Assessment of Close-Range Remote Sensing Methods for DTM Estimation in a Lowland Deciduous Forest

Digital terrain models (DTMs) are important for a variety of applications in geosciences as a valuable information source in forest management planning, forest inventory, hydrology, etc. Despite their value, a DTM in a forest area is typically lower quality due to inaccessibility and limited data sources that can be used in the forest environment. In this paper, we assessed the accuracy of close-range remote sensing techniques for DTM data collection. In total, four data sources were examined, i.e., handheld personal laser scanning (PLShh, GeoSLAM Horizon), terrestrial laser scanning (TLS, FARO S70), unmanned aerial vehicle (UAV) photogrammetry (UAVimage), and UAV laser scanning (ULS, LS Nano M8). Data were collected within six sample plots located in a lowland pedunculate oak forest. The reference data were of the highest quality available, i.e., total station measurements. After normality and outliers testing, both robust and non-robust statistics were calculated for all close-range remote sensing data sources. The results indicate that close-range remote sensing techniques are capable of achieving higher accuracy (root mean square error < 15 cm; normalized median absolute deviation < 10 cm) than airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) data that are generally understood to be the best data sources for DTM on a large scale.

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Integrating Airborne Laser Scanning and 3D Ground-Penetrating Radar for the Investigation of Protohistoric Structures in Croatian Istria

Applied Sciences ◽

10.3390/app11178166 ◽

2021 ◽

Vol 11 (17) ◽

pp. 8166 ◽

Cited By ~ 1

Author(s):

Federico Bernardini ◽

Giacomo Vinci ◽

Emanuele Forte ◽

Arianna Mocnik ◽

Josip Višnjić ◽

...

Keyword(s):

Remote Sensing ◽

Cross Sections ◽

Laser Scanning ◽

Integrated Approach ◽

Heritage Management ◽

Burial Mound ◽

Volume Reconstruction ◽

Remote Sensing Techniques ◽

Ground Penetrating ◽

2D And 3D

We present the investigation of two rather ephemeral archaeological sites located in the municipality of Oprtalj/Portole (Croatian Istria) by means of integrated archaeological, geophysical and remote sensing techniques. The results obtained confirm the first interpretation of these contexts; a protohistoric burial mound and a small hillfort, respectively. We further obtained detailed information about both deposits through 2D and 3D remote sensing and geophysical studies that produced maps, volumes, profiles and cross-sections. At the first site, the volume reconstruction of both the inner stone core and the superimposed earth of the putative stone mound also allowed us to estimate the labour necessary to erect the structure. In conclusion, our study demonstrates that the integrated approach can be valuable not only to acquire novel data about the archaeological deposits but also to calibrate future investigations and to plan effective measures for heritage management, monitoring and valorization.

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3D COMPARISON TOWARDS A COMPREHENSIVE ANALYSIS OF A BUILDING IN CULTURAL HERITAGE

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

10.5194/isprs-archives-xlii-2-1061-2018 ◽

2018 ◽

Vol XLII-2 ◽

pp. 1061-1066 ◽

Cited By ~ 1

Author(s):

I. Selvaggi ◽

M. Dellapasqua ◽

F. Franci ◽

A. Spangher ◽

D. Visintini ◽

...

Keyword(s):

Cultural Heritage ◽

Point Cloud ◽

Laser Scanning ◽

Three Dimensional ◽

Deformation Analysis ◽

Point Cloud Data ◽

Cloud Data ◽

Site Restoration ◽

Close Range ◽

Remote Sensing Techniques

Terrestrial remote sensing techniques, including both Terrestrial Laser Scanning (TLS) and Close-Range Photogrammetry (CRP), have been recently used in multiple applications and projects with particular reference to the documentation/inspection of a wide variety of Cultural Heritage structures. The high density of TLS point cloud data allows to perform structure survey in an unprecedented level of detail, providing a direct solution for the digital three-dimensional modelling, the site restoration and the analysis of the structural conditions. Textural information provided by CRP can be used for the photorealistic representation of the surveyed structure. With respect to many studies, the combination of TLS and CRP techniques produces the best results for Cultural Heritage documentation purposes. Moreover, TLS and CRP point cloud data have been proved to be useful in the field of deformation analysis and structural health monitoring. They can be the input data for the Finite Element Method (FEM), providing some prior knowledge concerning the material and the boundary conditions such as constraints and loading. The paper investigates the capabilities and advantages of TLS and CRP data integration for the three-dimensional modelling compared to a simplified geometric reconstruction. This work presents some results concerning the Baptistery of Aquileia in Italy, characterized by an octagonal plan and walls composed by masonry stones with good texture.

