Release of a new version of simulated EPS-SG IASI-NG L1D test data


EUMETSAT Polar System-Second Generation (EPS-SG) simulated IASI-NG (Infrared Atmospheric Sounder Interferometer – New Generation) Level-1D test data are now available for user familiarisation (July 2020).

Last Updated

21 January 2021

Published on

23 July 2020

The EPS-SG IASI-NG has a direct heritage from the IASI instrument on board EUMETSAT Polar System (EPS) satellites. IASI-NG will ensure continuity to EPS Infrared Atmospheric Sounder mission, with improved spectral and radiometric performances.

Test data description

The test data are available here:


The L1D test data set is generated by the IASI-NG L1D IPP (In-house Prototype Processor) using simulated L1C test data and auxiliary data as input. The auxiliary data contains the IASI-NG eigenvectors and the static parameters to configure the Principal Component Compression, the format of which is according to the EPS-SG — IASI-NG Level 1D Auxiliary Data Specification document available with this release.

The L1D test data contain in netCDF format the same information as the L1C data, but the radiances are compressed using Principal Component scores. The data format is explained in the document EPS-SG IASI-NG L1D Product Format Specification (version 3E), available along with the test data. Format specifications common to all EPS-SG products are now available in the EPS-SG Generic Product Format Specification document.

The data covers three full orbits and two partial orbits.

Corresponding data file is IASI-NG-L1D_V2.tar.gz and associated checksum file is IASI-NG-L1D_V2.md5

These test data are intended for format familiarisation and system testing.

Documentation available via FTP

EPS-SG IASI-NG L1D Product Format Specification
EPS-SG — IASI-NG Level 1D Auxiliary Data Specification
EPS-SG Generic Product Format Specification
Readme file

For more information and feedback on the test data, contact our User Service Helpdesk.