Correction of systematic image misalignment in direct georeferencing of UAV multispectral imagery DOI
Hui Ying Pak, Weisi Lin, Adrian Wing‐Keung Law

et al.

International Journal of Remote Sensing, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 23

Published: Dec. 26, 2024

Mosaicking of Unmanned Aerial Vehicles (UAV) imagery over featureless water bodies has been known to be challenging, and poses a significant impediment monitoring applications. Techniques such as Structure-from-motion typically fail under conditions due the lack distinctive features in scene, direct georeferencing is currently only practical solution, albeit lower accuracy expected. However, hardware issues, particularly typical time delay between GPS unit image capture, can lead systematic misalignment further reducing accuracy. The arises recording geographical coordinates by may not precisely correspond exact moment exposure, exposure always occur at mid-exposure time. Hardware solutions mitigate this issue but require technical expertise resources. Alternatively, software address problem without necessitating any modifications. This study introduces an open-source solution for correction alignment accounting distance discrepancy measurements capture. method was validated with field UAV surveys conducted various flight configurations (different altitudes overlap ratios), effective obtained using proposed which reduced error around 67.7%. Specifically, RMSE = 1.409 m σ 0.6356 achieved use ground control points (GCPs). Finally, demonstrated study, low (e.g. 15 m) should discouraged errors could amplify limited GPS, resulting visual artefacts.

Language: Английский

Comparative analysis of Sentinel-2 and PlanetScope imagery for chlorophyll-a prediction using machine learning models DOI Creative Commons
Eden T. Wasehun, Leila Hashemi-Beni, Courtney A. Di Vittorio

et al.

Ecological Informatics, Journal Year: 2024, Volume and Issue: unknown, P. 102988 - 102988

Published: Dec. 1, 2024

Language: Английский

Citations

4
Practical Guidelines for Performing UAV Mapping Flights with Snapshot Sensors DOI Creative Commons
Wouter H. Maes

Remote Sensing, Journal Year: 2025, Volume and Issue: 17(4), P. 606 - 606

Published: Feb. 10, 2025

Uncrewed aerial vehicles (UAVs) have transformed remote sensing, offering unparalleled flexibility and spatial resolution across diverse applications. Many of these applications rely on mapping flights using snapshot imaging sensors for creating 3D models the area or generating orthomosaics from RGB, multispectral, hyperspectral, thermal cameras. Based a literature review, this paper provides comprehensive guidelines best practices executing such flights. It addresses critical aspects flight preparation execution. Key considerations in covered include sensor selection, height GSD, speed, overlap settings, pattern, direction, viewing angle; execution on-site preparations (GCPs, camera calibration, reference targets) as well conditions (weather conditions, time flights) to take into account. In all steps, high-resolution high-quality data acquisition needs be balanced with feasibility constraints time, volume, post-flight processing time. For reflectance measurements, BRDF issues also influence correct setting. The formulated are based consensus. However, identifies knowledge gaps particularly angle general. aim advance harmonization UAV practices, promoting reproducibility enhanced quality

Language: Английский

Citations

0
Location optimization of unmanned aerial vehicle (UAV) drone port for coastal zone management: The case of Guangdong coastal zone in China DOI

Jia Lin Sun,

Sijing Shu,

Hongda Hu

et al.

Ocean & Coastal Management, Journal Year: 2025, Volume and Issue: 262, P. 107576 - 107576

Published: Feb. 12, 2025

Language: Английский

Citations

0
A Novel Method for Eliminating Glint in Water-Leaving Radiance from UAV Multispectral Imagery DOI Creative Commons
Jong‐Seok Lee, Sin-Young Kim, Young‐Heon Jo

et al.

Remote Sensing, Journal Year: 2025, Volume and Issue: 17(6), P. 996 - 996

Published: March 12, 2025

Unmanned Aerial Vehicle (UAV) high-resolution remote sensing imagery has been used for unprecedented coastal environment monitoring with ground sampling distance and time intervals of a few centimeters seconds, respectively. However, high spatial-time resolutions UAV data consist unexpected signals from water surface level changes induced by wind-driven currents waves. This leads to non-linear non-stationary forms sun sky glints in the sea image. Consequently, these interfere detection body reflections objects, reducing accuracy usability measurements. study employed Fast Adaptive Multidimensional Empirical Mode Decomposition (FA-MEMD) separate spatial periodicity time-continuous multispectral images original retain non-oscillatory called residual images. The effectively represented spatial-temporal radiance flow variations correcting regions glint. presents three key findings: First, homogeneous glint removed raw image sequence was acquired using FA-MEMD. Second, continuous removal effect is validated through water-leaving (Lw-SBA) measurements obtained via Skylight-Blocked Approach (SBA) method. Comparisons showed that R2 values clear before after were 0.02 0.56 RMSE 8.37 × 10−5 5.51 W·m−2·sr−1, respectively, indicating an improvement rate 34.19%. Third, comparative analysis previous methods demonstrated our approach yielded spatially temporally uniform less variability than traditional methods. synchronized Lw-SBA similarity, confirming FA-MEMD technique wave-induced roughness, enhancing reliability color observations.

Language: Английский

Citations

0
A novel approach for tracking the diurnal dynamics of chlorophyll-a in lakes using UAV hyperspectral images DOI
Yi Xiao, Xiran Li, Jiahao Chen

et al.