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Quantificação da perda de água por evapotranspiração em diferentes usos da terra da Bacia do Rio Vieira / Quantification of water loss by evapotranspiration in different land uses of the River Vieira Basin

Caderno de Geografia ◽

10.5752/p.2318-2962.2019v29n58p746-764 ◽

2019 ◽

Vol 29 (58) ◽

pp. 746-764

Author(s):

Marcos Esdras Leite ◽

Maria Ivete Soares De Almeida ◽

Lucas Augusto Pereira da Silva ◽

Manoel Reinaldo Leite

Keyword(s):

Remote Sensing ◽

Deciduous Forest ◽

Minas Gerais ◽

Tropical Deciduous Forest ◽

Winter Period ◽

Native Vegetation ◽

Land Uses ◽

Grassland Soil ◽

Sparse Vegetation ◽

Remote Sensing Techniques

Este trabalho teve como objetivo quantificar a perda de água por evapotranspiração real diária em diferentes usos da terra na bacia do rio Vieira em Minas Gerais, por meio de técnicas de sensoriamento remoto para o período de 17/06/2016. Diante dos dados obtidos, pode-se analisar os usos da terra que perdem maior quantidade de água por evapotranspiração, sendo as áreas de vegetação nativa (com vegetação rala inserida), as grandes potencialidades para a perda de água por meio de evapotranspiração exceto as áreas de Floresta Tropical Caducifólia, devido as suas características fenológicas de perder parte de sua folhagem durante o inverno (período analisado neste estudo). As áreas de eucalipto (uso antropogênico) também entram na estatística de uso da terra que perde mais água por evapotranspiração. Já as menores perdas são destinadas aos usos da terra de Pastagem, solo exposto, urbano e influência mineradora e pasto degradado.Palavras–chave: SEBAL, Usos da terra e Evapotranspiração Real Diária.Abstract The objective of this work was to quantify the loss of water by daily real evapotranspiration in different Land uses in the Vieira river basin in Minas Gerais, using remote sensing techniques for the period of 06/17/2016. Considering the obtained data, it is possible to analyze the land uses that lose more water by evapotranspiration, being the areas of native vegetation (with sparse vegetation inserted), the great potentialities for the loss of water through evapotranspiration except for the areas of tropical deciduous forest, which due to its phenological characteristics of losing part of its foliage during winter (period analyzed in this study). The areas of eucalyptus (anthropogenic use) also enter into the statistics of land use that loses more water by evapotranspiration. Already the smaller losses are destined to the uses of the Land of, Grassland, soil exposed, urban and mining influence and degraded grass.Keywords: SEBAL, Land Uses and Daily Real Evapotranspiration.

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Radar vision in the mapping of forest biodiversity from space

Nature Communications ◽

10.1038/s41467-019-12737-x ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 13

Author(s):

Soyeon Bae ◽

Shaun R. Levick ◽

Lea Heidrich ◽

Paul Magdon ◽

Benjamin F. Leutner ◽

...

