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AATSR Data Formats Products
SST record 50 km cell MDS
BT/TOA Sea record 17 km cell MDS
Vegetation fraction for Land Surface Temperature Retrieval GADS
Topographic Variance data for Land Surface Temperature Retrieval GADS
Land Surface Temperature retrieval coefficients GADS
General Parameters for Land Surface Temperature Retrieval GADS
Climatology Variance Data for Land Surface Temperature Retrieval GADS
Level 0 SPH
Level 0 MDSR
Auxilliary Data SPH with N = 1
1.6 micron nadir view MDS
Summary Quality ADS
Scan pixel x and y ADS
Grid pixel latitude and longtitude topographic corrections ADS
Across-track Band Mapping Look-up Table
Configuration Data GADS
Processor configuration GADS
LST record 50 km cell MDS
Distributed product MDS
Level 2 SPH
10-arcminute mds
Limits GADS
Validation Parameters GADS
BT/TOA Land record 17 km cell MDS
General Parameters GADS
Temperature to Radiance LUT GADS
Radiance to Brightness Temperature LUT GADS
Medium/High Level Test LUT GADS
Infrared Histogram Test LUT GADS
11 Micron Spatial Coherence Test LUT GADS
11/3.7 Micron Nadir/Forward Test LUT GADS
11/12 Micron Nadir/Forward Test LUT GADS
Characterisation GADS
Browse Day_Time Colour LUT GADS
Browse SPH
Grid pixel latitude and longtitude topographic correction ADS
Level 2 SPH
Auxilliary Products
ATS_VC1_AX: Visible Calibration data
ATS_SST_AX: SST Retrieval Coeficients data
ATS_PC1_AX: Level-1B Processing configuration data
ATS_INS_AX: AATSR Instrument data
ATS_GC1_AX: General Calibration data
ATS_CH1_AX: Level-1B Characterization data
ATS_BRW_AX: Browse Product LUT data
Level 0 Products
ATS_NL__0P: AATSR Level 0 product
Browse Products
ATS_AST_BP: AATSR browse image
Level 1 Products
ATS_TOA_1P: AATSR Gridded brightness temperature and reflectance
Level 2 Products
ATS_NR__2P: AATSR geophysical product (full resolution)
ATS_MET_2P: AATSR Spatially Averaged Sea Surface Temperature for Meteo Users
ATS_AR__2P: AATSR averaged geophysical product
Frequently Asked Questions
The AATSR Instrument
Instrument Characteristics and Performance
In-flight performance verification
Instrument Description
Internal Data Flow
Instrument Functionality
AATSR Products and Algorithms
Common Auxiliary data sets
Auxiliary Data Sets for Level 2 processing
Instrument Specific Topics
Level 2 Products
Level 1B Products and Algorithms
Level 1B Products
Instrument Pixel Geolocation
The Level 0 Product
Differences Between ATSR-2 and AATSR Source Packets
Definitions and Conventions
Organisation of Products
Relationship Between AATSR and ATSR Products
AATSR Product Organisation
Data Handling Cookbook
Characterisation and Calibration
Monitoring of AATSR VISCAL Parameters
Latency, Throughput and Data Volume
Data Processing Software
Data Processing Centres
The AATSR Products User Guide
Image Gallery
Breakup of the Ross Ice Shelf
Land cover in the Middle East
Typhoon Saomai
Mutsu Bay, Japan
Deforestation in Brazil
Spatially Averaged Global SST, September 1993
Further Reading
How to use AATSR data
Why Choose AATSR Data?
Why Choose AATSR Data?
Special Features of AATSR
Principles of Measurement
Scientific Background
The AATSR Handbook
SST record 17 km cell MDS
Surface Vegetation class for Land Surface Temperature Retrieval GADS
1.6 micron forward view MDS
12 micron nadir view MDS
12 micron forward view MDS
Summary Quality ADS
Surveillance Limits GADS
Master Unpacking Definition Table GADS
1.6 micron Non-Linearity Correction LUT GADS
General Parameters GADS
Thin Cirrus Test LUT GADS
Fog/low Stratus Test LUT GADS
1.6 Micron Histogram
Browse MDS
ATS_CL1_AX: Cloud LUT data
Pre-flight characteristics and expected performance
Payload description, position on the platform
Auxiliary products
Auxiliary Data Sets for Level 1B processing
Summary of auxiliary data sets
Calculate Solar Angles
Image Pixel Geolocation
Level 0 Products
Acquisition and On-Board Data Processing
Product Evolution History
Hints and Algorithms for Higher Level Processing
Data Volume
Software tools
Summary of Applications vs Products
Geophysical Coverage
Geophysical Measurements
Visible calibration coefficients GADS
Level 1B SPH
LST record 17 km cell MDS
Conversion Parameters GADS
12 Micron Gross Cloud Test LUT GADS
ATS_PC2_AX: Level-2 Processor Configuration data
Level 2 Products
Hints and Algorithms for Data Use
BT/TOA Sea record 50 km cell MDS
BT/TOA Land record 50 km cell MDS
Level 2 Algorithms
Signal Calibration
Site Map
Frequently asked questions
Terms of use
Contact us


