High-throughput calculation of organ-scale traits with reconstructed accurate 3D canopy structures using a UAV RGB camera with an advanced cross-circling oblique route

Xiao, Shunfu; Ye, Yulu; Fei, Shuaipeng; Chen, Haochong; Zhang, Bingyu; Li, Qing; Cai, Zhenzhai; Che, Yingpu; Wang, Qing; Ghafoor, A.; Bi, Kaiyi; Shao, Kwang‐Tsao; Wang, Ruili; Guo, Yan; Li, Baoguo; Meng, Zhigang; Chen, Zhe; Ma, Yuntao

doi:10.1016/j.isprsjprs.2023.05.016

Cited by 26 publications

(2 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lower UAV flight height as well as an adapted flight strategy (i.e. Xiao et al 2023) with a high resolution RGB camera could allow this. However, the resolution of SPC sensors is typically lower, again suggesting further investigation and development of methods using RGB sensors.…”

Section: Discussionmentioning

confidence: 99%

Temporal resolution trumps spectral resolution in UAV-based monitoring of canopy senescence dynamics

Tschurr,

Roth,

Storni

et al. 2023

Preprint

View full text Add to dashboard Cite

Senescence is a dynamic process that is affected by many environmental, genetic, and physiological factors. Quantifying this process is important for breeding wheat varieties with high yield and of high quality. We present a method that allows up-scaling of the state of the art method - visual scoring - by using image sequences acquired from Unmanned Aerial Vehicles (UAV). This reduces measurement time and environmental changes during the measurement as well as rater bias. We compared the potential of a widely used multispectral sensor and a cheaper high-resolution RGB camera to track the dynamics of senescence. A UAV each was equipped with one of these sensors and used to measure canopy reflectance throughout the senescence process that lasted several weeks, for more than 400 winter wheat cultivars across three field seasons. Multiple spectral and RGB indices were calculated at the experimental plot level and used to model the dynamics of senescence. Model fits were further processed to extract key time points of the senescence phase. By comparing the results of the two sensors with each other and with the visual evaluation, respectively, we show that both sensors allow monitoring of senescence dynamics and measure key time points of the phase with a precision close to that of more sophisticated proximal sensing approaches. Optimal timing of measurements proved to be more important than the choice of sensor, confirming that timely and frequent measurements should be prioritized over more expensive sensors that provide a higher spectral resolution.

show abstract

Section: Discussionmentioning

confidence: 99%

Temporal resolution trumps spectral resolution in UAV-based monitoring of canopy senescence dynamics

Tschurr,

Roth,

Storni

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…To this end, (i) traditional orthomosaics are generated to compare different approaches in a crop water stress analysis; (ii) moreover, this study adopts multiple flight configurations, including nadir and oblique flights, as well as their combination, to investigate the potential impact of flight configuration on CWSI results. Previous research has shown that oblique imagery combined with nadir images is better for generating 3D models [32][33][34]. However, there is limited research on the influence of nadir and oblique multispectral and thermal images on orthomosaics and 3D point clouds when studied separately.…”

Section: Introductionmentioning

confidence: 99%

Comparing Nadir and Oblique Thermal Imagery in UAV-Based 3D Crop Water Stress Index Applications for Precision Viticulture with LiDAR Validation

Buunk,

Vélez,

Ariza-Sentís

et al. 2023

Sensors

View full text Add to dashboard Cite

Unmanned Aerial Vehicle (UAV) thermal imagery is rapidly becoming an essential tool in precision agriculture. Its ability to enable widespread crop status assessment is increasingly critical, given escalating water demands and limited resources, which drive the need for optimizing water use and crop yield through well-planned irrigation and vegetation management. Despite advancements in crop assessment methodologies, including the use of vegetation indices, 2D mapping, and 3D point cloud technologies, some aspects remain less understood. For instance, mission plans often capture nadir and oblique images simultaneously, which can be time- and resource-intensive, without a clear understanding of each image type’s impact. This issue is particularly critical for crops with specific growth patterns, such as woody crops, which grow vertically. This research aims to investigate the role of nadir and oblique images in the generation of CWSI (Crop Water Stress Index) maps and CWSI point clouds, that is 2D and 3D products, in woody crops for precision agriculture. To this end, products were generated using Agisoft Metashape, ArcGIS Pro, and CloudCompare to explore the effects of various flight configurations on the final outcome, seeking to identify the most efficient workflow for each remote sensing product. A linear regression analysis reveals that, for generating 2D products (orthomosaics), combining flight angles is redundant, while 3D products (point clouds) are generated equally from nadir and oblique images. Volume calculations show that combining nadir and oblique flights yields the most accurate results for CWSI point clouds compared to LiDAR in terms of geometric representation (R2 = 0.72), followed by the nadir flight (R2 = 0.68), and, finally, the oblique flight (R2 = 0.54). Thus, point clouds offer a fuller perspective of the canopy. To our knowledge, this is the first time that CWSI point clouds have been used for precision viticulture, and this knowledge can aid farm managers, technicians, or UAV pilots in optimizing the capture of UAV image datasets in line with their specific goals.

show abstract

Enhancing leaf area index and biomass estimation in maize with feature augmentation from unmanned aerial vehicle-based nadir and cross-circling oblique photography

Fei,

Xiao,

et al. 2023

Computers and Electronics in Agriculture

View full text Add to dashboard Cite

High-throughput calculation of organ-scale traits with reconstructed accurate 3D canopy structures using a UAV RGB camera with an advanced cross-circling oblique route

Cited by 26 publications

References 69 publications

Temporal resolution trumps spectral resolution in UAV-based monitoring of canopy senescence dynamics

Temporal resolution trumps spectral resolution in UAV-based monitoring of canopy senescence dynamics

Comparing Nadir and Oblique Thermal Imagery in UAV-Based 3D Crop Water Stress Index Applications for Precision Viticulture with LiDAR Validation

Enhancing leaf area index and biomass estimation in maize with feature augmentation from unmanned aerial vehicle-based nadir and cross-circling oblique photography

Contact Info

Product

Resources

About