Keyword(s):

Remote Sensing ◽

Laser Scanning ◽

Large Scale ◽

External Validation ◽

Predictive Ability ◽

Radar Data ◽

Forest Regions ◽

Local Species ◽

Spatio Temporal ◽

Derived Data

Abstract Recent progress in remote sensing provides much-needed, large-scale spatio-temporal information on habitat structures important for biodiversity conservation. Here we examine the potential of a newly launched satellite-borne radar system (Sentinel-1) to map the biodiversity of twelve taxa across five temperate forest regions in central Europe. We show that the sensitivity of radar to habitat structure is similar to that of airborne laser scanning (ALS), the current gold standard in the measurement of forest structure. Our models of different facets of biodiversity reveal that radar performs as well as ALS; median R² over twelve taxa by ALS and radar are 0.51 and 0.57 respectively for the first non-metric multidimensional scaling axes representing assemblage composition. We further demonstrate the promising predictive ability of radar-derived data with external validation based on the species composition of birds and saproxylic beetles. Establishing new area-wide biodiversity monitoring by remote sensing will require the coupling of radar data to stratified and standardized collected local species data.

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Very-high-resolution mapping of river-immersed topography by remote sensing

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133308096030 ◽

2008 ◽

Vol 32 (4) ◽

pp. 403-419 ◽

Cited By ~ 72

Author(s):

Denis Feurer ◽

Jean-Stéphane Bailly ◽

Christian Puech ◽

Yann Le Coarer ◽

Alain A. Viau

Keyword(s):

Remote Sensing ◽

High Resolution ◽

Large Scale ◽

Aerial Image ◽

Depth Measurement ◽

Very High Spatial Resolution ◽

Remote Sensing Techniques ◽

Logarithmic Relationship ◽

Ground Penetrating ◽

Very High

Remote sensing has been used to map river bathymetry for several decades. Non-contact methods are necessary in several cases: inaccessible rivers, large-scale depth mapping, very shallow rivers. The remote sensing techniques used for river bathymetry are reviewed. Frequently, these techniques have been developed for marine environment and have then been transposed to riverine environments. These techniques can be divided into two types: active remote sensing, such as ground penetrating radar and bathymetric lidar; or passive remote sensing, such as through-water photogrammetry and radiometric models. This last technique — which consists of finding a logarithmic relationship between river depth and image values — appears to be the most used. Fewer references exist for the other techniques, but lidar is an emerging technique. For each depth measurement method, we detail the physical principles and then a review of the results obtained in the field. This review shows a lack of data for very shallow rivers, where a very high spatial resolution is needed. Moreover, the cost related to aerial image acquisition is often huge. Hence we propose an application of two techniques, radiometric models and through-water photogrammetry, with very- high-resolution passive optical imagery, light platforms, and off-the-shelf cameras. We show that, in the case of the radiometric models, measurement is possible with a spatial filtering of about 1 m and a homogeneous river bottom. In contrast, with through-water photogrammetry, fine ground resolution and bottom textures are necessary.

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Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling

Natural Hazards and Earth System Science ◽

10.5194/nhess-18-583-2018 ◽

2018 ◽

Vol 18 (2) ◽

pp. 583-597 ◽

Cited By ~ 17

Author(s):

Ákos Török ◽

Árpád Barsi ◽

Gyula Bögöly ◽

Tamás Lovas ◽

Árpád Somogyi ◽

...

Keyword(s):

Remote Sensing ◽

Cross Sections ◽

Laser Scanning ◽

Digital Terrain Model ◽

Field Measurements ◽

Satellite System ◽

Surface Model ◽

Rockfall Hazard ◽

Terrain Model ◽

Remote Sensing Techniques

Abstract. Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System) was used to collect images which were processed by Pix4D mapper (structure from motion technology) to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS) with the use of seven ground control points. The obtained digital surface model (DSM) was processed (vegetation removal) and the derived digital terrain model (DTM) allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method). Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE–WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS).

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Close-range sensing and object-based analysis of shallow landslides and erosion in grasslands

10.5194/egusphere-egu2020-19847 ◽

2020 ◽

Author(s):

Andreas Mayr ◽

Martin Rutzinger ◽

Magnus Bremer ◽

Clemens Geitner

Keyword(s):

