Table Error Reaction Plan

The following is the reaction plan for a Table Error on either AIA or HMI.

Anomaly Description

Likely caused by a single bit hit from a charged particle, errors can occur in the three different table types on the AIA or HMI DCHRI boards: CROP, LOOKUP, CAMERA. There have been 5 such table errors since launch (4 in HMI tables and 1 in an AIA table) (as of January 2012).

Recognizing a table has been hit is achieved by looking at the parity bit associated with the tables. A limit has been set on the parity bit so we will be alerted if an error occurs. We are checking for limit violations via the history log twice a day with our daily health and safety check activity. We plan to soon incorporate their recognition into our local ANS and thus receive text messages on our phones. The damage to the science data by a table hit can be highly variable ranging from no significant effect to quite significant.

Reaction Plan for AIA or HMI

• If discovered during normal working hours the team will follow the steps in the procedure (link provided below). A phone call should be made to FOT and an email sent to the FOT and jsoc_ops.

• If outside of normal working hours and the error qualifies as "very significant" (like harming the data from the HMI Doppler Camera) or right before a unique opportunity (like a comet or a planet transit), we should activate the fix-it ASAP strategy no matter what day or time of day it was discovered. An email should be sent to the FOT to the emergency address or a phone call made. Emails and phone calls should be made to the local team.

• If outside of normal working hours and of "modest significance", we should typically wait until the next day to make the fix (regardless of the next day being a working day or a non-working day). An email should be sent to the non-emergency FOT email list as well as the jsoc_ops email distribution list.

• If the error appears to be of "low significance", we should wait until the next working day. An email should be sent to the non-emergency FOT email list as well as the jsoc_ops email distribution list.

Recovery Procedure:

The recovery procedure can be found here: https://aia.lmsal.com/doc?cmd=vcur&proj_num=AIA03838