Spectro-Gonio Radiometer
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| + | This spectro-gonio radiometer has been specially designed to measure with a high photometric accuracy the bidirectional reflectance of bright planetary materials over most of the solar spectrum and under wide illumination/observation configurations. | ||
| + | |||
| + | '''Location:''' | ||
| + | Institut de Planétologie et Astrophysique de Grenoble | ||
| + | CNRS - Université Grenoble Alpes | ||
| + | Saint Martin d’Hères, France | ||
| + | |||
| + | '''Persons in charge''': | ||
| + | - Scientific : Bernard Schmitt, Research director | ||
| + | - Technical : Olivier Brissaud, Engineer | ||
| + | |||
| + | - Type: Laboratory Experiment facility | ||
| + | |||
| + | [[Spectral range]] : 0.3 - 4.5 µm (-> 5.0 µm: lower S/N) (4.2-4.3µm: atm. CO2 limited) | ||
| + | [[Spectral resolution]] : variable | ||
| + | - mini : < 0.1 nm (but S/N limited) | ||
| + | - maxi : 6 nm (<750nm), 12 nm (<1500nm), 24 nm (<3000nm), 48nm (>3000nm) | ||
| + | |||
| + | [[Bidirectional Reflectance]] | ||
| + | - Incidence angle : 0° to 85° | ||
| + | resolution: 0.1° | ||
| + | maximum sampling : 0.1° | ||
| + | - Emergence angle : 0° to 80° (to 83° for dark / fine grained samples) | ||
| + | resolution : ± 2° (may be reduced to < ± 0.5°, but S/N limited) | ||
| + | max. sampling : 0.1° | ||
| + | - Azimuth angle : 0° to 180° | ||
| + | resolution : ± 2° (may be reduced to < ± 0.5°, but S/N limited) | ||
| + | max. sampling : 0.1° | ||
| + | - Phase angle : mini to 165° | ||
| + | mini : ~ 8° for bright / large grained samples | ||
| + | ~ 4° for dark / fine grained samples | ||
| + | |||
| + | - Illumination diameter (nadir) : 200 mm | ||
| + | - Observation diameter (nadir) : 20 mm | ||
| + | |||
| + | |||
| + | [[Photometry]] : absolute: 0.3-1.0 µm: better than 1% over all configurations | ||
| + | (relative to a calibrated Spectralon 0.99 reference panel) | ||
| + | 1.0-2.5 µm: better than 1% over all configurations | ||
| + | 2.5-5 µm : better than 2% over all configurations | ||
| + | relative : better than 0.5% (0.3-2.5 µm) | ||
| + | |||
| + | [[Polarimetry options]] (only partly tested) | ||
| + | - Illumination : linear polarization : variable 0 to 90° | ||
| + | spectral range : 0.3 - 2.8 µm | ||
| + | - Observation : 1 component over the 0.3 - 5µm range + unpolarized | ||
| + | or || and ┴ components over restricted spectral range | ||
| + | |||
| + | [[Samples]] | ||
| + | - Types: rocks, minerals, snow / ice, sulfur, ... (from very bright to dark) | ||
| + | - Texture: compact or granular | ||
| + | - Grain size: micrometer to a few millimeters | ||
| + | - Size: maxi: 300mm diameter, 250 mm deep (bright & coarse grained samples) 120 mm in diameter, 2-10 mm deep (dark or fine grained samples) | ||
| + | mini: 25 mm x 120 mm (for principal plane observation down to 80°) | ||
| + | 25 mm x 45 mm (for principal plane observation down to 60°) | ||
