigation satellite systems (GNSS), computer-aided design (CAD) and computer animations.

Qualitative and quantitative photogrammetric techniques for multi-temporal landslide analysis

The results of two survey methods, geological photointerpretation and historical photogrammetry, are compared in order to evaluate the temporal evolution of a unstable slope located in the Tuscan-Emilian Apennines (Italy). Historical aerial photos of the area, derived from photogrammetric surveys conducted in 1954 (scale 1:60000), in 1971 (scale 1:20000), and in 1976 (scale 1:17000) were available. A photogrammetric flight was further conducted in 2000, at a scale of 1:4400, with a traditional GPS ground survey support. First, the results of photographic analysis with the photointerpretation method are presented: the landslides are described from a geological point of view, showing its temporal evolution. To quantitatively assess the landslide movements, Digital Terrain Models were generated by means of an analytical plotter and a digital photogrammetric workstation, with semi-automatic and automatic procedures. To generate these products, it was necessary to solve problems related to a lack of data concerning the aerial cameras used for the historical flights (internal orientation) and the difficulty identifying control points on the photos in order to define the external orientation. An unconventional photogrammetric methodology, based on identification of homologous points in zones considered outside the landslide area, has been there developed and tested to insert the various surveys into a single reference system.

Metrical use of declassified satellite imagery for an area of archaeological interest in Turkey

Abstract The adoption of satellite imagery in archaeology is well recognized today, and is rapidly increasing with the greater availability of high resolution sensors, in the past limited solely to military applications. The metrical use of declassified satellite images from the intelligence CORONA project, the first US operational space photo reconnaissance project operating in the period 1960–1972, has been verified within the framework of a multidisciplinary research project carried out by the University of Bologna, in collaboration with Istanbul University and Gaziantep archaeological museum, at the archaeological site of Tilmen Hoyuk (south-eastern Turkey) and its surrounding landscape. These images, characterized by a panoramic geometry, indeed represent an important historical resource for photointerpretation in archaeology, but their metrical use is difficult, owing to the severe distortions affecting the acquisition together with the problems of finding technical data related to the missions. In order to produce metric products of sufficient quality for mapping purposes, a high resolution scanned copy of a CORONA image of the relevant area was processed using commercial digital photogrammetric workstations operating with different approaches, whose aim was to evaluate the potential and specific problems connected to these kinds of data. A full orientation and digital triangulation of these images is possible if all the technical data on the sensor and the acquisition are well-known, and in any case the existence of well-distributed and reliable ground control points in the study area is crucial. The results obtained are interesting as they allow for integration, on a common cartographic reference base, with current aerial and satellite imagery (medium to very high geometric resolution) to perform automatic or visual change analysis procedures.

Landslide dynamics from high-resolution aerial photographs: A case study from the Western Carpathians, Slovakia

The Ľubietová landslide is one of the largest landslide events in the Central Slovakia Neogene Volcanic Field area. Its present morphology resulted from several reactivation events. The latest one took place in 1977. We applied archive digital photogrammetry to build the historical topography of the landslide area and reconstructed its evolution from 1969 to 1998 at approximately decadal scale. Four sets of aerial photos of the area taken in 1969 (scale 1:16 000), 1977 (scale 1:14 000), 1988 (scale 1:17 000), and 1998 (scale 1:20 000) were processed using a digital photogrammetric workstation. Elevation data were extracted from all the photo sets. Then four high-resolution digital elevation models (DEMs) were generated and compared. Particular interest was placed on quantification of vertical ground displacements and volumetric mass redistribution. Both of them were calculated by subtracting two subsequent DEMs. Consequently, distribution and temporal variation of the landslide activity over three decades are outlined through differential raster images (differential DEMs) and cross-sections. According to our results, the 1977 reactivation event caused considerable vertical displacements up to ± 5–7 m in the peak areas of depletion and accumulation zones. Accordingly, large volumes of material (− 148 000 m 3/+ 84 000 m 3) were redistributed during this event. The dynamics of the 1977 reactivation event shows some specific features that are discussed within the broader context. Besides the new quantitative data, reconstruction of 3D topography of the site before and after the 1977 reactivation brought geomorphic evidence that the area was affected by more than one landslide event in the past.

Kinematics of a landslide derived from archival photogrammetry and GPS data

The evolution of the Patigno landslide, a deep-seated gravitational slope deformation in the Northern Apennine range (Italy), was investigated using archival photogrammetry, and GPS observations from a permanent station located inside the landslide. Historical aerial photographs of the area taken in 1975 (scale 1:13,000), 1987 (1:13,000) and 2004 (1:30,000) were co-registered into the same reference frame using an unconventional method based on the detection of homologous points in multi-temporal models. Three DTMs were produced using a Digital Photogrammetric Workstation and compared. The displacement vectors of 293 points in the landslide were determined. The average movement velocity of the GPS station since 2004 (about 3.5 cm yr − 1 ) agrees with the mean displacement rate obtained from photogrammetry. Furthermore, the estimated velocity varies seasonally between 3 and 6 cm yr − 1 . This variability correlated with rainfall suggests that the creep of the landslide is influenced by hydrological factors.

3D Reconstrution with Rational Function Model

Rational Function Model (RFM) is the alternate sensor Model to the rigorous sensor model that allows end user to perform sensor-independent photogrammetric processing. Nowadays, commercial off-the-shelf (COTS) digital photogrammetric work stations have incorporated RFM as a method for image restitution. It is technically applicable to all types of airborne and space borne sensors. In this paper, we describe the derivations of the algorithmic procedure for third order inverse and forward RFM method for 3-D reconstruction. Model accuracy is evaluated for aerial image, TK-350 Russian image and IRS-1C PAN image. The results ensure that properly constructed RFM are accurate enough to be used in place of the original rigorous models. The test results are reported and summarised.

Impact of multiple glacier surges—a geomorphological map from Brúarjökull, East Iceland

Please click here to download the map associated with this article. Simultaneously with geological field investigations at the surge-type glacier Brúarjökull in August 2003, aerial photographs covering the central part of the glacier including the Kringilsárrani area were recorded with the purpose of mapping glacial landforms. A glacial geomorphological map has been completed at a scale 1:16,000 including more than 20,000 landforms from an area of c. 8 km2. Manual classification of landforms was carried out directly in stereoscopic view using a digital photogrammetric workstation taking full advantage of the texture, topography and spatial context of individual landforms. We mapped subglacial lineations such as flutes and drumlins on till plains, pitted outwash, eskers, minor meandering ridges, crevasse fill ridges, ice-free dead-ice moraine and concertina ridges, outwash fans and lake sediment plains. In addition, erosional drainage channels, ice-marginal ridges, overridden end-moraines, and extra-marginal ice wedge polygons and collapsed palsas were mapped. The mapped glacial landforms originate from at least four surges: pre-1810, 1810, 1890 and 1964. The distribution of landforms on the Brúarjökull fore-eld has close resemblance to landform assemblages of palaeo-ice streams. The present terrain surface at Brúarjökull is the cumulated result of multiple landform generations because each surge has superimposed a new association of landforms on older surfaces.