Browsing by Subject "mapping"

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  • Veikkolainen, Toni H.; Biggin, Andrew John; Pesonen, Lauri J.; Evans, David A.; Jarboe, Nicholas A. (2017)
    State-of-the-art measurements of the direction and intensity of Earth’s ancient magnetic field have made important contributions to our understanding of the geology and palaeogeography of Precambrian Earth. The PALEOMAGIA and PINT(QPI) databases provide thorough public collections of important palaeomagnetic data of this kind. They comprise more than 4,100 observations in total and have been essential in supporting our international collaborative efforts to understand Earth's magnetic history on a timescale far longer than that of the present Phanerozoic Eon. Here, we provide an overview of the technical structure and applications of both databases, paying particular attention to recent improvements and discoveries.
  • Vastaranta, Mikko; Yrttimaa, Tuomas; Saarinen, Ninni; Yu, Xiaowei; Karjalainen, Mika; Nurminen, Kimmo; Karila, Kirsi; Kankare, Ville; Luoma, Ville; Pyörälä, Jiri; Junttila, Samuli; Tanhuanpaa, Topi; Kaartinen, Harri; Kukko, Antero; Honkavaara, Eija; Jaakkola, Anttoni; Liang, Xinlian; Wang, Yunsheng; Vaaja, Matti; Hyyppä, Hannu; Katoh, Masato; Wulder, Michael A.; Holopainen, Markus; Hyyppä, Juha (2018)
    The objective of this study is to better understand the relationship between forest structure and point cloud features generated from certain airborne and space borne sensors. Point cloud features derived from airborne laser scanning (ALS), aerial imagery (AI), WorldView-2 imagery (WV2), TerraSAR-X, and Tandem-X (TDX) data were classified as features characterizing forest height and density as well as variation in tree height. Correlations between these features and field-measured attributes describing forest height, density and tree height variation were investigated at plot scale. From the field-measured attributes, basal area (G) and the number of trees per unit area (N) were used as forest density indicators whereas maximum tree height (H-max) and standard deviation in tree height (H-std) were used as indicators for forest height and tree height variation, respectively. In the analyses, field observations from 91 sample plots (32 m x 32 m) located in southern Finland were used. Even though ALS was found to be the most accurate data source in characterizing forest structure, AI, WV2, and TDX were also capable of characterizing forest height at plot scale with correlation coefficients stronger than 0.85. However, ALS was the only data source capable of providing separate features for characterizing also the variation in tree height and forest density. Features related to forest height, generated from the other data sources besides ALS, also provided strongest correlation with the forest density attributes and variation in tree height, in addition to H-max. Due to these more diverse characterization capabilities, forest structural attributes can be predicted more accurately by using ALS, also in the areas where the relation between the attributes of interest is not solely dependent on forest height, compared to the other investigated 3D remote sensing data sources.
  • Hyvärinen, Heini; Skyttä, Annaliina; Jernberg, Susanna; Meissner, Kristian; Kuosa, Harri; Uusitalo, Laura (Springer, 2021)
    Environmental Monitoring and Assessment 193: 400
    Global deterioration of marine ecosystems, together with increasing pressure to use them, has created a demand for new, more efficient and cost-efficient monitoring tools that enable assessing changes in the status of marine ecosystems. However, demonstrating the cost-efficiency of a monitoring method is not straightforward as there are no generally applicable guidelines. Our study provides a systematic literature mapping of methods and criteria that have been proposed or used since the year 2000 to evaluate the cost-efficiency of marine monitoring methods. We aimed to investigate these methods but discovered that examples of actual cost-efficiency assessments in literature were rare, contradicting the prevalent use of the term “cost-efficiency.” We identified five different ways to compare the cost-efficiency of a marine monitoring method: (1) the cost–benefit ratio, (2) comparative studies based on an experiment, (3) comparative studies based on a literature review, (4) comparisons with other methods based on literature, and (5) subjective comparisons with other methods based on experience or intuition. Because of the observed high frequency of insufficient cost–benefit assessments, we strongly advise that more attention is paid to the coverage of both cost and efficiency parameters when evaluating the actual cost-efficiency of novel methods. Our results emphasize the need to improve the reliability and comparability of cost-efficiency assessments. We provide guidelines for future initiatives to develop a cost-efficiency assessment framework and suggestions for more unified cost-efficiency criteria.
