Maanmittauslaitos: Recent submissions

Now showing items 1-20 of 426
  • Adekola, Oluwafemi; Krigsholm, Pauliina; Riekkinen, Kirsikka (Elsevier, 2021)
    Land Use Policy
    Land laws provide a legal basis for addressing a country’s land-related strategies and are the central land policy instruments through which governments realise land policy objectives. Considering their vital role, it is imperative that land laws be evaluated to ensure that policy objectives are followed and that the laws are not ineffective or counterproductive. The extant literature, however, provides only a fragmentary basis for evaluation. The present study addresses this gap and constructs a novel framework to support the holistic evaluation of land law performance in the context of sub-Saharan Africa (SSA). The framework was developed through a review of systematically selected literature on land laws in SSA. Four key evaluation perspectives emerged: land access; land tenure; land use and development; and land administration institutions. The framework was then used to assess the overall performance of Rwanda’s Organic Land Law (OLL) 2005 through a content analysis of secondary data on the land reform outcomes. The OLL application suggests that the framework may provide stakeholders with insights into the overall effects of land law and potential areas of improvement. However, the framework must be further explored in various cases of SSA countries to validate its functionality.
  • Bilker-Koivula, Mirjam; Mäkinen, Jaakko; Ruotsalainen, Hannu; Näränen, Jyri; Saari, Timo (Springer, 2021)
    Journal of Geodesy
    Postglacial rebound in Fennoscandia causes striking trends in gravity measurements of the area. We present time series of absolute gravity data collected between 1976 and 2019 on 12 stations in Finland with different types of instruments. First, we determine the trends at each station and analyse the effect of the instrument types. We estimate, for example, an offset of 6.8 μgal for the JILAg-5 instrument with respect to the FG5-type instruments. Applying the offsets in the trend analysis strengthens the trends being in good agreement with the NKG2016LU_gdot model of gravity change. Trends of seven stations were found robust and were used to analyse the stabilization of the trends in time and to determine the relationship between gravity change rates and land uplift rates as measured with global navigation satellite systems (GNSS) as well as from the NKG2016LU_abs land uplift model. Trends calculated from combined and offset-corrected measurements of JILAg-5- and FG5-type instruments stabilized in 15 to 20 years and at some stations even faster. The trends of FG5-type instrument data alone stabilized generally within 10 years. The ratio between gravity change rates and vertical rates from different data sets yields values between − 0.206 ± 0.017 and − 0.227 ± 0.024 µGal/mm and axis intercept values between 0.248 ± 0.089 and 0.335 ± 0.136 µGal/yr. These values are larger than previous estimates for Fennoscandia.
  • Saaranen, Veikko; Lehmuskoski, Pekka; Takalo, Mikko; Rouhiainen, Paavo (National Land Survey of Finland, 2021)
    FGI Publications
    The Third Precise Levelling of Finland was performed in 1978–2006 by The Finnish Geodetic Institute (FGI). The levelling network consisted 9158 km of levelled lines including 29 closed loops, 13 side lines to the tide gauges and 21 connections to the neighbouring countries. The mean standard error of the Third Levelling, calculated from the closing errors of the levelling loops, is ±0.86 mm/ √km. In this publication, measuring methods, equipment, computation of the observations, and the adjustments are presented. In the appendices, yearly progress of the measuring work, the rod corrections, and the observations are presented. The new height system N2000 is a realization of a European Vertical Reference System (EVRS). It is a normal height system, where the permanent tidal deformation is in a zero tidal system. The observations were reduced to the epoch 2000.0 using the Nordic land uplift model NKG2005LU. The Normaal Amsterdams Peil (NAP) is a datum of the N2000 height system. The fundamental benchmark PP2000 for the adjustment of the Finnish observations is located in Metsähovi and its height is 54.4233 m. This height was determined by using the Finnish version of the Baltic Levelling Ring adjustment. The N2000 adjustment contained the measurements of the Third Levelling of Finland and some observations of Sweden and Norway near the Finnish border in order to ensure the compatibility of the new height systems between the neighbouring countries.
