"What's new" Archive: 2007

13 April 2008: MLS data algorithm update
Contact: Nathaniel Livesey

The MLS data processing algorithms have recently been updated to version v02.23. The only changes between v02.22 and v02.23 are modifications to the level 1 (radiance calibration) software to handle two separate issues. The first modification is in response to a change in operation of the MLS THz laser local oscillator on January 28, 2008, which resulted in a dramatic reduction in the number of useful level 2 (geophysical product data) OHprofiles in v02.22 (because of data quality control screening that was too conservative). When (re)processed with v02.23 algorithms, these days will have the typical (~90%) fraction of useful profiles for OH. The second modification is better handling of occasional (0.001%) corrupted instrument data packets arising from an ongoing anomaly with the Aura spacecraft data handling system commencing on December 4, 2007. The impact of this change on level 2 data is minimal. There is no need to reprocess data prior to December 2007 unaffected by either issue, and - for simplicity - the few remaining (2004) days still to be reprocessed to v02.2x are being run using v02.22.

12 February 2008: Aura Spacecraft FMU Anomaly Dates
Contact: David Cuddy

In December 2007, the Aura Spacecraft experienced anomalies with its FMU. These anomalies effected the output of spacecraft attitude data used in standard MLS processing. The attitude data has been re-processed using S-Band data as its source and below is a table of times and dates for which we received this updated attitude data. Users of Level 2 data should see no effect.

Hour

year

DOY

Dec

2007

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352