OMI Product Quality Documentation for Collection 3 Data

OMI team members have made every attempt to ensure high quality of OMI data products. The staff members follow all the steps of quality assessment in their investigative efforts. The current version of OMI data is collection 3 data that has been improved from collection 2 data with straylight problems. We are documenting below all the OMI data products and the associated quality information that is contained in the respective README files to be checked to be certain about the usage of the data.

Note: Please read the Important OMI Information about row anomalies.

OMI QA staff members have developed a quality assessment tool OMI QA Viewer to visualize the OMI Level 1B and Level 2 data products.

The records of events that might affect the quality of OMI data are captured in QA Events document.

OMI Level 1 Products

PRODUCT	DESCRIPTION	QA (README)	Contents	Known Issues
OML1BRUG	OMI Geolocated Earth Radiances for 716 UV Channels (264-383 nm)	QA (README)	Contents	Known Issues
OML1BRUZ	OMI Zoom-in Geolocated Earth Radiances for 716 UV Channels (264-383 nm)	QA (README)	Contents	Known Issues
OML1BRVG	OMI Geolocated Earth Radiances for 716 Visible Channels (349-504 nm)	QA (README)	Contents	Known Issues
OML1BRVZ	OMI Zoom-in Geolocated Earth Radiances for 716 Visible Channels (349-504 nm)	QA (README)	Contents	Known Issues
OML1BIRR	OMI Solar Irradiances for 716 UV and 751 Visible Channels (264-504 nm)	QA (README)	Contents	Known Issues

OMI Level 2 Ozone Products

PRODUCT	DESCRIPTION	QA (README)	Contents	Known Issues
OMTO3	O3 Total Column (TOMS V8 method)	QA (README)	Contents	Known Issues
OMDOAS	O3 Total Column (DOAS method)	QA (README)	Contents	Known Issues

OMI Level 2 Clouds, Aerosols and Surface UV Irradiance Products

PRODUCT	DESCRIPTION	QA (README)	Contents	Known Issues
OMCLDO2	Cloud Fraction and Cloud Pressure (O2-O2 Absorption Method)	QA (README)	Contents	Known Issues
OMCLDRR	Cloud Fraction and Cloud Pressure (Rotational Raman Scattering Method)	QA (README)	Contents	Known Issues
OMAERO	Aerosol Extinction Optical Depth and Aerosol Types	QA (README)	Contents	Known Issues
OMAERUV	Aerosol Extinction and Absorption Optical Depth	QA (README)	Contents	Known Issues
OMUVB (Collection 2)	OMI Surface UV Irradiances	QA (README)	Contents	Known Issues

OMI Level 2 Trace Gas Products

PRODUCT	DESCRIPTION	QA (README)	Contents	Known Issues
OMNO2	Nitrogen Dioxide (NO2) Total and Tropospheric Column	QA (README)	Contents	Known Issues
OMBRO	OMI Bromine Monoxide (BrO) Total Column	QA (README)	Contents	De-Striping Readme
OMHCHO	OMI Formaldehyde (HCHO) Total Column	QA (README)	Contents	De-Striping Readme
OMOCLO	OMI Chlorine Dioxide (OClO) Slant Column	QA (README)	Contents	De-Striping Readme
OMSO2	OMI Sulphur Dioxide (SO2) Total Column	QA (README)	Contents	Known Issues

Important Information for OMI Data Users

Row Anomalies

Several row anomalies have occurred in the recent past. These anomalies affect the quality of the Level 1B and Level 2 data products. Please read this information carefully prior to using OMI data. Please respect the dates mentioned as the anomalies have occurred recently.

Anomaly 1:		Since June 25th, 2007,		cross-track scenes 53-54 (0-based).
Anomaly 2:		Since May 11th, 2008,		cross-track scenes 37-44 (0-based)
Anomaly 3:		Since January 24th, 2009,		cross-track scenes 27-44 (0-based).

Please be aware that for all other rows the data are of optimal quality and not affected.

Also all OMI data before these anomalies are of optimal quality.

Row Anomaly Corrections

Please be aware that these anomalies are known to the OMI team and are currently under investigation to examine whether corrections for the effects can be implemented in the Level 1b data. Please visit this information page regularly for updates on the status of corrections implemented and visit our detailed technical information page.

Row Anomaly Flagging

The Level 1B data are partially flagged for the anomalies listed above. Please visit our detailed technical information page for details on the current flagging status of the Level 1B and Level 2 products.

Recommendations To Users

At the moment no corrections have been implemented in the operational Level 1B and Level 2 data. It is recommended not to use the affected cross-track scenes.

Please respect the dates mentioned above. All other OMI data, meaning other cross track scenes and earlier observations, is of optimal quality.

Level-3 products are being produced after filtering for the cross track scenes mentioned per anomaly.