2.6 Level 1B Products and Algorithms

Details of how to order AATSR data are given in Section 1.1.

The following sections describe the AATSR L1B processing algorithms, and the products they produce, in more detail:

A short summary of the processing applied to each product, and a discussion of the AATSR ungridded products, is provided below.

Disclaimers addressing issues affecting AATSR L1b product quality are published at .


The primary Level 1B product comprises calibrated and geolocated images of brightness temperature (for the three infra-red channels) or reflectance (for the near-visible and visible channels), together with cloud and land identification. This product is used as the starting point of scientific processing to produce the Level 2 product. The processes required to generate the Level 1B product are as follows.

  • First, source packets are processed to unpack and validate the science and auxiliary data that they contain. Calibration coefficients for the instrument channels are derived using the data from the on-board calibration targets and auxiliary temperature data.
  • Signal calibration uses these calibration coefficients to convert the science data in each channel to units of brightness temperature or reflectance, as appropriate.
  • Geolocation makes use of orbit propagation software in conjunction with available satellite orbit state vectors to determine the position on the Earth's surface of each instrument pixel.
  • Because the conical scan images the Earth in a sequence of curved lines, it is necessary to rectify the data into a rectangular grid. This is done by assimilating each pixel of the instrument scan onto the nearest point of a Cartesian grid having the y axis aligned to the satellite along track direction and the x-axis aligned to the across track direction, using the pixel co-ordinates derived at the Geolocation stage. The same grid is used for both the nadir and forward view images, and therefore the collocation of the two images is ensured. This process may lead to gaps in the image, particularly in the forward view, where the density of instrument pixels is lower than the density of points on the Cartesian grid. A process of cosmetic filling of these gaps using the nearest neighbour method is therefore also applied.
  • Finally, land flagging and cloud clearing algorithms are applied to the images to distinguish pixels over land from those over sea, and to identify those regions of the image that contain cloud.

The high level organisation of this product is described in section .

ATS_AST_BP (Browse)

The Browse product provides the user with a quick-look illustrating the contents of the data from which it is derived, to assist users with product selection. It is a sub-sampled image at 4 km x 4 km resolution, based on the Level 1B nadir view brightness temperature and reflectance data. The product is partitioned into a day form in which different bands from the ATS_TOA_1P product are chosen to form a colour composite image showing the key features of the data, and a night form derived using the 11 micron channel brightness temperatures only. The latter image is essentially monochromatic, and transition processing is applied to the day time data at low solar elevations to minimise the visual discontinuity at the day-night transition.

The high level organisation of this product is described in section .

AATSR Ungridded Products

The AATSR ungridded products (UCOUNTS and UBTR) are provided to support instrument commissioning activities, and to provide any users wishing to do their own regridding of the data with ungridded data.

The high level organisation of the UCOUNTS and UBTR products is described in section and section respectively.