  • Bhattacharjee, Joy; Marttila, Hannu; Haghighi, Ali Torabi; Saarimaa, Miia; Tolvanen, Anne; Lepistö, Ahti; Futter, Martyn N.; Kløve, Bjørn (American Society of Civil Engineers, 2021)
    Journal of Irrigation and Drainage Engineering, 147(4), 04021006
    Spatiotemporal information on historical peatland drainage is needed to relate past land use to observed changes in catchment hydrology. Comprehensive knowledge of historical development of peatland management is largely unknown at the catchment scale. Aerial photos and light detection and ranging (LIDAR) data enlarge the possibilities for identifying past peatland drainage patterns. Here, our objectives are (1) to develop techniques for semiautomatically mapping the location of ditch networks in peat-dominated catchments using aerial photos and LIDAR data, and (2) to generate time series of drainage networks. Our approaches provide open-access techniques to systematically map ditches in peat-dominated catchments through time. We focused on the algorithm in such a way that we can identify the ditch networks from raw aerial images and LIDAR data based on the modification of multiple filters and number of threshold values. Such data are needed to relate spatiotemporal drainage patterns to observed changes in many northern rivers. We demonstrate our approach using data from the Simojoki River catchment (3,160  km2) in northern Finland. The catchment is dominated by forests and peatlands that were almost all drained after 1960. For two representative locations in cultivated peatland (downstream) and peatland forest (upstream) areas of the catchment; we found total ditch length density (km/km2), estimated from aerial images and LIDAR data based on our proposed algorithm, to have varied from 2% to 50% compared with the monitored ditch length available from the National Land survey of Finland (NLSF) in 2018. A different pattern of source variation in ditch network density was observed for whole-catchment estimates and for the available drained-peatland database from Natural Resources Institute Finland (LUKE). Despite such differences, no significant differences were found using the nonparametric Mann-Whitney U test with a 0.05 significance level based on the samples of pixel-identified ditches between (1) aerial images and NLSF vector files and (2) LIDAR data and NLSF vector files.
  • Ouattara, Issouf; Hyyti, Heikki; Visala, Arto (Elsevier, 2020)
    IFAC-PapersOnLine, Proceedings of the 21th IFAC World Congress, Berlin, Germany, 12-17 July 2020
    We propose a novel method to locate spruces in a young stand with a low cost unmanned aerial vehicle. The method has three stages: 1) the forest area is mapped and a digital surface model and terrain models are generated, 2) the locations of trees are found from a canopy height model using local maximum and watershed algorithms, and 3) these locations are used in a convolution neural network architecture to detect young spruces. Our result for detecting young spruce trees among other vegetation using only color images from a single RGB camera were promising. The proposed method is able to achieve a detection accuracy of more than 91%. As low cost unmanned aerial vehicles with color cameras are versatile today, the proposed work is enabling low cost forest inventory for automating forest management.
  • BEEHIVE Collaboration; Wymant, Chris; Blanquart, Francois; Golubchik, Tanya; Gall, Astrid; Bakker, Margreet; Bezemer, Daniela; Croucher, Nicholas J.; Hall, Matthew; Hillebregt, Mariska; Ong, Swee Hoe; Ratmann, Oliver; Albert, Jan; Bannert, Norbert; Fellay, Jacques; Fransen, Katrien; Gourlay, Annabelle; Grabowski, M. Kate; Gunsenheimer-Bartmeyer, Barbara; Gunthard, Huldrych F.; Kivelä, Pia; Kouyos, Roger; Laeyendecker, Oliver; Liitsola, Kirsi; Meyer, Laurence; Porter, Kholoud; Ristola, Matti; van Sighem, Ard; Berkhout, Ben; Cornelissen, Marion; Kellam, Paul; Reiss, Peter; Fraser, Christophe (2018)
    Studying the evolution of viruses and their molecular epidemiology relies on accurate viral sequence data, so that small differences between similar viruses can be meaningfully interpreted. Despite its higher throughput and more detailed minority variant data, next-generation sequencing has yet to be widely adopted for HIV. The difficulty of accurately reconstructing the consensus sequence of a quasispecies from reads (short fragments of DNA) in the presence of large between-and within-host diversity, including frequent indels, may have presented a barrier. In particular, mapping (aligning) reads to a reference sequence leads to biased loss of information; this bias can distort epidemiological and evolutionary conclusions. De novo assembly avoids this bias by aligning the reads to themselves, producing a set of sequences called contigs. However contigs provide only a partial summary of the reads, misassembly may result in their having an incorrect structure, and no information is available at parts of the genome where contigs could not be assembled. To address these problems we developed the tool shiver to pre-process reads for quality and contamination, then map them to a reference tailored to the sample using corrected contigs supplemented with the user's choice of existing reference sequences. Run with two commands per sample, it can easily be used for large heterogeneous data sets. We used shiver to reconstruct the consensus sequence and minority variant information from paired-end short-read whole-genome data produced with the Illumina platform, for sixty-five existing publicly available samples and fifty new samples. We show the systematic superiority of mapping to shiver's constructed reference compared with mapping the same reads to the closest of 3,249 real references: median values of 13 bases called differently and more accurately, 0 bases called differently and less accurately, and 205 bases of missing sequence recovered. We also successfully applied shiver to whole-genome samples of Hepatitis C Virus and Respiratory Syncytial Virus. shiver is publicly available from https://github.com/ChrisHIV/shiver.
