11 research outputs found

    Zmienność rzeźby terenu w strefie brzegowej na wybranym odcinku Mierzei Łebskiej w latach 2001-2007

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    Niniejsza praca zawiera charakterystykę ilościową zmienności rzeźby terenu w strefie brzegowej. W latach 2001–2007 na odcinku 250 m strefy brzegowej Mierzei Łebskiej, obejmującym obszar plaży i wału wydmowego, prowadzono pomiary wysokościowe metodą tachimetrii, wykorzystując urządzenie firmy TOPCON GTS 229. Na podstawie danych z pomiarów geodezyjnych stworzono cyfrowe modele terenu. Opierając się na nich, wykonano obliczenia ubytku, dostawy, bilansu i transportu piasku poprzez porównanie wartości rzędnych dla wszystkich możliwych okresów – jednorocznych i wieloletnich (01–04, 01–04, 01–05, 01–06, 01–07, 04–05, 04–06, 04–07, 05–06, 05–07 i 06–07). Średnio w okresach jednorocznych transport objął około 13,3% kubatury powierzchni badawczej, czyli trzy razy więcej niż wynika to z pracy MISZALSKIEGO (1973), analizujacego przede wszystkim duże formy wydmowe. Maksymalnie w okresie jednorocznym, 2004–2005, przemieszczeniu uległo ponad 14,5 tys. m3 piasku na obszarze 2,38 ha, co stanowiło około 20% kubatury powierzchni badawczej. Średnia wartość transportu dla powierzchni 1 m2 zmieniała się od 0,31 m3 w okresie 06–07 do 0,67 m3 w okresie 04–06. Średni bilans ubytku i dostawy dla powierzchni 1m2 zmieniały się odpowiednio od –0,38 m3 w okresie 04–06 do +0,05 m3 w okresie 06–07.5910512

    Uses of Sentinel-1 and -2 Images in Heritage Management: A Case Study from Lednica Landscape Park (Poland)

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    This article aims to demonstrate the use of Sentinel images to develop strategies for heritage protection and management in rural landscapes that are currently undergoing dynamic transformations. Construction works are causing rapid and extensive land use changes that threaten archaeological structures. Moreover, the modernisation of farming practices may also negatively affect the efficiency of archaeological prospection. The rapidity of those processes requires the application of relevant tools to monitor changes and highlight negative tendencies in areas surrounding archaeological sites. High frequency of Sentinel-1 and -2′s acquisition may offer an immediate insight into current tendencies. Radar and optical data obtained from those satellites between 2016 and 2020 were analysed to identify trends in building development and land use/cover changes in Lednica Landscape Park. Preliminary results indicate a considerable potential of spectral analysis based on Sentinel-2 to monitor changes related to building development, as well as for the precise planning of a field survey. Sentinel-1 proved more problematic due to a range of factors related to data characteristics and processing. Using those results, we will discuss the potential and limitations of the proposed methodology and data

    Uses of Sentinel-1 and -2 Images in Heritage Management: A Case Study from Lednica Landscape Park (Poland)

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    This article aims to demonstrate the use of Sentinel images to develop strategies for heritage protection and management in rural landscapes that are currently undergoing dynamic transformations. Construction works are causing rapid and extensive land use changes that threaten archaeological structures. Moreover, the modernisation of farming practices may also negatively affect the efficiency of archaeological prospection. The rapidity of those processes requires the application of relevant tools to monitor changes and highlight negative tendencies in areas surrounding archaeological sites. High frequency of Sentinel-1 and -2′s acquisition may offer an immediate insight into current tendencies. Radar and optical data obtained from those satellites between 2016 and 2020 were analysed to identify trends in building development and land use/cover changes in Lednica Landscape Park. Preliminary results indicate a considerable potential of spectral analysis based on Sentinel-2 to monitor changes related to building development, as well as for the precise planning of a field survey. Sentinel-1 proved more problematic due to a range of factors related to data characteristics and processing. Using those results, we will discuss the potential and limitations of the proposed methodology and data

    Study of the possibility of using dynamic imagery (video) from a low level (BSP) for photogrammetric studies