| + | [[Temperature]]: room temperature or heated | ||
| + | down to -20°C (in cold room) | ||
| + | down to -40°C (in SERAC environmental cell) | ||
| + | |||
| + | |||
| + | [[Experiment control]]: PC/Windows, fully software controlled (LabView©). | ||
| + | automatic acquisition of all spectral/geometric configurations | ||
| + | |||
| + | [[Acquisition time]]: typical 15 mn for 200 spectral channels in visible (S/N dependent) total : 15 hours for 100 spectral channels and 100 geometries | ||
| + | |||
| + | [[Current state of system]]: 0.3 - 5 µm range : fully calibrated | ||
| + | polarization : tested -> 2003 | ||
| + | low temperature : tested in cold room down to -20°C | ||
| + | [[ | ||
| + | Availability to community]]: Technical improvements/calibration (20%) | ||
| + | LPG + associated laboratories measurements (60%) | ||
| + | open to specific collaborations w. funding (20%) | ||
| + | |||
| + | '''References''': | ||
| + | Bonnefoy, N., O. Brissaud, B. Schmitt, S. Douté, M. Fily, W. Grundy, and P. Rabou 2000. Experimental system for the study of planetary surface materials’ BRDF. Remote Sensing. Rev., 19, 59-74. | ||
| + | |||
| + | Bonnefoy, N. 2001. Développement d’un spectrophoto-goniomètre pour l’étude de la réflectance bidirectionnelle des surfaces géophysiques. Application au soufre et perspectives pour le satellite Io. PhD Thesis, LPG - Université Joseph Fourier, Grenoble (20/11/2001). | ||
| + | |||
| + | Brissaud, O., B. Schmitt, N. Bonnefoy, S. Douté, P. Rabou, W. Grundy, and M. Fily 2004. Spectrogonio radiometer for the study of the bidirectional reflectance and polarization functions of planetary surfaces: I. Design and tests. Appl. Optics, 43 (9), 1926-1937. | ||
| + | |||
| + | Pommerol, A., and B. Schmitt 2008. Strength of the H2O near-infrared absorption bands in hydrated minerals: Effects of particle size and correlation with albedo. J. Geophys. Res E, 113, E10009 [doi:10.1029/2007JE003069] | ||
| + | |||
| + | Pommerol, A., and B. Schmitt 2008. Strength of the H2O near-infrared absorption bands in hydrated minerals: Effects of measurement geometry. J. Geophys. Res E, 113, E12008 [doi: 10.1029/2008JE003197]. | ||
| + | |||
| + | Pommerol, A., Schmitt B., Beck, P., Brissaud, O. 2009. Water sorption on Martian regolith analogs: thermodynamics and near-IR reflectance spectroscopy. Icarus soumis | ||
| + | |||
| + | |||
* Characteristics: [[File:Spectro-Gonio_characteristics.pdf]] | * Characteristics: [[File:Spectro-Gonio_characteristics.pdf]] | ||
* Article Brissaud et al. 2004: [[File:brissaud04-AplOpt-43-1926_spectrogonio-radiometer.pdf]] | * Article Brissaud et al. 2004: [[File:brissaud04-AplOpt-43-1926_spectrogonio-radiometer.pdf]] | ||
Revision as of 21:43, 3 November 2014
This spectro-gonio radiometer has been specially designed to measure with a high photometric accuracy the bidirectional reflectance of bright planetary materials over most of the solar spectrum and under wide illumination/observation configurations.