Remote Sensing ◽

Data Acquisition ◽

Case Studies ◽

Laser Scanning ◽

Regional Scale ◽

Shallow Landslides ◽

Range Sensing ◽

Erosion Processes ◽

Object Based ◽

Close Range

Close-range sensing methods for topographic data acquisition, such as Structure-from-Motion with multi-view stereo (SfM-MVS) photogrammetry and laser scanning from the ground or from unmanned aerial systems (UAS), have strongly improved over the last decade. As they are providing data with sub-decimetre resolution and accuracy, these methods open new possibilities for bridging the gap between local in-situ observations and area-wide space-borne or aerial remote sensing. For assessments of shallow landslides and erosion patches, which are wide-spread phenomena in mountain grasslands, the potential of close-range sensing is two-fold: Firstly, it could provide accurate reference data for assessing the geometric accuracy of a catchment or regional scale eroded area monitoring based on aerial or satellite remote sensing systems. Secondly, selected sites can be monitored at a very detailed local scale to reveal processes of secondary erosion or natural vegetation succession and slope stabilisation. Furthermore, high-resolution 4D data from multi-temporal close-range sensing make it possible to quantify volumes and rates of displacement at erosion features. In this contribution, we propose to exploit this potential of close-range sensing for landslide and erosion studies with object-based approaches for raster and 3D point cloud analyses. Assuming that erosion features can be discriminated from undisturbed grassland and from trees and shrubs, based on their morphometric and spectral signatures, we show how computer vision and machine learning techniques help to detect and label these features automatically as spatial objects in the data. We combine this object detection and labelling with 2.5D differential elevation models and with 3D deformation analysis of point clouds. This strategy addresses one of the key challenges of automatically analysing close-range sensing data in geomorphological studies, i.e. linking geometric information (such as the size and shape of erosion features or the surface change across a time series) with semantic information (e.g. separating vegetation from complex ground structures). In three case studies from recent projects in the Alps, where we acquired data by UAS, terrestrial laser scanning and terrestrial photogrammetry, we demonstrate the use of these new methodological developments. The methods tested can reliably detect changes with minimum magnitudes of centimetre to decimetre level, depending primarily on the specific data acquisition setup. By automatically relating these changes to erosion features of different scales (i.e. both at entire eroded areas and at their components, e.g. collapsing parts of the scarp), such analyses can provide valuable insights regarding process dynamics. In our tests, close-range sensing and automated data analysis workflows helped to understand both the development of new eroded areas as well as their enlargement by secondary erosion processes or episodic landslide reactivation. Based on the experience from these case studies, we also discuss the main challenges and limitations of these methods for erosion monitoring applications.

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Developing statistically driven eco-engineering designs from LiDAR and structure from motion surveys for marine artificial structures.

10.5194/egusphere-egu2020-3435 ◽

2020 ◽

Author(s):

Peter Lawrence ◽

Ally Evans ◽

Paul Brooks ◽

Tim D'Urban Jackson ◽

Stuart Jenkins ◽

...

Keyword(s):

Remote Sensing ◽

Habitat Loss ◽

Structure From Motion ◽

Laser Scanning ◽

Large Scale ◽

Spatial Scales ◽

Coastal Development ◽

Ecological Design ◽

Artificial Structures ◽

Engineering Research

Coastal ecosystems are threatened by habitat loss and anthropogenic &#8220;smoothing&#8221; as hard engineering approaches to sea defence, such as sea-walls, rock armouring, and offshore reefs, become common place. These artificial structures use homogenous materials (e.g. concrete or quarried rock) and as a result, lack the surface heterogeneity of natural rocky shoreline known to play a key role in niche creation and higher species diversity. Despite significant investment and research into soft engineering and ecologically sensitive approaches to coastal development, there are still knowledge gaps, particularly in relation to how patterns that are observed in nature can be utilised to improve artificial shores.Given the technical improvements and significant reductions in cost within the portable remote sensing field (structure from motion and laser scanning), we are now able to plug gaps in our understanding of how habitat heterogeneity can influence overall site diversity. These improvements represent an excellent opportunity to improve our understanding of the spatial scales and complexity of habitats that species occur within and ultimately improve the ecological design of engineered structures in areas experiencing &#8220;smoothing&#8221; and habitat loss.In this talk, I will highlight how advances in remote sensing techniques can be applied to context-specific ecological problems, such as low diversity and loss of rare species within marine infrastructure. I will describe our approach to combining large-scale ecological, 3D geophysical and engineering research to design statistically-derived ecologically-inspired solutions to smooth artificial surfaces. We created experimental concrete enhancement units and deployed them at a number of coastal locations. I will present preliminary ecological results, provide a workflow of unit development and statistical approaches, and finally discuss how these advances may improve future ecological intervention and design options.

