Détail de l'auteur
Auteur Freek Van Der Meer |
Documents disponibles écrits par cet auteur (3)
Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externesContinuum removed band depth analysis for detecting the effects of natural gas, methane and ethane reflectance / M.F. Noomen in Remote sensing of environment, vol 105 n° 3 (15/12/2006)
Titre : Continuum removed band depth analysis for detecting the effects of natural gas, methane and ethane reflectance Type de document : Article/Communication Auteurs : M.F. Noomen, Auteur ; Andrew K. Skidmore, Auteur ; Freek Van Der Meer, Auteur ; Herbert H.T. Prins, Auteur Année de publication : 2006 Article en page(s) : pp 262 - 270 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] bande visible
[Termes IGN] gaz naturel
[Termes IGN] photosynthèse
[Termes IGN] réflectance végétale
[Termes IGN] santé
[Termes IGN] spectrophotométrie
[Termes IGN] végétationRésumé : (Auteur) It is known that natural gas in the soil affects vegetation health, which may be detected through analysis of reflectance spectra. Since natural gas is invisible, changes in the vegetation could potentially indicate gas leakage. Although it is known that gas in soil affects plant reflectance, the relationship between natural gas and the development and reflectance properties of plants has not been studied. The objective of this study was to test whether natural gas and its two main components, methane and ethane, affect vegetation reflectance in the chlorophyll and water absorption regions. An experiment was carried out in which maize (Zea mays) plants were grown in pots that were flushed with 10 l of gas per day for 39 + 4 days. Leaf reflectance was measured once a week with a spectrophotometer. The reflectance was analysed using continuum removal of the blue (400–550 nm), red (550–750 nm) and two water absorption features (1370–1570 nm and 1870–2170 nm), after which the band depths and normalized band depths were analyzed for each treatment. The band depth analysis showed that ethane caused an initial increase of 10% in reflectance between 560 and 590 nm, followed by a decrease during the course of the experiment. Normalized band depth analysis showed that ethane caused a reflectance shift of 1 to 5 nm towards longer wavelengths compared to the control reflectance in the visible region. All gases caused an increase in reflectance in the water absorption bands. The physiological reflectance index, PRI, which has previously linked water stress to photosynthetic activity, suggested that the hydrocarbon gases (particularly ethane) decreased the photosynthetic activity of the plants. The combination of reduced band depths in the chlorophyll and water absorption regions and the increased PRI suggests that ethane gas in the soil hampered a normal water uptake by maize plants in an early stage of their growth. Although further research is necessary to upscale the results from the laboratory to the field, the increased reflectance in the 560–590 nm region caused by ethane together with the increased PRI are promising indicators for gas leakage. Copyright Elsevier Numéro de notice : A2006-558 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2006.07.009 En ligne : https://doi.org/10.1016/j.rse.2006.07.009 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28281
in Remote sensing of environment > vol 105 n° 3 (15/12/2006) . - pp 262 - 270[article]
Titre : Effectiveness of spectroscopy in identification of swelling indicator clay minerals Type de document : Article/Communication Auteurs : P.C. Kariuki, Auteur ; T. Woldai, Auteur ; Freek Van Der Meer, Auteur Année de publication : 2004 Article en page(s) : pp 455 - 469 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photo-interprétation
[Termes IGN] Argile
[Termes IGN] Espagne
[Termes IGN] humidité du sol
[Termes IGN] risque naturelRésumé : (Auteur) Swelling soils are a major geological hazard worldwide and their identification is a major concern. Swelling is due to the presence of clay minerals with a potential to accommodate water within their crystal structure. Three common groups, namely smectite, illite and kaolinite, have been identified as indicators of high, moderate and low swelling potential soils where in abundance. This study assessed the potential of spectral data as a tool to recognize the presence of these minerals in soils of varying swelling potential collected from the Antequera area of southern Spain, with the aim of establishing spectral parameters that would in future be applied in remote sensing applications for mapping swelling soils. The coefficient of linear extensibility (COLE) and the linear extensibility (Lerod), which are established methods for assessing swelling potential and tentative clay mineral allocation, were used as the controlling methods to classify the soils into swelling potential groups and to assign them to dominant clay mineral types. Several spectral parameters were identified as giving a good basis for assigning the soils to domination by either of these clay minerals, and thus to a swelling potential class based on their diagnostic assignment to hydroxyl (OH) and molecular water vibrational processes in clay minerals. The parameters consisted of asymmetries (1400 nm and 2200 nm) that were strong in the presence of the more ordered kaolinite, wavelength position and depth at 1900 nm, in abundant smectites, first and second derivative peaks at or near the molecular water feature and the unique presence of absorptions at 2170 nm and 2340 nm in abundant kaolinite and illite. The results show the potential for using reflectance spectroscopy as a tool in the classification of soils into domination by these indicator minerals and thus into swelling potential classes. However, high organic matter and the presence of moisture were found to affect area and depth intensities and would require consideration in such applications. Numéro de notice : A2004-058 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116031000084314 En ligne : https://doi.org/10.1080/0143116031000084314 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26586
in International Journal of Remote Sensing IJRS > vol 25 n° 2 (January 2004) . - pp 455 - 469[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-04021 RAB Revue Centre de documentation En réserve L003 Exclu du prêt vol 57 n° 3 - December 2002 - January 2003 - Image stereoscopy and hyperspectral imaging (Bulletin de ISPRS Journal of photogrammetry and remote sensing) / A.K. Skimode
Contient
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Code-barres Cote Support Localisation Section Disponibilité 081-02051 SL Revue Centre de documentation Revues en salle Disponible
