Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1109/TGRS.2012.2194156
Titel (primär) Using diurnal variation in backscatter to detect vegetation water stress
Autor Steele-Dunne, S.C.; Friesen, J. ORCID logo ; van de Giesen, N.
Quelle IEEE Transactions on Geoscience and Remote Sensing
Erscheinungsjahr 2012
Department CHS; CATHYD
Band/Volume 50
Heft 7
Seite von 2618
Seite bis 2629
Sprache englisch
Keywords radar remote sensing;soil moisture;vegetation

A difference has been detected between the C-band wind scatterometer measurements from the morning (descending) and evening (ascending) passes of the European Remote Sensing (ERS) 1/2 satellite. In the West African savanna, for example, these differences correspond to the onset of vegetation water stress. A literature review of the current state of knowledge regarding the diurnal variation in vegetation dielectric properties and its influence on observed backscatter is presented. A numerical sensitivity study using the Michigan microwave canopy scattering model was performed to investigate whether this difference might be explained by diurnal variation in the dielectric properties of the canopy. For vertically copolarized backscatter, as in the case of the ERS wind scatterometer, the greatest sensitivity is to leaf moisture (and, hence, dielectric constant), but the trunk moisture is significant at low values of leaf moisture content. This suggests that the ERS wind scatterometer may well detect changes in vegetation water status. The impact of leaf, branch, trunk, and soil moisture contents on L-band HH, VV, and HV backscatter was also investigated to explore the implications for the National Aeronautics and Space Administration's upcoming Soil Moisture Active Passive (SMAP) mission. Results suggest that combining the morning and evening passes of the SMAP radar observations might yield valuable insight into water stress in areas otherwise considered too densely vegetated for traditional soil moisture retrieval.
dauerhafte UFZ-Verlinkung
Steele-Dunne, S.C., Friesen, J., van de Giesen, N. (2012):
Using diurnal variation in backscatter to detect vegetation water stress
IEEE Trans. Geosci. Remote Sensing 50 (7), 2618 - 2629 10.1109/TGRS.2012.2194156