Natural and Anthropogenic Coastal System Comparison Using DSM from a Low Cost UAV Survey (Capão Novo, RS/Brazil)

Morpho–Sedimentary Monitoring in a Coastal Area, from 1D to 2.5D, Using Airborne Drone Imagery

“…The drone development for civilian use [10,11] opens new perspectives for coastal expertise by overcoming the limits observed with the previous monitoring methods. This technology offers the possibility of a very high spatial (VHR, <0.05 m) and temporal resolution (<1 month) monitoring of sedimentary structures [12][13][14].…”

A calibration workflow for coastal dune models

“…Structure-from-Motion Multi-view-Stereo (SfM) photogrammetry is a technique whereby many photos of a surface, captured from varying perspectives, are used to generate an orthophotomosaic (a composite of images that preserves spatial scales) and a digital surface model (e.g. James andRobson 2012, Westoby et al 2012;Fonstad et al 2013;Bryson et al 2013, Mancini et al 2013Scarelli et al 2016;Scarelli et al 2017). Recent work indicates that a kite-based camera is able to provide images that are ideally suited to the SfM process over coastal dunes (Goldstein et al The worst solution is removed and replaced by a "mutated" version of the "crossover" (mutations in green).…”

Examining the utility of Simultaneous Localisation and Mapping (SLAM) LiDAR on a low-altitude unmanned aerial vehicle (UAV) across environments of various composition and dynamic complexity

“…Effective in creating, detecting and measuring change using Digital Surface Models (DSMs) with sub-metre resolution [37][38][39][40][41], such studies, however, may be limited by the characteristics of the surface being measured, presence of vegetation, water and small scale texture contributing to inaccuracies [42,43]. Unlike that of the SfM approach, UAV LiDAR is not restricted to the development of DSMs but is able to 'penetrate' vegetation and produce accurate Digital Terrain Models (DTMs) from which additional metrics can be derived to better inform the theory, models and predictions that scientists, engineers, planners, managers and policy makers require [24].…”

“…Dune management is considered a prime coastal management tool [82] and whilst prior monitoring efforts to capture fine-scale features required laborious field surveys over relatively limited spatial scales (due to the intensive labour requirements) [12,83] and are proving to be an efficient, cost-effective tool for topological mapping and measurement with deployment flexibility and spatial-temporal resolution ('microscales' [24]), not previously feasible within the coastal zone [94,96]. To date, studies utilising UAVs have focused almost exclusively on the use of structure-from-motion photogrammetry (SfM) and whilst this has shown to be very effective in creating, detecting and measuring change using Digital Surface Models (DSMs) with submetre resolution [37][38][39][40][41], such studies may be somewhat limited by the characteristics of the surface being measured, presence of vegetation, water and small scale texture contributing to inaccuracies [42,43].…”

“…flight Pattern, Speed and Altitude (independent variables) onHovermap point cloud Density, Ground Sample Distance (GSD) and accuracy (response variables), a total of 24 flights were conducted using a full factorial experimental design including two patterns ('single-flight', 'cross-flight'), three speeds (1.5, 2.5, 3.5m s -1 ) and four altitudes(10,20,40, 80m AGL). Here, a focus on lower altitudes (<50m) were applied based on the previous work of Wallace et al[44], speeds were similar to that of Tulldahl et al[49] and the 'cross-flight' patterns discussed by Gerke and Przybilla[69].Each flight was planned using a geo-referenced LiDAR data of the study area previously collected with a Phoenix AL3-32 (Phoenix LiDAR Systems, U.S.A) and Global Mapper (v.18.2, Blue Marble Geographics, U.S.A.) software.…”