Near real-time IASI SO2

Example images of IASI SO2 total column measurements


The near-real time IASI SO2 product provides several variables including a quality flag, SO2 columns at different altitudes and SO2 brightness temperature difference.


Near real-time. Based on product requirements, the product files must be available to users within three hours after observation.

Theoretical basis

The retrieval of this product is based on brightness temperature differences and look up tables and uses IASI L2 pressure and temperature profiles when available (otherwise it uses ECMWF forecast data).


The Brescia algorithm is a dedicated radiative transfer and retrieval software for IASI. It was developed at ULB in collaboration with LATMOS, with the objective to provide global distributions of SO2.

Units and spatial resolution

SO2 total columns are given in Dobson Units, and brightness temperature in Kelvins. In 8 seconds a total of 120 views are collected over a swath of ∼2200 km, divided as 30 arrays of four individual pixels varying in size from 36 x π km2 at nadir (circular pixel 12 km in diameter) to 10 x 20 x π km2 at larger viewing angles.


This product is validated by LAP/AUTH and BIRA-IASB. Validation is based on detailed comparisons with ground-based and satellite data. See the validation report for more details.


The product quality is constantly monitored by ULB/LATMOS. Internal daily reports assess the daily match between the offline local product and the operational EUMETSAT product.


See NRT access information.

File format

This product is available in BUFR format.

Algorithm version information