scholarly journals Results of Integrated Geoarchaeological Prospection of Unique Iron Age Hillfort Located on Radomno Lake Island in North-Eastern Poland

2018 ◽  
Vol 35 (1) ◽  
pp. 55-71 ◽  
Author(s):  
Fabian Welc ◽  
Jerzy Nitychoruk ◽  
Rafał Solecki ◽  
Kamil Rabiega ◽  
Jacek Wysocki
Keyword(s):  
Iron Age ◽  
Laser Scanning ◽  
Geological Structure ◽  
Light Detection And Ranging ◽  
Archaeological Sites ◽  
Airborne Laser ◽  
North Eastern ◽  
Forested Areas ◽  
Archaeological Objects ◽  
Geophysical Prospection

Abstract Archaeology of north-eastern Poland has been poorly recognized owing to vast forest areas and numerous lakes. This particularly refers to the Warmian-Masurian Voivodship, where forest covers over 30% of its area. Prospection of forested areas has become possible in Poland just over 10 years ago with the Airborne Laser Scanning (ALS) and Light Detection and Ranging (LiDAR). These techniques allow obtaining 3-D documentation of recognized and also unknown archaeological sites in the forested areas. Thanks to ALS/LiDAR prospection a significant number of archaeological structures have been identified also in the Warmia and Masuria regions. Among them oval-shaped hillforts, surrounded by perfectly spaced concentric moats and ramparts, located mainly on islands and in wetland areas, have raised particular attention. Based on field prospection and results of preliminary excavations, these objects have been considered as Iron Age hillforts. One of the best preserved objects of this type is on the Radomno Lake island, located several kilometres to the south of Iława town. Integrated geoarchaeological prospection of this hillfort emphasized benefits of using LiDAR in combination with results of geophysical prospection and shallow drillings. Applied methodology enabled to document the hillfort shape, and to study its geological structure and stratigraphy. The results clearly indicate that integration of LiDAR data with geophysical prospecting is indispensable in future archaeological surveys. It is a perfect tool for remote sensing of archaeological objects in forest areas, so far not available for traditional archaeology.

Archaeological prospection of forested areas using full-waveform airborne laser scanning

2008 ◽  
Vol 35 (4) ◽  
pp. 882-893 ◽  
Author(s):  
Michael Doneus ◽  
Christian Briese ◽  
Martin Fera ◽  
Martin Janner
Keyword(s):  
Laser Scanning ◽  
Airborne Laser Scanning ◽  
Archaeological Prospection ◽  
Full Waveform ◽  
Airborne Laser ◽  
Forested Areas

scholarly journals A novel automated method for the improvement of photogrammetric DTM accuracy in forests

2018 ◽  
Vol 142 (11-12) ◽  
pp. 576-577 ◽  
Author(s):  
Mateo Gašparović ◽  
Ivan Balenović ◽  
Ante Seletković ◽  
Anita Simic Milas
Keyword(s):  
Quercus Robur ◽  
Laser Scanning ◽  
Digital Terrain Model ◽  
Light Detection And Ranging ◽  
Mean Square ◽  
Terrain Model ◽  
Digital Terrain ◽  
Automated Method ◽  
Airborne Laser ◽  
Fraxinus Angustifolia

