(SPectroscopy for the Investigation of the Characteristics of the Atmosphere of Venus)
SPICAV is a spectrometer with 3 channels:
- SPICAV-UV: a UV spectrometer (118-320 nm) for nadir or limb aiming and determining the atmosphere’s vertical profile using solar and stellar occultation. This channel could quantify CO2, SO2, and aerosol presence. It also helped study the ionosphere and the atmosphere’s vertical temperature profile.
- SPICAV-IR: an IR spectrometer (0.7-1.7 µm) for nadir sounding and H20 solar-occultation.
- SOIR (Solar Occultation and Infrared): this additional channel was added on Venus-Express to observe the Sun through the Venusian atmosphere in infrared wavelengths.
- DPU (Data Processing Unit): this electronic unit was able to interface the satellite with the 3 channels.
SPICAV had a dedicated entrance aperture for solar occultation, separate from the one used in nadir aiming and stellar occultation.
The instrument was developed in a partnership involving 3 institutes:
- LATMOS (France) was the prime contractor on the instrument.
- BIRA-IASB (Royal Belgian Institute for Space Aeronomy) was in charge of manufacturing the mechanical elements and providing the SOIR channel.
- IKI (Russian Space Research Institute) developed the IR spectrometer.
The following tables present the main specifications for the UV and IR channels:
|Telescope||Off-axis parabolic mirror|
|Field of view||1 ° x 3.16 °|
|Spectrometer||Holographic diffraction grating|
|Detector||CCD Thomson TH 7863 (384x288 pixels)|
+ Hamamatsu intensifier
|Detector dimensions||8.8 x 6.6 mm|
|Pixel size||23 x 23 µm|
|Range||118 - 320 nm|
|Spectral resolution||1.5 nm|
|Instantaneous field of view||1 °|
|Spectrometer||AOTF (Acousto Optic Tunable Filter)|
|Detector||Hamamatsu InGaAs photodiode|
|Detector dimensions||1 mm²|
|Pixel size||1 mm²|
|Range||0.7 - 1.7 µm|
|Spectral resolution||1 nm|
The following table presents SPICAV’s general specifications:
|Flight model data|
|Mass||UV + IR channels||4.14 kg|
|SOIR channel||7 kg|
|IR channel||8 W|
|UV channel||15 W|
|SOIR channel||30 W|
100 to 400 Mb/day