Page 1 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN AATSR Cal/Val Data Distribution Hannah Tait AATSR System Analysis Engineer (EOP-PPP) ESA ESTEC Keplerlaan 1, PO Box 299, Noordwijk, NL

Page 2 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN L1b Data Distribution (1)  Ordered by cal/val data co-ordinator.  Orders sent via PERL scripts to the USF.  PERL scripts are prepared using the orbit numbers and child product start and stop times given in overpass tables.  The resulting child products are put on an FTP server for users to collect (single directory, 2 week retention time).  Problems with the child product extraction process were experienced during September.  In parallel, responsibility for child product generation moved from Kiruna to the UK-PAC.  The service has been open since 22 October.

Page 3 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN L1b Data Distribution (2)  Orders by PERL script involve 2 steps: Query inventory to find suitable parent for child; Order child.  In many cases the query returns zero results: Product not generated within PDS; Product not arrived at PAC yet (~2 weeks for consolidation at LRAC); Blind orbit.  Therefore not all overpasses result in a child product.  These requests will need to be re-run again later when the inventory is more complete.

Page 4 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN L1b Data Distribution (3) SitePIOverpass RangeSitePIOverpass Range ThangooDS,OH,FP+LST1 Sept – 23 NovCabauJF1 Aug – 27 Oct AmburlaDS,OH,FP+LST1 Sept – 23 NovGeesthachtJF1 Aug – 27 Oct HayDS,OH,FP+LST1 Sept – 23 NovLindenburgJF1 Aug – 17 Nov DunhuangDS,OH,FP+LST1 Sept – 23 NovCloud TargetsCP4 MERIS equiv. prods SonoraDS,OH,FP+LST1 Sept – 23 NovTahooSH1 Aug – 17 Nov Sudan 1DS,OH,FP1 Aug – 27 OctLady Basten 3/4IB14 overpasses Arabia 1DS,OH,FP1 Aug – 27 OctIshigakeJN1 Aug – 17 Nov Algeria 5DS,OH,FP1 Aug – 27 OctBorneoLST1 Sep – 23 Nov Algeria 3DS,OH,FP1 Aug – 10 NovKamchatkaLSTNov Libya1DS,OH,FP1 Aug – 10 NovSpainLSTNov Libya2DS,OH,FP1 Aug – 10 NovSaharaLST1 Sep – 23 Nov Algeria 1DS,OH,FP1 Aug – 17 NovSiberiaLST1 Sep – 23 Nov Algeria 2DS,OH,FP1 Aug – 17 Nov Algeria 4DS,OH,FP1 Aug – 17 Nov Arabia 2DS,OH,FP1 Aug – 17 Nov Arabia 3DS,OH,FP1 Aug – 17 Nov

Page 5 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN L1b Data Distribution (4)  A positive query is returned if any part of the child is inside a parent, but the order step will fail if: The child product spans 2 parent products. The start or end of the child is actually outside the parent.  A few delivered child products have been found to be empty - MDSs set to –8 (unfilled pixel).

Page 6 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN L2 Data Distribution (1)  Systematic distribution of NR and AR products for all visible orbits (until November and then for all orbits) on CD.  Responsibility of the UK-PAC.  First CDs received at the end of October. Data received to date as follows: 01 – 07 Sept09 – 12 Oct01 – 04 Nov 12 – 14 Sept13 – 17 Oct05 – 06 Nov 15 – 16 Sept18 – 20 Oct07 – 10 Nov 17 – 19 Sept21 – 24 Oct 20 – 22 Sept25, 27, 29, 30 Oct 23 – 25 Sept26, 28, 31 Oct  There is an unexplained gap in supply at the end of September/start of October.  A few instances of CRC problems have been reported whilst copying products from the CDs.  Since early November, L2 products have also been available soon after generation via an FTP server at ESRIN (retention time 4 days).

Page 7 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN L2 Data Distribution (2)  The Meteo product has been disseminated daily via FTP since August.  Originally ~10 orbits per day from Kiruna.  Since November the blind orbits are being supplied from ESRIN (via Svalbard).  There have been a few interruptions due to hardware failures, facilities updates, changes to BUFR tables etc.  The level of information from the PDS about these incidents could be improved.  The strategy for recovery of missing Meteo products is currently TBD.

Page 8 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN Early Data  Certain AATSR data are required from the early part of the mission: A number of ground campaigns took place in May/June/July 02; Several autonomous instruments were also operating at that time.  Many of these data are not in the current inventory, or only exist at L0.  A request for these data was submitted in early Sept: I. Barton (Lady Basten cruises 1 and 2) T. Nightingale (SCIPIO cruise) P. Minnett (Explorer of the Seas “best” overpasses for that period) C. Donlon (Val de Loire May “best” overpasses for that period) D. Smith (Sudan1, Arabia1, Algeria5 for that period) J. Sobrino (ground campaign in Finland) C. Coll (ground campaign near Valencia)  Work is underway to process these data at the UK-PAC.  Orbits 2509 and 2510 (23 August) are also required by P. Stammes and B. Kerridge for comparison with SCIAMACHY.

Page 9 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN Conclusions  There was a significant delay to the availability of data at the start of the Cal/Val phase.  Now up and running, the existing mechanisms are providing data satisfactorily: Empty childs to be investigated CRC errors from data on CD to be investigated Few FTP issues to be resolved (directory structure/ease of access etc.)  Ordering L1b scenes manually over permanent sites and disseminating via FTP GET may not be most efficient method for the future, e.g.: FTP PUSH requested by S. Hook; Monthly deliveries of data over desert sites on media would be better for D. Smith.  L2 data on CD could be replaced by other media (DLT, DVD).  The provision of missing Meteo products need to be addressed.  The retrieval and processing of data from May/June/July is essential.

Page 10 ENVISAT Validation Workshop, 9 – 13 Dec 02, ESRIN AATSR Visible Calibration  AATSR visible channels calibrated using ATS_VC1_AX file.  Pre-launch test file (23 June 2001) was used at launch, but was based on ATSR-2 parameters giving unusually low visible channel values, so was not intended to be used for long.  New INS file also required to correctly convert BB TM  VC1 files supposed to be updated every day.  Unexpected change in VISCAL monitor TM necessitated change to PP (and OP).  Whilst PP being updated, “hand-crafted” file (28 April 02) submitted early May.  PP now updated and VC1 generation process tested, but daily files not in use yet.  Manually created VC1 files supplied ~ weekly since September 02.  Vicarious calibration PIs advised to check date of VISCAL peak used in generation of their data (see VC1 filename in product DSDs).