Journal of Hydrology, Journal Year: 2025, Volume and Issue: unknown, P. 133403 - 133403

Published: April 1, 2025

Language: Английский

Citations

0
CoastalWQL: An Open-Source Tool for Drone-Based Mapping of Coastal Turbidity Using Push Broom Hyperspectral Imagery DOI Creative Commons
Hui Ying Pak, Hieu Trung Kieu, Weisi Lin

et al.

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(4), P. 708 - 708

Published: Feb. 17, 2024

Uncrewed-Aerial Vehicles (UAVs) and hyperspectral sensors are emerging as effective alternatives for monitoring water quality on-demand. However, image mosaicking largely featureless coastal surfaces or open seas has shown to be challenging. Another pertinent issue observed is the systematic misalignment between adjacent flight lines due time delay UAV-borne sensor GNSS system. To overcome these challenges, this study introduces a workflow that entails GPS-based method push-broom images, together with correction address aforementioned misalignment. An open-source toolkit, CoastalWQL, was developed facilitate workflow, which includes essential pre-processing procedures improving mosaic’s quality, such radiometric correction, de-striping, sun glint object masking classification. For validation, UAV-based imaging surveys were conducted monitor turbidity in Singapore, implementation of CoastalWQL’s evaluated at each step via retrieval. Overall, results confirm imagery over surface using CoastalWQL enabled better localisation plume. Radiometric de-striping also found most important procedures, improved prediction by 46.5%.

Language: Английский

Citations

3
Tourism Investment and Land Use Change in the Northern Piedmont of the Western High Atlas (1989-2022) DOI Creative Commons

Hamza Ait Zamzami,

Mohammed Elaanzouli,

Ayoub Zahrani

et al.

Forum Geografi, Journal Year: 2024, Volume and Issue: 38(1), P. 83 - 93

Published: March 28, 2024

This study aimed to investigate the profound influence of tourism investment on Northern Piedmont western High Atlas over 34 years in response escalating global trend tourism-driven land-use changes, particularly Marrakesh region. In this context, driving forces behind significant transformation agricultural land and bare soils into investments were evaluated as well critical role accessibility shaping spatial shifts. The method used high-resolution (10 m) satellite images from Spot 1 (1989), 5 (2003 & 2010), Sentinel 2 (2022) through remote sensing methods historical changes years. results showed transformations based correlation between improved transportation infrastructure growth ventures, underscoring roads facilities catalysts. analysis suggested need for reflection consequences unregulated growth, aiming balance economic benefits with environmental socio-cultural challenges sensitive regions. Although significantly contributed development employment opportunities, it also posed risks when not managed prudently. underscored strike a harmonious equilibrium prosperity preserving unique natural beauty cultural heritage insights provided had broader implications responsible planning management ecological conclusion, thoughtful sustainable approach was needed safeguard delicate preservation.

Language: Английский

Citations

1
A UAV Thermal Imaging Format Conversion System and Its Application in Mosaic Surface Microthermal Environment Analysis DOI Creative Commons
Lu Jiang, Haitao Zhao, Biao Cao

et al.

Sensors, Journal Year: 2024, Volume and Issue: 24(19), P. 6267 - 6267

Published: Sept. 27, 2024

UAV thermal infrared remote sensing technology, with its high flexibility and temporal spatial resolution, is crucial for understanding surface microthermal environments. Despite DJI Drones' industry-leading position, the JPG format of their images limits direct image stitching further analysis, hindering broad application. To address this, a conversion system, ThermoSwitcher, was developed images, this system applied to environment taking two regions various local zones in Nanjing as research area. The results showed that ThermoSwitcher can quickly losslessly convert Geotiff format, which convenient producing mosaics temperature extraction. also indicated significant heterogeneity study area's distribution, temperatures concentrated on sunlit artificial surfaces, low corresponding building shadows, dense vegetation, water areas. distribution change rates different were significantly influenced by cover type, material properties, vegetation coverage, layout. Higher observed high-rise subway station areas, while lower noted vegetation-covered Additionally, comparing before after revealed process affected uniformity some extent. described enhances preprocessing efficiency, promoting advancements drone refined research.

Language: Английский

Citations

1
Mapping intertidal microphytobenthic biomass with very high-resolution remote sensing imagery in an estuarine system DOI Creative Commons
Alejandro Román, Simon Oiry, Bede Ffinian Rowe Davies

et al.

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 955, P. 177025 - 177025

Published: Oct. 19, 2024

Language: Английский

Citations

1
High-resolution ocean color imagery from the SeaHawk-HawkEye CubeSat mission DOI Creative Commons
Philip J. Bresnahan, Sara Rivero‐Calle,

John M. Morrison

et al.

Scientific Data, Journal Year: 2024, Volume and Issue: 11(1)

Published: Nov. 18, 2024

Here we describe the data obtained by a successful proof-of-concept initiative to launch first ocean color imager on board CubeSat satellite and collect research-grade imagery at severalfold higher spatial resolution than any other mission. The 3U CubeSat, named SeaHawk, flew nominal altitude of 585 km. Its sensor, HawkEye, collected 7,471 push-broom images 230 × 780 km2 best-in-class 130 m2 per pixel. sensor is built with comparatively low-cost commercial off-the-shelf optoelectronics was designed match NASA SeaWiFS specifications, including wavelengths, bandwidths, signal-to-noise ratios. HawkEye's design for remote sensing combined its high make especially well-suited coastal, estuarine, limnological applications. Ultimately, mission provided open access rich global dataset calibrated quality-controlled use in aquatic ecology environmental change studies.

Language: Английский

Citations

1