OMI row anomaly

Updated flagging of rows 41-45

2011-08-11T13:58:09+00:00

Following a changing row anomaly behaviour as already mentioned in the previous RSS feed from 5 July 2011, the row anomaly behaviour started to change again recently. To account for this changing behaviour we now have started flagging rows 41-45 for the entire orbit. Several rows seem to have improved, but we will continue to flag those as long as the situation has not stabilized.

The improved flagging has been implemented in the forward stream starting with orbit 37585.

Rows 42 - 45 are affected but not flagged

2011-07-19T10:10:12+00:00

Since July 5th, 2011, row 42 - 45 are affected by the row anomaly. These rows are not yet flagged. The anomaly in these rows now occurs over the whole orbit, not just over part of the orbit as was previously the case.

Update to the row anomaly flagging

2011-05-25T10:32:33+00:00

Recently, the row anomaly has been found to change slightly. Most notably, rows 24 and 50/51 (0-based) are found to be affected by blockage and wavelength shift. Also, the stray-sunlight effect in UV-1 has been underestimated until now. As of orbit 36390, the new flagging is in effect. More information can be found on the background page of the row anomaly and Figure 1 contained therein.

Flagging row 41 (0-based) corrected

2010-10-13T09:15:33+00:00

The OMI row anomaly has been stable for almost a year now. Nevertheless, it was found that the row anomaly flagging in the Level-1B radiance products was inadequate: row 41 (0-based) is affected by stray sunlight in the northern part of the orbit, but was not flagged accordingly. As of orbit 33113 (2010-10-06), this has been corrected.

More rows flagged as affected by the row anomaly

2010-06-09T07:41:27+00:00

The OMI row anomaly has been stable for months now. However, thanks to feedback from Level-2 users, we found that not enough rows were flagged for being affected by the OMI row anomaly. This has now been fixed. The extra rows are all on the edges of the rows that were already flagged. Most notably, the area that is flagged for possible stray sunlight has been expanded. Also, the lower orbit phase limits for anomalies that occur only on the northern side of orbits have been harmonized: all will use a lower limit of 0.58. The changes pertain to orbits 25350 (21 April 2009) and higher, but will, for the time being, only affect data produced in the forward stream, starting with orbit number 31366 (8 June 2010).

New version of OMI level 0 to level 1B software running in forward stream

2010-02-16T13:11:07+00:00

Starting on Feb 1st 2010 / orbit 29515, a new version 1.1.3 of the L0 -> L1b data processing software is operational on the OSIPS. The L1b dataproducts now contain important information on the OMI row anomaly for each ground pixel. You are urgently advised to read the presentation on the KNMI OMI website (PDF) that contains information on this new version.

Inaugural message of the OMI row anomaly RSS feed

2009-12-14T14:22:49+00:00

This is an inaugural message for the OMI row anomaly RSS feed. Certain rows in the OMI data are currently affected by the so called row anomaly. This is widely announced on the OMI data download sites. The row anomaly shows a dynamic behavior, and changes in time. To help us communicate these changes in the OMI row anomaly to the user community, we have set up this RSS feed to announce changes in the row anomaly.

In addition to the RSS feed to communicate with you, we also have created an email address to receive your feedback on our monitoring and flagging of the OMI row anomaly. You can send your remarks to omi-ra@knmi.nl.