(A)ATSR Multimission Archive

General Info

Title:	(A)ATSR Multimission Archive
Type:	Data Entity
Sub-Type:	Analysis
Abbreviation:	aatsr_multimission
Publication State:	published
The publication state of this metadata: 'old' - for redundant records; 'working' - for new/in progress records; 'published' - for records approaching maturity, which may still change, but should be available via the discovery services; and 'Published' for mature records that are unlikely to change and should be available via the discovery services.

URI:	http://badc.nerc.ac.uk/view/neodc.nerc.ac.uk__ATOM__dataent_11954635582925507

Summary
A brief description of the data.

Data products from the (A)ATSR Multimission Archive covering the ATSR-1, ATSR-2 and AATSR missions. Level 1b products contain gridded brightness temperature and reflectance. Level 2 products contain land and sea-surface temperature, and NDVI at a range of spatial resolutions.

Content
The actual data being described by this document. NB, in the case of data granules, this content may just be a reference to an ingested CSML or CDML file.

LATEST NEWS:

09-May-2012: ESA declares end of mission for Envisat - see ESA Press Release for details

Introduction

A major activity is currently underway at the NERC Earth Observation Data Centre (NEODC) at RAL to produce a 15-year archive of high-quality sea-surface temperature and image products from the (A)ATSR series of instruments in a common format.

Using a conversion tool produced at RAL, the entire dataset of ATSR-1 and -2 UBT products has been processed to produce ENVISAT-compatible Level 1b, Level 2 and METEO products, which populate the archive alongside the equivalent set of products from AATSR. The dataset is now part of the NEODC archive, with L1b and L2 products from all 3 missions already available in ENVISAT format. AATSR-format outputs of this project have been duplicated to ESA for inclusion in its own archive which will serve the international community. The project is a joint venture involving ESA, the UK Department of Energy and Climate Change (DECC), Natural Environment Research Council (NERC) and STFC/RAL.

The Advanced Along Track Scanning Radiometer (AATSR) was built by Astrium, subsequently calibrated and characterised at the Rutherford Appleton Laboratory, and continues the ATSR-1 and ATSR-2 mission data sets of precise sea surface temperature (SST), thereby ensuring the production of a 15 year near-continuous data set from the ERS-1, ERS-2 and ENVISAT missions at the levels of accuracy of 0.3 K or better for climate research. AATSR was launched on board the Envisat satellite on 1st March 2002. ATSR-1 and 2 are described in more detail on the ATSR-1/2 fact sheet. For more details on Envisat and its other instruments see the Envisat fact sheet.

AATSR has the same signal channels and embodies exactly the same viewing principle as ATSR-2. These are: thermal channels at 3.7, 10.8, and 12 microns wavelength; and reflected visible/near infrared channels at 0.555, 0.659, 0.865, and 1.61 microns wavelength. Like its predecessors, ATSR-1 and ATSR-2, AATSR has on-board calibration systems for the thermal channels, using two black bodies, viewed every scan, and for the visible channel a sample of solar radiation scattered from a diffuser plate is viewed once per orbit. Unlike ATSR-2 it maintains full digitisation of all channels all the time and has no limited-data-rate operating modes.

For the latest information see http://envisat.esa.int/.

Fig. 1 Flight model of AATSR. Image from http://envisat.esa.int

For more details about AATSR see http://www.atsr.rl.ac.uk/ and http://envisat.esa.int/instruments/tour-index/aatsr/.

Restricted Data Access

The AATSR Multimission data stored at the NEODC are available to registered NEODC users who meet the following requirements:

Bona fide research or education by UK users only
ATSR science team and science user group or
NERC award holders or staff or
ESA Cat-1 project holders

To obtain access to the data please:

Register as a NEODC user. If you already are a NEODC registered user, skip this step. If you have forgotten your NEODC user ID and/or password, please contact the NEODC helpdesk at neodc@rl.ac.uk.
Apply for access to the AATSR Multimission data. Application involves the agreement with the AATSR Conditions of Use

Data availability and file format

Availability of (A)ATSR products in the NEODC (A)ATSR archive is shown in the table below. Click the link for each mission to browse products in the archive and (if authorised) download via HTTP. The same directory structure is also available via ftp at ftp.neodc.rl.ac.uk starting with directory /neodc/aatsr_multimission/.

(A)ATSR product availability
Mission	Level 1b	Level 2	METEO	Current coverage
AATSR	Yes	Yes	Yes	2002 - present. Diagram (pdf)
ATSR-2	Yes	Yes	Yes	1995 - June 2003. Diagram (pdf)
ATSR-1	Yes	Yes	Yes	1991 - 1997. Diagram (pdf)

ESA - For currently available information about ENVISAT data products and availability, see http://envisat.esa.int/dataproducts/.

