MODIS Instrument Operations Team Health and Status Explained

Below is a description of the items that one might see on the MODIS Health web page. The examples give are for the AM-1 "Terra" MODIS (PFM), but they apply for their counterpart systems on PM-1 "Aqua" MODIS (FM1).

2000/001-12:00 GMT

* This is the date (year/day of year) and GMT (Zulu) time of the report. Note: EST is GMT -5 hours.

Terra (AM-1) is in xxx Mode

* This is the current configuration mode of the Terra Spacecraft.

Terra (AM-1) xxx Anomalies

* This describes any anomalies that the Terra Spacecraft is in or attempting to resolve.

MODIS is in xxx Mode

* This is the current configuration mode of the MODIS Instrument.

MODIS xxx Anomalies

* This is the anomaly situation of MODIS.

PSx: OFF/ON, Shutdown: ENABLED/DISABLED, Survival Heater: ENABLED/DISABLED

* Here is the state of the two Power Supplies (1 and 2). The Shutdowns are automatic safety mechanisms used to protect the Power Supplies and MODIS (like a circuit breaker). The Survival Heaters are a set of heaters positioned in strategic locations on MODIS that keep the MODIS components from cooling beyond thermal safety limits.

CP ON: x

* Either Control Processor A or B will be active while MODIS is powered.

CE ON: x

* The Calibration Electronics, A or B-side, are used for controlling the different calibrators on MODIS (BB, SD/SM, SRCA). If no calibration is underway, then neither of the Calibration Electronics will be powered.

BB Power ON: x

* The Blackbody has two operational sides, A or B. When it is not in use, neither side will be powered.

SDSM Power ON: x

* The Solar Diffuser Stability Monitor has two operational sides, A or B. When it is not in use, neither side will be powered.

SRCA Power ON: x

* The Spectro-Radiometric Calibration Assembly has two operational sides, A or B. When it is not in use, neither side will be powered.

Formatter ON: x

* The Data Formatter Engine has two operational sides, A or B. When it is not in use, neither side will be powered.

FIFO Blocks ON: x

* The FIFO Blocs have four operational units, Any two must be engaged for normal data formatting to take place.

FDDI ON: NEITHER

* The Fiber Data Distribution Interface to the Spacecraft has two operational sides, A or B. When it is not in use, neither side will be powered.

PV/C xxx ON: x

* The Photo-Conductive/Voltaic VIS/NIR/SM(IR)/LW(IR) must be powered for data collection to occur.

PV xxx ECAL/CSUB ON: x

* The Photo-Conductive/Voltaic VIS/NIR/SM(IR)/LW(IR) have ECAL and CSUB, A and B-sides which are powered during calibration and adjustment phases.

Scan Assembly Motor ON: NEITHER

* The Scan Mirror Assembly Motor has two operational sides, A or B. When it is not in use, neither side will be powered.

xxx Position: xxx, Latched: xxx, Fail Safe: ON/OFF

* The NAD, SVD, and SDD all have multiple positions (open, closed, screened (SVD), and outgas (SVD)). Each door has one or more sets of launch storage latches that must be disengaged before the doors may be opened. The fail-safes are used in the case of an emergency situation in which a door may be stuck in an undesirable position.

RC Heaters Enabled: xxx

* This is the list of Radiative Cooler outgas and focal plane heaters enabled (active).

S/C FS Side: x

* This is the current operations side of the Spacecraft's Flight Software.

MODIS Inhibit IDs Set: 32, 33, and 54

* These are the currently set Command Inhibit IDs that pertains to MODIS.

These prevent stored commands from being issued to subsystems of MODIS in the event that an emergency situation has arisen since the loading of the stored commands.

MODIS TMONs Enabled: 66, and 67

* These are the currently enabled Telemetry Monitors that pertain to MODIS. These are similar in purpose to Inhibit IDs however, they are triggered by "dangerous" telemetry conditions and activate a sequence of commands intended to safely "clean up" a potentially hazardous configuration for MODIS.

Email the MODIS IOT to report any problem with the MODIS IOT Web Pages.
Email the MCST Webmaster to report any problem with the MCST Web Pages.
Email the MCST Helpdesk to ask a question about Level 1B usage, algorithms or software.

Last Update: Tuesday, 26-Nov-2002 16:33:47 EST