1. 1 M. Auvergne. Natal October 2004 Instrument performances. Signal perturbations: Radiations. Scattered light. ACS. Temperature. Readout electronic. Calibrations and ground based corrections. Performances on the two channels. Based on lab calibrations and simulations with the instrument model Michel Auvergne: Instrument scientist

2. 2 M. Auvergne. Natal October 2004 Aperture photometry PF CCD image and apertures of selected targets PF channel: for each target an optimal aperture (best S/N) is chosen among 256 predefined apertures. AS channel: an optimal aperture is computed for each target. AS target image and aperture.

3. 3 M. Auvergne. Natal October 2004 Radiations. Depends on the shielding which is thicker than 10 mm in most directions. With 10 mm aluminium no e-, only p+ Ep > 50 MeV. Perturbations inside the SAA. Time spent in the SAA ~ 4% Max flux ~ 4000 p+/cm2/sec. Number of charges in an impact ~ 6000 e- Data acquisition interrupted on the planet finding channel for flux larger than 300 p+/cm2/sec Number of glitches in an aperture during an exposure in the SAA. AS ~ 0-3 PF ~ 10 See Leonardo talk Protons flux (AP8 min) function of time

4. 4 M. Auvergne. Natal October 2004 Scattered Light from the earth Depends on the Line Of Sight (LOS) For a LOS orthogonal to the orbit plane the SL is ≤ 1 e-/px/sec and reach 100 e-/px/sec for a depointing of 12 degrees Variations of the maximum SL level on 150 days for several LOS. The background is measured on board on the two channels. 200 background windows on the PF channel. 10 background windows on the AS channel. Background light curve. Ordinate unit e-/px/sec. SL Zodiacal light

5. 5 M. Auvergne. Natal October 2004 Attitude Control System. Four orbital components (orbit period and harmonics), due to gravity torque and magnetic field, plus a random component. The main photometric effect comes from the I/O of the image from the aperture (side effect) for AS and from frontiers effect on PF channel. Spectrum of the x component of the ACS jitter PF: Frontiers effect on colored photometry AS: side effect due to image jitter Jitter~0.06 px

6. 6 M. Auvergne. Natal October 2004 Temperature. Photometric variations comes from: Quantum efficiency (100-500 ppm/K) Readout Gain (20 ppm/K) Readout Offset (500 ppm/K) The offset is measured on board. The CCDs temperature is stabilized at -40 C with white fluctuations of 0.005 C. The orbital amplitude of readout electronics is less than 0.3 K Orbital temperature variations of the readout electronic Annual amplitude variations of the readout electronic Total amplitude in the light curve. Porb -> A< 20 ppm Harmonics < 2 ppm

7. 7 M. Auvergne. Natal October 2004 Calibrations. Corrections are based on ground-based (CCDs), and on-board calibrations and Housekeeping (temperatures and voltages). Ground based calibrations. CCDs Temperature sensitivity PRNU Gain Full Well capacity Traps and bright pixels. Polarisation voltages Linearity Dark current (before and after irradiation) Readout electronics Temperature sensitivity Gain Readout noise Linearity On-board calibrations will be used also to define parametrization of the flight software (see Leonardo’s talk). Full well capacity map

8. 8 M. Auvergne. Natal October 2004 Corrections: Scattered light On the AS channel,the background is measured in 50*50 pixels windows close to the target, with a binning of 5*5 pixels. Substraction is made on board. On the PF channel, the background is measured in 10*10 pixels windows. Substraction is made on ground. The measurement precision is 5%. The residual noise is the background photon noise.

9. 9 M. Auvergne. Natal October 2004 Corrections: ACS Jitter. On the AS channel the jitter effect is very small. The periodic components can be reduced by a factor 2. On the PF channel the frontiers effects are efficiently reduced. More details in Fabio’s talk. Blue: light curve with jitter fluctuations only. Black: light curve after correction.

10. 10 M. Auvergne. Natal October 2004 ordinate adu/exposure Raw AS light curves. AS: raw light curve for a 6 mag. Star Background corrections are made on board

11. 11 M. Auvergne. Natal October 2004 PF Light curve PF white light curve with background removed. Missing data are due to the SAA crossing. Ordinate adu/exposure. PF raw light curves for a 14 mag. star Blue curve: blue LC Red curve: red LC Green curve:green LC Black curve: background

12. 12 M. Auvergne. Natal October 2004 Brazilian contribution. Leonardo Pinheiro da Silva (thesis) Calibrations processing. (See following talk) Fabio de Oliveira Fialho (thesis) Aperture definition and ACS corrections.(See following talk) Eduardo Costa da Silva (post-doc) Photometric corrections, in particular background gradients Tools for statistical analysis of the signal. Claudia Angeli (post-doc) Tools for statistical analysis of the signal. MMI, tbc

13. 13 M. Auvergne. Natal October 2004 Estimated White noise budget error: Dominant noise: readout Dominant noise: jitter+readout+background AsteroseismologyPlanet Finding

14. 14 M. Auvergne. Natal October 2004 Global Budget error. ASWhite noise 5 d.Orbital components Comment mv = 6. Teff = 6250. 0.62N0: 20, 12 10, 6 N1: 6,4,3,2 H1: corrections reduce amplitude by a factor 3 PFWhite noise 1hOrbital components mv=14 Sp. Type: K 2.2E-4N0: 120 ppm N1: 60 ppm H1: corrections reduce amplitude by a factor 2. mv = 15.5 Sp. Type: K 7.4E-4120 ppm