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    The use of unmanned aerial vehicles is becoming more and more popular for making high-altitude and orthophotomap models. In this process, series of images are taken at specific intervals, usually lasting several seconds. This article demonstrates the ability to make models and orthophotomaps from dynamic images – video recorded from UAV. The best mutual coverage of photographs was indicated (95–96%) and the photogrammetric process for joining images was presented, through the creation of a point cloud to obtain a digital terrain model and the orotfotomap. The data was processed in 150 different variants and the usefulness of this method was demonstrated. Problems and errors that may occur during the processing of recorded image data are also described

    Assessment of soil characteristics using three bands agri-cultural digital camera

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    Remote sensing techniques based on soil spectral characteristics are the key to future land management; however, they still require field measurement and an agrochemical laboratory for the calibration of the soil property model. Visible and near-infrared diffuse reflectance spectroscopy has proven to be a rapid and effective method. This study aimed to assess the suitability of multispectral data acquired with the agricultural digital camera in determining soil properties. This 3.2-Mpx camera captures images in three spectral bands – green, red and near-infrared. First, the reference data were collected, which consist of 151 samples that were later examined in the laboratory to specify the granulometric composition and to quantify some chemical elements. Second, additional soil properties such as cation exchange capacity, organic carbon and soil pH were measured. Finally, the agricultural digital camera photograph was taken for every soil sample. Reflectance values in three available spectra bands were used to calculate the spectra indices. The relationships between the collected data were calculated using the independent validation regression model such as Cubist and cross-validation model like partial least square in R Studio. Additionally, different types of data normalisation multiplicative scatter correction, standard normal variate, min–max normalisation, conversion into absorbance] were used. The results proved that the agricultural digital camera is suitable for soil property assessment of sand and silt, pH, K, Cu, Pb, Mn, F, cation exchange capacity and organic carbon content. Coefficient of determina-tion varied from 0.563 (for K) to 0.986 (for soil organic carbon). Higher values were obtained with the Cubist regression model than with partial least squares

    Digital aerial images land cover classification based on vegetation indices

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    Knowledge of how land cover has changed over time improve assessments of the changes in the future. Wide availability of remote sensed data and relatively low cost of their acquisition make them very attractive data source for Geographical Information Systems (GIS). The main goal of this paper is to prepare, run and evaluate image classification using a block of raw aerial images obtained from Digital Mapping Camera (DMC). Classification was preceded by preparation of raw images. It contained geometric and radiometric correction of every image in block. Initial images processing lead to compensate their brightness differences. It was obtained by calculating two vegetation indices: Normalized Difference Vegetation Index (NDVI) and Green Normalized Vegetation Index (gNDVI). These vegetation indices were the foundation of image classification. PCI Geomatics Geomatica 10.2 and Microimages TNT Mips software platforms were used for this purpose

    Experience Gained When Using the Yuneec E10T Thermal Camera in Environmental Research

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    Thermal imaging is an important source of information for geographic information systems (GIS) in various aspects of environmental research. This work contains a variety of experiences related to the use of the Yuneec E10T thermal imaging camera with a 320 × 240 pixel matrix and 4.3 mm focal length dedicated to working with the Yuneec H520 UAV in obtaining data on the natural environment. Unfortunately, as a commercial product, the camera is available without radiometric characteristics. Using the heated bed of the Omni3d Factory 1.0 printer, radiometric calibration was performed in the range of 18–100 °C (high sensitivity range–high gain settings of the camera). The stability of the thermal camera operation was assessed using several sets of a large number of photos, acquired over three areas in the form of aerial blocks composed of parallel rows with a specific sidelap and longitudinal coverage. For these image sets, statistical parameters of thermal images such as the mean, minimum and maximum were calculated and then analyzed according to the order of registration. Analysis of photos taken every 10 m in vertical profiles up to 120 m above ground level (AGL) were also performed to show the changes in image temperature established within the reference surface. Using the established radiometric calibration, it was found that the camera maintains linearity between the observed temperature and the measured brightness temperature in the form of a digital number (DN). It was also found that the camera is sometimes unstable after being turned on, which indicates the necessity of adjusting the device’s operating conditions to external conditions for several minutes or taking photos over an area larger than the region of interest

