Determination of tree height according to data of raster images different resolution

The collection of information on the growth and development of trees is the basis for planning forestry and horticulture, while the relevance and reliability of such data defines the quality of forest and park inventory outputs. Currently in Ukraine, the height of growing trees and shrubs is measured mostly by clinometer. The enhancement of unmanned aerial vehicles (UAVs) and methods of processing the collected information allow to amplify the level of quality and accuracy of the collected data. Our goal was to consider the possibility of determining the height of trees based on aerial photography materials obtained by UAVs and to assess the accuracy of measured indicators modeling crown height at different spatial resolutions. Here we used methods of creating a digital canopy height model (CHM) from aerial photographs obtained by UAVs. We produced 8 digital elevation and terrain models for the calculation of CHM. Raster image analysis was performed using the ArcGIS software and Spatial Analyst toolkit using the Focal statistics filter. We have confirmed the possibility of CHM utilization to measure the height of trees in structurally homogeneous stands. Here we have shown the change of height values of Scots pine trees (Pinus sylvestris L.) and the deviation of the arithmetic mean value of the height for model trees applying the raster images with different spatial resolutions. Predicted tree heights were compared with the empirical values, which were obtained directly measuring the felled sample trees with the addition of stump height. CHM analysis with a cell size of 0.04 m2 and 0.1 m2 shows the smallest height deviations for model trees in the stand. The deviations relative to arithmetic mean were 2.3 % and 2.6 %. Raster images with a more coarse resolution (more than 1 m2) are not recommended in forest practice, since their utilizing entails a measurement error of 17% and higher, and thus exceeding the permissible deviations in tree height measurements according to the forest inventory guidelines currently applied in Ukraine.

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SETI, Evolution and Human History Merged into a Mathematical Model

International Journal of Astrobiology ◽

10.1017/s1473550413000086 ◽

2013 ◽

Vol 12 (3) ◽

pp. 218-245 ◽

Cited By ~ 17

Author(s):

Claudio Maccone

Keyword(s):

Mathematical Model ◽

Exponential Growth ◽

Numerical Estimate ◽

Mean Value ◽

Darwinian Evolution ◽

Human History ◽

The Galaxy ◽

Positive Time ◽

A Cell ◽

Geometric Locus

AbstractIn this paper we propose a new mathematical model capable of merging Darwinian Evolution, Human History and SETI into a single mathematical scheme:(1) Darwinian Evolution over the last 3.5 billion years is defined as one particular realization of a certain stochastic process called Geometric Brownian Motion (GBM). This GBM yields the fluctuations in time of the number of species living on Earth. Its mean value curve is an increasing exponential curve, i.e. the exponential growth of Evolution.(2) In 2008 this author provided the statistical generalization of the Drake equation yielding the number N of communicating ET civilizations in the Galaxy. N was shown to follow the lognormal probability distribution.(3) We call “b-lognormals” those lognormals starting at any positive time b (“birth”) larger than zero. Then the exponential growth curve becomes the geometric locus of the peaks of a one-parameter family of b-lognormals: this is our way to re-define Cladistics.(4) b-lognormals may be also be interpreted as the lifespan of any living being (a cell, or an animal, a plant, a human, or even the historic lifetime of any civilization). Applying this new mathematical apparatus to Human History, leads to the discovery of the exponential progress between Ancient Greece and the current USA as the envelope of all b-lognormals of Western Civilizations over a period of 2500 years.(5) We then invoke Shannon's Information Theory. The b-lognormals' entropy turns out to be the index of “development level” reached by each historic civilization. We thus get a numerical estimate of the entropy difference between any two civilizations, like the Aztec-Spaniard difference in 1519.(6) In conclusion, we have derived a mathematical scheme capable of estimating how much more advanced than Humans an Alien Civilization will be when the SETI scientists will detect the first hints about ETs.