Version 2.0 Products

During 2008, harmonisation and re-processing efforts created a new set of products, available in the NEODC archive. The following information summaries the changes:

AATSR v2.0

Archive products have been reprocessed by ESA to match the current version (IPF v6.01) of the AATSR Operational Processor.

	AATSR v2.0 improvements
28 March 2007 IPF v6.0	IPF 6.0 includes improvements to the LST algorithm and cloud clearing tests
	The improvement of the performance of the cloud clearing tests over land
	An improved treatment of pixels in areas of marginal cloud
	LST retrieval over inland lakes
	Spatially averaged LST retrieval
23 June 2007 IPF v6.01 (used for v2.0 processing)	Corrects for an erroneous calculation of the ANX during consolidated processing, leading to mission Viscal GADS in the L1b product.
23 June 2007 IPF v6.01 (used for v2.0 processing)	The improvement of the performance of the cloud clearing tests over land

For further details, please consult the technical documentation available from the ENVISAT website, in particular

AATSR Handbook
Technical note: IPF Improvements in Land Surface Temperature Retrieval and Cloud Clearing over Land
Additional technical note
AATSR Cyclic reports
Essential visible calibration information and IDL tools (NB this site is temporarily unavailable (Nov 2010). In the meantime please access the data here: temporary link to calibration data)

ATSR-1/2 v2.0

ATSR-1, 2 : The RAL Archive Product Processor (APP) has been updated to align with the ESA Operational Processor/IPF and both missions reprocessed with the new processor.

Issue	ATSR-1/2 v2.0 Level 1b improvements
001	Forward-view Solar angles in 1st 2 frames of L1b (and therefore L2) products (fixed)
002	Incorrect number of DSDs in MPH (fixed)
003	Forward view blanking-pulse flags (fixed)
009	APP L1b processing updated to match IPF extended cloud flagging
010	Snow flag bug in extended cloud-flagging scheme (fixed)
013	ATSR-1 NDVI and NSDI tests should be switched off due to no visible channels (fixed)

Issue	ATSR-1/2 v2.0 Level 2 improvements
005	AST confidence word does not flag 3.7u used in SST retrieval (fixed)
006	AST confidence word fixed to match the IPF rather than the original specification (fixed)
007	LST values in L2 averaged product invalid (fixed)
008	Yaw correction flag not set in PROC_CENTER field of METEO (fixed)
011	30 arcmin SST MDS in AR product has anomalous content in 3 fields ; Std Dev of DV-SST, CTT/FRWRD, PCC/FRWRD (fixed)
012	AR and NR products have unfilled "Referencing DSD" for LST auxdata (fixed)

Documentation and Links to further information and references

Further Information

ENVISAT - ESA website contains various additional information :

ENVISAT main page and ENVISAT data format specification documents
ENVISAT product status including important product disclaimers

For particular sites regarding AATSR please use these links:

ESA website: AATSR instrument
ESA website: AATSR product handbook
University of Leicester : AATSR project page

ERS Mission details are available here: from the ESA website: ERS Missions

Additional useful documents can be found by following the these links:

ATSR Product user guide (RAL)
ATSR Image FAQ (RAL)
Current SPRs (software problem reports) detailng known issues with the RAL Archive Product Processsors for ATSR-1/2
Technical note (draft) describing differences between ENVISAT-format products ATSR-1/2 and AATSR products.
ER-RP-OXF-AT-0001.pdf Atsr-1 test and calibration report ER-RP-OXF-AT-OOOI (G. Mason, 1991)
ER-RP-OXF-AT-2001.pdf Atsr-2 test and calibration report ER-RP-OXF-AT-2001 (D.L. Smith, R.E.J. Watkins & D.R. Corney, 1993)
Auxiliary files used to produce (A)ATSR archive products vPO-TR-RAL-AT-0024 (pdf) AATSR Infra-Red Radiometric Calibration Report (D.L. Smith, 1999)
PO-TR-RAL-AT-0023 (pdf) AATSR Visible Calibration Report (D.L.Smith, 1999)
PR-TN-RAL-AT-0538 (pdf) Technical Note : Updates to AATSR In-Band Solar Irradiances (D.L.Smith, 2004)
(A)ATSR-related documents in CEDA document repository CEDA (NEODC/BADC) maintains a document respository into which it has started to add dataset-related technical information, including AATSR user bulletins and similar documentation

Platform Parameters

Launch date	1/03/2002
Status / projected mission lifetime	> 5years
Orbit parameters	30 km in front of ERS2
Nominal altitude	800 km : same as ERS2, near circular
Orbit type	near-polar, sun-synchronous
Inclination	98.55 ?
Repeat period	35 days
Equatorial crossing time	10:00 local time (descending node)
Swath width	various
Resolution	various
Special features

Citation

Date of citation

Who to contact

For assistance accessing this dataset please contact the NEODC helpdesk

Author
The principal author of the actual underlying data. Only one author can be specified per atom; if there are multiple authors, these should be specified as 'contributors'. NB, an atom MUST have an author specified.

