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AATSR Cal/Val Data Distribution. Hannah Tait AATSR System Analysis Engineer (EOP-PPP) ESA ESTEC Keplerlaan 1, PO Box 299, Noordwijk, NL Hannah.Tait@esa.int. L1b Data Distribution (1). Ordered by cal/val data co-ordinator. Orders sent via PERL scripts to the USF.
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AATSR Cal/Val Data Distribution Hannah Tait AATSR System Analysis Engineer (EOP-PPP) ESA ESTEC Keplerlaan 1, PO Box 299, Noordwijk, NL Hannah.Tait@esa.int
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.
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.
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).
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 Sept 09 – 12 Oct 01 – 04 Nov 12 – 14 Sept 13 – 17 Oct 05 – 06 Nov 15 – 16 Sept 18 – 20 Oct 07 – 10 Nov 17 – 19 Sept 21 – 24 Oct 20 – 22 Sept 25, 27, 29, 30 Oct 23 – 25 Sept 26, 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).
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.
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.
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.
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).