All subsystems on the AIM spacecraft continue to function as expected except, of course, for the usual lack of bitlock. We broke the record for longest period of bitlock outage by one day. The previous record number of days without bitlock was 36, but the new record is now 37 days. But since then we’ve been able to perform all of our desired command operations for October and November, including loading the CIPS Northern Hemisphere Flat Field imaging for October 14-17, a Southern Hemisphere Flat Field imaging set for November 25-28, and a special calibration sequence for SOFIE to run Nov 25-28.
The SOFIE instrument continues to operate nominally.
SOFIE band 2 appears to have come out of saturation on around Nov 1. We have started routine band 2 extinction retrievals from Nov 1 on. The band 2 PMC extinctions will provide (1) UV PMC extinctions which will allow better PMC size characterization, (2) accurate PMC corrections in the band 1 ozone retrievals in upcoming PMC seasons, and (3) meteoric smoke retrievals in both hemispheres and in the presence of PMC’s.
SOFIE on-orbit calibration data have been used to refine the off-axis FOV response.
CIPS continues to operate nominally. We acquired a full set of calibration images in October. These have been processed to calculate new delta flat images and camera-to-camera normalizations. The results compare well to the calibration data used thus far in the operational processing for the NH 2009 season. Delta flat fields are within 2% of the operational results, and the camera normalizations are within 0.2% of the operational results. The next processing will use these new calibration data, but we do not expect them to cause significant differences compared to the operational data that are currently available.
We continue to make progress on implementing a new retrieval algorithm, for which the primary goals are to improve the background removal process and to introduce a more rigorous error analysis using an optimal estimation approach. We are on schedule to have all seasons processed with the new algorithm by the end of November. Most recent analyses focus on improving our quantification of uncertainties in the cloud retrievals. These uncertainties depend on several observational parameters, including view angle, scattering angle, and number of scattering angles sampled for any given location.
The diagram here gives a qualitative picture for how these factors combine to give an overall uncertainty over an orbit of observations. Red areas indicate regions with highest quality data (lowest uncertainties), and blue areas indicate regions with lowest quality (highest uncertainties). This information is being utilized in the new retrieval algorithms.