Subject: Administrative: NOAA-19 Yaw Error Correction scheduled for --bcaec52c5fbdce8a970518cf3857 Content-Type: text/plain; charset=UTF-8 Topic: Upcoming NOAA-19 Yaw Error Correction Date/Time Issued: June 18, 2015, 1845 UTC Product(s) or Data Impacted: All data and products from NOAA-19 (AVHRR, AMSU-A, HIRS, MHS, & SBUV) Date/Time of Initial Impact: July 15, 2015 Date/Time of Expected End: Permanent change Length of Outage: Change is Permanent Details/Specifics of Change: NOAA-19 Yaw error correction is scheduled to be uplinked to the spacecraft on Wednesday, July 15, 2015. As we near the flight software change date, NOAA Engineering will publish the UTC time for this commanding. The ground geo-location image correction parameters will change for Yaw. On 5 August 2009 the J2000 Solar Lunar Planetary (SLP) file was used for the first time to determine sun vectors for polar spacecraft, which resulted in a change in yaw pointing for all polar spacecraft. Since that time NOAA-19 has had a yaw error of +0.35 degrees, which has required a correction in image processing. In order to correct this error a +0.35 degree correction factor will be uplinked to the spacecraft flight software to be applied to the sun sensor assembly (SSA) alignment data. This will cause the spacecraft in-orbit yaw pointing to be shifted by 0.35 degrees in a positive direction. This should drive the average ground image correction to zero. The actual yaw correction will occur on the first yaw update following the correction to SSA alignment data. After the correction is applied it will take about half a day for yaw pointing to converge to its new average value, but errors are not expected to exceed 0.35 degrees during this time. Engineering will be monitoring the spacecraft ACS subsystem during this time paying close attention to the Yaw laser gyro rate. ESPC will be computing the Yaw error from the AVHRR imagery. Preliminary Yaw, Roll, and Pitch values will be published shortly (24 hours) after this commanding is done and permanent values will follow for correction to the L1B data products produced by NOAA. Direct Readout Users ability to map imagery will be affected by the Yaw error correction. Direct Readout Users should check with their Vendors to assist in recalculation of geo-location mapping. All data and products from NOAA-19 (AVHRR, AMSU-A, HIRS, MHS, & SBUV) might be affected. Contact Information for Further Information: ESPC Operations at ESPCOperations@noaa.gov or (301)817-3880; Carl Gliniak at carl.gliniak@noaa.gov at 301-817-4207, or Dejiang Han at dejiang.han@noaa.gov at 301-817-4119 Web Site(s) for applicable information: See http://www.ssd.noaa.gov/PS/SATS/messages.html for this and other satellite related messages. 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 may take up to two business days to process your unsubscribe request. --bcaec52c5fbdce8a970518cf3857 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable