The results of the tests performed with ORM during the Commissioning Phase of MIPAS are described in the following TNs.

The results of the tests performed with ORM during the Commissioning Phase of MIPAS are described in the following TN.

TN Cal. Val. Results, first part;

TN Cal. Val. Results, second part.

The presentation of the ORM team at EGS (Nice, April 2003) can be downloaded here.

We are aware of the following problems in MIPAS Level 2 products that are currently distributed by ESA:

the thresholds for convergence criteria are not very stringent;

the values of the retrieved profile at the borders of the retrieval range are affected by the errors due to the assumption of the profile outside the retrieval range;

oscillations are present in the retrieved profiles.

Work is in progress in order to reduce the effects of these problems.

(see Rob Koopman e-mail, link )
Upgrades in Level 2 processor: from version 4.57 to version 4.59.

The most important algorithm change is the implementation of cloud detection.
The cloud detection algorithm is currently only used to reject sweeps in processing in order to improve the quality of the product retrieval, no cloud information is provided in the product data file.

The second modification is the upgrade of relevant level 2 Auxiliary Data Files

MIP_OM2_AX from 20030723

MIP_PI2_AX from 20030723

MIP_PS2_AX from 20030723

MIP_SP2_AX from 20030723

MIP_IG2_AXfrom 20030601>

This upgrade is mainly aimed at activation of the cloud-detection algorithm, but also involves improvement of microwindows and occupation matrices (including elimination of gaps between altitude validity ranges), activation of the new spectroscopic database.

An error in Level 2 pre-processor has been detected by BOMEM in the computation of the Instrument Line Shape (ILS). This error has been proved to be the cause of the error in the AILS width detected during the Commissioning Phase. A short-term correction will be implemented soon.

Further details can be found here

Current investigations are dedicated to the non-linearity correction (probably related to the oscillations detected in retrieved profiles).

The following strategy has been defined by ESA:

The Near Real Time processor must remain 'as is' in terms of computing time. Improvements in the data due to new convergence criteria and extended range (see July 2003 activity) will not be implemented since these require additional computing time. Short-term correction of the bug in the computation of the ILS will be implemented.
The Off-line processor will take care of the product quality, a new auxiliary data set that allows:

• full retrieval range extension down to 6 km;
• improved convergence;
• short-term correction of the bug in the computation of the ILS.

will be used soon.