Digitalni model reljefa (DTM, engl. Digital Terrain Model) ima široku i važnu primjenu u mnogim djelatnostima, uključujući i šumarstvo. Međutim, precizno modeliranje terena, odnosno izrada DTM-a u šumama, bilo korištenjem terenskih metoda ili metoda daljinskih istraživanja, izazovan je i vrlo zahtjevan zadatak. U većini razvijenih zemalja svijeta, zračno lasersko skeniranje (ALS, engl. Airborne Laser Scanning) bazirano na LiDAR (engl. Light Detection and Ranging) tehnologiji trenutno predstavlja glavnu metodu za izradu DTM-a. Uslijed mogućnosti laserskog zračenja da penetrira kroz krošnje drveća, LiDAR tehnologija se pokazala kao efektivna i brza metoda za izradu DTM-a u šumskim područjima s vrlo velikom točnošću. Međutim, u mnogim zemljama svijeta, uključujući i Hrvatsku, zračno lasersko skeniranje nije u potpunosti provedeno, tj. samo su manji dijelovi zemlje pokriveni s podacima zračnog laserskog skeniranja. U tim slučajevima, DTM temeljen na stereo-fotogrametrijskoj izmjeri aerosnimaka potpomognut s terenskim podacima najčešće predstavlja glavni izvor informacija za izradu DTM-a. Poznato je da tako izrađen DTM u šumskim predjelima ima manju točnost od DTM-a dobivenog na temelju zračnog laserskog skeniranja zbog pokrivenosti terena vegetacijom. Također, u okviru nedavno provedenog istraživanja (Balenović i dr., 2018) utvrđeno je da takvi službeni fotogrametrijski digitalni podaci terena u šumskim predjelima sadrže određen broj tzv. grubih grešaka, koje mogu značajno utjecati na točnost izrađenog DTM-a. Nakon vizualnog detektiranja i manualnog uklanjanja tih pogrešaka, Balenović i dr. (2018) utvrdili su značajno poboljšanje točnosti fotogrametrijskog DTM-a. Stoga je glavni cilj ovoga rada razviti automatsku metodu za detekciju i eliminaciju vertikalnih pogrešaka u fotogrametrijskim digitalnim podacima terena te na taj način poboljšati točnost fotogrametrijskog DTM-a u nizinskim šumskim područjima Hrvatske. Ideja je razviti brzu, jednostavnu i učinkovitu metodu koja će biti primjenjiva i za druga šumska područja sličnih karakteristika, a za koja ne postoje DTM dobiven zračnim laserskim skeniranjem. Istraživanje je provedeno u nizinskim šumama na području gospodarske jedinice Jastrebarski lugovi, u neposrednoj blizini Jastrebarskog (Slika 1). Istraživanjem je obuhvaćena površina od 2.005,74 ha, na kojoj su u najvećoj mjeri zastupljene jednodobne sastojine hrasta lužnjaka (Quercus robur L.), a u ma­njoj mjeri jednodobne sastojine poljskog jasena (Fraxinus angustifolia L.) te jednodobne sastojine običnoga graba (Carpinus betulus L.). Nadmorska visina područja istraživanja kreće se u rasponu od 105 do 121 m. Fotogrametrijski DTM (DTM<sub>PHM</sub>) je izrađen iz digitalnih vektorskih podataka terena (prijelomnice, linije oblika, markantne točke terena i pravokutne mreže visinskih točaka) nabavljenih iz Državne geodetske uprave (Slika 2). Ti podaci predstavljaju nacionalni standard i jedini su dostupni podaci za izradu DTM-a u Hrvatskoj. Detaljan opis vektorskih podataka dan je u radu Balenović i dr. (2018). Prvo je iz digitalnih terenskih podataka izrađena nepravilna mreža trokuta, koja je potom linearnom interpolacijom pretvorena u rasterski DTM<sub>PHM</sub> prostorne rezolucije (veličine piksela) 0,5 m. Automatska metoda za detekciju i eliminaciju vertikalnih pogrešaka fotogrametrijskog DTM-a u nizinskim šumskim područjima razvijena je u slobodnom programskom paketu Grass GIS (Slika 3). Kombinacijom vrijednosti nagiba i tangencijalne zakrivljenosti terena rasterskog DTM<sub>PHM</sub> (Slika 4), automatskom metodom su detektirane 91 grube greške (engl. outliers). Drugim riječima, utvrđeno je da 91 točkasti vektorski objekt pogrešno prikazuje stvarnu visinu terena. Navedeni broj čini 3,2 % od ukupnog broja točkastih objekata korištenih za izradu DTM<sub>PHM</sub>-a. Nakon eliminacije detektiranih pogrešaka izrađen je novi, korigirani fotogrametrijski DTM (DTM<sub>PHMc</sub>). Za ocjenu vertikalne točnosti izvornog (DTM<sub>PHM</sub>) i korigiranog DTM-a (DTM<sub>PHMc</sub>) korišten je visoko precizni DTM dobiven zračnim laserskim skeniranjem (DTM<sub>LiD</sub>). U tu svrhu su izrađeni rasteri razlika između DTM<sub>PHM </sub>i DTM<sub>LiD</sub>, te između DTM<sub>PHMc </sub>i DTM<sub>LiD</sub>. Kako je preliminarnom analizom utvrđeno da vertikalne razlike između DTM<sub>PHM </sub>i DTM<sub>LiD</sub> nisu normalno distribuirane (Slika 5), za ocjenu točnosti su uz normalne mjere točnosti korištene i tzv. robusne mjere točnosti (Tablica 2). Dobiveni rezultati ukazuju na poboljšanje vertikalne točnosti fotogrametrijskog DTM-a primjenom razvijene automatske metode. To je posebice uočljivo na podpodručjima 2 i 3 (Slika 6 i 7) u kojima se nakon uklanjanja detektiranih grešaka, korijen srednje kvadratne pogreške (RMSE, engl. root mean square error) smanjio za 8 % odnosno 50 % (Tablica 2). Na temelju dobivenih rezultata i usporedbe s DTM<sub>LiD</sub>, može se zaključiti da predložena metoda uspješno detektira i eliminira vertikalne pogreške fotogrametrijskog DTM-a u nizinskim šumskim područjima, te slijedom toga poboljšava njegovu vertikalnu točnost.

