Update 1:M-B The M-bM-^@M-^\giant stepM-bM-^@M-^] function was initialized at 1617Z. It took longer than anticipated for the giant step procedure to move all contaminants out of the full range of the grating drive, the grating drive motor hadnM-bM-^@M-^Yt fully driven through the debris by the end of the pass. The giant step function was allowed to run for two orbits before commanding it back to the wavelength range used to produce ozone science data at 1923Z.

Topic: NOAA-19 SBUV Giant Step

Date/Time Issued: June 14, 2018 2055Z

Product(s) or Data Impacted: SBUV Products

Date/Time of Initial Impact: June 14, 2018 1615Z

Impacts on Users and Significance: SBUV products will be impacted.

Date/Time of Expected End: June 14, 2018 1625Z

Length of Outage: ~10 minutes

Details/Specifics of Change:

The NOAA-19SBUV/2 instrument has experience problems with grating position selection for Channel 12 since mid-2011. We have attempted to mitigate this problem by shifting the channel 12 wavelengths, howeverin each case, grating drive errors eventually returned after the switch was made. Any further shift to a shorter wavelength would cause significant problems for the ozone retrieval algorithm. To reduce grating drive errors, the M-bM-^@M-^\giant stepM-bM-^@M-^] procedure will be used. This sequence uses rapid motion of the grating drive over its full range (230nm to 360nm) in an effort to move presumed contaminants out of the wavelength range sampled for ozone data. This test will be run for ~10 minutes before returning the SBUV to its previous configuration.

Contact Information for Further Information: ESPC Operations at ESPCOperations@noaa.gov at 301-817-3880 and/or other contacts as necessary

Web Site(s) for applicable information: N/A

This message was sent to ESPC.Notification@noaa.gov. You have been sent this and other notifications because you have opted in to receive it. If for any reason, you wish to unsubscribe, please contact ESPC Help Desk at ESPCOperations@noaa.gov or (301) 817-3880. Please note: it make take up to two business days to process your unsubscribe request.