Example of sensitivity analysis Sophie Lachérade, Bertrand Fougnie CNES Ouahid Aznay CS-SI Lunar WS – 3rd December 2014, Darmstadt

Sensitivity tree Data source, Measurement technique Non-linearity Source of degradation: Out of band rejection On-orbit degradation Non-linearity Spectral response Dark signal correction Oversampling Integration step Absolute calibration Data source Sensitivity study parameters ΔSRF ΔI Δ(x,y,z) SRF Sensor Irradiances Satellite position GIRO inputs GIRO

Sensitivity tree Data source, Measurement technique Non-linearity Source of degradation: Out of band rejection On-orbit degradation Non-linearity Spectral response Dark signal correction Oversampling Integration step Absolute calibration Data source Sensitivity study parameters ΔSRF ΔI Δ(x,y,z) SRF Sensor Irradiances Satellite position GIRO inputs GIRO

Summary Oversampling Dark Signal ROLO inputs

Oversampling Inputs of the oversampling study: Questions: 2012_02_14_17_58_56_B2 2012_02_14_17_58_56_B2 + 90° 2012_02_14_18_49_30_B2 Questions: - What is the impact of a resampling error on the integrated irradiances ? - Is it the same impact whatever the orientation of the Moon in the image ?

Oversampling Oversampling errors introduced in the image: Resampling grids used to simulate an resampling error in the lunar processings

Oversampling Reference image

Oversampling

Dark signal correction

Dark signal correction 1% of IPHR when g=90° 0.1% of IPHR when g=3° IPHR= IPHR+5x10-6 (w/m²/sr/µm)

Dark signal correction 2.5% of IPHR when g=90° 0.2% of IPHR when g=3° IPHR= IPHR+1x10-5 (w/m²/sr/µm)

Dark signal correction 5% of IPHR when g=90° 0.4% of IPHR when g=3° IPHR= IPHR+2x10-5 (w/m²/sr/µm)

ROLO inputs ROLO → Impact of a bias (±1°) in the librations components: - satellite latitude - satellite longitude - sun longitude → Impact of a bias (±1°) in the lunar phase angle

Satellite position Impact of a bias in the satellite latitude

Satellite position Impact of a bias in the satellite longitude

Satellite position Impact of a bias in the sun longitude

ROLO inputs Impact of a bias in the lunar phase angle

Conclusions: just an example ! Data source, Measurement technique Source of degradation: Out of band rejection On-orbit degradation Non-linearity Spectral response Dark signal correction Oversampling Integration step Absolute calibration Data source Sensitivity study parameters ΔSRF ΔI Δ(x,y,z) SRF Sensor Irradiances Satellite position GIRO inputs GIRO

Conclusions Lunar sensitivity analysis very useful to Better understanding the lunar calibration processing chain Determining the more sensitive component of the chain - depending of the system - depending of the observed lunar phase angle Associating uncertainties to each step of the processing chain