Remotely piloted aircraft imagery for automatic tree counting in forest restoration areas: a case study in the Amazon

2020 ◽  
Vol 8 (3) ◽  
pp. 207-223
Author(s):  
Rafael Walter Albuquerque ◽  
Marcelo Oliveira Costa ◽  
Manuel Eduardo Ferreira ◽  
Gabriel Cardoso Carrero ◽  
Carlos Henrique Grohmann
Keyword(s):  
Forest Restoration ◽  
Digital Terrain Model ◽  
Surface Model ◽  
Terrain Model ◽  
Brazilian Government ◽  
Digital Terrain ◽  
Processing Step ◽  
Remotely Piloted Aircraft ◽  
The Difference

Throughout the world, restoration of degraded areas (RDA) is not only a global but also a local challenge. In this context, the Brazilian government committed itself to restore 12 million hectares of forests by 2030. RDA monitoring customarily depends on extensive fieldwork to collect data on all individuals planted. As remotely piloted aircrafts (RPAs) can reduce costs and time of fieldwork activities, studying this technology is therefore timely given. A crucial metric for RDA is the number of trees established in the area. Methods using RPAs on automatic tree counting showed good accuracy using algorithms based on the canopy height model (CHM), which is the difference between a digital surface model (DSM) and a digital terrain model (DTM). However, obtaining a DTM demands an extra computational processing step and may require field control points or manually delimiting objects on the surface. The study presented here proposes and evaluates a semi-automated methodology for counting trees directly on DSM in RDAs in the Amazon using RPA coupled with a red–green–blue standard photographic sensor. The DSM method obtained good overall accuracy and F-score indexes, superior to the CHM method for all study areas even when overall accuracy was low for both methods.

scholarly journals THE LATEST DTM USING INSAR FOR DYNAMICS DETECTION OF SEMANGKO FAULT-INDONESIA

2021 ◽  
Vol 47 (3) ◽  
pp. 118-130
Author(s):  
Atriyon Julzarika ◽  
Trias Aditya ◽  
Subaryono Subaryono ◽  
Harintaka Harintaka
Keyword(s):  
Accuracy Assessment ◽  
Digital Terrain Model ◽  
Surface Model ◽  
Vertical Deformation ◽  
Alos Palsar ◽  
Terrain Model ◽  
Digital Terrain ◽  
A Value ◽  
Vertical Accuracy

The latest Digital Terrain Model (DTM) is seen as an upgradable DTM that is fitted to the latest combination of DTM master and its displacement. The latest DTM can be used to overcome the problem of static DTM weaknesses in displaying the latest topographic changes. DTM masters are obtained from InSAR and Digital Surface Model (DSM) ALOS PALSAR conversions. Meanwhile, the displacement is obtained from Sentinel-1 images, which can be updated every 6–12 days or at least every month. ALOS PALSAR data were the images acquired in 2008 and 2017, while Sentinel-1 data used were images acquired in 2018 and 2020. This study aims to reveal the importance of an upgradable DTM so called latest DTM which is combination of DTM master and its displacement in order to show the latest condition of study area. The case study is the dynamics analyze of the Semangko fault specifically in the Sianok and Sumani segments situated in Indonesia. The vertical accuracy assessment was done to evaluate the DSM to DTM conversion with a tolerance of 1.96σ. The result obtained is the latest DTM. It is derived from the integration of the DTM master with displacement. The latest DTM can be used to detect the dynamics of Semangko fault. The study area has vertical deformation at a value of –50 cm to 30 cm. The Semangko fault area is dominated by –25 to 5 cm deformation. In general, this region has decreased. The decline in this region ranges from 7.5 cm to 10 cm per year. The latest DTM vertical accuracy is 2.158 m (95% confidence level) with a scale of 1: 10,000 to 1: 20,000.

scholarly journals Automated Generation of Digital Terrain Model using Point Clouds of Digital Surface Model in Forest Area

