AATSR Conclusions, Actions and Recommendations

1. AATSRConclusions, Actions and Recommendations Hannah Tait AATSR System Analysis Engineer (EOP-PPP) ESA ESTEC Keplerlaan 1, PO Box 299, Noordwijk, NL Hannah.Tait@esa.int

2. Instrument Performance (1) • Very good instrument performance to date • AATSR operating nominally and reliably since end May • Meeting performance requirements • Good quality science data being acquired • Radiometric performance is comparable to ATSR-2 • Data processing for BB cross-over test Part 2 to be completed • Some points will require longer-term assessment • SAA • Visible channel calibration over stable sites (more of a validation activity)

3. Instrument Performance (2) • Condensation monitoring and outgassing already included in nominal operations scenario • Current indications are that rates are slowing • Nevertheless, more co-ordination at satellite level and between instruments would be useful to understand the source • A long-term instrument performance verification plan is in place • AATSR is ready to support the routine phase • Good results from early comparison with MERIS • In addition to the planned activities (Smith, Hagolle, Watts, Stammes), other opportunities for cross-comparison should be encouraged (e.g. science Aos and external users) • Periodic systematic comparisons for monitoring purposes would also be useful

4. L1b Processor Verification (1) • No product format errors found • No major errors found in product contents • Overall, L1b data are of good quality • Minor observations raised and SPRs under discussion with IPF contractor • New VISCAL algorithm already implemented in IPF and under test • Outstanding issues • Auxiliary files (primarily ATS_CH1_AX file) • Quantitative verification of solar and viewing angles (cosmetic fill problem in initial scans already reported from inspection of cloud flags) • Comprehensive check of cloud flags (no problems expected, PP/OP compared visually) • Verification of confidence flags for a complete orbit (visual inspection of limited area so far) • Verification of VISCAL GADS (awaits introduction of new algo. into PDS) • Final verification of geolocation (awaits CH1 file)

5. L1b Processor Verification (2) • Two proposals for additional enhancements • Exception flags (address ASAP) • Pixel exception values are small negative values • At night, noise in the visible channels can mimic exception values • Causes confidence flags to be wrongly set • Regridding scheme (address over longer-term) • Current IPF (minus VISCAL GADS) already OK for cal val purposes – periodic manually constructed VC1 files are sufficient • Recommend that next IPF update should include: VISCAL + SPRs + Exception Flags

6. Level 2 Validation • Comprehensive plan in place (dedicated cruises, autonomous instruments, vicarious techniques) • Measurements being collected since end May • Preliminary results from Met Office buoy comparison very encouraging • Anomalous behaviour at high latitudes being investigated (L2 verification issue) • Opportunities for new cruises towards end of year are being identified • This activity has been most affected by lack of data • delaying results from other PIs • difficult to motivate team • If regular data flow not established soon • provide sample whole orbit products on FTP site, for familiarisation • consider making more use of PP

7. Level 2 Verification • Format verification complete • Inspection of ATS_NR_2P and ATS_AR_2P ongoing (limited to preliminary visual inspection so far)