Location: Institut de Planétologie et Astrophysique de Grenoble CNRS - Université Grenoble Alpes Saint Martin d’Hères, France
Persons in charge: - Scientific : Bernard Schmitt, Research director - Technical : Olivier Brissaud, Engineer
- Type: Laboratory Experiment facility
Spectral range : 0.3 - 4.5 µm (-> 5.0 µm: lower S/N) (4.2-4.3µm: atm. CO2 limited) Spectral resolution : variable - mini : < 0.1 nm (but S/N limited) - maxi : 6 nm (<750nm), 12 nm (<1500nm), 24 nm (<3000nm), 48nm (>3000nm)
Bidirectional Reflectance - Incidence angle : 0° to 85° resolution: 0.1° maximum sampling : 0.1° - Emergence angle : 0° to 80° (to 83° for dark / fine grained samples) resolution : ± 2° (may be reduced to < ± 0.5°, but S/N limited) max. sampling : 0.1° - Azimuth angle : 0° to 180° resolution : ± 2° (may be reduced to < ± 0.5°, but S/N limited) max. sampling : 0.1° - Phase angle : mini to 165° mini : ~ 8° for bright / large grained samples ~ 4° for dark / fine grained samples
- Illumination diameter (nadir) : 200 mm - Observation diameter (nadir) : 20 mm
Photometry : absolute: 0.3-1.0 µm: better than 1% over all configurations
(relative to a calibrated Spectralon 0.99 reference panel)
1.0-2.5 µm: better than 1% over all configurations 2.5-5 µm : better than 2% over all configurations relative : better than 0.5% (0.3-2.5 µm)
Polarimetry options (only partly tested) - Illumination : linear polarization : variable 0 to 90° spectral range : 0.3 - 2.8 µm - Observation : 1 component over the 0.3 - 5µm range + unpolarized or || and ┴ components over restricted spectral range
Samples - Types: rocks, minerals, snow / ice, sulfur, ... (from very bright to dark) - Texture: compact or granular - Grain size: micrometer to a few millimeters - Size: maxi: 300mm diameter, 250 mm deep (bright & coarse grained samples) 120 mm in diameter, 2-10 mm deep (dark or fine grained samples) mini: 25 mm x 120 mm (for principal plane observation down to 80°) 25 mm x 45 mm (for principal plane observation down to 60°) Temperature: room temperature or heated down to -20°C (in cold room) down to -40°C (in SERAC environmental cell)
Experiment control: PC/Windows, fully software controlled (LabView©).
automatic acquisition of all spectral/geometric configurations
Acquisition time: typical 15 mn for 200 spectral channels in visible (S/N dependent) total : 15 hours for 100 spectral channels and 100 geometries
Current state of system: 0.3 - 5 µm range : fully calibrated polarization : tested -> 2003 low temperature : tested in cold room down to -20°C [[ Availability to community]]: Technical improvements/calibration (20%) LPG + associated laboratories measurements (60%) open to specific collaborations w. funding (20%)
References: Bonnefoy, N., O. Brissaud, B. Schmitt, S. Douté, M. Fily, W. Grundy, and P. Rabou 2000. Experimental system for the study of planetary surface materials’ BRDF. Remote Sensing. Rev., 19, 59-74.
Bonnefoy, N. 2001. Développement d’un spectrophoto-goniomètre pour l’étude de la réflectance bidirectionnelle des surfaces géophysiques. Application au soufre et perspectives pour le satellite Io. PhD Thesis, LPG - Université Joseph Fourier, Grenoble (20/11/2001).
Brissaud, O., B. Schmitt, N. Bonnefoy, S. Douté, P. Rabou, W. Grundy, and M. Fily 2004. Spectrogonio radiometer for the study of the bidirectional reflectance and polarization functions of planetary surfaces: I. Design and tests. Appl. Optics, 43 (9), 1926-1937.
Pommerol, A., and B. Schmitt 2008. Strength of the H2O near-infrared absorption bands in hydrated minerals: Effects of particle size and correlation with albedo. J. Geophys. Res E, 113, E10009 [doi:10.1029/2007JE003069]
Pommerol, A., and B. Schmitt 2008. Strength of the H2O near-infrared absorption bands in hydrated minerals: Effects of measurement geometry. J. Geophys. Res E, 113, E12008 [doi: 10.1029/2008JE003197].
Pommerol, A., Schmitt B., Beck, P., Brissaud, O. 2009. Water sorption on Martian regolith analogs: thermodynamics and near-IR reflectance spectroscopy. Icarus soumis
- Characteristics: File:Spectro-Gonio characteristics.pdf
- Article Brissaud et al. 2004: File:Brissaud04-AplOpt-43-1926 spectrogonio-radiometer.pdf
