UPDATE: Automatic scheduling of CAM-CVF observations to be Resumed


The mission planning software has now been updated to prevent an SWS observation following a CAM-CVF one more closely than 30 mins; this software will become operational on 22 September and full automatic scheduling of CAM-CVF observations will then be resumed.

Martin F. Kessler,

12 September 1997.


CAM CVF Observations Influence SWS Dark Currents


Trend analysis has shown that CAM-CVF observations (AOT CAM04) can raise the temperature of the structure that supports all four instruments. This rise is sufficient to cause an increase in the dark currents of the SWS band 3 (12 - 29 um) detectors. While it is not thought that this increase impacts the signal- to-noise of the SWS observation, it complicates the dark current subtraction and may well reduce the accuracy of the flux calibration.

Thus, it has been decided that no SWS observation should be scheduled within 30 mins of a CAM04 AOT.

A software update to the Mission Planning is necessary for long-term implementation of this decision. In the short-term, CAM-CVF and SWS observations will be kept apart manually. To achieve this, all CAM04 observations in the Mission Data Base have been "blocked" from the automatic scheduling routines and will, as necesary, be scheduled manually at the end of the daily scheduling periods. The status of CAM-CVF observations with fixed time constraints and/or on targets located in closing sky bins will be carefully monitored to prevent and observations from being lost due to this temporary blocking.

Martin F. Kessler,
ISO Project Scientist.