Matches in SemOpenAlex for { <https://semopenalex.org/work/W4220709076> ?p ?o ?g. }
Showing items 1 to 75 of
75
with 100 items per page.
- W4220709076 abstract "<p>This work deals with crop monitoring in a semi-arid environment, the Mediterranean region, where up to 80-90% of already over-exploited water resources are used for irrigation. To help sustainable use of water resources in agriculture, more efforts have to be made to water use through a better assessment of crop water stress, evapotranspiration, and soil moisture at the plot scale on large areas.</p><p>This study is focused on the diurnal and seasonal variation of the backscatter coefficient and the interferometric coherence over an olive orchard, located in the Chichaoua region (central Morocco), that has an area of 2.4ha, irrigated by drip system, with olives trees of 20-years-old. The study site was equipped, since May-2019, with a radar device consisting of 7 C-band horn-antennas at the top of a 20m-high-tower, that collects measurements at 4-polarizations allowing radar acquisitions in high temporal frequency with a timestep of 15min.&#160; An <em>Eddy-covariance </em>system has been also installed for measuring energy balance and the physiological functioning of olives trees with sapflow and dendrometer sensors on olives trunks. The study site is visible at the intersection of three different sentinel-1 orbit passes allowing to have six acquisitions every 10days to compare them with in-situ radar measurements at different incidence angles.</p><p>Both the backscattering coefficient <em>s<sup>0 </sup></em>&#160;and the interferometric coherences are analyzed. At a seasonal scale, all <em>s<sup>0 </sup></em>&#160;polarizations show a low temporal frequency profile with amplitude lower than 3dB. For VV-polarization, in 2021, it is quite constant, with a slight decrease of 1 dB during the summer, while for 2020, an increase of 2dB is observed at the end of the spring. At HV-polarization no particular seasonal behavior can be seen. On the contrary, a marked diurnal profile is observed at VV-polarization, which is closely correlated with plant activity, with daily amplitude varying between 3dB in winter to 5dB in summer. The diurnal <em>s<sup>0 </sup></em>&#160;signature is low during night, increases from 6AM, reaches its maximum during 2 to 6PM, and then decreases to recover its low value around midnight.</p><p>Concerning the interferometric coherence <em></em><em>r</em><em></em>, similar behavior to the one observed over tropical forest is noted. The <em></em><em>r</em><em></em> daily evolution shows a clear diurnal cycle, with amplitude varying between 0.3 in winter to 0.7 in summer. During this latter, <em></em><em>r</em><em></em> is high (~0.9) at night when the wind and vegetation activity are low, and begins to decrease at 7AM, with vegetation activity start, before the wind picks up at 8AM, reaching minimum value at 7PM (~0,4). It then follows a rapid increase to reach its maximum value (0.9) at midnight. A high sensitivity to rainy events is also noted, corresponding to very low <em></em><em>r</em><em></em> values. It is worth noticing than <em></em><em>r</em><em></em> estimated between measurements separated by 6 days, show similar diurnal profiles, with <em></em><em>r</em><em></em> lower amplitude (0.2 to 0.4), suggesting it can be characterized by Sentinel-1 morning and evening observations. Additional work as to be carried on to relate this radar diurnal cycle to water cycle, that would be good omen to monitor water stress from spaceborne C-band radar sensors.</p>" @default.
- W4220709076 created "2022-04-03" @default.
- W4220709076 creator A5012242287 @default.
- W4220709076 creator A5019685499 @default.
- W4220709076 creator A5028242808 @default.
- W4220709076 creator A5053743538 @default.
- W4220709076 creator A5073035703 @default.
- W4220709076 creator A5077034276 @default.
- W4220709076 creator A5080297557 @default.
- W4220709076 creator A5081619726 @default.
- W4220709076 creator A5082834779 @default.
- W4220709076 creator A5091783354 @default.
- W4220709076 date "2022-03-27" @default.
- W4220709076 modified "2023-10-14" @default.
