ROM SAF - NRT Notification Detail

NRT Notification Detail

PPF upgrade and expected POD reset

DATE: 2009-07-29 07:05
TYPE: NRT-GTS

Description

Dear GRAS SAF GTS user Issued 2009-07-29 09:05 UTC We are expecting a POD reset due to an upgrade of the PPF at Eumetsat Central Facility. The upgrade is not expected to influence the GRAS data below 45 km. Data will be flagged for eight hours after the reset. Please see message from Eumetsat below. ---snip--- Dear all, tomorrow, Wednesday, 29 July 2009, we will perform an upgrade of the operational processing software for GRAS. This upgrade does not introduce scientific changes to the processing of the radio occultation data; it merely fixes some minor technical issues and enhances the monitoring and logging capabilities of the software for the controlles in Eumetsat HQ. The changes that do affect users of GRAS data now or in the future are the following: - The version number in level 1b products has been corrected (until now, it's incorrectly given as '2.12', although it actually is 2.14); from tomorrow on, it will be '2.15'. - We now apply a fixed correction for the different antenna phase centers of the GRAS zenith antenna which is used for the Precise Orbit Determination (POD). This will remove a constant ~20 cm along- track bias in the Metop position that we have lived with for quite some time now. Extensive offline testing has shown that there is now measurable impact on bending angle data at altitudes below 45 km (and above, one needs rather strong looking glasses to find them). - We have added the capability to process data from one more GPS satellite. We will introduce another (configuration) change shortly (probably next week) which will result in actually using this additional satellite. The update of the configration will increase the number of occultations available from GRAS slightly when it is introduced next week. Because of the last two changes, we formally have to perform a POD reset. When testing this procedure on the spare ground segment, the transistion actually went fine and had no impact on GRAS level 1b data quality. Nevertheless, data products will come with a 'degraded' flag for eight hours after the reset; we unfortunately cannot avoid this behaviour for technical reasons, even if the transistion goes smoothly. I will keep you updated on the data quality during tomorrow. With respect to the addition of a new satellite being used, I will send a separate email when we are closer to the configuration change. With kind regards, Christian. -- Dr. Christian Marquardt, Polar System Product Expert EUMETSAT, Am Kavalleriesand 31, D-64295 Darmstadt, Germany Tel: +49-6151-807456, Fax: +49-6151-807304 ---snip--- Best Regards The GRAS SAF Team

Back to NRT Notifications List

Newer

Older

The ROM SAF products are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0) by EUMETSAT. Whether you're displaying the product as-is or if you have used it as input data, please use the attribution suggested on ROM SAF usage policy and acknowledgement.