Detection of fallen trees in forested areas using small footprint airborne laser scanning data

2013 ◽  
Vol 39 (sup1) ◽  
pp. S32-S40 ◽  
Author(s):  
Werner Mücke ◽  
Balázs Deák ◽  
Anke Schroiff ◽  
Markus Hollaus ◽  
Norbert Pfeifer
Keyword(s):  
Laser Scanning ◽  
Airborne Laser Scanning ◽  
Airborne Laser ◽  
Forested Areas ◽  
Small Footprint

scholarly journals Dostrzec i zrozumieć. Porównanie wybranych metod wizualizacji danych ALS wykorzystywanych w archeologii

2018 ◽  
Vol 22 ◽  
pp. 233-270 ◽  
Author(s):  
Grzegorz Kiarszys ◽  
Łukasz Banaszek
Keyword(s):  
Laser Scanning ◽  
Spatial Information ◽  
Human Mind ◽  
Airborne Laser Scanning ◽  
Airborne Laser ◽  
Visual Phenomena ◽  
Visualization Techniques ◽  
Archaeological Objects

Application of airborne laser scanning (ALS) for archaeological purposes allows for identification of relief features. Unless the detection is automated, the recognition of archaeological objects in the observed dataset is bounded by the interaction between human mind, eye and visual phenomena that are displayed on the screen. To improve effectiveness of ALS interpretation several visualization techniques have been developed. However, due to their complexity the spatial information produced by these algorithms differs. The aim of the paper is to present the discrepancies between the most popular visualization techniques used for archaeological purposes. Unlike previous attempts, the presented comparison is based on the vector outputs of the interpretative mapping. Therefore, we demonstrate in detail the differences in the morphology as well as quantity of identified archaeological features due to the use of various visualization techniques.

Comparing airborne laser scanning-imagery fusion methods based on geometric accuracy in forested areas

2011 ◽  
Vol 115 (8) ◽  
pp. 1942-1954 ◽  
Author(s):  
Rubén Valbuena ◽  
Francisco Mauro ◽  
Francisco José Arjonilla ◽  
José Antonio Manzanera
Keyword(s):  
Laser Scanning ◽  
Airborne Laser Scanning ◽  
Geometric Accuracy ◽  
Airborne Laser ◽  
Fusion Methods ◽  
Forested Areas

scholarly journals EVALUATION OF VERTICAL LACUNARITY PROFILES IN FORESTED AREAS USING AIRBORNE LASER SCANNING POINT CLOUDS

2016 ◽  
Vol III-8 ◽  
pp. 93-99
Author(s):  
B. Székely ◽  
A. Kania ◽  
T. Standovár ◽  
H. Heilmeier
Keyword(s):  
Laser Scanning ◽  
Dynamic Range ◽  
Canopy Structure ◽  
Three Dimensional ◽  
Point Clouds ◽  
Reference Points ◽  
Airborne Laser Scanning ◽  
Topographic Effects ◽  
Airborne Laser ◽  
Forested Areas