    Seasonal Net Shortwave Radiation of Bare Arable Land in Poland and Israel According to Roughness and Atmospheric Irradiance

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    International audienceTillage of arable fields, using for instance a smoothing harrow, may increase the magnitude of albedo of such soil surfaces depending on the location, the sun’s illumination and atmospheric components. As these soil surfaces absorb less shortwave radiation compared to plowed soils, the result is an atmospheric cooling and a positive effect on the Earth’s climate. This paper is the follow-on of a previous study aimed at quantifying the seasonal dynamics of net shortwave radiation reflected by bare air-dried arable land areas located in contrasting environments, i.e. Poland and Israel. Soil tillage includes a plow, a disk harrow, and a smoothing harrow. Previous work concentrated on the estimate of net shortwave radiation under clear-sky theoretical scenarios, whereas the present study deals with a realistic atmosphere throughout the year 2014. This latter is characterized by the observations of the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument on board the Meteosat Second Generation (MSG). The variations of the net shortwave radiation for the selected bare arable land areas were assessed in combining observations from Landsat 8 images and digital maps of land use and soil, plus model equations that calculate the diurnal variations of the broadband blue-sky albedo with roughness inclusive. The daily amount of net shortwave radiation for air-dried bare arable land in Poland and Israel for the time their spatial coverage is the largest was found to be about 40–50% and 10% lower, respectively, in cloudy-sky conditions compared to clear-sky conditions

    Spectral Indices as a Tool to Assess the Moisture Status of Forest Habitats

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    Measurement of water content in forest habitats is considered essential in ecological research on forests, climate change, or forest management. In the traditional forest habitat classification, two systems of habitat conditions analysis are found: single factor and multifactor methods. Both are laborious and therefore costly. Remote sensing methods provide a low-cost alternative. The aim of the presented study was to find the relationship between the spectral indices obtained from satellite images and the forest habitats moisture indices used traditionally in the Polish forest habitats classification. The scientific hypothesis of the research is as follows: it is possible to assess the variation in the humidity of forest habitats on the basis of spectral indices. Using advanced geographic information system (GIS) technology, 923 research plots were tested, where habitat studies performed with the traditional methods were compared with the analysis of 191 spectral indices calculated for Sentinel-2 image data. The normalized difference vegetation index (NDVI) has proved to be the most useful to the assessing of moisture of forest habitats. The ranking of the most correlated indices was calculated as Eintg—the product of the absolute value of the slope and the mean square error complement, and for the top five indices was as follows: NDVI = 0.248619, EXG = 0.242112, OSAVI = 0.239412, DSWI-4 = 0.238784, and RDVI = 0.236995. The results also highlight the impact of water reservoirs on the humidity and trophicity of forest habitats, showing a decrease in the fertility of habitats with an increase in distance from the water reservoir. The results of the study can be used to preparing maps of the diversity of forest types, especially in hard-to-reach places, as well as to assess changes in the moisture status of habitats, which may be useful, for example, in the assessment of the fire risk of forest habitats. We have proved that NDVI can be used in applications for which it was not originally designed

    Shortwave Radiation Affected by Agricultural Practices

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    The albedo of bare soil depends on its organic matter, iron oxide, carbonate contents, and reflectance geometry, features considered stable over time, and also depends on salinity, moisture and roughness, which change dynamically due to agricultural practices. This paper deals with the quantitative estimation of the amount of shortwave radiation that could be reflected by air-dried bare soils in clear-sky conditions within arable lands in Israel throughout the year, assuming that they were shaped by a plough, a disk harrow, or a smoothing harrow. An area of bare soils was extracted from Landsat 8 images, within the contours of arable lands. The radiation reflected from the bare soils was calculated by equations predicting variations in their half-diurnal albedo as the solar zenith angle function. Accordingly, laboratory reflectance data of Israeli soil samples were used. The results clearly showed annual variation in the amount of short-wave radiation reflected from all bare soils within arable lands. The minimum radiation occurred in the winter, between the 1st and 70th day of the year (DOY), and the maximum was identified in the summer between 200th and 250th DOY. This could reach about 3–5 PJ/day and 16–23 PJ/day, respectively
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