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

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

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

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

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

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

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

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

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

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

Internal calibration configuration Phase observation Session date Spectrometer (prism) temperature (K) FPA temperature (K) ESB1 Earth fly-by 2005-03-04 140.41 79.58 140.77 79.51 MSB Mars fly-by 2007-02-24 137.06 79.16 137.83 79.24 ESB2 Earth fly-by 2007-11-13 143.88 79.88 142.27 79.78 AFB1 Steins fly-by 2008-09-05 135.62 78.61 ESB3 Earth fly-by 2009-11-08 139.38 84.27 139.90 84.50 Paris 10-11th May 2010 Jean-Michel REESS

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

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

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

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

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

Rework radiometric calibration order 0 and 1 Observations ESB3 (Earth day side) Averaged 100-200 MSB (Mars) Averaged 100-200 ESB3 (Earth night side) Averaged 100-200 Rework radiometric calibration order 0 and 1 Paris 10-11th May 2010 Jean-Michel REESS

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

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

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

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

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

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

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