The horizontal variation and vertical layering of the vegetation are important properties of the canopy structure determining the habitat; three-dimensional (3D) distribution of objects (shrub layers, understory vegetation, etc.) is related to the environmental factors (e.g., illumination, visibility). It has been shown that gaps in forests, mosaic-like structures are essential to biodiversity; various methods have been introduced to quantify this property. As the distribution of gaps in the vegetation is a multi-scale phenomenon, in order to capture it in its entirety, scale-independent methods are preferred; one of these is the calculation of lacunarity. <br><br> We used Airborne Laser Scanning point clouds measured over a forest plantation situated in a former floodplain. The flat topographic relief ensured that the tree growth is independent of the topographic effects. The tree pattern in the plantation crops provided various quasi-regular and irregular patterns, as well as various ages of the stands. The point clouds were voxelized and layers of voxels were considered as images for two-dimensional input. These images calculated for a certain vicinity of reference points were taken as images for the computation of lacunarity curves, providing a stack of lacunarity curves for each reference points. These sets of curves have been compared to reveal spatial changes of this property. As the dynamic range of the lacunarity values is very large, the natural logarithms of the values were considered. Logarithms of lacunarity functions show canopy-related variations, we analysed these variations along transects. The spatial variation can be related to forest properties and ecology-specific aspects.

scholarly journals The utility of fused airborne laser scanning and multispectral data for improved wind damage risk assessment over a managed forest landscape in Finland

2020 ◽  
Vol 77 (4) ◽  
Author(s):  
Ranjith Gopalakrishnan ◽  
Petteri Packalen ◽  
Veli-Pekka Ikonen ◽  
Janne Räty ◽  
Ari Venäläinen ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Laser Scanning ◽  
Remote Sensing Data ◽  
Wind Damage ◽  
Sensing Data ◽  
Wind Speeds ◽  
Airborne Laser ◽  
Forested Areas ◽  
Risk Maps ◽  
Damage Risk

Abstract Key message The potential of airborne laser scanning (ALS) and multispectral remote sensing data to aid in generating improved wind damage risk maps over large forested areas is demonstrated. This article outlines a framework to generate such maps, primarily utilizing the horizontal structural information contained in the ALS data. Validation was done over an area in Eastern Finland that had experienced sporadic wind damage. Context Wind is the most prominent disturbance element for Finnish forests. Hence, tools are needed to generate wind damage risk maps for large forested areas, and their possible changes under planned silvicultural operations. Aims (1) How effective are ALS-based forest variables (e.g. distance to upwind forest stand edge, gap size) for identifying high wind damage risk areas? (2) Can robust estimates of predicted critical wind speeds for uprooting of trees be derived from these variables? (3) Can these critical wind speed estimates be improved using wind multipliers, which factor in topography and terrain roughness effects? Methods We first outline a framework to generate several wind damage risk–related parameters from remote sensing data (ALS + multispectral). Then, we assess if such parameters have predictive power. That is, whether they help differentiate between damaged and background points. This verification exercise used 42 wind damaged points spread over a large area. Results Parameters derived from remote sensing data are shown to have predictive power. Risk models based on critical wind speeds are not that robust, but show potential for improvement. Conclusion Overall, this work described a framework to get several wind risk–related parameters from remote sensing data. These parameters are shown to have potential in generating wind damage risk maps over large forested areas.

scholarly journals EVALUATION OF VERTICAL LACUNARITY PROFILES IN FORESTED AREAS USING AIRBORNE LASER SCANNING POINT CLOUDS

2016 ◽  
Vol III-8 ◽  
pp. 93-99
Author(s):  
B. Székely ◽  
A. Kania ◽  
T. Standovár ◽  
H. Heilmeier
Keyword(s):  
Laser Scanning ◽  
Dynamic Range ◽  
Canopy Structure ◽  
Three Dimensional ◽  
Point Clouds ◽  
Reference Points ◽  
Airborne Laser Scanning ◽  
Topographic Effects ◽  
Airborne Laser ◽  
Forested Areas

The horizontal variation and vertical layering of the vegetation are important properties of the canopy structure determining the habitat; three-dimensional (3D) distribution of objects (shrub layers, understory vegetation, etc.) is related to the environmental factors (e.g., illumination, visibility). It has been shown that gaps in forests, mosaic-like structures are essential to biodiversity; various methods have been introduced to quantify this property. As the distribution of gaps in the vegetation is a multi-scale phenomenon, in order to capture it in its entirety, scale-independent methods are preferred; one of these is the calculation of lacunarity. &lt;br&gt;&lt;br&gt; We used Airborne Laser Scanning point clouds measured over a forest plantation situated in a former floodplain. The flat topographic relief ensured that the tree growth is independent of the topographic effects. The tree pattern in the plantation crops provided various quasi-regular and irregular patterns, as well as various ages of the stands. The point clouds were voxelized and layers of voxels were considered as images for two-dimensional input. These images calculated for a certain vicinity of reference points were taken as images for the computation of lacunarity curves, providing a stack of lacunarity curves for each reference points. These sets of curves have been compared to reveal spatial changes of this property. As the dynamic range of the lacunarity values is very large, the natural logarithms of the values were considered. Logarithms of lacunarity functions show canopy-related variations, we analysed these variations along transects. The spatial variation can be related to forest properties and ecology-specific aspects.