  • Junttila, Samuli; Hölttä, Teemu; Puttonen, Eetu; Katoh, Masato; Vastaranta, Mikko; Kaartinen, Harri; Holopainen, Markus; Hyyppä, Hannu (Elsevier, 2021)
    Remote Sensing of Environment
    During the past decades, extreme events have become more prevalent and last longer, and as a result drought-induced plant mortality has increased globally. Timely in-formation on plant water dynamics is essential for under-standing and anticipating drought-induced plant mortality. Leaf water potential (ΨL), which is usually measured de-structively, is the most common metric that has been used for decades for measuring water stress. Remote sensing methods have been developed to obtain information on water dynamics from trees and forested landscapes. However, the spatial and temporal resolutions of the existing methods have limited our understanding of the water dynamics and diurnal variation of ΨL within single trees. Thus, we investi-gated the capability of terrestrial laser scanning (TLS) in-tensity in observing diurnal variation in ΨL during a 50-h monitoring period. We aimed to improve the understanding on how large a part of the diurnal variation in ΨL can be captured using TLS intensity observations. We found that TLS intensity at the 905 nm wavelength measured from a static position was able to explain 77% of the variation in ΨL for three trees of two tree species with a root mean square error of 0.141 MPa. Based on our experiment with three trees, a time series of TLS intensity measurements can be used in detecting changes in ΨL, and thus it is worthwhile to expand the investigations to cover a wider range of tree species and forests and further increase our understanding of plant water dynamics at wider spatial and temporal scales.
  • Campos, Mariana Batista; Litkey, Paula; Wang, Yunsheng; Chen, Yuwei; Hyyti, Heikki; Hyyppä, Juha; Puttonen, Eetu (Frontiers Research Foundation, 2021)
    Frontiers in Plant Science
    The terrestrial laser scanner (TLS) has become standard technology for vegetation dynamics monitoring. TLS time series have significant underlying application in investigating structural development and dynamics on a daily and seasonal scale. However, the high potential of TLS for the monitoring of long-term temporal phenomena in fully grown trees with high spatial and temporal resolution has not yet been fully explored. Automated TLS platforms for long-term data collection and monitoring of forest dynamics are rare; and long-term TLS time series data is not yet readily available to potential end-user, such as forestry researchers and plant biologists. This work presents an automated and permanent TLS measurement station that collects high frequency and high spatial resolution TLS time series, aiming to monitor short- and long-term phenological changes at a boreal forestry field station (0.006◦ angular resolution, one scan per hour). The measurement station is the first of its kind considering the scope, accuracy, and length of the time series it produces. The TLS measurement station provides a unique dataset to monitor the 3D physical structure of a boreal forest, enabling new insights into forest dynamics. For instance, the information collected by the TLS station can be used to accurately detect structural changes in tree crowns surrounding the station. These changes and their timing can be linked with the phenological state of plants, such as the start of leaf-out during spring growing season. As the first results of this novel station, we present time series data products collected with the station and what detailed information it provides about the phenological changes in the test site during the leaf sprout in spring.
  • Herrero-Huerta, Mónica; Bucksch, Alexander; Puttonen, Eetu; Rainey, Katy Martin (American Association for the Advancement of Science (AAAS), 2020)
    Plant Phenomics
    Cost-effective phenotyping methods are urgently needed to advance crop genetics in order to meet the food, fuel, and fiber demands of the coming decades. Concretely, charac-terizing plot level traits in fields is of particular interest. Re-cent developments in high resolution imaging sensors for UAS (unmanned aerial systems) focused on collecting de-tailed phenotypic measurements are a potential solution. We introduce canopy roughness as a new plant plot-level trait. We tested its usability with soybean by optical data collect-ed from UAS to estimate biomass. We validate canopy roughness on a panel of 108 soybean [Glycine max (L.) Merr.] recombinant inbred lines in a multienvironment trial during the R2 growth stage. A senseFly eBee UAS platform obtained aerial images with a senseFly S.O.D.A. compact digital camera. Using a structure from motion (SfM) tech-nique, we reconstructed 3D point clouds of the soybean experiment. A novel pipeline for feature extraction was de-veloped to compute canopy roughness from point clouds. We used regression analysis to correlate canopy roughness with field-measured aboveground biomass (AGB) with a leave-one-out cross-validation. Overall, our models achieved a coefficient of determination (R2) greater than 0.5 in all trials. Moreover, we found that canopy roughness has the ability to discern AGB variations among different geno-types. Our test trials demonstrate the potential of canopy roughness as a reliable trait for high-throughput phenotyping to estimate AGB. As such, canopy roughness provides practical information to breeders in order to select pheno-types on the basis of UAS data.