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Improving the accuracy of forming a digital terrain model along the railway

Izmeritel`naya Tekhnika ◽

10.32446/0368-1025it.2021-2-22-29 ◽

2021 ◽

pp. 22-29

Author(s):

Dmitriy A. Roshchin

Keyword(s):

High Efficiency ◽

Digital Terrain Model ◽

Digital Processing ◽

Aerial Photographs ◽

Railway Track ◽

Technical Solution ◽

Digital Terrain Models ◽

Terrain Model ◽

Digital Terrain ◽

Terrain Models

The problem of improving the accuracy of digital terrain models created for monitoring and diagnostics of the railway track and the surrounding area is considered. A technical solution to this problem is presented, which includes a method for joint aerial photography and laser scanning, as well as a method for digital processing of the obtained data. The relevance of using this solution is due to the existence of zones of weak reception of signals from the global navigation satellite system, since in these zones the accuracy of constructing digital terrain models using currently used diagnostic spatial scanning systems is reduced. The technical solution is based on the method of digital processing of aerial photographs of the railway track. In this case, as elements of external orientation, the threads of the rail track located at a normalized distance from each other are used. The use of this method made it possible to increase the accuracy of determining the flight path of an aircraft over railway tracks and, as a result, the accuracy of calculating the coordinates of points on the earth's surface. As a result, a digital terrain model was created that is suitable for diagnostics and monitoring the condition of the railway trackbed. During simulation modeling, it was found that the application of the proposed method allowed to reduce to 50 % the confidence interval of the distribution of the error in determining the coordinates of points on the terrain and increase the accuracy of forming a digital terrain model. This promising technical solution for improving the accuracy of digital terrain models for railway track diagnostics is implemented using unmanned aerial vehicles that are part of the mobile diagnostic complex. The advantages of the proposed solution include high efficiency and availability of application.

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Precise computation of the direct and indirect topographic effects of Helmert's 2nd method of condensation using SRTM30 digital elevation model

Journal of Geodetic Science ◽

10.2478/v10156-011-0009-8 ◽

2011 ◽

Vol 1 (4) ◽

pp. 305-312 ◽

Cited By ~ 2

Author(s):

Y. Wang

Keyword(s):

Standard Deviation ◽

Digital Elevation Model ◽

Outer Zone ◽

Mean Value ◽

Constant Density ◽

Topographic Effects ◽

Topographic Effect ◽

Digital Elevation ◽

The Mean ◽

Elevation Model

Precise computation of the direct and indirect topographic effects of Helmert's 2nd method of condensation using SRTM30 digital elevation modelThe direct topographic effect (DTE) and indirect topographic effect (ITE) of Helmert's 2nd method of condensation are computed using the digital elevation model (DEM) SRTM30 in 30 arc-seconds globally. The computations assume a constant density of the topographic masses. Closed formulas are used in the inner zone of half degree, and Nagy's formulas are used in the innermost column to treat the singularity of integrals. To speed up the computations, 1-dimensional fast Fourier transform (1D FFT) is applied in outer zone computations. The computation accuracy is limited to 0.1 mGal and 0.1cm for the direct and indirect effect, respectively.The mean value and standard deviation of the DTE are -0.8 and ±7.6 mGal over land areas. The extreme value -274.3 mGal is located at latitude -13.579° and longitude 289.496°, at the height of 1426 meter in the Andes Mountains. The ITE is negative everywhere and has its minimum of -235.9 cm at the peak of Himalayas (8685 meter). The standard deviation and mean value over land areas are ±15.6 cm and -6.4 cm, respectively. Because the Stokes kernel does not contain the zero and first degree spherical harmonics, the mean value of the ITE can't be compensated through the remove-restore procedure under the Stokes-Helmert scheme, and careful treatment of the mean value in the ITE is required.

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Visible and near-infrared digital images for determination of ice velocities and surface elevation during a surge on Osbornebreen, a tidewater glacier in Svalbard

Annals of Glaciology ◽

10.3189/s026030550001226x ◽

1997 ◽

Vol 24 ◽

pp. 255-261 ◽

Cited By ~ 8

Author(s):

Cecilie Rolstad ◽

Jostein Amlien ◽

Jon-Ove Hagen ◽

Bengt Lundén

Keyword(s):

