Oxford MIPAS meeting#134
26 Feb 08

Summary of the January Monthly Report

F. Niro, ESRIN

• MIPAS is back to full-time mission (100% duty cycle) since 1st December 2007.
• During this second month of full-time operations MIPAS performed very well, in fact only 2 IDU errors were recorded, however a HSM anomaly prevents the transmission of all the ENVISAT low bit rate data on 17th January (see §2.2.2).
• The Baseline scenario for 100% duty cycle was planned; it consists of the following schema: 8 days NOM + 1 day MA + 1 day UA, furthermore special Aircraft Emission modes were planned during 1 – 2 January. A more detailed description of the instrument planning for the reporting month can be found in §2.2.1.
• The availability of the instrument was very high (98.6% of the planned time) due to very good performances of the interferometer. The measurement segments not processed to L0 due to failures in the PDS were less than 1% of the planned measurement time (see § 2.2.4).
• The long term analysis of L0 data availability shows the increased duty cycle since April 2006 and highlights the improved instrument performances in the last year (see §2.2.4.2).
• The availability of L1 D-PAC products with respect to the expected time is approaching 95% in the last months (see §2.2.5).
• The instrument temperatures are stable during the reporting month, the variations are in the range of 1 – 2 K (see § 2.3.1).
• The cooler performs well during the reporting month; the vibrations were well below the warning level of 8 mg (see § 2.3.3).
• The long term trend of ADC max counts in channel A1 shows a strong correlation with the instrument self-emission and with the detector ice contamination. During the reporting month the ADC counts slightly decrease following the variation of the instrument temperature (see §2.3.4).
• The monitoring of the spectral correction factor shows a slight decreasing trend; nevertheless the variations over more than two years of operations are really small (∼ 2 ppm). The observed spreading of the points is due to the noise in the determination of this parameter (see § 2.4.2).
• The gain weekly increase during the reporting month is nominal, the maximum of gain increase in all the MIPAS bands remains well below the acceptance criterion of 1%/week (see § 2.4.3.1).
• The analysis of the accumulated gain allows monitoring the level of detector ice contamination. During the last months we observed a decreasing slope of the gain curve, showing that the detector is more and more “ice-free”. This is due to the better performances of the cooler obtained with more frequent decontamination (see §2.4.3.2).
• The absolute mispointing is stable around a value of -25mdeg. The seasonal variations of the pointing error are small and below the fixed threshold of 8mdeg. Less and less stars are available in the last months for the LOS calibration, as a result the mispointing estimation is becoming less precise (see §2.4.4).
• The long term monitoring of fringe count errors (FCE) shows that the width of the statistical distribution of the FCE can be used as a measure of the INT performances. In particular we observed that the FCE can be correlated with the number of IDU errors. This correlation is evident during the bad period of the MIPAS mission (June 2005 February 2006), while in the last months, with the improved instrument performances, no clear correlation can be found (see § 2.4.5.1).
• The long term monitoring of the detected spikes shows that the number of detected spikes in channels A1, A2, B1 and B2 is varying with time with some peaks probably related to variation of the solar activity. The channels C and D (the detector most affected by spikes) didn’t show any trend so far. From this analysis we can conclude that the number of detected spikes is still really small to impact the L1b products quality (see § 2.4.5.2).
• The level 0 NRT daily reports can be accessed at the following address: http://earth.esa.int/pcs/envisat/mipas/reports/daily/Level_0_NRT/
• The level 1b OFL daily reports can be accessed at the following address: http://earth.esa.int/pcs/envisat/mipas/reports/daily/Level_1_OFL/

From Thorsten.Fehr@esa.int Tue Feb 26 13:48:54 2008
Date: Tue, 26 Feb 2008 14:48:09 +0100

Dear Colleagues,

while the MIPAS instrument is operating at an ever more stable level and
the near real-time production of MIPAS Level 1b (v4.67) data has been
reinstalled, we are still facing problems with the new IPF Version 5.00.

The implementation of the MIPAS processor baseline 5.00 in the IPF was
identified to be much more difficult as first estimated by our industrial
partner..
This will result in a slip in the schedule by two months, with now a
foreseen IPF delivery end of April.
Industry justifies this delay with the additional time required for the
implementation of the complex baseline changes and migration to LINUX.

I am sorry for this further delay and will keep you updated on the
development of the processor.