  • Rahkonen, Jukka (2020)
    Positio
  • Jakobsson, Antti (2020)
    Positio
  • Lahtinen, Sonja; Saaranen, Veikko (2020)
    Positio
  • Kivekäs, Riikka (2020)
    Positio
  • Kivekäs, Riikka (2020)
    Positio
  • Gruber, Thomas; Ågren, Jonas; Angermann, Detlef; Ellmann, Artu; Engfeldt, Andreas; Gisinger, Christoph; Jaworski, Leszek; Marila, Simo; Nastula, Jolanta; Nilfouroushan, Faramarz; Oikonomidou, Xanthi; Poutanen, Markku; Saari, Timo; Schlaak, Marius; Swiatek, Anna; Varbla, Sander; Zdunek, Ryszard (MDPI, 2020)
    Remote Sensing
    Traditionally, sea level is observed at tide gauge stations, which usually also serve as height reference stations for national leveling networks and therefore define a height system of a country. One of the main deficiencies to use tide gauge data for geodetic sea level research and height systems unification is that only a few stations are connected to the geometric network of a country by operating permanent GNSS receivers next to the tide gauge. As a new observation technique, absolute positioning by SAR using active transponders on ground can fill this gap by systematically observing time series of geometric heights at tide gauge stations. By additionally knowing the tide gauge geoid heights in a global height reference frame, one can finally obtain absolute sea level heights at each tide gauge. With this information the impact of climate change on the sea level can be quantified in an absolute manner and height systems can be connected across the oceans. First results from applying this technique at selected tide gauges at the Baltic coasts are promising but also exhibit some problems related to the new technique. The paper presents the concept of using the new observation type in an integrated sea level observing system and provides some early results for SAR positioning in the Baltic sea area.
  • Kirkko-Jaakkola, Martti; Marila, Simo; Sarang, Thombre; Honkala, Salomon; Koivula, Hannu; Kuusniemi, Heidi; Söderholm, Stefan (2019)
    Proceedings of the 32nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2019) September 16 - 20, 2019, Hyatt Regency Miami, Miami, Florida
    This paper presents a hybrid navigation algorithm based on loose coupling of the on-board speedometer and inertial sensors of a land vehicle with a GNSS receiver. An Extended Kalman Filter estimating ten error states is used as the hybridization framework. The algorithm is developed to serve as a baseline for the evaluation of the navigation infrastructure of the Aurora ecosystem which is an Arctic test bed for autonomous vehicles and intelligent transport systems. In the experimental tests we focus on the performance of the navigation algorithm during GNSS outages. First, the tests indicate that the quality of GNSS updates has an immediate effect on how fast the position errors accumulate when GNSS becomes unavailable. Second, using low-cost sensors together with the current navigation infrastructure available at the Aurora test site, GNSS position fixes need to be obtained at intervals no longer than 4 seconds in order to maintain a 95 % horizontal positioning accuracy better than 0.2 meters. The results serve as a basis for recommendations for further development of the Aurora ecosystem, suggesting that further positioning infrastructure could be deployed for guaranteeing a navigation performance adequate for autonomous vehicles.