  • Risbøl, Ole; Langhammer, Daniel; Mauritsen, Esben Schlosser; Seitsonen, Oula (2020)
    This paper gives a presentation of how airborne laser scanning (ALS) has been adopted in archaeology in the North over the period 2005-2019. Almost two decades have passed since ALS first emerged as a potential tool to add to the archaeologist's toolbox. Soon after, it attracted the attention of researchers within archaeological communities engaged with remote sensing in the Fenno-Scandinavian region. The first archaeological ALS projects gave immediate good results and led to further use, research, and development through new projects that followed various tracks. The bulk of the research and development focused on studying how well-suited ALS is for identifying, mapping, and documenting archaeological features in outfield land, mainly in forested areas. The poor situation in terms of lack of information on archaeological records in outfield areas has been challenging for research and especially for cultural heritage management for a long period of time. Consequently, an obvious direction was to study how ALS-based mapping of cultural features in forests could help to improve the survey situation. This led to various statistical analyses and studies covering research questions related to for instance effects on detection success of laser pulse density, and the size and shape of the targeted features. Substantial research has also been devoted to the development and assessment of semi-automatic detection of archaeological features based on the use of algorithms. This has been studied as an alternative approach to human desk-based visual analyses and interpretations of ALS data. This approach has considerable potential for detecting sites over large regions such as the vast roadless and unbuilt wilderness regions of northern Fennoscandia, and has proven highly successful. In addition, the current review presents how ALS has been employed for monitoring purposes and for landscape studies, including how it can influence landscape understanding. Finally, the most recent advance within ALS research and development has been discussed: testing of the use of drones for data acquisition. In conclusion, aspects related to the utilization of ALS in archaeological research and cultural heritage management are summarized and discussed, together with thoughts about future perspectives.
  • Pitkänen, Timo P.; Sirro, Laura; Häme, Lauri; Häme, Tuomas; Törmä, Markus; Kangas, Annika (ScienceDirect, 2020)
    International Journal of Applied Earth Observation and Geoinformation 86 (2020)
    The majority of the boreal forests in Finland are regularly thinned or clear-cut, and these actions are regulated by the Forest Act. To generate a near-real time tool for monitoring management actions, an automatic change detection modelling chain was developed using Sentinel-2 satellite images. In this paper, we focus mainly on the error evaluation of this automatized workflow to understand and mitigate incorrect change detections. Validation material related to clear-cut, thinned and unchanged areas was collected by visual evaluation of VHR images, which provided a feasible and relatively accurate way of evaluating forest characteristics without a need for prohibitively expensive fieldwork. This validation data was then compared to model predictions classified in similar change categories. The results indicate that clear-cuts can be distinguished very reliably, but thinned stands exhibit more variation. For thinned stands, coverage of broadleaved trees and detections from certain single dates were found to correlate with the success of the modelling results. In our understanding, this relates mainly to image quality regarding haziness and translucent clouds. However, if the growing season is short and cloudiness frequent, there is a clear trade-off between the availability of good-quality images and their preferred annual span. Gaining optimal results therefore depends both on the targeted change types, and the requirements of the mapping frequency.