2011 ◽  
Vol 3 (5) ◽  
pp. 845-858 ◽  
Author(s):  
Kande R.M.U. Bandara ◽  
Lal Samarakoon ◽  
Rajendra P. Shrestha ◽  
Yoshikazu Kamiya
Keyword(s):  
Digital Terrain Model ◽  
Point Clouds ◽  
Forest Area ◽  
Surface Model ◽  
Digital Surface Model ◽  
Automated Generation ◽  
Terrain Model ◽  
Digital Terrain

scholarly journals Photogrammetric surveying forests and woodlands with UAVs: techniques for automatic removal of vegetation and digital terrain model production for hydrological applications

2019 ◽  
Vol 7 (1) ◽  
pp. 1-20
Author(s):  
Fotis Giagkas ◽  
Petros Patias ◽  
Charalampos Georgiadis
Keyword(s):  
Vegetation Type ◽  
Digital Terrain Model ◽  
Point Clouds ◽  
Aerial Images ◽  
Surface Model ◽  
Terrain Model ◽  
Vegetation Height ◽  
Digital Terrain ◽  
Dense Point ◽  
Height Model

The purpose of this study is the photogrammetric survey of a forested area using unmanned aerial vehicles (UAV), and the estimation of the digital terrain model (DTM) of the area, based on the photogrammetrically produced digital surface model (DSM). Furthermore, through the classification of the height difference between a DSM and a DTM, a vegetation height model is estimated, and a vegetation type map is produced. Finally, the generated DTM was used in a hydrological analysis study to determine its suitability compared to the usage of the DSM. The selected study area was the forest of Seih-Sou (Thessaloniki). The DTM extraction methodology applies classification and filtering of point clouds, and aims to produce a surface model including only terrain points (DTM). The method yielded a DTM that functioned satisfactorily as a basis for the hydrological analysis. Also, by classifying the DSM–DTM difference, a vegetation height model was generated. For the photogrammetric survey, 495 aerial images were used, taken by a UAV from a height of ∼200 m. A total of 44 ground control points were measured with an accuracy of 5 cm. The accuracy of the aerial triangulation was approximately 13 cm. The produced dense point cloud, counted 146 593 725 points.

scholarly journals 3D-Modelling of Charlemagne’s Summit Canal (Southern Germany)—Merging Remote Sensing and Geoarchaeological Subsurface Data

2019 ◽  
Vol 11 (9) ◽  
pp. 1111 ◽  
Author(s):  
Johannes Schmidt ◽  
Johannes Rabiger-Völlmer ◽  
Lukas Werther ◽  
Ulrike Werban ◽  
Peter Dietrich ◽  
...  
Keyword(s):  
Cross Sections ◽  
3D Model ◽  
Digital Terrain Model ◽  
Airborne Lidar ◽  
Engineering Construction ◽  
Terrain Model ◽  
Digital Terrain ◽  
Danube Catchment ◽  
The Difference ◽  
Airborne Lidar Data

The Early Medieval Fossa Carolina is the first hydro-engineering construction that bridges the Central European Watershed. The canal was built in 792/793 AD on order of Charlemagne and should connect the drainage systems of the Rhine-Main catchment and the Danube catchment. In this study, we show for the first time, the integration of Airborne LiDAR (Light Detection and Ranging) and geoarchaeological subsurface datasets with the aim to create a 3D-model of Charlemagne’s summit canal. We used a purged Digital Terrain Model that reflects the pre-modern topography. The geometries of buried canal cross-sections are derived from three archaeological excavations and four high-resolution direct push sensing transects. By means of extensive core data, we interpolate the trench bottom and adjacent edges along the entire canal course. As a result, we are able to create a 3D-model that reflects the maximum construction depth of the Carolingian canal and calculate an excavation volume of approx. 297,000 m3. Additionally, we compute the volume of the present dam remnants by Airborne LiDAR data. Surprisingly, the volume of the dam remnants reveals only 120,000 m3 and is much smaller than the computed Carolingian excavation volume. The difference reflects the erosion and anthropogenic overprint since the 8th century AD.

scholarly journals Estimating Pasture Biomass and Canopy Height in Brazilian Savanna Using UAV Photogrammetry

