DOI: 10.1016/j.jag.2017.07.009
Scopus记录号: 2-s2.0-85032502283
论文题名: Implications of sensor design for coral reef detection: Upscaling ground hyperspectral imagery in spatial and spectral scales
作者: Caras T ; , Hedley J ; , Karnieli A
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2017
卷: 63 起始页码: 68
结束页码: 77
语种: 英语
英文关键词: Benthic
; Classification
; Coral reefs
; Hyperspectral
; Monitoring
; Scale
; Spatial resolution
; Spectral resolution
; Survey
Scopus关键词: benthos
; classification
; coral reef
; environmental monitoring
; multispectral image
; remote sensing
; sensor
; spatial resolution
; spectral analysis
; survey method
; Eilat
; Gulf of Aqaba
; Indian Ocean
; Israel
; Red Sea [Indian Ocean]
; Southern District
; Anthozoa
英文摘要: Remote sensing offers a potential tool for large scale environmental surveying and monitoring. However, remote observations of coral reefs are difficult especially due to the spatial and spectral complexity of the target compared to sensor specifications as well as the environmental implications of the water medium above. The development of sensors is driven by technological advances and the desired products. Currently, spaceborne systems are technologically limited to a choice between high spectral resolution and high spatial resolution, but not both. The current study explores the dilemma of whether future sensor design for marine monitoring should prioritise on improving their spatial or spectral resolution. To address this question, a spatially and spectrally resampled ground-level hyperspectral image was used to test two classification elements: (1) how the tradeoff between spatial and spectral resolutions affects classification; and (2) how a noise reduction by majority filter might improve classification accuracy. The studied reef, in the Gulf of Aqaba (Eilat), Israel, is heterogeneous and complex so the local substrate patches are generally finer than currently available imagery. Therefore, the tested spatial resolution was broadly divided into four scale categories from five millimeters to one meter. Spectral resolution resampling aimed to mimic currently available and forthcoming spaceborne sensors such as (1) Environmental Mapping and Analysis Program (EnMAP) that is characterized by 25 bands of 6.5 nm width; (2) VENμS with 12 narrow bands; and (3) the WorldView series with broadband multispectral resolution. Results suggest that spatial resolution should generally be prioritized for coral reef classification because the finer spatial scale tested (pixel size < 0.1 m) may compensate for some low spectral resolution drawbacks. In this regard, it is shown that the post-classification majority filtering substantially improves the accuracy of all pixel sizes up to the point where the kernel size reaches the average unit size (pixel < 0.25 m). However, careful investigation as to the effect of band distribution and choice could improve the sensor suitability for the marine environment task. This in mind, while the focus in this study was on the technologically limited spaceborne design, aerial sensors may presently provide an opportunity to implement the suggested setup. © 2017 The Authors
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79970
Appears in Collections: 气候变化事实与影响
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作者单位: The Remote Sensing Laboratory, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boker Campus, Israel; Numerical Optics Ltd., Belmont House, 19 West St., Witheridge, Tiverton, Devon, United Kingdom
Recommended Citation:
Caras T,, Hedley J,, Karnieli A. Implications of sensor design for coral reef detection: Upscaling ground hyperspectral imagery in spatial and spectral scales[J]. International Journal of Applied Earth Observation and Geoinformation,2017-01-01,63