  • Koskela, Elli (Helsingfors universitet, 2009)
    Strawberry (Fragaria × ananassa) is the most important berry crop cultivated in Finland. Due to the species' economic importance, there is a national breeding programme aimed at extending the cropping season from the current one month to up to three months. This could be achieved by growing cultivars which would initiate flowers throughout the summer months, without the requirement of a period of short days as is the case with currently grown cultivars. The cultivated strawberry is an octoploid and therefore has complex patterns of inheritance. It is desirable to study the genetic mechanisms of flowering in the closely related but diploid species F. vesca (L). In the diploid Fragaria, a mutation in a single locus, namely the SEASONAL FLOWERING LOCUS (Sfl), changes the flowering phenotype from seasonal to perpetual flowering. There is also an array of genetic tools available for F. vesca, which facilitate genetic studies at molecular level. Experiments described here aimed at elucidating the identity of the gene which confers perpetual flowering in F. vesca by exploring the flowering characteristics and genotypes of five F2 populations (crosses between seasonal × perpetual flowering cultivars). The study took advantage of a genetic map for diploid Fragaria, publicly available EST and genomic Fragaria sequences and a recently developed BAC library. Sequence information was used for designing gene–specific primers for a host of flowering–related candidate genes, which were subsequently mapped on the diploid Fragaria genetic map. BAC library was screened with molecular markers supposedly located close to the Sfl, with the aim of positionally cloning the Sfl. Segregation of flowering phenotypes in the five F2 populations showed, that the Sfl indeed controls flowering in all the tested cultivars. A genetic map was constructed of the chromosome with the Sfl, and a positional cloning attempt was initiated with the closest flanking markers. 45 gene–specific primers pairs were designed for 21 flowering–related genes, and eight genes were successfully mapped on the diploid Fragaria map. One of the mapped genes, namely PRR7, located very close to the Sfl, and is a potential candidate for the gene that has evaded identification so far.
  • Georgiou, Christina (2013)
    Mapping the Body, Embodying the Map: A corporeal taxonomy into a topographical transformation at the border of Nicosia is a project realized along and across the buffer zone within the Venetian walls of Nicosia, the capital city of Cyprus. The focus of this project is the area that divides the city into two parts and it has been mentioned as buffer zone, green line, borderline, dividing line, dead zone and many more. This restricted area has activated not only physical barriers for people but also caused emotional and mental restrain. The motivation is my wish to reveal the significance of this area and uncover the impact it creates on the body: physical, mental and emotional. Also my intention is to deform and reconstruct the psychophysical perceptions of the dividing line through artistic means. The approach and method of working consists of artistic research, and a practical and theoretical framework. I have used live performance as my creative technique to realize a series of site-specific performance interventions along and across the Nicosia buffer zone in order to generate knowledge about that area, examined in my research. In addition, the written part of this project includes a description and analysis of my artistic work at the border, supported with theories focusing mainly on José Esteban Muñoz’s work, “Disidentifications” (1999) and Sarah Pink’s “Doing Sensory Ethnography” (2009). This thesis project questions: How the conventional idea of the border and its solidified historicity can be transformed to a new perception through performing, while bringing a psychophysical transformation to this experience? To come to an answer, the body is used as a tool to create live actions and the Nicosia border is used as a site to be experienced through non covnentional ways. Finally, the outcome is an experiential mapping, which is shaped while the body is used to measure, archive, experience and re-experience, and therefore memorize the border anew.
  • Kozhin, Mikhail N.; Lommi, Sampsa; Sennikov, Alexander N. (2020)
    Background The present-day demand for digital availability of distributional data in biodiversity studies requires a special effort in assembling and editing the data otherwise scattered in paper literature and herbarium collections, which can be poorly accessible or little understood to present-day users and especially automatic data processors. Although the vascular plants of Murmansk Region (northern part of European Russia) are well studied and represented in publications, the accessibility of this knowledge is highly insufficient. The most widely known source is the Flora of Murmansk Region (published in 1953-1966), which remains in use because of its high original quality, detailed elaboration and completeness. We consider digitising this source to be of primary importance in biodiversity studies in the Arctic Region because of its point occurrence maps, which were based on the comprehensive inventory of contemporary herbarium collections. New information We have compiled a dataset based on 554 printed point occurrence maps of species distributions published in the Flora of Murmansk Region, which includes 25,555 records of georeferenced plant occurrences that belong to 1,073 species and 5 hybrids. The occurrences are ultimately based on herbarium specimens kept at KPABG and LE, which were collected during 1837-1965. We estimate that these specimens represent ca. 60% of the current global herbarium holdings originated from Murmansk Region; this means that the dataset gives a fair representation of the regional flora.
