Fine-Resolution Repeat Topographic Surveying of Dryland Landscapes Using UAS-Based Structure-from-Motion Photogrammetry: Assessing Accuracy and Precision against Traditional Ground-Based Erosion MeasurementsReportar como inadecuado


Fine-Resolution Repeat Topographic Surveying of Dryland Landscapes Using UAS-Based Structure-from-Motion Photogrammetry: Assessing Accuracy and Precision against Traditional Ground-Based Erosion Measurements


Fine-Resolution Repeat Topographic Surveying of Dryland Landscapes Using UAS-Based Structure-from-Motion Photogrammetry: Assessing Accuracy and Precision against Traditional Ground-Based Erosion Measurements - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

1

US Department of Agriculture–Agricultural Research Service, Jornada Experimental Range, New Mexico State University, Las Cruces, NM 88001, USA

2

Civil Engineering Department, College of Engineering, California Polytechnical State University, Pomona, CA 91766, USA

3

US Geological Survey, Southwest Biological Science Center, Moab, UT 84532, USA





*

Author to whom correspondence should be addressed.



Academic Editors: Ioannis Gitas, Magaly Koch and Prasad S. Thenkabail

Abstract Structure-from-motion SfM photogrammetry from unmanned aerial system UAS imagery is an emerging tool for repeat topographic surveying of dryland erosion. These methods are particularly appealing due to the ability to cover large landscapes compared to field methods and at reduced costs and finer spatial resolution compared to airborne laser scanning. Accuracy and precision of high-resolution digital terrain models DTMs derived from UAS imagery have been explored in many studies, typically by comparing image coordinates to surveyed check points or LiDAR datasets. In addition to traditional check points, this study compared 5 cm resolution DTMs derived from fixed-wing UAS imagery with a traditional ground-based method of measuring soil surface change called erosion bridges. We assessed accuracy by comparing the elevation values between DTMs and erosion bridges along thirty topographic transects each 6.1 m long. Comparisons occurred at two points in time June 2014, February 2015 which enabled us to assess vertical accuracy with 3314 data points and vertical precision i.e., repeatability with 1657 data points. We found strong vertical agreement accuracy between the methods RMSE 2.9 and 3.2 cm in June 2014 and February 2015, respectively and high vertical precision for the DTMs RMSE 2.8 cm. Our results from comparing SfM-generated DTMs to check points, and strong agreement with erosion bridge measurements suggests repeat UAS imagery and SfM processing could replace erosion bridges for a more synoptic landscape assessment of shifting soil surfaces for some studies. However, while collecting the UAS imagery and generating the SfM DTMs for this study was faster than collecting erosion bridge measurements, technical challenges related to the need for ground control networks and image processing requirements must be addressed before this technique could be applied effectively to large landscapes. View Full-Text

Keywords: dryland erosion; photogrammetry; road network disturbance; UAS; erosion bridge dryland erosion; photogrammetry; road network disturbance; UAS; erosion bridge





Autor: Jeffrey K. Gillan 1,* , Jason W. Karl 1, Ahmed Elaksher 2 and Michael C. Duniway 3

Fuente: http://mdpi.com/



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