- W4220709076 title "Diurnal and seasonal behavior observed by C-band radar measurements at high temporal frequencies over an olive orchard in a Mediterranean region" @default.
- W4220709076 doi "https://doi.org/10.5194/egusphere-egu22-4151" @default.
- W4220709076 hasPublicationYear "2022" @default.
- W4220709076 type Work @default.
- W4220709076 citedByCount "0" @default.
- W4220709076 crossrefType "posted-content" @default.
- W4220709076 hasAuthorship W4220709076A5012242287 @default.
- W4220709076 hasAuthorship W4220709076A5019685499 @default.
- W4220709076 hasAuthorship W4220709076A5028242808 @default.
- W4220709076 hasAuthorship W4220709076A5053743538 @default.
- W4220709076 hasAuthorship W4220709076A5073035703 @default.
- W4220709076 hasAuthorship W4220709076A5077034276 @default.
- W4220709076 hasAuthorship W4220709076A5080297557 @default.
- W4220709076 hasAuthorship W4220709076A5081619726 @default.
- W4220709076 hasAuthorship W4220709076A5082834779 @default.
- W4220709076 hasAuthorship W4220709076A5091783354 @default.
- W4220709076 hasConcept C110872660 @default.
- W4220709076 hasConcept C127313418 @default.
- W4220709076 hasConcept C176783924 @default.
- W4220709076 hasConcept C18903297 @default.
- W4220709076 hasConcept C35187779 @default.
- W4220709076 hasConcept C39432304 @default.
- W4220709076 hasConcept C41008148 @default.
- W4220709076 hasConcept C4646841 @default.
- W4220709076 hasConcept C554190296 @default.
- W4220709076 hasConcept C6557445 @default.
- W4220709076 hasConcept C76155785 @default.
- W4220709076 hasConcept C86803240 @default.
- W4220709076 hasConcept C88862950 @default.
- W4220709076 hasConcept C91586092 @default.
- W4220709076 hasConceptScore W4220709076C110872660 @default.
- W4220709076 hasConceptScore W4220709076C127313418 @default.
- W4220709076 hasConceptScore W4220709076C176783924 @default.
- W4220709076 hasConceptScore W4220709076C18903297 @default.
- W4220709076 hasConceptScore W4220709076C35187779 @default.
- W4220709076 hasConceptScore W4220709076C39432304 @default.
- W4220709076 hasConceptScore W4220709076C41008148 @default.
- W4220709076 hasConceptScore W4220709076C4646841 @default.
- W4220709076 hasConceptScore W4220709076C554190296 @default.
- W4220709076 hasConceptScore W4220709076C6557445 @default.
- W4220709076 hasConceptScore W4220709076C76155785 @default.
- W4220709076 hasConceptScore W4220709076C86803240 @default.
- W4220709076 hasConceptScore W4220709076C88862950 @default.
- W4220709076 hasConceptScore W4220709076C91586092 @default.
- W4220709076 hasLocation W42207090761 @default.
- W4220709076 hasLocation W42207090762 @default.
- W4220709076 hasOpenAccess W4220709076 @default.
- W4220709076 hasPrimaryLocation W42207090761 @default.
- W4220709076 hasRelatedWork W2038382006 @default.
- W4220709076 hasRelatedWork W2040693669 @default.
- W4220709076 hasRelatedWork W2424470468 @default.
- W4220709076 hasRelatedWork W2726517715 @default.
- W4220709076 hasRelatedWork W2796090099 @default.
- W4220709076 hasRelatedWork W3018935317 @default.
- W4220709076 hasRelatedWork W3143790976 @default.
- W4220709076 hasRelatedWork W3164066767 @default.
- W4220709076 hasRelatedWork W4295168957 @default.
- W4220709076 hasRelatedWork W4297282674 @default.
- W4220709076 isParatext "false" @default.
- W4220709076 isRetracted "false" @default.
- W4220709076 workType "article" @default.