Velocity Field ◽

Near Infrared ◽

Aerial Photographs ◽

Correlation Technique ◽

Digital Elevation ◽

Compressive Flow ◽

Tidewater Glacier ◽

Extension Zone ◽

Elevation Model ◽

Cross Correlation Technique

A field of vectors showing the average velocity of the surging glacier Osbornebreen, Svalbard, was determined by comparing sequential SPOT (Système pour l’Observation de la Terre) and Landsat thematic mapper images. Crevasses which developed during the initial phase of the surge in the winter of 1986–87 were tracked using a fast Fourier chip cross-correlation technique. A digital elevation model (DEM) was developed using digital photogrammetry on aerial photographs from 1990. This new DEM was compared with a map drawn in 1966. The velocity field could be almost entirely determined with 1 month separation of the images, but only partly determined with images 1 year apart, due to changes of the crevasse pattern. The velocity field is similar to that found for Kronebreen, a continuously fast-moving tidewater glacier. No distinct zones of compressive flow were present and the data gave no evidence of a compression zone/surge front traveling downstream. The velocity field, the rapid advance of the terminus and the development of transverse crevasses in the upper accumulation area within a 6 month period may indicate that the surge developed as a zone of extension starting near the terminus and propagating quickly upstream. The crevasse pattern in the images is therefore interpreted to be the result of the extension zone traveling upstream, and, as the whole glacier starts to slide, the crevasse pattern alters according to the bedrock topography.

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Estimating plot-level tree height and volume of Eucalyptus grandis plantations using small-footprint, discrete return lidar data

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133310365596 ◽

2010 ◽

Vol 34 (4) ◽

pp. 515-540 ◽

Cited By ~ 43

Author(s):

S.G. Tesfamichael ◽

J.A.N. van Aardt ◽

F. Ahmed

Keyword(s):

Eucalyptus Grandis ◽

Tree Height ◽

Mean Value ◽

Primary Objective ◽

Stand Age ◽

Lidar Data ◽

Maximum Height ◽

Density Level ◽

Local Maxima ◽

Small Footprint

This study explores the utility of small-footprint, discrete return lidar data in deriving important forest structural attributes with the primary objective of estimating plot-level mean tree height, dominant height, and volume of Eucalyptus grandis plantations. The secondary objectives of the study were related to investigating the effect of lidar point densities (1 point/m2, 3 points/m2, and 5 points/m2) on height and volume estimates. Tree tops were located by applying local maxima (LM) filtering to canopy height surfaces created at each density level, followed by buffering using circular polygons. Maximum and mean height values of the original lidar points falling within each tree polygon were used to generate lidar mean and dominant heights. Lidar mean value was superior to the maximum lidar value approach in estimating mean plot height (R2∼0.95; RMSE∼7%), while the maximum height approach resulted in superior estimates for dominant plot height (R2 ∼0.95; RMSE∼5%). These observations were similar across all lidar point density levels. Plot-level volume was calculated using approaches based on lidar-derived height variables and stems per hectare, as well as stand age. The level of association between estimated and observed volume was relatively high (R2=0.82—0.94) with non-significant differences among estimates at high lidar point densities and field observation. Nearly all estimates, however, exhibited negative biases and RMSE ranging in the order of 20—43%. Overall, the results of the study demonstrate the potential of lidar-based approaches for forest structural assessment in commercial plantations, even though further research is required on improving stems per hectare (SPHA) estimation.

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Within-ring δ13C spatial variability and interannual variations in wood cellulose of two contrasting provenances of Pinus pinaster

Canadian Journal of Forest Research ◽

10.1139/x98-044 ◽

1998 ◽

Vol 28 (5) ◽

pp. 766-773 ◽

Cited By ~ 1

Author(s):

Anne Nguyen-Queyrens ◽

André Ferhi ◽

Denis Loustau ◽

Jean-Marc Guehl

Keyword(s):