Name	email
www.esa.int (European Space Agency)

Online References
Online references with a specific relationship to the data being described here. NB, if links are supplied they must be valid and include the transport protocol - e.g. 'http://blah.co.uk'. Also, note, three online references can be added at once; after these are added a further three may be specified - and so on.

Relation	Title
Download	Data Directory
Logo	Logo
Apply for access	Apply for access

Parent Data Entity
Define the parent of this record. There should probably only be one parent, but this is not enforced.

No data specified at present

Sub Data Entities
Lists all entities which have the current entity as their parent.

None

Associated Deployments

Parameters - summary

BRIGHTNESSTEMPERATURE	INFRAREDWAVELENGTHS	ENGINEERING	SPECTRAL
EARTHSCIENCE	EARTH SCIENCE	NULL	CLOUDTOPTEMPERATURE
CLOUDS	ATMOSPHERE	REFLECTANCE	OCEANOPTICS
OCEANS	SURFACERADIATIVEPROPERTIES	LANDSURFACE	ATMOSPHERICRADIATION
NORMALISEDDIFFERENCEVEGETATIONINDEX(NDVI)	VEGETATIONINDEX	VEGETATION	BIOSPHERE
SEASURFACETEMPERATURE	OCEANTEMPERATURE	LANDSURFACETEMPERATURE	LANDTEMPERATURE

Parameters - details
Parameters to describe the data - with vocab URL and term IDs for further classification. Note, three parameters can be added at once; after these are added a further three may be specified - and so on.

Label	Vocab Term URL	Vocab Term ID
BRIGHTNESSTEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
INFRAREDWAVELENGTHS	http://vocab.ndg.nerc.ac.uk/term/null	NULL
ENGINEERING	http://vocab.ndg.nerc.ac.uk/term/null	NULL
SPECTRAL	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
EARTHSCIENCE	http://vocab.ndg.nerc.ac.uk/term/P131	NULL
EARTH SCIENCE	http://vocab.ndg.nerc.ac.uk/term/P111	GCAT0001
NULL	general_units	0
CLOUDTOPTEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
CLOUDS	http://vocab.ndg.nerc.ac.uk/term/null	NULL
ATMOSPHERE	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
REFLECTANCE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
OCEANOPTICS	http://vocab.ndg.nerc.ac.uk/term/null	NULL
OCEANS	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
SURFACERADIATIVEPROPERTIES	http://vocab.ndg.nerc.ac.uk/term/null	NULL
LANDSURFACE	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
ATMOSPHERICRADIATION	http://vocab.ndg.nerc.ac.uk/term/null	NULL
NORMALISEDDIFFERENCEVEGETATIONINDEX(NDVI)	http://vocab.ndg.nerc.ac.uk/term/null	NULL
VEGETATIONINDEX	http://vocab.ndg.nerc.ac.uk/term/null	NULL
VEGETATION	http://vocab.ndg.nerc.ac.uk/term/null	NULL
BIOSPHERE	http://vocab.ndg.nerc.ac.uk/term/P141	NULL
SEASURFACETEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
OCEANTEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
LANDSURFACETEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL
LANDTEMPERATURE	http://vocab.ndg.nerc.ac.uk/term/null	NULL

Data Coverage
Summary of the temporal and spatial data coverage for the data.

Spatial coverage
Max Y: 90
Min X: -180	Max X 180
Min Y -90

Temporal coverage
Start Date:	1995-06-01
End Date:

Spatial resolution

No spatial resoultion information available.

Vertical extent

No vertical extent information available.

Responsible Parties
Parties responsible for the metadata - e.g. data curator. Responsible parties can have a role specified to make their function clearer. Multiple responsible parties can be specified.

Role	Name	URI
Data Curator	neodc.nerc.ac.uk	http://www.neodc.rl.ac.uk

Other Info
Other miscellaneous information. Note, update frequency relates to the update frequency of the underlying data, not the metadata.

Dataset language

English

Update frequency

asNeeded

Links and Services
	Downloadable XML version of this record

Not all information in this record may be rendered in this view. Please see the XML version for complete content

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