scholarly journals Reconstructing Aircraft Trajectories from Multi-Return Airborne Laser-Scanning Data

2019 ◽  
Vol 11 (19) ◽  
pp. 2258
Author(s):  
Demetrios Gatziolis ◽  
Robert J. McGaughey
Keyword(s):  
Pacific Northwest ◽  
Laser Scanning ◽  
Airborne Laser Scanning ◽  
Airborne Laser ◽  
The Us ◽  
Forested Areas ◽  
Additional Costs ◽  
Novel Method ◽  
Aircraft Trajectories ◽  
Northwest Region

Data describing aircraft position and attitude are essential to computing return positions from ranging data collected during airborne laser scanning (ALS) campaigns. However, these data are often excluded from the products delivered to the client and their recovery after the contract is complete can require negotiations with the data provider, may involve additional costs, or even be infeasible. This paper presents a rigorous, fully automated, novel method for recovering aircraft positions using only the point cloud. The study used ALS data from five acquisitions in the US Pacific Northwest region states of Oregon and Washington and validated derived aircraft positions using the smoothed best estimate of trajectory (SBET) provided for the acquisitions. The computational requirements of the method are reduced and precision is improved by relying on subsets of multiple-return pulses, common in forested areas, with widely separated first and last returns positioned at opposite sides of the aircraft to calculate their intersection, or closest point of approach. To provide a continuous trajectory, a cubic spline is fit to the intersection points. While it varies by acquisition and parameter settings, the error in the computed aircraft position seldom exceeded a few meters. This level of error is acceptable for most applications. To facilitate use and encourage modifications to the algorithm, the authors provide a code that can be applied to data from most ALS acquisitions.

scholarly journals Bronze Weapon of the Early Iron Age from the Collection of Findings Gathered by Alexander Gustav von Schrenck in the 1840s in the Irtysh Region

2019 ◽  
Vol 18 (3) ◽  
pp. 17-23
Author(s):  
Yu. S. Khudyakov ◽  
A. Yu. Borisenko
Keyword(s):  
Central Asia ◽  
Iron Age ◽  
Archaeological Sites ◽  
Early Iron Age ◽  
Russian Scientist ◽  
Saint Petersburg ◽  
Peter The Great ◽  
Eurasian Steppe ◽  
The 19Th Century ◽  
Archaeological Objects

Purpose. The article introduces single findings of bronze armament objects that were gathered in the course of an expeditionary journey during 1840–1843 on the territory of the Irtysh region (within the limits of southern steppe regions of Western Siberia, Altai Steppes and Eastern Kazakhstan) by a famous Russian scientist, botanist, officer of Saint Petersburg Botanical Gardens Alexander Gustav von Schrenck. Results. The archaeological objects gathered by the explorer are presently stored in the collection of the Peter the Great Museum of Anthropology and Ethnography of RAS in Saint Petersburg. They include various objects of armament and accessories of horse harness. The archaeological objects considered in the article are armament objects of close and hand-to-hand combats of ancient nomads. They are analyzed and classified on formal grounds according to the previously developed scientific methodology. The collection features a bronze spearhead with a bilobated feather and conical plug, a bronze dagger with a guard and a top and two bronze plug chisels with tetrahedral and circular peen and elongated butt ends. We provide some comments on chronology and the territory where similar objects were found in the sites of the Early Iron Age in Eurasian Steppe. Our classification is based on analogues of the objects studied, which were found at several archaeological sites on the contiguous territories of Southern Siberia and Central Asia. We also made certain assumptions on the cultural identity of the findings of the bronze armament objects of close and hand-to-hand combats which we analyzed. Conclusion. Having considered the analogues, we refer the objects of the ancient bronze weapon studied as a part of the museum collection and stored there, which were gathered on the territory of the Irtysh Region in the middle of the 19th century by A. G. von Schrenck, to the complex of battlefield assets of the ancient Eurasian Steppe nomads of Scythian times. The analysis provided and our introduction of these materials expands the range of available sources on armament and military science of the ancient nomadic population gathered by A. G. von Schrenck in several regions of Northern and Central Asia.

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