Spatial Variability ◽

Pinus Pinaster ◽

Isotope Composition ◽

Tree Height ◽

Stress Index ◽

Mature Stage ◽

Water Stress Index ◽

Pinus Pinaster Ait ◽

Pine Trees ◽

Drought Resistant

The carbon isotope composition (δ13C) of cellulose extracted from wood samples was measured on 26-year-old maritime pine trees (Pinus pinaster Ait.) of the mesic French provenance Landes and of the drought-resistant Moroccan provenance Tamjoute, all growing at the same location in France. Analysis of spatial variability revealed that intra-ring δ13C values varied over a range of about 0.5%o (mean SD = 0.12%o) for circumference and of about 1%o (mean SD = 0.22%o) for height and that interannual variability of δ13C was 3%o. The successive year-to-year δ13C values on four trees (from 1972 to 1991) were found to roughly parallel the variations of a water stress index, calculated by taking into account climatic variables as well as the level of the water table in the soil: δ13C increased with drought. The two provenances (30 trees per provenance) were compared at a juvenile stage (old rings) and at a mature stage (recent rings). The drought-resistant provenance (Tamjoute) presented lower δ13C values, independent of ring age. Relationships between δ13C and tree height are discussed both at the within- and between-provenance levels.

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Changing the geometry of basins and water resources of Lakes Gopło and Ostrowskie under the influence of anthropopressure

Limnological Review ◽

10.2478/limre-2014-0004 ◽

2014 ◽

Vol 14 (1) ◽

pp. 33-43 ◽

Cited By ~ 3

Author(s):

Piasecki Adam ◽

Skowron Rajmund

Keyword(s):

Water Resources ◽

Surface Area ◽

Water Cycle ◽

Field Measurements ◽

Aerial Photographs ◽

Maximum Width ◽

Digital Terrain ◽

Terrain Models ◽

Basic Parameters ◽

Area And Volume

Abstract The paper presents the changes that have occurred in the morphometry of Lakes Gopło and Ostrowskie, which are located in central Poland. The analysis covered the period characterised by increased human interference into the water cycle, which has been taking place continually since the mid-eighteenth century. On the basis of available cartographic materials (aerial photographs, topographic maps, bathymetric charts of the lakes) and the authors’ own field measurements digital terrain models were developed for the immediate environment of the surveyed lakes. These models, in turn, were used for measuring basic parameters characterising the external dimensions of the lakes (surface area, length and maximum width, shoreline length) and their underwater relief (volume, maximum and average depth). In addition, the selected indicators of the shape and form of the lake basins were determined. The results showed a drastic reduction of water resources of the two lakes. The basin of Lake Gopło covers only the deepest parts of the former reservoir, accounting for only 23.3% of the lake before 1772, and 32.5% of its former volume. In the case of Lake Ostrowskie the surface area and volume decreased, respectively, by 23.5% (74.9 ha) and 21.3% (6 695 000 m3). Such large changes in surface area and volume of both lakes have contributed to significant changes in other morphometric parameters and indicators. In particular, significant changes were observed in relation to such morphometric characteristics as length and maximum width, as well as average and maximum depth.

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DETERMINING THE SUITABILITY OF DIFFERENT DIGITAL ELEVATION MODELS AND SATELLITE IMAGES FOR FANCY MAPS. AN EXAMPLE OF CYPRUS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xli-b4-591-2016 ◽

2016 ◽

Vol XLI-B4 ◽

pp. 591-597

Author(s):

J. Drachal ◽

A. K. Kawel

Keyword(s):

Small Area ◽

Satellite Images ◽

Digital Elevation Models ◽

Test Area ◽

Landsat 8 ◽

Digital Terrain Models ◽

Digital Terrain ◽

Terrain Models ◽

Digital Elevation ◽

Shaded Relief

The article describes the possibility of developing an overall map of the selected area on the basis of publicly available data. Such a map would take the form designed by the author with the colors that meets his expectations and a content, which he considers to be appropriate. Among the data available it was considered the use of satellite images of the terrain in real colors and, in the form of shaded relief, digital terrain models with different resolutions of the terrain mesh. Specifically the considered data were: MODIS, Landsat 8, GTOPO-30, SRTM-30, SRTM-1, SRTM-3, ASTER. For the test area the island of Cyprus was chosen because of the importance in tourism, a relatively small area and a clearly defined boundary. In the paper there are shown and discussed various options of the Cyprus terrain image obtained synthetically from variants of Modis, Landsat and digital elevation models of different resolutions.

