Goniometers

The goniometers part of PLANETIPAG is composed of two spectro-gonio radiometers SHINE and SHADOWS developed at IPAG. They allow measurement of bidirectional reflectance spectra and photometric distribution functions of various types of planetary materials (granular to compact), from visible to near IR (from 0.4 to 4.8 µm), with high radiometric accuracy ( better than +/- 0.5% relative) under most geometries (illumination and observation up to almost 80°, azimuths 0° to 180°, phase angle 5° to 160°)

The instruments are located in two dark cold rooms which can be cooled to -20° C. They are fully automated, calibration and data acquisition are performed with software developed in the laboratory. Different types of measurements can be programmed with different environmental cryogenic cells.

The SHINE instrument is fully described in Brissaud et al. 2004, Appl. Optics, 43, 1926 :
– measurements: reflectance, samples: powders, ice, mixtures, various surfaces (from 10 to 300 mm in diameter, thickness from 1 to 250 mm depending on the absorbance of the grains)

The SHADOWS instrument is fully described in Potin et al. 2018, Appl. Optics, 57, 8279 :
– reflectance measurements: samples: powders, ice, mixtures, various surfaces ( 2 mm (in micro-beam mode) or 5.7 mm (in normal mode) minimum diameter, thickness from 0.25 to 2.5 mm depending on the absorbance of the albedo grains from 0.0003 to 1).
– transmittance measurements: samples: deposits / films on optical windows

This installation is one of the experimental platforms of the ’Trans-National Access’ activity of the Europlanet 2024-RI program

SHINE Spectro-Gonio Radiometer

Technical characteristics

• Spectral range: 400 - 4700 nm
• Spectral resolution: min <0.1 nm (but weak S / N), max: 6 nm (<750 nm), 12 nm (<1500 nm), 24 nm (<3000 nm), 48 nm (> 3000 nm)
• Angle of incidence: 0° - 85°
• Emergence angle: 0° - 80°
• Azimuth angle: 0° - 180°
• Phase angle: 8° - 165°
• Illumination diameter: 200 mm (nadir)
• Observation diameter: 20 mm (nadir)
• Photometric accuracy: <1% (0.4-2.5µm); <2% (2.5-4.2µm) and <0.5% relative
• Operating temperature from -20° C to +30° C

Associated simulation chambers:

• SERAC (from -40 to + 80°C)
• CARBONIR (from -210 to +17°C)

SHADOWS Micro Spectro-Gonio Radiometer

Technical characteristics

• Spectral range: 360 - 4800 nm
• Spectral resolution: min <0.1 nm (but weak S / N), max 3.8 nm (200 - 1400 nm), 7.6 nm (600 - 2500 nm), 15.2 nm (1100 - 3400 nm), 31 nm (> 2500 nm)
• Angle of incidence: 0° - 75°
• Emergence angle: 0° - 85°
• Azimuth angle: 0° - 180°
• Phase angle: 5° - 160°
• Illumination diameter: 5.2 mm (nadir)
• Observation diameter: 20 mm (nadir)
• Photometric accuracy: <1% (0.4-2.5µm); <2% (2.5-4.7µm) and <0.5% relative
• Temperature of use from -20° C to +30° C

Associated simulation chambers:

• MIRAGE (high temperature, up to 250° C)
• ICEBERG (low temperature, down to -200° C)

– De Angelis, S. et al. (2021). Temperature-dependent, VIS-NIR reflectance spectroscopy of sodium sulfates, Icarus, 357, 114165. https://doi.org/10.1016/j.icarus.2020.114165
– Potin, S. et al. (2020). Style and intensity of hydration among C-complex asteroids: a comparison to desiccated carbonaceous chondrites. Icarus, 348, 113826. https://doi.org/10.1016/j.icarus.2020.113826
– Poch, O. et al. (2020). Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids, Science 367, 10.1126/science.aaw7462.
– Sultana, R., O. Poch, P. Beck, B. Schmitt and E. Quirico (2021). Visible and Near-Infrared reflectance of hyperfine and hyperporous particulate surfaces. Icarus. https://doi.org/10.1016/j.icarus.2020.114141