JANUS
PI: P.Palumbo (Universita’ Parthenope, Napoli, Italy)
CoPI: R.Jaumann (DLR, Berlin, Germany)
Deputy PI & Instrument Scientist: G.Cremonese (INAF-OAPD, Padova, Italy)
Instrument Scientist: H. Hoffmann (DLR, Berlin, Germany)
National Team Leaders: L.M.Lara (CSIC-IAA, Granada, Spain), A.Holland (Open University, Milton Keynes, UK)
JANUS (Jovis, Amorum ac Natorum Undique Scrutator) is the visible camera on board the ESA mission JUICE (JUpiter ICy moon Explorer).
JUICE will fully characterize Ganymede as a planetary object and will carry out through investigation of the Jupiter system, including Europa, Callisto, enhancement of spatial and temporal coverage of the Jovian atmosphere and the other components of the Jovian system.
The man goals of JANUS can be summarized as follows:
Will characterize Ganymede, Callisto, and Europa as planetary bodies, including their potential habitability, with special focus on Ganymede;
Will study and monitor Jupiter’s atmosphere;
Will characterize and study the physical properties of other satellites of the Jupiter system, including Io, the irregular and inner satellites;
Will perform a physical characterization of the ring system;
Will study the interactions between the magnetosphere and satellite surfaces
The instrument characteristics and expected performances are reported in the following table.
Parameter |
Unit |
Value / Description |
Notes |
Type of optics |
N/A |
Catoptric |
Off-axis aplanatic three-mirror design |
Type of camera |
N/A |
Matrix scanner |
|
Aperture dia |
mm |
100 |
|
FOV |
° |
1.72 across track 1.30 along track |
Allows swath of about 15 km from 500 km and 3 104 km from 106 km |
IFOV |
mrad |
15 |
Allows GIFOV of 7.5 m/pix from 500 km, 3 m/pix from 200 km and 15 km/pix from 106 km |
Spectral range |
nm |
350-1050 |
Optical quality parameters met on a wide wavelength range; sensitivity at 1064 to allow cross-calibration |
Filters |
# |
≥13 |
|
|
|
|
|
MTF at Nyquist frequency |
% |
worst case in the field |
|
Binning |
N/A |
2x2, 3x3, 4x4, 6x6, 8x8 |
Increase instrument flexibility to cope with data volume limitation and frame rate in all obs. phases |
Windowing |
N/A |
Any dimension and position |
Same as above; |
Compression factor |
N/A |
1 to 28 |
Values considered for nominal operations: 3 ¸ 7. Wavelet |
Max acquisition rate |
Mpix/s |
2 |
Through compression unit |