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Mapping Paddy Rice with Satellite Remote Sensing: A Review

Sustainability ◽

10.3390/su13020503 ◽

2021 ◽

Vol 13 (2) ◽

pp. 503

Author(s):

Rongkun Zhao ◽

Yuechen Li ◽

Mingguo Ma

Keyword(s):

Remote Sensing ◽

Data Integration ◽

Large Scale ◽

Microwave Remote Sensing ◽

Paddy Rice ◽

Data Sources ◽

Accurate Estimation ◽

Global Changes ◽

Optical Remote Sensing ◽

Advantages And Disadvantages

Paddy rice is a staple food of three billion people in the world. Timely and accurate estimation of the paddy rice planting area and paddy rice yield can provide valuable information for the government, planners and decision makers to formulate policies. This article reviews the existing paddy rice mapping methods presented in the literature since 2010, classifies these methods, and analyzes and summarizes the basic principles, advantages and disadvantages of these methods. According to the data sources used, the methods are divided into three categories: (I) Optical mapping methods based on remote sensing; (II) Mapping methods based on microwave remote sensing; and (III) Mapping methods based on the integration of optical and microwave remote sensing. We found that the optical remote sensing data sources are mainly MODIS, Landsat, and Sentinel-2, and the emergence of Sentinel-1 data has promoted research on radar mapping methods for paddy rice. Multisource data integration further enhances the accuracy of paddy rice mapping. The best methods are phenology algorithms, paddy rice mapping combined with machine learning, and multisource data integration. Innovative methods include the time series similarity method, threshold method combined with mathematical models, and object-oriented image classification. With the development of computer technology and the establishment of cloud computing platforms, opportunities are provided for obtaining large-scale high-resolution rice maps. Multisource data integration, paddy rice mapping under different planting systems and the connection with global changes are the focus of future development priorities.

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Investigating Remote-Sensing Techniques to Reveal Stealth Coronal Mass Ejections

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2021.695966 ◽

2021 ◽

Vol 8 ◽

Author(s):

Erika Palmerio ◽

Nariaki V. Nitta ◽

Tamitha Mulligan ◽

Marilena Mierla ◽

Jennifer O’Kane ◽

...

Keyword(s):

Remote Sensing ◽

Coronal Mass Ejections ◽

Large Scale ◽

Geomagnetic Storms ◽

A Priori ◽

Source Region ◽

Remote Sensing Data ◽

Additional Information ◽

Remote Sensing Techniques ◽

Geometric Techniques

Eruptions of coronal mass ejections (CMEs) from the Sun are usually associated with a number of signatures that can be identified in solar disc imagery. However, there are cases in which a CME that is well observed in coronagraph data is missing a clear low-coronal counterpart. These events have received attention during recent years, mainly as a result of the increased availability of multi-point observations, and are now known as “stealth CMEs.” In this work, we analyze examples of stealth CMEs featuring various levels of ambiguity. All the selected case studies produced a large-scale CME detected by coronagraphs and were observed from at least one secondary viewpoint, enabling a priori knowledge of their approximate source region. To each event, we apply several image processing and geometric techniques with the aim to evaluate whether such methods can provide additional information compared to the study of “normal” intensity images. We are able to identify at least weak eruptive signatures for all events upon careful investigation of remote-sensing data, noting that differently processed images may be needed to properly interpret and analyze elusive observations. We also find that the effectiveness of geometric techniques strongly depends on the CME propagation direction with respect to the observers and the relative spacecraft separation. Being able to observe and therefore forecast stealth CMEs is of great importance in the context of space weather, since such events are occasionally the solar counterparts of so-called “problem geomagnetic storms.”

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