1. VIRTIS –H Status
Paris 10-11th May 2010
Jean-Michel REESS

2. HK survey – I_lamp ESB1 MSB ESB2 AFB1 ESB3 Paris 10-11th May 2010
Jean-Michel REESS

3. HK survey – I_shutter ESB1 MSB ESB2 AFB1 ESB3 Paris 10-11th May 2010
Jean-Michel REESS

4. HK survey – tempFPA ESB1 MSB ESB2 AFB1 ESB3 Paris 10-11th May 2010
Jean-Michel REESS

5. VIRTIS-H detection chain status (1) from launch (March 2004) to Earth flyby #3
Housekeeping return :
Power supplies voltage and current: all nominal
Detector biases, control and current: all nominal
Detector temperature and temperature reference voltage: all nominal
Calibration lamp current: all nominal
Paris 10-11th May 2010
Jean-Michel REESS

6. VIRTIS-H detection chain status (2) from launch (March 2004) to Earth flyby #3
Detector analysis (number of dead pixels and dark current)
no significant variation for blind pixels and dark current. Slight increase of hot pixels number (<10), not to worry but has to be watched
Paris 10-11th May 2010
Jean-Michel REESS

7. Observations ESB3 (Earth day side) MSB (Mars) Averaged 100-200
ESB3 (Earth night side)
Averaged
Paris 10-11th May 2010
Jean-Michel REESS

8. VIRTIS –H Datahandling
Paris 10-11th May 2010
Jean-Michel REESS

9. Telecommands
Current procedure : Fabrizio asks us our needs, creates the telecommand files, and send them to us for validation.
Always wait/ask the Virtis-H « go/nogo » before submitting the telecommands to ESA.
A lack of answer does not mean an implicit « go »
We need to access the submitted files to ESA (instrument timeline and spacecraft pointing) for filling our database
Is it possible to have an access to the RSOC CVS file repository ?
One hour is needed to cool down the detector. An internal calibration is then needed at least one hour before the science observations.
Paris 10-11th May 2010
Jean-Michel REESS

10. VIRTIS –H Calibration
Paris 10-11th May 2010
Jean-Michel REESS

11. Internal calibration configuration
Phase observation
Session date
Spectrometer
(prism)
temperature (K)
FPA temperature
(K)
ESB1 Earth fly-by
140.41
79.58
140.77
79.51
MSB Mars fly-by
137.06
79.16
137.83
79.24
ESB2 Earth fly-by
143.88
79.88
142.27
79.78
AFB1 Steins fly-by
135.62
78.61
ESB3 Earth fly-by
139.38
84.27
139.90
84.50
Paris 10-11th May 2010
Jean-Michel REESS

12. Radiometric calibration
Straighlight
Paris 10-11th May 2010
Jean-Michel REESS

13. Radiometric calibration
Pixelmap error
Paris 10-11th May 2010
Jean-Michel REESS

14. Spectral calibration
Paris 10-11th May 2010
Jean-Michel REESS

15. Spectral calibration
Paris 10-11th May 2010
Jean-Michel REESS

16. Observations ESB3 (Earth day side) MSB (Mars) Averaged 100-200
ESB3 (Earth night side)
Averaged
Paris 10-11th May 2010
Jean-Michel REESS

17. Rework radiometric calibration order 0 and 1
Observations
ESB3 (Earth day side)
Averaged
MSB (Mars)
Averaged
ESB3 (Earth night side)
Averaged
Rework radiometric calibration order 0 and 1
Paris 10-11th May 2010
Jean-Michel REESS

18. Observations Wrong registration of order 7
Bad superposition of orders 6 & 7
Very good superposition of orders 4-5-6
Superposition of orders 6 & 7 improved
Before FP-recalibration
Error of 1 Dl in the FP comb
After FP re-calibration
 Rework and change registration and calibration of order 7 in archive
Paris 10-11th May 2010
Jean-Michel REESS

19. Improvement of VH spectral registration
Iterative process that optimizes correlation between measurements and simulation for high frequencies features
Iteration done on reference registered pixels that yield to polynomial functions
Converging iterative process
Paris 10-11th May 2010
Jean-Michel REESS

20. Radiance with corrected grid
Paris 10-11th May 2010
Jean-Michel REESS

21. Convolution process for V-H
Calculated using diffraction theory in VH
2mm order 7
Red line: VH profile
Blue line: pixel size  Dl=1.05nm
5mm order 0
Red line: VH profile
Blue line: pixel size  Dl=1.54nm
Paris 10-11th May 2010
Jean-Michel REESS

22. Convolution process for V-H
order 7
order 0
Paris 10-11th May 2010
Jean-Michel REESS

23. Spectral calibration
Simple internal spectral calibration applied (order 6)
Initial
Black line: VH
Blue line: Model
Recalibrated
Black line: VH
Blue line: Model
Paris 10-11th May 2010
Jean-Michel REESS

24. Conclusions
Improvement could be achieved by combining both methods (convolution should be performed at each registration process iteration… this is computer time consuming)
need simulated spectra to compare to observations
Implement process in the internal spectral calibration to monitor accurately the shifts with respect to instrument temperature
Paris 10-11th May 2010
Jean-Michel REESS