2019 ◽  
Vol 11 (20) ◽  
pp. 2447 ◽  
Author(s):  
Juliana Batistoti ◽  
José Marcato Junior ◽  
Luís Ítavo ◽  
Edson Matsubara ◽  
Eva Gomes ◽  
...  
Keyword(s):  
Digital Terrain Model ◽  
Technical Note ◽  
Canopy Height ◽  
Brazilian Savanna ◽  
Surface Model ◽  
Panicum Maximum ◽  
Ground Sample ◽  
Terrain Model ◽  
Sampling Height ◽  
The Difference

The Brazilian territory contains approximately 160 million hectares of pastures, and it is necessary to develop techniques to automate their management and increase their production. This technical note has two objectives: First, to estimate the canopy height using unmanned aerial vehicle (UAV) photogrammetry; second, to propose an equation for the estimation of biomass of Brazilian savanna (Cerrado) pastures based on UAV canopy height. Four experimental units of Panicum maximum cv. BRS Tamani were evaluated. Herbage mass sampling, height measurements, and UAV image collection were simultaneously performed. The UAVs were flown at a height of 50 m, and images were generated with a mean ground sample distance (GSD) of approximately 1.55 cm. The forage canopy height estimated by UAVs was calculated as the difference between the digital surface model (DSM) and the digital terrain model (DTM). The R2 between ruler height and UAV height was 0.80; between biomass (kg ha−1 GB—green biomass) and ruler height, 0.81; and between biomass (kg ha−1 GB) and UAV height, 0.74. UAV photogrammetry proved to be a potential technique to estimate height and biomass in Brazilian Panicum maximum cv. BRS Tamani pastures located in the endangered Brazilian savanna (Cerrado) biome.

The Making of Digital Orthophoto Map Based on INPHO

2011 ◽  
Vol 90-93 ◽  
pp. 2818-2821
Author(s):  
Dong Ling Ma ◽  
Jian Cui ◽  
Ning Ding
Keyword(s):  
Production Efficiency ◽  
Digital Terrain Model ◽  
Model Matching ◽  
Terrain Model ◽  
Digital Terrain ◽  
Production Practice ◽  
Mode Of Operation ◽  
Speed Up ◽  
Digital Orthophoto

INPHO is foreign professional digital photogrammetry software, including aerial triangulation encryption, digital terrain model matching, the digital orthophoto rectification and image mosaic series modules. This paper, taking DMC image as a case study, according to production practice, states the method of making Digital Orthophoto Map (DOM) using all relevant modules of INPHO, and further points out several notes in the process of making DOM. Practice shows that making DOM using INPHO series software and paying attention to the mentioned precautions can speed up production rate, improve production efficiency, while its mode of operation is also greatly simplified compared with the normal mode of operation. It is a good way of making DOM.

scholarly journals Comparison of Digital Elevation Models by Visibility Analysis in Landscape

2016 ◽  
Vol 19 (2) ◽  
pp. 28-31
Author(s):  
Jozef Sedláček ◽  
Ondřej Šesták ◽  
Miroslava Sliacka
Keyword(s):  
Field Survey ◽  
Reference Model ◽  
Digital Terrain Model ◽  
Surface Model ◽  
Digital Surface Model ◽  
Visibility Analysis ◽  
Terrain Model ◽  
Digital Terrain ◽  
Model Average ◽  
Digital Elevation

Abstract The paper investigates suitability of digital surface model for visibility analysis in GIS. In experiment there were analysed viewsheds from 14 observer points calculated on digital surface model, digital terrain model and its comparison to field survey. Data sources for the investigated models were LiDAR digital terrain model and LiDAR digital surface model with vegetation distributed by the Czech Administration for Land Surveying and Cadastre. The overlay method was used for comparing accuracy of models and the reference model was LiDAR digital surface model. Average equalities in comparison with LiDAR digital terrain model, ZABAGED model and field survey were 15.5 %, 17.3% and 20.9%, respectively.

