The Improved Dual-view Field Goniometer System FIGOS
In spectrodirectional Remote Sensing (RS) the Earth’s surface reflectance characteristics are studied by means of their angular dimensions. Almost all natural surfaces exhibit an individual anisotropic reflectance behaviour due to the contrast between the optical properties of surface elements...
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| Format: | Article |
| Language: | English |
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MDPI AG
2008-08-01
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| Series: | Sensors |
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| Online Access: | http://www.mdpi.com/1424-8220/8/8/5120/ |
| _version_ | 1797999067604713472 |
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| author | Klaus I. Itten Mathias Kneubühler Stefan Dangel Jürg Schopfer |
| author_facet | Klaus I. Itten Mathias Kneubühler Stefan Dangel Jürg Schopfer |
| author_sort | Klaus I. Itten |
| collection | DOAJ |
| description | In spectrodirectional Remote Sensing (RS) the Earth’s surface reflectance characteristics are studied by means of their angular dimensions. Almost all natural surfaces exhibit an individual anisotropic reflectance behaviour due to the contrast between the optical properties of surface elements and background and the geometric surface properties of the observed scene. The underlying concept, which describes the reflectance characteristic of a specific surface area, is called the bidirectional reflectance distribution function (BRDF). BRDF knowledge is essential for both correction of directional effects in RS data and quantitative retrieval of surface parameters. Ground-based spectrodirectional measurements are usually performed with goniometer systems. An accurate retrieval of the bidirectional reflectance factors (BRF) from field goniometer measurements requires hyperspectral knowledge of the angular distribution of the reflected and the incident radiation. However, prior to the study at hand, no operational goniometer system was able to fulfill this requirement. This study presents the first dual-view field goniometer system, which is able to simultaneously collect both the reflected and the incident radiation at high angular and spectral resolution and, thus, providing the necessary spectrodirectional datasets to accurately retrieve the surface specific BRF. Furthermore, the angular distribution of the incoming diffuse radiation is characterized for various atmospheric conditions and the BRF retrieval is performed for an artificial target and compared to laboratory spectrodirectional measurement results obtained with the same goniometer system. Suggestions for further improving goniometer systems are given and the need for intercalibration of various goniometers as well as for standardizing spectrodirectional measurements is expressed. |
| first_indexed | 2024-04-11T10:58:42Z |
| format | Article |
| id | doaj.art-686fc385933344c380fd15ef5967746b |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-11T10:58:42Z |
| publishDate | 2008-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-686fc385933344c380fd15ef5967746b2022-12-22T04:28:41ZengMDPI AGSensors1424-82202008-08-018851205140The Improved Dual-view Field Goniometer System FIGOSKlaus I. IttenMathias KneubühlerStefan DangelJürg SchopferIn spectrodirectional Remote Sensing (RS) the Earth’s surface reflectance characteristics are studied by means of their angular dimensions. Almost all natural surfaces exhibit an individual anisotropic reflectance behaviour due to the contrast between the optical properties of surface elements and background and the geometric surface properties of the observed scene. The underlying concept, which describes the reflectance characteristic of a specific surface area, is called the bidirectional reflectance distribution function (BRDF). BRDF knowledge is essential for both correction of directional effects in RS data and quantitative retrieval of surface parameters. Ground-based spectrodirectional measurements are usually performed with goniometer systems. An accurate retrieval of the bidirectional reflectance factors (BRF) from field goniometer measurements requires hyperspectral knowledge of the angular distribution of the reflected and the incident radiation. However, prior to the study at hand, no operational goniometer system was able to fulfill this requirement. This study presents the first dual-view field goniometer system, which is able to simultaneously collect both the reflected and the incident radiation at high angular and spectral resolution and, thus, providing the necessary spectrodirectional datasets to accurately retrieve the surface specific BRF. Furthermore, the angular distribution of the incoming diffuse radiation is characterized for various atmospheric conditions and the BRF retrieval is performed for an artificial target and compared to laboratory spectrodirectional measurement results obtained with the same goniometer system. Suggestions for further improving goniometer systems are given and the need for intercalibration of various goniometers as well as for standardizing spectrodirectional measurements is expressed.http://www.mdpi.com/1424-8220/8/8/5120/Dual-view field goniometer system FIGOSBRF retrievalBRDFatmospheric influencediffuse illuminationspectrodirectional Remote Sensing |
| spellingShingle | Klaus I. Itten Mathias Kneubühler Stefan Dangel Jürg Schopfer The Improved Dual-view Field Goniometer System FIGOS Sensors Dual-view field goniometer system FIGOS BRF retrieval BRDF atmospheric influence diffuse illumination spectrodirectional Remote Sensing |
| title | The Improved Dual-view Field Goniometer System FIGOS |
| title_full | The Improved Dual-view Field Goniometer System FIGOS |
| title_fullStr | The Improved Dual-view Field Goniometer System FIGOS |
| title_full_unstemmed | The Improved Dual-view Field Goniometer System FIGOS |
| title_short | The Improved Dual-view Field Goniometer System FIGOS |
| title_sort | improved dual view field goniometer system figos |
| topic | Dual-view field goniometer system FIGOS BRF retrieval BRDF atmospheric influence diffuse illumination spectrodirectional Remote Sensing |
| url | http://www.mdpi.com/1424-8220/8/8/5120/ |
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