1 st post launch SCIAMACHY calibration & Verification Meeting L1b Astrium Friedrichshafen – Germany 24 July 2002 First Level 1b General Product Quality analysis

2 Level 1b General Product Quality analysis: content Related Verification Tasks Analysis specifics First results on Validation Tasks analysed Conclusions

3 Related Verification Tasks L : State corner coordinates L : Pixel coordinates and viewing geometry L : Wavelength calibration differences monitoring L : Leakage Current from Limb - monitoring L : Sun glint region flag - monitoring L : Rainbow region flag - monitoring L : SAA region flag - monitoring L : Rainbow flag - MDS data L : Saturation flag - MDS data L : Check the consistent usage of timestamps in level 1b product

4 Analysis specifics Level 1b product: SCI_NL__1PNPDK _045922_ _00191_01748_0354.N1 Orbits: 1748 Timeline: T/L ID= 50 States: 19 States, Limb/Nadir sequence

5 State corner coordinates Pixel coordinates and viewing geometry The level 0/1b processor determines geo-location of measurement data: it needs to be verified that pixel coordinates are consistent with state corners and the viewing geometries are plausible.

6 Wavelength calibration differences monitoring An alternative spectral calibration is based on known Fraunhofer lines out of the atmospheric spectrum: analysis of the mean wavelength difference of these lines compared to the calibration parameters yields information about the stability of the spectral calibration. Orbit 1748

7 Leakage Current from Limb - monitoring For the Limb states, the leakage current is determined also from the last limb elevation step, where the instrument points into dark space: analysis of the average difference between nominal state analysis and limb above atmosphere yields information about the stability of the leakage current calibration. Orbit 1748

8 Sun glint region flag - monitoring Sun glint phenomenon invalidates the calculation of air mass factors in the level 1b to 2 processing. The meaning of this flag is: 0=no sun glint danger, 1=sun glint danger. Orbit 1748

9 Rainbow region flag - monitoring Rainbow phenomenon, above water clouds, yields high polarisation which may invalidate some of the assumptions made in the interpolation of fractional polarisation parameters. The meaning of this flag is: 0= no Rainbow, 1= Rainbow. Orbit 1748

10 SAA region flag - monitoring In case one of the calibration measurements are within the South Atlantic Anomaly, the whole state is skip for processing. The meaning of this flag is: 0= no in the SAA region, 1= within the SAA region. Orbit 1748

11 Consistent usage of time-stamps: Nadir (1) Time-stamps in ADS and MDS have to be consistent, as data sets might refer to each other: consistency of Start_time for NADIR MDS, orbit 1748.

12 Consistent usage of time-stamps: Nadir (2) Time-stamps in ADS and MDS have to be consistent, as data sets might refer to each other: consistency of state duration for NADIR MDS, orbit 1748.

13 Consistent usage of time-stamps: Limb (1) Time-stamps in ADS and MDS have to be consistent, as data sets might refer to each other: consistency of Start_time for LIMB MDS, orbit 1748.

14 Consistent usage of time-stamps: Limb (2) Time-stamps in ADS and MDS have to be consistent, as data sets might refer to each other: consistency of state duration for LIMB MDS, orbit 1748.

15 Consistency of Level 1b Consistency between State ID defined from the Time Line and State ID in the STATES ADS, orbit 1748.

16 State corner coordinates and viewing geometry: plausible Monitoring of Wavelength calibration differences: further investigation needed Monitoring of Leakage Current from Limb: further investigation needed Sun glint, Rainbow and SAA region flags : consistent Rainbow and Saturation flags - MDS: to be analysed Usage of time-stamps : (almost) consistent General Product Quality analysis: Conclusions