  • Näsi, Roope; Honkavaara, Eija; Blomqvist, Minna; Lyytikäinen-Saarenmaa, Päivi Marja Emilia; Hakala, Teemu; Viljanen, Niko; Kantola, Tuula Anneli; Holopainen, Markus Edvard (2018)
    Climate-related extended outbreaks and range shifts of destructive bark beetle species pose a serious threat to urban boreal forests in North America and Fennoscandia. Recent developments in low-cost remote sensing technologies offer an attractive means for early detection and management of environmental change. They are of great interest to the actors responsible for monitoring and managing forest health. The objective of this investigation was to develop, assess, and compare automated remote sensing procedures based on novel, low-cost hyperspectral imaging technology for the identification of bark beetle infestations at the individual tree level in urban forests. A hyperspectral camera based on a tunable Fabry-Perot interferometer was operated from a small, unmanned airborne vehicle (UAV) platform and a small Cessna-type aircraft platform. This study compared aspects of using UAV datasets with a spatial extent of a few hectares (ha) and a ground sample distance (GSD) of 10-12 cm to the aircraft data covering areas of several km(2) and having a GSD of 50 cm. An empirical assessment of the automated identification of mature Norway spruce (Picea abies L. Karst.) trees suffering from infestation (representing different colonization phases) by the European spruce bark beetle (Ips typographus L.) was carried out in the urban forests of Lahti, a city in southern Finland. Individual spruces were classified as healthy, infested, or dead. For the entire test area, the best aircraft data results for overall accuracy were 79% (Cohen's kappa: 0.54) when using three crown color classes (green as healthy, yellow as infested, and gray as dead). For two color classes (healthy, dead) in the same area, the best overall accuracy was 93% (kappa: 0.77). The finer resolution UAV dataset provided better results, with an overall accuracy of 81% (kappa: 0.70), compared to the aircraft results of 73% (kappa: 0.56) in a smaller sub-area. The results showed that novel, low-cost remote sensing technologies based on individual tree analysis and calibrated remote sensing imagery offer great potential for affordable and timely assessments of the health condition of vulnerable urban forests.
  • Khapugin, Anatoliy A.; Soltys-Lelek, Anna; Fedoronchuk, Nikolay M.; Muldashev, Albert A.; Agafonov, Vladimir A.; Kazmina, Elena S.; Vasjukov, Vladimir M.; Baranova, Olga G.; Buzunova, Irina O.; Teteryuk, Lyudmila; Dubovik, Dmitriy; Gudzinskas, Zigmantas; Kukk, Toomas; Kravchenko, Alexey; Yena, Andrey; Kozhin, Mikhail N.; Sennikov, Alexander N. (2021)
    By the method of data re-collection and re-assessment, we here test the completeness of distribution areas of the species and species aggregates of Rosa in Eastern Europe as mapped in volume 13 of Atlas Florae Europaeae (AFE), and discuss insights into the issues connected with the data. We found many new occurrences which are additions to the published maps: 1068 records of species and 570 records of species aggregates. The new occurrences are listed with references to the sources, and the updated AFE maps are provided. The greatest increase by new native occurrences was revealed for the species that are widespread or taxonomically complicated, and by new alien occurrences for the species that currently expand their secondary distribution areas. The mapping work published in 2004 is considered good, with minor omissions caused by possible oversights and incomplete sampling. The majority of new additions originated in the period after the original data collection. Nearly the same amount of new data originated from larger and smaller herbarium collections, underlining the value of small collections for chorological studies. We found that only ca 20% of new records based on herbarium specimens have been published, thus highlighting the need for data papers for publication of distributional data. The greatest increase by new records based on herbarium specimens was found for insufficiently studied territories (Belarus, central, northern and eastern parts of Russia), whereas the same level of increase for the territories with reasonably good coverage (Latvia) was achieved by observations. We conclude that the overall sparsity of published records in Eastern Europe is caused by a lower level of data collection rather than by poor data availability, and that floristic surveys based on herbarium specimens cannot compete in speed and density of records with observation-based surveys, which may become the main source of distributional information in the future.
  • Mohammad, Imangholiloo (Helsingin yliopisto, 2017)
    Land use and land cover maps are vital sources of information for many uses. Recently, the use of high resolution and open access satellite images are being preferred for mapping large areas. Sentinel satellites exhibit such valuable traits. This study was designed to analyze the potential of Sentinel-1A SAR images for land use mapping in Pakistan. Machine learning methods were employed for image analysis. Random forest classifier algorithm performed significantly better than others in the training step. Thus, we took the model for tuning parameters. After several image processing steps, we classified the final image to 23 classes and achieved 42 % of an overall accuracy. The present study showed the potential advantages of using Sentinel-1 images in land use mapping besides highlighting some characteristics of Sentinel-1A images. This study also compares the results with an earlier study using Landsat-8 optical multispectral images over the same area. Similar to the prior study, overestimation in dominant classes and underestimation in rare classes were observed. The method and findings of this study could be beneficial for future studies in the use of Sentinel-1A images for land use/cover mapping over large areas.