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Evolution of a beach–dune system following a catastrophic storm overwash event: Greenwich Dunes, Prince Edward Island, 1936–2005

Canadian Journal of Earth Sciences ◽

10.1139/e09-078 ◽

2010 ◽

Vol 47 (3) ◽

pp. 273-290 ◽

Cited By ~ 41

Author(s):

Sojan Mathew ◽

Robin G.D. Davidson-Arnott ◽

Jeff Ollerhead

Keyword(s):

Prince Edward Island ◽

National Park ◽

Aerial Photographs ◽

Dune System ◽

Aerial Photos ◽

Sand Supply ◽

Digital Elevation ◽

Intense Storm ◽

Geomorphic Units ◽

Subsequent Stabilization

Greenwich Dunes, Prince Edward Island National Park, is a sandy mainland and barrier spit beach–dune complex stretching for about 10 km along the northeast shore of Prince Edward Island, Canada. In October 1923, surge associated with an intense storm produced catastrophic overwash along the whole length of the study area. Subsequent evolution of the system was quantified from historic aerial photographs taken in 1936, 1953, 1971, 1997, and 2005. Orthophoto mosaics were generated for each photo set using PCI Geomatica OrthoEngine, a digital photogrammetric software. Linear changes in shoreline position and areal changes in geomorphic units were evaluated for each photo set. In addition, digital elevation models (DEMs) were extracted from the 1953, 1971, and 1997 aerial photos, enabling analysis of topographic and volumetric changes. The 1936 photos show complete destruction of all foredunes, with overwash and transgressive dunes extending 300 to 600 m inland. A descriptive model of the stages of evolution of the system is proposed based on the processes controlling overwash healing and dune stabilization. Detailed topographic and volumetric changes associated with the development of an extensive transgressive dunefield and subsequent stabilization as a result of reduced sand supply due to the growth of a new vegetated foredune complex and vegetation colonization are doccumented for each stage. It was nearly 40 years before a continuous foredune system was re-established and a further 30 years before the inland transgressive dunes became completely stabilized.

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Recent, rapid and profound changes to glacier morphology and dynamics, Juneau Icefield, Alaska

10.5194/egusphere-egu21-1539 ◽

2021 ◽

Author(s):

Bethan Davies ◽

Jacob Bendle ◽

Robert McNabb ◽

Jonathan Carrivick ◽

Christopher McNeil ◽

...

Keyword(s):

Little Ice Age ◽

Ice Age ◽

Aerial Photographs ◽

Equilibrium Line Altitude ◽

Regional Warming ◽

Geomorphological Mapping ◽

Glacier Recession ◽

Digital Elevation ◽

High Resolution Satellite Imagery ◽

Global Sea Level

The Alaskan region (comprising glaciers in Alaska, British Columbia and Yukon) contains the third largest ice volume outside of the Greenland and Antarctic ice sheets, and contributes more to global sea level rise than any other glacierised region defined by the Randolph Glacier Inventory. However, ice loss in this area is not linear, but in part controlled by glacier hypsometry as valley and outlet glaciers are at risk of becoming detached from their accumulation areas during thinning. Plateau icefields, such as Juneau Icefield in Alaska, are very sensitive to changes in Equilibrium Line Altitude (ELA) as this can result in rapidly shrinking accumulation areas. Here, we present detailed geomorphological mapping around Juneau Icefield and use this data to reconstruct the icefield during the &#8220;Little Ice Age&#8221;. We use topographic maps, archival aerial photographs, high-resolution satellite imagery and digital elevation models to map glacier lake and glacier area and volume change from the Little Ice Age to the present day (1770, 1948, 1979, 1990, 2005, 2015 and 2019 AD). Structural glaciological mapping (1979 and 2019) highlights structural and topographic controls on non-linear glacier recession.&#160; Our data shows pronounced glacier thinning and recession in response to widespread detachment of outlet glaciers from their plateau accumulation areas. Glacier detachments became common after 2005, and occurred with increasing frequency since then. Total summed rates of area change increased eightfold from 1770-1948 (-6.14 km2 a-1) to 2015-2019 (-45.23 km2 a-1). Total rates of recession were consistent from 1770 to 1990 AD, and grew increasingly rapid after 2005, in line with regional warming.

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