  • Perheentupa, Viljami; Mäkinen, Ville; Habicht, Hando-Laur; Oksanen, Juha (Elsevier, 2020)
    Applied Computing and Geosciences
    Post-glacial land uplift and shore displacement are dynamic processes that are challenging to present with cartography and geovisualization. To communicate these phenomena, we have created a dynamic visualization in the form of high-quality animation, utilizing automated processes in the computation and rendering of large raster datasets. We have developed a simplified model to assess the past and future elevation models, and applied it to the High Coast/Kvarken Archipelago UNESCO World Heritage Site, which is considered one of the best places in the world to observe land uplift. Additionally, the ice decline in the area has been evaluated and visualized. Based on the model and the present-day topography/bathymetry data, we provide a 40 fps 4K-resolution animation with an 80-s duration of the post-glacial history at the World Heritage Site and its vicinity, extending from 10,500 years ago to 1000 years in the future. Although they do not aim to contain the precision of thorough paleogeographic reconstructions, we have found that the individual frames of the animation are closely aligned with comparable geological data. We also present the computational process flow and the visualization principles used in the automated rendering, and thus aim to contribute to the cartographic presentation of geodynamic processes.
  • Kettunen, Pyry; Koski, Christian; Rönneberg, Mikko; Oksanen, Juha; Hansen, Henning Sten; Schrøder, Lise (2020)
    BONUS BASMATI
    This deliverable presents Baltic Explorer, a collaborative GIS and spatial decision support system (SDSS) for the maritime spatial planning (MSP), that was designed, built, and studied in the BONUS BASMATI Work Package 5. Sec-tion 1 summarises the general concept, key functionalities, use tests and free release of the Baltic Explorer, and Sec-tion 2 describes and guides the usage of the system. Previ-ous deliverables and published or forthcoming scientific articles provide more information about the creation and assessment of the Baltic Explorer. Baltic Explorer is available for use at http://balticexplorer.eu and its source code at https://github.com/FGI-GEOINFO/Baltic-Explorer. Key functionalities of the Baltic Explorer: • User-friendly map interface • Multi-device usability • Multi-user access model • Workspaces for group work • Up-to-date spatial maritime data from a large num-ber of providers • Create, edit and add vector features Use tests of the Baltic Explorer: 1. MSP workshop, Umeå, Sweden 2. PhD course, Turku, Finland 3. MSP workshop, Riga. Latvia 4. MSP course, University of Turku, Finland 5. MSP course, University of Gothenburg, Sweden 6. Denmark
  • Brauer, Anna; Mäkinen, Ville; Oksanen, Juha (Elsevier, 2021)
    Computers Environment and Urban Systems
    Mobile activity tracking data, i.e. data collected by mobile applications that enable activity tracking based on the use of the Global Navigation Satellite Systems (GNSS), contains information on cycling in urban areas at an un-precedented spatial and temporal extent and resolution. It can be a valuable source of information about the quality of bicycling in the city. Required is a notion of quality that is derivable from plain GNSS trajectories. In this article, we quantify urban cycling quality by esti-mating the fluency of cycling traffic using a large set of GNSS trajectories recorded with a mobile tracking appli-cation. Earlier studies have shown that cyclists prefer to travel continuously and without halting, i.e. fluently. Our method extracts trajectory properties that describe the stopping behaviour and dynamics of cyclists. It aggre-gates these properties to segments of a street network and combines them in a descriptive index. The suitability of the data to describe the cyclists' behaviour with street-level detail is evaluated by comparison with various data from independent sources. Our approach to characterizing cycling traffic fluency offers a novel view on the cyclability of a city that could be valuable for urban planners, application providers, and cyclists alike. We find clear indications for the data's ability to estimate characteristics of city cycling quality correctly, despite behaviour patterns of cyclists not caused by external circumstances and the data's inher-ent bias. The proposed quality measure is adaptable for different applications, e.g. as an infrastructure quality measure or as a routing criterion.
  • Häkli, Pasi; Koivula, Hannu (2020)
    Positio
  • Kettunen, Pyry; Koski, Christian; Rönneberg, Mikko; Oksanen, Juha (2020)
    Positio