MODIS IOT Terra Weekly Report

Mission Operations Days: 2002/250 to 2002/256
September 6, 2002 20:00:00 GMT to September 13, 2002 20:00:00 GMT

Note: A PFM MODIS configuration change is planned for Tuesday, September 17th, 2002. The Formatter will be switched from the A-side to the B-side. See the "Upcoming MODIS Events" section below.

Terra Spacecraft and MODIS Instrument Status:

This Week's Completed MODIS Activities:

None

None

None

None

None

2002/254 14:25 Real-time MOD_MEM_DUMP('FR_OPERAND',3,27493,0,1,1) Memory dump of xx13 Formatter Event information
2002/254 20:53:51 ATC MOD_OA16_SD_SCREEN_FXD_SUN_A.1 SD Calibration: SDD screened, SDSM fixed at the sun
2002/254 21:45:21 - 22:18:54 ATC MOD_OA19_SRCA_FULL_RAD_A.3 SRCA Full Radiometric Calibration, A-side
2002/254 22:32:45 ATC MOD_OA15_SD_OPEN_FIXED_SD_A.1 SD Calibration: SDD open, SDSM fixed at the SD

2002/255 15:53:10 - 16:50:41 ATC MOD_OA23_SRCA_FULL_SPAT_A.2 SRCA Full Spatial Calibration, A-side

None

This Week's Scheduled MODIS Activities Not Completed:

None

Upcoming MODIS Events:

On Tuesday, September 17th, beginning at approximately 14:00 GMT, the PFM MODIS will be reconfigured from using the A-side Formatter to using the B-side Formatter. This is being done to prevent further science data loss due to the millions of formatter errors observed each day with the A- side Formatter.

Under nominal conditions, the following steps will be taken to complete the configuration change. These changes will require several hours to complete.

1. Turn off FIFO blocks 1 & 2; science data production ceases
2. Switch to the B-side formatter
3. Load/Dump formatter error prevention patches to the B-side formatter
4. Turn on FIFO blocks 1 & 2; science data production resumes
5. Load/Dump "science tweak" patches
   1. 1000 ms time code patch
   2. Modify Band 5 gains
   3. Modify the Ideal Blackbody Output table
6. After the instrument has maintained stable operations (a few days), load the formatter error prevention patch the B-side Formatter EEPROM

Terra SD/SDSM calibrations may be scheduled every week (instead of bi-weekly) for the next few weeks. In addition, a lunar calibration (via roll maneuver) is planned for September 26th, 2002 (2002/269).

Maneuvers:

The next MODIS lunar calibration maneuver is planned for September 26th, 2002 (2002/269). Data collection will be from 15:08:10 to 15:14:40 GMT and the roll angle will be -9.8585 degrees.

The sixth Terra inclination adjust maneuver is currently planned for September 25th, 2002 at approximately 15:54 GMT. There will be no change to the MODIS operations schedule for this event (although the SD/SDSM calibrations may shift by one day), but contingency Nadir Door and Space View door closing activities will be scheduled in case the return yaw slew is not successful.

The Terra Deep Space Calibration Maneuver is still postponed. The next possible maneuver date is currently being planned for December of 2002.

MODIS Anomalies:

The current patches loaded into the MODIS Formatter record the number of formatter error events, but not the address where they occurred. The error rate has peaked at near 70 million errors per day.

The xx17 and xx18 formatter event messages reported last week have correlated very well to the instances of repeated MODIS data packets identified by EDOS. These instances of repeated packets are still continuing and are one of the drivers for changing the formatter from the A-side to the B-side.

The most recent error tracking spreadsheets can be retrieved from:

An MS Excel spreadsheet in a WinZip compressed archive called, AM1_FR_error_rollovers_current.zip contains the data for the times each error count "roll over" occurs.

General Instrument Comments:

MODIS is in A-side Science Mode with the blackbody maintained at 290K.

MODIS Telemetry Trends:

Tracking of the Formatter Error Rate is continuing.

Non-MODIS Significant Events:

The EMOS mission status webpage (which includes instrument data loss records) can be found at the following URL. Note that a password is now required to access the EOS mission links web pages. There are directions at the URL below for how to obtain a username/password.

Limited Life Item Status:

Note: An error was detected in the lamp usage times from the previous report. The error has been corrected and the updated lamp-use times are listed below.

SRCA 10W Lamp #1: 204.2 of 500 hours
SRCA 10W Lamp #2: 154.7 of 500 hours
SRCA 10W Lamp #3: 163.9 of 500 hours
SRCA 10W Lamp #4: 61.5 of 500 hours

SRCA 1W Lamp #1: 560.3 of 4000 hours
SRCA 1W Lamp #2: 276.3 of 4000 hours

Solar Diffuser Door: 1913 of 3022 Movements
Nadir Aperture Door: 536 of 1316 Movements
Space View Door: 439 of 1316 Movements

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Last Update: Thursday, 04-Sep-2003 18:14:23 EDT