scholarly journals BACKPACK MOBILE MAPPING SOLUTION FOR DTM EXTRACTION OF LARGE INACCESSIBLE SPACES

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 473-480
Author(s):  
F. Fassi ◽  
L. Perfetti
Keyword(s):  
Digital Terrain Model ◽  
Small Scale ◽  
Mobile Mapping ◽  
Terrain Model ◽  
Digital Terrain ◽  
Mapping System ◽  
Mobile Mapping System ◽  
The One ◽  
Mapping Solution

<p><strong>Abstract.</strong> The paper presents the case study of the complete 3D survey of the area of the Fort of Pietole in Borgo Virgilio using the Leica Pegasus Backpack wearable Mobile Mapping System (MMS). Surveying the site is challenging because of its complex topology on the one hand (with notably narrow passages) and because of the presence of vegetation on the other. The framework within which this research takes place is the Fort of Pietole survey project that aims at the extraction of the Digital Terrain Model (DTM) of the area and the georeferencing of the fort defensive structures. The requirement of the project is the 3D reconstruction of the whole area at an accuracy that stands between a big scale environmental survey and a small-scale architectonic survey (1&amp;thinsp;:&amp;thinsp;500).</p> <p>The project is the opportunity to discuss the state of the art of wearable MMS, and to test the versatility and accuracy outcomes of the Pegasus Backpack under varying and challenging condition (indoor-outdoor, even-uneven pavement, satellite covered-denied areas) with the ambitious goal to use only the backpack MMS to record all the data from the DTM to the indoor narrow structures.</p>

scholarly journals The utilization of landscape pictures extracted from open picture collections for the determination of interest in spatial features

2018 ◽  
Author(s):  
Jens Ingensand ◽  
Jean Christophe Foltête ◽  
Stéphane Cretegny ◽  
Nicolas Blanc ◽  
Sarah Composto
Keyword(s):  
Focal Length ◽  
Digital Terrain Model ◽  
Field Of View ◽  
Terrain Model ◽  
Digital Terrain ◽  
Spatial Features ◽  
Automated Method ◽  
Camera Position

This paper describes a method that uses georeferenced landscape pictures extracted from open picture collections for the determination of the population's interest in spatial features. The automated method takes into account the coordinates of the camera position as well as the azimuth angle, the focal length and the crop factor in order to calculate a field of view using a digital terrain model (DTM). This field of view can thereafter be used for the determination of interest in spatial features. In a case study involving more than 3'000 georeferenced pictures we investigate the potential of the method.

scholarly journals Application of the global SRTM and AW3D30 digital elevation models to mapping folds at cave sites

2021 ◽  
Vol 50 (1) ◽  
pp. 75-89
Author(s):  
Mark Abolins ◽  
Albert Ogden
Keyword(s):  
Cell Size ◽  
Forest Canopy ◽  
Digital Elevation Models ◽  
Digital Terrain Model ◽  
Surface Model ◽  
M Cell ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
The Mean

A novel method to map and quantitatively describe very gentle folds (limb dip <5°) at cratonic cave sites was evaluated at Snail Shell and Nanna caves, central Tennessee, USA. Elevations from the global SRTM digital terrain model (DTM) were assigned to points on late Ordovician geologic contacts, and the elevations of the points were used to interpolate 28 m cell size natural neighbor digital elevation models (DEM’s) of the contacts. The global Forest Canopy Height Dataset was subtracted from the global 28 m cell size AW3D30 digital surface model (DSM) to create a DTM, and that DTM was applied in the same way. Comparison of mean and modal strikes of the interpolated surfaces with mean and modal cave passage trend shows that many passages are sub-parallel to the trend of an anticline. WithiSn 500 m of the caves, the SRTM- and AW3D30-based interpolated surfaces have mean strikes within 8° of the mean strike of an interpolated reference surface created with a high resolution (~0.76 m cell size and 10 cm RMSE) Tennessee, USA LiDAR DTM. This evaluation shows that the SRTM- and AW3D30-based method has the potential to reveal a relationship between the trend of a fold, on one hand, and cave passages, on the other, at sites where a geologic contact varies in elevation by >35 m within an area of <12.4 km2 and the mean dip of bedding is >0.9°.

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